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BACKGROUND: In recent years, there has been an explosion of research in the field of physical activity and cognition of older adults, and the research hotspots and topics in this field are constantly evolving. However, a comprehensive review of the literature in this field is lacking. OBJECTIVE: To explore the current international research hotspots and contents in the field of physical activity and cognition of older adults using bibliometrics. METHODS: The Web of Science Core Collection Database, including SCI-EXPANDED, SSCI, A&HCI, CPCI-S, CPCI-SSH, BKCI-S, BKCI-SSH, ESCI, CCR-EXPANDED, IC, etc., was searched for relevant literature in English. CiteSpace software was used to visualize and analyze 2593 documents collected in the Web of Science database. RESULTS AND CONCLUSION: The evolution of the topics of physical activity and cognition of older adults includes five stages: research on companion robots for older adults, research on the risk of diseases such as dementia, research on cognitive ability and its related ability, research on the relationship between physical activity level and cognitive ability in older adults, and research on different intervention methods and their mechanisms. The research in this field tends to be diversified. On the basis of the research on diseases and cognitive risk reduction, more attention has been paid to the effects of different physical activity modalities on cognition and the related mechanisms, which is the current research hotspot and will be the main research trend in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND: Gradient artificial bone repair scaffolds can mimic unique anatomical features in musculoskeletal tissues, showing great potential for repairing injured musculoskeletal tissues. OBJECTIVE: To review the latest research advances in gradient artificial bone repair scaffolds for tissue engineering in the musculoskeletal system and describe their advantages and fabrication strategies. METHODS: The first author of the article searched the Web of Science and PubMed databases for articles published from 2000 to 2023 with search terms "gradient, bone regeneration, scaffold". Finally, 76 papers were analyzed and summarized after the screening. RESULTS AND CONCLUSION: (1) As an important means of efficient and high-quality repair of skeletal system tissues, gradient artificial bone repair scaffolds are currently designed bionically for the natural gradient characteristics of bone tissue, bone-cartilage, and tendon-bone tissue. These scaffolds can mimic the extracellular matrix of native tissues to a certain extent in terms of structure and composition, thus promoting cell adhesion, migration, proliferation, differentiation, and regenerative recovery of damaged tissues to their native state. (2) Advanced manufacturing technology provides more possibilities for gradient artificial bone repair scaffold preparation: Gradient electrospun fiber scaffolds constructed by spatially differentiated fiber arrangement and loading of biologically active substances have been developed; gradient 3D printed scaffolds fabricated by layered stacking, graded porosity, and bio-3D printing technology; gradient hydrogel scaffolds fabricated by in-situ layered injections, simple layer-by-layer stacking, and freeze-drying method; and in addition, there are also scaffolds made by other modalities or multi-method coupling. These scaffolds have demonstrated good biocompatibility in vitro experiments, were able to accelerate tissue regeneration in small animal tests, and were observed to have significantly improved histological structure. (3) The currently developed gradient artificial bone repair scaffolds have problems such as mismatch of gradient scales, unclear material-tissue interactions, and side effects caused by degradation products, which need to be further optimized by combining the strengths of related disciplines and clinical needs in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND: Lumbar disc degeneration is a common disease that causes lower back pain and lower limb neurological symptoms. The balance of collagen metabolism plays an important role in maintaining the stability of the intervertebral discs. OBJECTIVE: To review the research progress in the imbalance of collagen metabolism in intervertebral disc degeneration. METHODS: The first author searched for relevant literature published before May 2024 in CNKI, PubMed and Web of Science databases. Search terms were “degenerative disc disease,” “collagen metabolism,” “collagenase family,” “collagen synthesis related factors,” and “collagen breakdown related factors” in Chinese and English. Seventy-six articles were finally included for review. RESULTS AND CONCLUSION: In the process of intervertebral disc degeneration, the balance of collagen metabolism plays a crucial role in maintaining the stability of the normal intervertebral disc. When intervertebral disc degeneration occurs, a large amount of pro-inflammatory factors, collagenase, and oxidative stress reactions occur in the intervertebral disc, which increases the breakdown of collagen in the intervertebral disc. At the same time, it inhibits the generation of growth factors, collagen synthase, and collagen synthesis-related factors, resulting in a decrease in collagen synthesis in the intervertebral disc. The combined effect of the above two conditions disrupts the balance of collagen metabolism in the intervertebral disc, further exacerbating the process of intervertebral disc degeneration. [ABSTRACT FROM AUTHOR]

BACKGROUND: Research on physical activity and executive function continues to emerge, but no scholars have used visual tools to explore the dynamic evolution path of research topics in this field. OBJECTIVE: To explore the dynamic evolution process of research topics in the field of physical activity and executive function using bibliometrics methos, so as to clarify their development status and changes in knowledge structure. METHODS: The Web of Science database was searched by the search formula: TS=(“Physical activity” AND “Executive function*”) OR TS=(Exercise AND “Executive function*”). According to the inclusion and exclusion criteria, 4 386 relevant documents were selected as content, and SciMAT software was used for visual analysis. RESULTS AND CONCLUSION: The field of physical activity and executive function is booming, with more and more in-depth research and more room for future development. This field can be divided into four directions: executive function, children, the elderly, and intervention, and forms 11 main evolutionary paths. Topics such as “motor skills,” “lifestyle,” “aerobic exercise,” and “interventions” are likely to be the focus of future research, with the “adolescent” and “elderly” groups being the focus of research in this area. [ABSTRACT FROM AUTHOR]

BACKGROUND: As a common disease in middle-aged and elderly, osteoarthritis is difficult to cure, and the pathogenesis is not clear. Long non-coding RNA participates in the pathogenesis of osteoarthritis through many ways, such as regulating translation, promoting or inhibiting mRNA, and adsorbing miRNAs. OBJECTIVE: To review the types of common long non-coding RNA in osteoarthritis, and the influence of multiple long non-coding RNAs on the pathological factors related to osteoarthritis, to analyze the future application of long non-coding RNAs in osteoarthritis. METHODS: Literature retrieval was conducted in CNKI, WanFang Data, VIP database, PubMed, Web of Science and Sciencedirect databases, using the search terms of “osteoarthritis, degenerative joint disease, degenerative arthritis, OA, LncRNA, long non-coding RNA, long noncoding RNA, long intergenic non-coding RNA” in Chinese and English. All relevant literature published from 1976 and May 2024 was retrieved. After literature screening, induction, analysis and summary, 93 articles were finally included for review. RESULTS AND CONCLUSION: This review collected 25 long non-coding RNAs that are well studied with osteoarthritis. Long non-coding RNAs, as a molecular sponge for miRNA, are competing endogenous RNAs to competitively adsorb miRNAs and then affect downstream targets. Long non-coding RNAs can regulate physiopathological processes such as chondrocyte apoptosis and proliferation, cartilage extracellular matrix degradation, and inflammatory responses. Long non-coding RNAs are expected to become a biomarker and potential therapeutic target for the clinical diagnosis and therapeutic prognosis of osteoarthritis, and it may become a new strategy for the clinical treatment of osteoarthritis in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND: N6-methyladenosine (m6A) is a hot research topic in the mechanism of pathological cardiac remodeling and plays an important role in the development of cardiovascular diseases. OBJECTIVE: To summarize the possible mechanism by which m6A modification in non-coding RNAs regulates the main processes of pathological cardiac remodeling, such as pathological cardiac hypertrophy, cardiomyocyte death, myocardial fibrosis and vascular remodeling. METHODS: “m6A, non-coding RNA, pathological cardiac hypertrophy, cardiomyocyte apoptosis, cardiomyocyte pyroptosis, cardiomyocyte ferroptosis, myocardial fibrosis, vascular remodeling” were used as search terms in Chinese and English. Relevant literature from CNKI, PubMed and Web of Science databases published from January 1974 to April 2023 was retrieved, and finally 86 eligible articles were reviewed. RESULTS AND CONCLUSION: m6A modification is a highly dynamic and reversible modification. Pathological cardiac remodeling mainly involves pathological cardiac hypertrophy, cardiomyocyte apoptosis, cardiomyocyte pyroptosis, cardiomyocyte ferroptosis, myocardial fibrosis and vascular remodeling. m6A-related enzymes can regulate pathological cardiac remodeling processes through various non-coding RNAs and different signaling pathways, which can be used as a new potential intervention for cardiovascular diseases. In pathological cardiac remodeling, research on the regulatory relationship between m6A modification and non-coding RNAs is still in its infancy. With the development of epigenetics, m6A modification in non-coding RNAs is expected to have a new development in the regulation of pathological cardiac remodeling. [ABSTRACT FROM AUTHOR]

BACKGROUND: With the continuous improvement and progress of the magnetically controlled growing rod technology in the field of the treatment of spinal deformities, numerous studies have been put into this field, but the main research status, hot spots, and development trends are not clear enough. OBJECTIVE: Based on bibliometrics, this paper discusses the quality and quantity of articles in the field of using magnetically controlled growing rods to treat spinal deformities from different countries, aiming to clarify the global development trend of magnetically controlled growing rods and evaluate the research productivity, research trends, and research hotspots in the world. METHODS: The articles published from 1998 to 2023 were retrieved mainly based on the Web of Science database. CiteSpace 5.8 and VOSviewer 1.6.19 software were used to analyze the data and generate a visual knowledge map. The following parameters were evaluated for all studies: the total number of published papers, centrality, h index, the contribution of countries, authors, and journals, and the trend and hot spots were explored through the analysis of co-citation, highly cited literature, and literature keyword explosion. RESULTS AND CONCLUSION: (1) Finally, 138 articles were included. From 2009 to 2020, the number of published articles in this field gradually increased. The United States has the largest number of articles (53, 37.32%), and the United States has the highest h index and centrality of articles. (2) The results of keyword analysis showed that: the top ten keywords, such as early-onset scoliosis, surgery, complications, and so on, objectively and truly reflected the current situation and hot spots of magnetically controlled growing rod in the field of spinal deformity treatment. In recent years, the research focus in this field is the treatment failure caused by risk factors such as the pull-out of the magnetically controlled growing rod, implantation failure, and rod fracture, the accurate use of the corresponding medical classification, the monitoring and treatment of complications such as quality of life and cerebral palsy. (3) The co-citation results showed that: combined with the innovative and effective research of the magnetically controlled growing rod technology, the classification application of spinal deformity and the monitoring and treatment of related complications may be the research trend in this field. (4) Many highly cited articles further emphasized the therapeutic effect of magnetically controlled growing rod technology, providing an effective new idea and technical support for the field of spinal deformity correction. (5) The results of literature keyword explosion analysis demonstrate that the risk factors, medical classification, quality of life, and cerebral palsy of the application of magnetically controlled growing rods may become the research frontier in this field. (6) It can be seen that the application of magnetically controlled growing rod technology in the classification of spinal deformities and the in-depth study of related complications are the development trend in this field, but to further understand the effectiveness and safety of magnetically controlled growing rod technology in the treatment of spinal deformities, we still need long-term follow-up evidence. The overall research level of this field has steadily improved in recent years, but there are also problems such as the small number of high-quality articles and the unbalanced development of research in various regions. [ABSTRACT FROM AUTHOR]

BACKGROUND: Blood flow restriction training has broad application prospects in improving limb muscle strength. It has ideal effects on the upper limbs is ideal, and the specific application scheme has high research value. OBJECTIVE: To explain the influence of blood flow restriction training on the fitness benefits of upper limb muscles and summarize the specific programs of blood flow restriction training for upper limb, attempting to give suggestions on application programs based on existing studies. METHODS: Literature on the application of upper limb blood flow restriction training were searched in CNKI, WanFang, VIP, CBM, PubMed, Embase, EBSCO, Cochrane Library and Web of Science databases. The search terms were “blood flow restriction, blood flow restriction training, pressure training, upper limb, upper arm, forearm, arm, forearm” in Chinese and “blood flow restriction training, blood flow restriction exercise, blood flow restriction therapy, BFR therapy, occlusion training, KAATSU training, BFRT, upper extremity, upper limb, arm, forearm” in English. The relevant articles on the application of blood flow restriction training in the upper limbs included in the database from database inception to December 2022 were selected and screened according to inclusion criteria and exclusion criteria. RESULTS AND CONCLUSION: Firstly, blood flow restriction training is mainly applied to healthy people, special athletes and people with upper limb injury. Secondly, the influence of blood flow restriction training on upper limb muscle fitness is mainly reflected in the increase of upper limb circumference, muscle strength, muscle endurance, muscle thickness, muscle cross-sectional area and explosive power of upper limb, followed by the cross migration phenomenon of the upper limbs. Thirdly, blood flow restriction training for the upper limbs mainly uses inflatable blood flow restriction devices: the cuff width was 3-5 cm, the pressure position was 1/3 of the upper arm, the limiting pressure was 40%-60% arterial occlusion pressure or 80-160 mmHg, the training load is 20%-30% 1RM, the training volume is four sessions (30-15-15-15 times), the interval time was 30-60 seconds, and the training frequency was 2 or 3 times per week. [ABSTRACT FROM AUTHOR]

BACKGROUND: Vascularization is essential for wound healing and functional recovery during soft tissue repair. Adipose tissue is believed to be the body’s largest source of stem cells, and a number of different fat complexes have been developed for research and treatment. Its ability to promote angiogenesis and soft tissue repair has been extensively studied. OBJECTIVE: To review the progress of vascularization in soft tissue repair, and to summarize the preparation methods of adipose tissue and its derivative and their applications in vascularization and soft tissue repair. It is proven that adipose tissue and its derivative have excellent research value and clinical application prospects in vascular and soft tissue engineering. METHODS: PubMed, Web of Science and CNKI databases were used to search the related articles published from January 2010 to February 2023. The search terms were “soft tissue repair, wound healing, vascularization, angiogenesis, adipose tissue, stromal vascular fraction, adipose tissue-derived microvascular fragment, nanofat, adipose extracellular matrix/stromal vascular fraction gel” in Chinese and English. A small number of old classic literature was also included. An initial screening was performed by reading the titles and abstracts to exclude literature that was not relevant to the topic of the article, and 69 papers were finally included for the analysis of the result. RESULTS AND CONCLUSION: (1) Wound healing is an important physiological process, which mainly occurs when tissue is damaged, such as injury, surgery, burn, tumor, infection and vascular disease caused by tissue damage and defects. (2) Adequate vascularization of the wound site is essential for tissue repair, reconstruction of local homeostasis and functional recovery. (3) Adipose tissue is believed to be the body’s largest pool of stem cells and a number of different fat components have been used for research and treatment. (4) Due to its inherent composition and preparation advantages, adipose tissue will continue to play an important role in tissue engineering research and therapy. [ABSTRACT FROM AUTHOR]

BACKGROUND: Existing studies have confirmed that exosomes can effectively promote pulp regeneration. However, the biological functions and properties of exosomes from preconditioned sources can be significantly changed, which have different effects on cell proliferation, migration and odontogenic differentiation. OBJECTIVE: To discuss the application status of exosomes and their preconditioning methods in the field of pulp regeneration, and summarize the preconditioning methods that affect the function of exosomes, and explore the effect of exosomes and their preconditioning on pulp regeneration. METHODS: The relevant articles were searched in WanFang, CNKI, PubMed, and Web of Science databases from 2006 to 2022. The Chinese and English search terms were “exosomes, pulp regeneration; preconditioning method”. A total of 78 articles were included for analysis. RESULTS AND CONCLUSION: (1) Exosomes have the advantages of good biocompatibility, low immunogenicity and no cytotoxicity, and can induce the regeneration of pulp tissue by promoting stem cell tooth formation, neurogenesis and vascularization. (2) Exosomes derived from preconditioning can enhance the ability of tissue repair and regeneration and have a significant impact on the quality of regenerated dental pulp. (3) Currently, the preconditioning methods used in the field of dental pulp regeneration include inflammatory stimulation, hypoxia induction, conditioned medium and three-dimensional culture, and secreted exosomes can effectively improve the quality of regenerated dental pulp. Nevertheless, the specific effect and mechanism of different preconditioning methods on pulp regeneration need to be explored. [ABSTRACT FROM AUTHOR]

BACKGROUND: In recent years, functional near-infrared spectroscopy has shown extensive research significance and application potential in the fields of cognitive neuroscience, clinical medicine, and engineering technology due to its portability, low cost, non-invasiveness, and high temporal resolution. OBJECTIVE: To analyze the research progress, hot issues, and frontier trends of functional near-infrared spectroscopy in the past 10 years. METHODS: Web of Science database was searched for articles related to functional near-infrared spectroscopy published from January 1, 2013 to November 30, 2023. CiteSpace and VOSviewer software was used to conduct a visual analysis of publication statistics, journals, countries, institutions, authors, and keywords. RESULTS AND CONCLUSION: This article included a total of 2 714 documents, showing an overall upward trend in the volume of literature concerning functional near-infrared spectroscopy over the past decade. The 2 714 documents selected for this article were authored by 9 171 researchers from 2 400 institutions across 68 countries in 495 kinds of journals. The United States and University College London are representative countries and institutions, while Ehlis and Fallgatter are two influential authors in this research field. The journal NeuroImage ranks first with the highest citation rate. Functional near-infrared spectroscopy research primarily comes from University College London in the UK, Beijing Normal University in China, and the University of Tübingen in Germany. The keyword co-occurrence network map generated using VOSviewer 1.6.20 reveals six research clusters. By analyzing the specific keywords of each cluster, we further understand the research hotspots in this field. The burst analysis of keywords uncovers the research frontiers and development trends, providing important guidance for future research directions of functional near-infrared spectroscopy. [ABSTRACT FROM AUTHOR]

BACKGROUND: The parameters of the spine and pelvis are interrelated. The changes in their values are closely related to the occurrence, development and symptoms of degenerative spinal diseases. At the present stage, clinical workers focus on the changes in postoperative coronal and sagittal parameters to evaluate the overall balance of the spine after operation, while ignoring the relationship with paraspinal muscle and the role of paraspinal muscle in the process of spinal degeneration. OBJECTIVE: To summarize the previous studies on the relationship between the degeneration of paraspinal muscle and sagittal alignment, and analyze the interaction between changes in the relative position of skeleton structures and degeneration of paraspinal muscle during spinal degeneration. METHODS: A computer-based online retrieval of CNKI, WanFang, and VIP was conducted with the Chinese key words “sagittal spinal deformity, sagittal alignment, spinal-pelvic parameter, paraspinal muscle, degeneration, human cadaver model, imaging, MRI”. The retrieval of Medline, PubMed, and Web of Science databases was performed with the English key words “sagittal spinal deformity, sagittal alignment, spinal-pelvic parameter, paraspinal muscle, degeneration, imaging, MRI”. The preliminary screening was carried out by reading the title and abstract, and the literature was screened according to the inclusion and exclusion criteria. Finally, a total of 78 articles were included for result analysis. RESULTS AND CONCLUSION: (1) In recent years, researchers have noticed that paraspinal muscles play a corresponding role in maintaining sagittal alignment, and spinal degeneration can be delayed by protecting and improving paraspinal muscle function. (2) The researchers used different methods to detect the degree of paraspinal muscle degeneration, and selected different kinds of sagittal parameters to describe the sagittal alignment. After analyzing the degeneration of paraspinal muscles and the changes in sagittal parameters, we found that there was a correlation between them, and the correlation was affected by age, race and other factors. (3) Poor sagittal alignment is an important anatomic factor determining paraspinal muscle degeneration. A high pelvic incidence of anatomical parameters has often been reported as a risk factor for sagittal alignment. However, the smaller pelvic incidence is more prone to sagittal imbalance due to the smaller compensatory capacity of paraspinal muscles. (4) The paraspinal muscles continue to affect the sagittal alignment through a compensatory mechanism continuously. To combat spinal imbalance during spinal degeneration, the paraspinal muscles are in a state of high muscle load, causing pain, fatigue, atrophy and degeneration. [ABSTRACT FROM AUTHOR]

BACKGROUND: Recent evidence suggests that autophagy, as a cell self-protection mechanism, plays an important role in regulating osteoblast function and maintaining osteoblast homeostasis. It has an important influence on the treatment and prognosis of periprosthetic osteolysis. OBJECTIVE: To provide new therapeutic ideas and potential therapeutic targets for periprosthetic osteolysis by summarizing previous studies on the autophagy mechanism of osteoblasts. METHODS: The first author used the computer to search the articles published from 2015 to 2022. In Chinese, the search terms “wear particles, periprosthetic osteolysis, osteoblasts, signal pathways, autophagy” were used to search the databases of CNKI, WanFang, and VIP. In English, the PubMed and Web of Science databases were retrieved with “wear debris, wear particles, peri*prosthetic osteolysis, PPOL, aseptic loosening, osteoblast, OB, signal path, autophagy”. A total of 98 articles were included according to the inclusion criteria. RESULTS AND CONCLUSION: In periprosthetic osteolysis, the changes in the autophagy ability of osteoblasts induced by wear particles play a key role in the development and outcome of the disease. A variety of signaling pathways jointly mediate autophagy in osteoblasts, among which the key pathways include AMPK/ULK1/mTOR, nuclear factor-κB, Pink1/Parkin, etc. AMPK, mTOR, and ULK1 can regulate each other and jointly maintain the stability of the autophagy level. There is a complex crosstalk between the nuclear factor-κB pathway and autophagy. PINK1 and Parkin are accumulated on the surface of the damaged mitochondrial membrane, inducing autophagy. There is crosstalk among multiple signaling pathways, which form a complex autophagy network under their mutual influence. Moreover, the activation of the same autophagy pathway in different cells may bring about completely opposite effects. Moderate autophagy induced by wear particles can reduce the apoptosis of osteoblasts, enhance their differentiation and mineralization ability, and improve the prognosis of osteolysis around the prosthesis. On the contrary, insufficient or excessive activation of autophagy will cause damage to osteoblasts and promote the progress of osteolysis. Therefore, targeting the level of autophagy of osteoblasts induced by wear particles through drugs or genes may be one of the directions for the treatment of periprosthetic osteolysis. [ABSTRACT FROM AUTHOR]

BACKGROUND: Based on the superior properties of ceramics, bioceramic materials are widely used in bone transplantation and tissue engineering. However, it still faces the problems of low mechanical strength and single biological function, which cannot fully meet the clinical application of bone defect repair. OBJECTIVE: To summarize the research status of bioceramic scaffolds and the effect of manganese doping on the performance of ceramics. METHODS: Chinese and English search terms were “manganese, microelements, ceramic biomaterials, hydroxyapatite, tricalcium phosphate, 3D printing, bone tissue engineering”. Searches were carried out on CNKI, WanFang, PubMed, and Web of Science databases. Relevant articles published from January 1968 to September 2022 were retrieved. According to the inclusion criteria, 84 articles were finally included. RESULTS AND CONCLUSION: Manganese, as an important locally delivering therapeutically active ion, has a positive stimulating effect on cell function and bone formation. The doping of manganese elements can greatly improve the mechanical properties of ceramic scaffolds, further enhance the osteogenic induction ability of ceramic materials, and endow the scaffolds with additional antibacterial properties. (2) Based on manganese-containing bioceramics, the need for bone defect repair was further met through coating, covalently binding bioactive peptides and regulating the valence of doping elements. (3) It began to gradually change from single-element doping to multi-element doping, and strive to give the stent more characteristics. (4) Doping of manganese elements is an effective modification treatment method. Manganese-containing bioceramics have a good application prospect in the repair of fractures and bone defects by combining advanced material manufacturing technology and the excellent biological activity of manganese. [ABSTRACT FROM AUTHOR]

BACKGROUND: After over ten years of development, single-cell RNA sequencing has mellowed and in the last three years has been progressively adopted in the study of intervertebral disc degeneration. OBJECTIVE: To overview the utilization and the progress of single-cell RNA technology within the field of intervertebral disc degeneration research during the last few years. METHODS: The first author searched PubMed, ScienceDirect, and Web of Science databases with the key words “single cell RNA sequencing, intervertebral disc degeneration, nucleus pulposus, annulus fibrosus”. The literature was screened for relevance by reading and 58 articles were included in the final analysis. RESULTS AND CONCLUSION: As an emerging technology, single-cell RNA sequencing has been widely applied to the study of tumor heterogeneity, immune microenvironment, embryonic development, neuroscience, cell differentiation and many other fields. In recent years, an increasing number of scholars have applied single-cell RNA sequencing to research intervertebral disc degeneration. These studies have helped researchers to recognize the complex heterogeneity of the nucleus pulposus and fibrous rings: the newly discovered subpopulations of nucleus pulposus can be grouped into four groups: firstly, the nucleus pulposus cells that are more prevalent in normal nucleus pulposus tissue, often named “fibrous nucleus cells”, which can polydifferentiate to maintain fibrocartilage development; secondly, the “stable nucleus pulposus cells” that are more prevalent in mildly degenerated nucleus pulposus, which are responsible for regulating the homeostatic balance of chondrocyte metabolic activity in response to environmental signals and are highly expressed in collagen-related genes and extracellular matrix. Thirdly, the “inflammatory nucleus pulposus” is found only in degenerated nucleus pulposus tissue. In this subpopulation, the regulatory activity of NF-κB family transcription factors is enhanced. The fourth is the “adherent nucleus pulposus”, which is more abundant in severely degenerated nucleus pulposus tissue and has the FN1 marker gene. The discovery of these subpopulations adds to the understanding of the rich mechanisms of differentiation and degeneration within the tissue and the changes in intervertebral disc degeneration at the transcriptomic level. PROCR+ PDGFRA+ nucleus pulposus cells, CD90+ nucleus pulposus cells and UTS2R+ nucleus pulposus cells have the strong growth and differentiation potential, and the discovery of these nucleus pulposus progenitor cells offers the possibility to explore therapeutic tools for intervertebral disc degeneration from regenerative medicine and tissue engineering perspectives in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND: Macrophages have received extensive attention from scholars for their remarkable osteoimmunological effects, and their functions and applications have become a research hot spot. The current research mainly involves the origin, polarization and osteoimmunological effects of macrophages and their applications in bone repair. OBJECTIVE: To confirm the outstanding research value and application prospects of macrophages in bone tissue engineering through reviewing research advances in osteoimmunological effects of macrophages and their applications in bone repair. METHODS: PubMed, Web of Science and CNKI databases were used to search the related articles published from 2010 to 2022. The search terms were “macrophage polarization, bone, osteogenesis, osteoimmunology, biomaterials, tissue engineering”. The searches to English and Chinese language publications were limited. A small number of old classic literature was also included. An initial screening was performed by reading the titles and abstracts to exclude literature that was not relevant to the topic of the article, and 120 papers were finally included for the analysis of the results. RESULTS AND CONCLUSION: (1) Macrophages include monocyte-derived inflammatory macrophages and tissue-resident macrophages, of which different tissue-resident macrophages have different combinations of developmental origins; most tissue-resident macrophages originate from the yolk sac during the embryonic period. (2) Macrophages, highly pastic cells, undergo M1 or M2 macrophage polarization and release pro- or anti-inflammatory factors in response to different stimuli. Alternatively, macrophage polarization is regulated by multiple signaling pathways, including the AMPK-mTOR, Notch, MAPK, STAT, NF-кB, and Akt signaling pathways. (3) The osteoimmunological effects of macrophages involve the crosstalk between macrophages and skeletal cells. The effective application of osteoimmunological effects of macrophages in bone repair can be realized by modifying the physicochemical properties of biomaterials such as stiffness, roughness, pore size, and hydrophilicity or by combining single or multiple biologically active substances such as drugs, cytokines, metal ions, and microRNAs. [ABSTRACT FROM AUTHOR]

BACKGROUND: In recent years, metabolomics technology is developing rapidly, and its research scope is very extensive. It can detect the global dynamic changes of small molecule metabolites in the whole body, such as the specific metabolites produced by the body when studying oral diseases. It provides new ideas for exploring the pathogenesis, pathogenic process, early diagnosis and prognosis monitoring of oral diseases. OBJECTIVE: To review the application progress of metabolomics in periodontitis in recent years and prospect the existing problems and improvement methods, thereby providing reference for the diagnosis and treatment of periodontitis. METHODS: The first author searched the relevant literature from August 2010 to August 2020 in CNKI, WanFang, FMRS, Web of Science and PubMed databases. The search terms were “metabolomics, metabonomics, periodontitis, saliva, gingival sulcus fluid” in Chinese and English. After initial screening, 52 articles were included for review. RESULTS AND CONCLUSION: At present, the sample sources of metabolomics research on periodontitis are mainly saliva, gingival sulcus fluid, serum, urine, cells, bacteria and tissues. Different sample sources have different advantages and disadvantages. The related research results of metabolomics and periodontitis mainly focus on the changes in metabolic pathways, such as protein, fat, carbohydrate and nucleotid. And these results are applied to identify the biomarkers of periodontitis, explore the pathological mechanism, treatment, and relationship with systemic diseases. They provide a new idea for the clinical and experimental research on periodontitis from the perspective of small molecule metabolites. [ABSTRACT FROM AUTHOR]

BACKGROUND: The Hippo-YAP signaling pathway is a signaling cascade that is highly conserved across species and has attracted widespread attention in the study of physiological cardiac hypertrophy. Studies have found that many pathways such as mechanical force, autophagy, and energy metabolism are involved in the regulation of exercise-induced cardiac hypertrophy. These pathways may interact with the Hippo-YAP signaling pathway after exercise, thereby affecting the formation and development of exercise-induced cardiac hypertrophy. OBJECTIVE: To summarize the effects of exercise on Hippo-YAP signaling pathway, and describe the potential mechanism of Hippo-YAP signaling pathway in regulating exercise-induced cardiac hypertrophy. METHODS: “Hippo-YAP signaling pathway, YAP/TAZ, exercise-induced cardiac hypertrophy, heart, exercise” were used as keywords in Chinese and English. Relevant literatures included in CNKI, PubMed, and Web of Science databases from 1983 to 2022 were retrieved, and 70 articles that met the screening criteria were reviewed. RESULTS AND CONCLUSION: Hippo-YAP signaling pathway is affected by exercise and has a certain regulatory role in exercise-induced physiological cardiac hypertrophy. (1) Hippo-YAP signaling pathway induces mechanical stimulation triggered by exercise, which leads to changes in the activity and expression of YAP/TAZ, and mediates the response of cardiomyocytes to mechanical signals. (2) Hippo-YAP signaling pathway regulates autophagy in cardiomyocytes and maintains the homeostasis, normal structures and physiological functions of cardiomyocytes during exercise. (3) Hippo-YAP signaling pathway may mediate the oxidation and glycolysis of energy substances during exercise-induced cardiac hypertrophy, and may also be affected by energy changes during exercise. (4) Hippo-YAP signaling pathway may strengthen the connection with some non-coding RNAs related to physiological cardiac hypertrophy under the action of exercise, and multiple non-coding RNAs may jointly regulate Hippo-YAP signaling. (5) Hippo-YAP signaling pathway interacts with the classic pathways of exercise-induced cardiac hypertrophy. Exercise promotes the signaling interaction between them and participates in the regulation of exercise-induced cardiac hypertrophy. (6) To deeply study the regulatory role of Hippo-YAP signaling pathway in exercise-induced cardiac hypertrophy will help deepen the understanding of exercise-promoting heart health, and provide new ideas and strategies for the clinical prevention and treatment of cardiac diseases and myocardial tissue construction. [ABSTRACT FROM AUTHOR]

BACKGROUND: It is necessary to select an effective bone graft material in spinal fusion. Autograft was considered as the “gold standard” of spinal fusion, but there are complications such as donor site morbidity. Allograft can avoid complications associated with harvesting and donor’s volume is sufficient. Different allograft bone materials exhibit its excellent osteogenic ability when using at different sites of spine in spinal fusion. OBJECTIVE: To review the application status quo of allograft material in spinal fusion in recent years. METHODS: Relevant articles in Chinese and English published in PubMed, Web of Science and CNKI Database from 1990 to 2022 were retrieved. Search terms were “fresh frozen bone, autograft, allograft, freeze-dried bone, demineralized bone matrix, allograft spacer, spinal fusion” in English and Chinese, separately. After screening, 95 articles were included and reviewed. RESULTS AND CONCLUSION: Fresh frozen allograft is less used clinically due to its risk of immune rejection and transmission of disease. The fusion effect of freeze-dried bone is similar to autograft bone despite its delayed union in the end. Demineralized bone matrix is a useful graft material when it is used as a graft extender in combination with autograft or to fill the cages to play its biggest fusion ability. The combination with a carrier such as calcium sulfate or hydroxyapatite results in a significant increase in its plasticity and osteogenic activity. The new anatomic allograft spacer has good osteogenic activity, high clinical fusion rate and is effective in maintaining the intervertebral space height and the normal shape of intervertebral foramen. A large number of existing clinical studies have shown that allograft bone material can achieve the same fusion efficiency as autograft bone in spinal fusion, and is as safe and effective as autograft bone. It is a good choice for surgeons and has been widely used in clinical practice. [ABSTRACT FROM AUTHOR]

BACKGROUND: During orthodontic treatment, the arch wire is an important part of the fixed appliance. The choice of arch wire largely determines the efficiency of tooth alignment. Among them, nickel-titanium alloys are widely used in fixed orthodontics due to their superelasticity and shape memory effect, and have become a research hotspot. OBJECTIVE: To review the development history and research progress of nickel titanium arch wires. METHODS: The literature search was performed in PubMed, Web of Science and CNKI databases. The Chinese and English keywords were “orthodontics, NiTi”. The articles were screened according to the inclusion and exclusion criteria. Finally, 77 articles were included for review. RESULTS AND CONCLUSION: Many scholars did researches to overcome the drawbacks of the NiTi arch wire, such as improving the composition, manufacturing process and surface modification. However, the current finished nickel-titanium arch wires still have various drawbacks, such as poor aesthetic properties of the arch wires; the release of nickel ions may cause allergic reactions, and the aesthetic coating is easy to fall off. Although there are commercial products of NiTi arch wire and are widely used in clinical orthodontic treatment, due to the complexity of orthodontic process, and many researchers are still in the laboratory stage; there is no ideal NiTi arch wire to meet the needs of all aspects of orthodontic clinical treatment. The improvement of various types of NiTi arch wire is an important supplement and development to the existing NiTi arch wire, and is expected to play a huge role in clinical applications in the future. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Depression is one of the five major causes of the global burden of diseases. Currently available antidepressants have low efficacy, slow onset, and serious side effects, while exercise is a better way to treat depression. This paper systematically evaluates the effects of exercise on depression-related behaviors in chronic unpredictable mild stress (CUMS) animal models. METHODS: A systematic literature search from January 1, 2000 to February 28, 2022 was performed in WanFang, CNKI, PubMed, Embase, and Web of Science databases. Studies regarding the effects of treadmill running, swimming, and voluntary wheel running on forced swimming, tail suspension, and sugar water preference behavior of CUMS animal models were collected. Literature screening, data extraction and methodological quality assessments were completed by two researchers independently. The SYRCLE tool was used to assess the risk of bias in the included studies. RevMan 5.3 and Stata 13.0 analysis software were used for statistical analysis. RESULTS: A total of 23 controlled experimental studies were included, including 301 rodents in exercise group and 302 rodents in control group. Meta-analysis results showed that exercise significantly reduced the forced swimming latency [standardized mean difference (SMD)=-3.93, 95% confidence interval (CI): (-4.88, -2.98), P < 0.000 01] and tail suspension latency [SMD=-4.42, 95% CI: (-5.62, -3.23), P < 0.000 01] in CUMS modeling rats and mice. Exercise also increased the index of sucrose preference test [SMD=2.37, 95% CI: (1.62, 3.11), P < 0.000 01]. Subgroup analysis of exercise modes in the suspension test reduced heterogeneity [SMD=-3.68, 95% CI: (-4.16, -3.21), P < 0.000 01], but it did not affect the exercise effect. CONCLUSION: Exercise can effectively improve depression-like behaviors of forced swimming, tail suspension, and sucrose preference tests in CUMS model rodents. The mode of exercise may be the source of heterogeneity affecting the behavior of the suspension tail test. Modeling time, exercise stage, exercise mode, and exercise duration are not the main factors that affect the effect of exercise on depression. [ABSTRACT FROM AUTHOR]

BACKGROUND: With the improvement of women’s aesthetic and therapeutic needs, breast reconstruction has become a commonly used treatment option after breast cancer surgery, of which the use of expanders and implants is high. Infection, as the most common complication with the use of expanders and implants, can lead to a range of consequences and even affect the results of breast reconstruction. With the deep understanding of the risk factors leading to infection in breast reconstruction, the continuous improvement of treatment options and the application of new materials, the occurrence of infection can be reduced and the success rate of breast reconstruction can be improved. OBJECTIVE: To summarize the risk factors, prevention and treatment measures of infection associated with the use of expanders and implants in breast reconstruction, and to introduce the application prospects of new materials in breast reconstruction. METHODS: Related articles were retrieved on CNKI, Wanfang, PubMed, and Web of Science databases. Search terms were “tissue expander, breast implants, breast reconstruction, infection” in Chinese and English. According to the inclusion and exclusion criteria, after preliminary screening of articles, 119 articles with high relevance and reference value were reviewed. RESULTS AND CONCLUSION: (1) Breast reconstruction based on tissue expanders and implants is widely used in clinical practice, and multiple risk factors may lead to the occurrence of infection after breast reconstruction and, in severe cases, to the loss of expanders and implants. (2) Breast reconstruction expanders and implants are subdivided into multiple types according to different material characteristics, of which the roughness of surface is an important cause affecting the occurrence of infection. Although the smooth surface has a higher incidence of seroma than the textured surface, drainage is usually taken in advance to avoid the risk of infection caused by seroma in clinical practice. (3) Clinicians need to carefully evaluate the probability of infection and reasonably select expanders or implants in combination with the health status and treatment methods of breast reconstruction patients. For example, for patients with multiple preoperative infection factors, the selection of smooth surface expanders or implants may be more conducive to the prevention and control of infection. (4) Second-generation cephalosporins can be used to prevent infection after reconstruction, and can be used in combination with quinolones when necessary. For patients who have shown signs of infection, it is necessary to timely select bacteria-sensitive antibiotics for treatment according to bacterial culture and drug sensitivity test, and preserve expanders or implants for patients as far as possible. (5) At present, some studies have developed new breast reconstruction materials and drug coatings. Because such products have their own advantages of antibacterial and inhibition of bacterial attachment, they can fundamentally reduce the incidence of expander and implant infection and have shown positive therapeutic effect in some clinical case studies. However, further randomized controlled trials with large samples are needed to verify it in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND: Telomeres form special structures at the end of chromosomes in human cells, which have special functions and show a very close relationship with biological aging. Exercise can improve the activity of telomerases and protect the structure of telomeres, thus affecting human health. Shorter telomeres increase the incidence of diseases and decrease the survival rate. Therefore, telomeres are often considered as biological markers of cell aging and the “biological clock” that triggers aging. OBJECTIVE: Based on the relationship between telomeres and aging, to summarize and analyze the effect of exercise on telomeres and telomerases and to explore the mechanism of telomerase retardation by exercise, so as to provide theoretical basis and reference for anti-aging and health promotion by exercises. METHODS: We searched for relevant articles in CNKI, PubMed and Web of Science databases using the keywords of “telomeres, telomerase, exercise, senescence” in Chinese and English, and conducted preliminary screening of titles and abstracts according to inclusion criteria. After reading the full text, a total of 89 documents were included for further analysis. RESULTS AND CONCLUSION: Different exercises have different effects on telomeres. Exercise is positively correlated with telomere length, uncorrelated with telomere length, and has inverted U-shaped relationship with telemeter length. Exercise and telomerase activity are age-deviated. Suitable exercises can slow down the speed of telomere shortening, prevent the excessive consumption of telomeres, delay or prevent the occurrence of age-related diseases, and prolong life, but the mechanism has not been fully clarified. [ABSTRACT FROM AUTHOR]

BACKGROUND: How to obtain sufficient quantity and quality of hepatocytes in vitro is the core problem to be solved urgently in the clinical application of bioartificial liver. OBJECTIVE: To summarize the main research contents of the in vitro 3D large-scale expansion culture system of hepatocytes, summarize the current main sources of seed cells, 3D culture methods, bioreactor system, and the progress and limitations of real-time online monitoring of key indicators of the culture process, and prospects for the further development of automated and intelligent bioreactor systems. METHODS: The first author searched the Web of Science core database, ScienceDirect, EI, PubMed, and CNKI databases. The English and Chinese search terms were “hepatocyte, 3D culture, proliferate, bioreactor system, monitor and control”. The literature search time range was from January 2005 to March 2021. The types of articles included original research works, reviews and meta-analysis. Totally, 93 papers were selected for analysis. RESULTS AND CONCLUSION: (1) Researches on liver seed cell sources, 3D culture methods, bioreactor system construction, and real-time online monitoring methods for key biochemical indicators have all made progress, laying a solid foundation for the further construction of a large-scale in vitro 3D hepatocyte culture system. (2) Human hepatocarcinoma cell lines, immortalized hepatocytes, stem cell differentiation and other hepatocytes can be cultured and proliferated in vitro and express liver function. Among them, hepatocyte-like cells obtained from stem cell differentiation and direct reprogramming have cells similar to mature liver cells morphology, function, and gene expression profile will have greater application prospects in the future. (3) 3D suspension culture has excellent performance in terms of culture density and mass transfer efficiency, and has the advantages of easy amplification, convenient inoculation, and convenient access. It is the main development direction of in vitro 3D culture of hepatocytes. (4) Although the existing bioreactor system can realize in vitro culture and expansion of hepatocytes, it has a low degree of automation and lacks a real-time online detection method for key biochemical indicators. In addition, the current degree of mutual integration of these several aspects of research also restricts the progress of the in vitro 3D large-scale culture system of hepatocytes. (5) The future research is to combine the growth characteristics of liver seed cells from different sources, select suitable culture methods, and establish a real-time online monitoring method for key parameters during the culture process, so as to construct a highly automated and intelligent bioreactor system to achieve in vitro scale of liver cells large-scale preparation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Self-healing hydrogels are scaffold materials with superior self-healing capability and biocompatibility, and are widely used in bone tissue engineering. OBJECTIVE: To introduce the gelatin mechanism and composition of self-healing hydrogels and summarize their applications in bone tissue engineering. METHODS: The first author searched both Chinese and English articles with key words "self-healing hydrogels; bone tissue engineering; bone regeneration" on CNKl, Wanfang, VIP, PubMed, Embase and Web of Science databases published from 2000 to 2020. Totally 69 eligible articles were selected for review. RESULTS AND CONCLUSION: The gelation mechanisms of self-healing hydrogels include dynamic covalent bonds, supramolecular bonds and multi-mechanism cross-links. Self-healing hydrogels can be composed of natural polymers, synthetic polymers and nanocomposites. Self-healing hydrogels have been found to be applied in bone tissue engineering through scaffold modification as stem cells delivery vehicle. The application of self-healing hydrogels in bone tissue engineering can be broaden by enhancing the mechanical properties of the hydrogel while maintaining its self-healing capability. Additionally, the specific mechanism for better superiority of self-repairing hydrogels over traditional hydrogels in bone tissue engineering is still unclear. [ABSTRACT FROM AUTHOR]

BACKGROUND: Angiogenesis is a key component of bone reconstruction. Promoting bone vascularization thereby can accelerate bone repair. There are numerous research methods for promoting angiogenesis, and significant progress has been made in the field of bone defect repair in recent years. OBJECTIVE: To review several cutting-edge methods and developments in promoting angiogenesis and repairing bone defects in recent years, as well as their applications in bone tissue engineering. METHODS: The first author used the Chinese search terms “angiogenesis, osteogenesis, bone defect, tissue engineering, exosomes” and English search terms “angiogenesis, osteogenesis, bone defect, exosomes, vascularization” to find relevant publications in CNKI, WanFang, PubMed, and Web of Science databases. After screening and excluding articles irrelevant to the research purpose and repetitive articles, 69 articles were finally selected for review. RESULTS AND CONCLUSION: At present, promising results have been achieved in the bone defect remodeling research. Bone vascularization can be promoted by growth factors, delivery genes, biologically active ions, small molecule active peptides, and Chinese medicine monomers. Each has its own advantages and challenges, and faces different challenges. The synthesis of small molecule active peptides has low cost, high efficiency and safety, with obvious advantages. It has the potential to generate new ideas and methods for vascularization in bone tissue engineering. [ABSTRACT FROM AUTHOR]

BACKGROUND: Adipose-derived stem cells have become one of the popular seed cells in regenerative medicine due to abundant content and easy harvest. Adipose-derived stem cell exosomes are served as a bridge and link among adipose-derived stem cells and other cells and have the effects on regulating immune and inflammatory responses, promoting self-repair of damaged cells, and are considered as an alternative treatment for adipose-derived stem cells. OBJECTIVE: To review research progress and challenges in the adipose-derived stem cell exosomes regulating tissue regeneration. METHODS: CNKI, Wanfang database and PubMed, and Web of Science database were searched for related articles with the search terms of “adipose-derived stem cells; adipose stem cells; exosomes” in English and Chinese. After preliminary screening of articles based on inclusion and exclusion criteria, 70 articles with high relevance and reference value were retained for review. RESULTS AND CONCLUSION: Adipose-derived stem cell exosomes have shown the therapeutic potential in various diseases, such as skin wounds, neurodegenerative diseases, tumors, bone regeneration, kidney diseases, cardiovascular diseases, immune diseases, and fibrotic disease. [ABSTRACT FROM AUTHOR]

BACKGROUND: Patellofemoral pain syndrome is a common disease in the field of sports injuries. Research in and outside China is increasing year by year, but there is no visual analysis for patellofemoral pain syndrome. OBJECTIVE: To objectively analyze the literature research on patellofemoral pain syndrome in and outside China in the past 13 years, to summarize the recent research directions in this field and to sort out the knowledge structure in and outside China. METHODS: Relevant articles on patellofemoral pain syndrome were collected from Web of Science and CNKI. Citespace software was used for visual analysis to show the research hotspots and development trends of this field. RESULTS AND CONCLUSION: (1) A total of 1 679 articles were finally included in the Web of Science database. The authors with the most articles are De Oliveira Silva D from La Trobe University in Melbourne, Australia and Crossley KM from the University of Melbourne, Australia. Hot keywords are hip, biomechanics, prevention (prognosis), prevalence disease rate, consensus statement, gender differences, electromyographic activity, risk factor, and osteoarthritis. (2) A total of 214 articles were included and analyzed in the CNKI database. The author with the most articles is Miao Ping from the Rehabilitation Department of the Second Affiliated Hospital of Guangzhou Medical University. Hot keywords are arthroscopy, biomechanics, strength training, lateral femoral muscle, surface electromyography, patellofemoral arthritis, and joint replacement. (3) International research hotspots show the biomechanical characteristics of increased knee external rotation, increased hip adduction, and decreased hip internal rotation during patient exercise. Strengthening the hip abductors and external rotators can effectively improve the pain and function of patients. At present, the most appropriate method to treat the disease in the world is a customized multi-modal intervention program, including strengthening of the gluteal muscles and quadriceps, emphasizing education and activity adjustment. (4) The results of major Chinese studies in this field confirm that the use of arthroscopic surgery can improve the pain of patients with patellofemoral pain syndrome, and patellofemoral joint replacement has a certain effect on early severe patellofemoral arthritis in such patients. Rehabilitation training methods are mainly based on hip joint strength training, supplemented by core muscles, lower limb eccentric strength and neuromuscular control training. Compared with foreign countries, the unique research hotspots in China are acupuncture and Chinese medicine. [ABSTRACT FROM AUTHOR]

BACKGROUND: The exosomes are one of important active components of adult stem cells paracrine, providing the basis for stem cell “non-cellular” treatment. Exosomes from stem cells can play different roles in the wound through different mechanisms to promote the healing of diabetic wounds. OBJECTIVE: To summarize the main mechanism and application of stem cell derived exosomes in the treatment of diabetic wounds. METHODS: Computers were used to retrieve English databases such as PubMed database, Web of Science database, FMRS foreign language medical information resource retrieval platform, and Chinese databases such as CNKI and Wanfang Data Knowledge Service Platform. The retrieval scope was from the inception of the database to September 2020. The English and Chinese search terms were “stem cells, exosomes, wound healing, cell proliferation, neovascularization, inflammation, extracellular matrix, therapeutic use”. According to the inclusion and exclusion criteria, 66 articles were included and the results were analyzed. RESULTS AND CONCLUSION: (1) It is summarized that stem cell-derived exosomes can promote diabetic wound healing by regulating inflammation, promoting neovascularization, re-epithelialization and remodeling of extracellular matrix. (2) The application of stem cell-derived exosomes in diabetic wounds was listed. (3) The exosomes from stem cells can avoid the immune response of stem cells in the treatment of diabetic wounds, and the genetic material of stem cells carried by them is more widely regulated and more effective than that from ordinary cells in the treatment of diabetic wounds. (4) At present, the application of stem cell derived exosomes in diabetes wounds still has some problems, such as low purity, high cost of separation, low production efficiency, and the way to reach the target area, loss rate and diffusion efficiency. [ABSTRACT FROM AUTHOR]

BACKGROUND: Hyaluronic acid is a natural polysaccharide and a common glycosaminoglycan in human body. It has the highest concentration in eyes and joints. It is made into hydrogels because of its biocompatibility, degradability, and low immunogenicity, and is widely used in tissue engineering. OBJECTIVE: To introduce the characteristics of various hyaluronic acid composite hydrogels and their application in the repair of cartilage damage caused by osteoarthritis. METHODS: CNKI and Wanfang databases were searched with the key words of “hyaluronic acid, hydrogel, cartilage repair, osteoarthritis” in Chinese. PubMed and Web of Science databases were searched with the key words of “hyaluronic acid, hydrogel, cartilage repair, osteoarthritis” in English. The articles published from January 1995 to July 2020 were searched and further analyzed and summarized. RESULTS AND CONCLUSION: The excellent biological properties of hyaluronic acid hydrogel have made it widely studied in the cartilage repair of osteoarthritis, especially through the combination of biological factors, natural materials, synthetic materials, 3D printing technology, polypeptides, mechanical stimulation, etc., which improved the performance of hyaluronic acid hydrogel and promoted its application in cartilage tissue engineering. Although hyaluronic acid composite hydrogels have been studied more, with the comprehensive development of chemistry, materials, physics, biology and other disciplines in the future, a deeper understanding of the degradation mechanism of hyaluronic acid hydrogels and an exploration of the cartilage damage mechanism in osteoarthritis, the hyaluronic acid composite hydrogel is expected to be designed with high efficiency, no side effects and more suitable for cartilage tissue engineering. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Drug therapies have limited effect on neuropathic pain and result in many side effects. Comparatively speaking, exercise is a good way to relieve pain. Here, we systematically evaluate the interventional effect of exercise on neuropathic pain induced by sciatic nerve injury in rats and mice. METHODS: WanFang, CNKI, PubMed, Embase and Web of Science databases were retrieved before April 2020. A series of studies regarding the effect of treadmill, swimming, wheel and other exercises on neuropathic pain induced by sciatic nerve injury in rats and mice were collected. According to the inclusion criteria, two researchers independently completed literature screening, data extraction and conducted methodological quality evaluation using SYRCLE’ s risk of bias tool for animal studies. RevMan 5.3 and STATA 12.0 analysis software were used for statistical analysis. Results: A total of 12 literatures regarding controlled animal studies were included, and there were 133 rodents in the exercise group and 135 rodents in the sedentary group. Meta-analysis showed that exercise could significantly increase paw withdrawal mechanical threshold [standard mean difference (SMD)=0.84, 95% confidence interval (CI): 0.28-1.40, P=0.003] and paw withdrawal thermal latency (SMD=1.54, 95% CI: 0.93-2.15), P < 0.000 01) in rats and mice after sciatic nerve injury. Subgroup analyses were performed for duration of exercise, indicating a significant reduction in heterogeneity. Postoperative exercise duration ≤ 3 weeks could significantly elevate paw withdrawal mechanical threshold (SMD=1.04, 95% CI: 0.62-1.46, P < 0.000 01). Postoperative exercise duration ≤ 4 weeks could significantly improve paw withdrawal thermal latency (SMD=1.93, 95% CI:1.19-2.67, P < 0.000 01). CONCLUSION: Exercise can effectively improve mechanical and thermal hypersensitivity caused by sciatic nerve injury in rats and mice. Pain models, exercise start point, exercise forms, and species are not the main factors of exercise-induced hypoalgesia, while postoperative exercise duration has an important influence on exercise-induced hypoalgesia. [ABSTRACT FROM AUTHOR]

BACKGROUND: Bone marrow mesenchymal stem cells are one of the most popular seed cells in cartilage tissue engineering. With the continuous advancement of medical research, many experiments have shown that certain active ingredients of traditional Chinese medicine can promote the induction of bone marrow mesenchymal stem cells into chondrocytes. OBJECTIVE: To review the regulatory mechanism and existing problems of different types of compound Chinese medicines and single Chinese medicine and their application in promoting the differentiation of bone marrow mesenchymal stem cells into chondrocytes, in order to provide research ideas for the promoting effect of the effective ingredients of Chinese medicine on the differentiation of bone marrow mesenchymal stem cells into chondrocytes. METHODS: The first author searched the relevant articles in CNKI, Wanfang, PubMed, Scopus and Web of Science databases, and used “compound Chinese medicine; single Chinese medicine; bone marrow mesenchymal stem cell; chondrocytes; tissue engineering” as the Chinese and English search terms. Finally, 60 articles meeting the criteria were selected for review. RESULTS AND CONCLUSION: (1) The active ingredients of certain compound Chinese medicines and single Chinese medicine have a promoting effect on the induction of bone marrow mesenchymal stem cells into chondrocytes, which is an important part of the application of Chinese medicine in cartilage tissue engineering research. (2) Using the effective ingredients of traditional Chinese medicine to induce bone marrow mesenchymal stem cells to differentiate into chondrocytes, and gradually applying them to cartilage tissue engineering for cartilage repair, has become a hot trend in the continuous development and growth of Chinese medicine. Among them, Tougu Xiaotong Granules have good effects with ginsenosides, astragaloside IV, and ligustrazine, and more experimental projects can be launched for research. [ABSTRACT FROM AUTHOR]

BACKGROUND: Transcranial magnetic stimulation (TMS) technology has been widely used in neuropsychology, rehabilitation medicine, and pediatrics, due to its advantages of painlessness, non-invasiveness, effectiveness and safety. However, there is yet no visual analysis of literature on TMS for treating stroke. OBJECTIVE: To objectively analyze global research on TMS in the treatment of stroke in recent 10 years, and summarize the recent research direction of this field and sort out the knowledge structure worldwide. METHODS: Based on the relevant literature on TMS for stroke in databases of CNKI and Web of Science, Citespace software was used to visualize the use of TMS in the treatment of stroke. The number, countries, authors, research institutions, keywords, cited references and journals of relevant literatures and funding grants were analyzed to explore the research hotspot and development trend in this field. RESULTS AND CONCLUSION: A total of 1 729 articles were included in the Web of Science database. Among them, the institution with the most publications was Harvard Medical School, and the country with the most publications was the United States, followed by China. China ranks first in international fund support. The hot keywords included rehabilitation, excitability, motor cortex and etc. As described in a representative English article, TMS therapy at a frequency of 1 Hz was found to improve patients’ motor function to a greater extent. A total of 455 literatures were included in CNKI database. Among them, the institution with the most publications was the Department of Rehabilitation Medicine of Huashan Hospital affiliated to Fudan University, and the hot keywords were rehabilitation, depression, motor function, aphasia and so on. As described in a representative Chinese article, high-frequency TMS was found to be more effective than low-frequency TMS in improving post-stroke depression and daily living ability. Further analysis of the results shows that, in recent 10 years, the international research frontier and future development trend mainly focus on the mechanism of TMS on cerebral cortical motor areas and the efficacy of TMS combined with other rehabilitation therapies (motor learning and mirror therapy) in the treatment of various functional disorders after stroke. In China, the research frontier and future trend mainly focus on TMS in the treatment of post-stroke depression and motor function. [ABSTRACT FROM AUTHOR]

BACKGROUND: There are still many problems in orthopedic medical metal materials after many years of clinical application, including autoimmune reaction, the mismatch of elastic modulus and human bone, the non-fusion of bone and interface after implantation, and the direct or indirect impact of metal corrosion and wear. OBJECTIVE: To summarize the bio-functionalization of medical metal materials in orthopedic applications. METHODS: The first author used computer to search the relevant literature of PubMed, CNKI, and Web of Science database. The English search terms were “orthopedics, metallic material, bio-functionalization”, and the Chinese search terms were “orthopedic medical metals, 3D printing technology, biofunctionalization, surface modification, material surface coating”. Finally, 61 articles were included for review. RESULTS AND CONCLUSION: Medical metal materials are the earliest materials used in orthopedics. The initial research on medical metal materials focused on the nature of metal materials. With the continuous research on bone substitute materials, the properties of materials are developing from biological inertness to biological activity and biological functionalization. Under the premise of not changing the properties of the body material, the organic coupling of the biological functions of metal materials was carried out by using surface physical modification, chemical modification and surface biological modification to further realize the bio-functionalization of medical metal materials, so that orthopedic medical metal materials not only have good mechanical properties and biocompatibility, as well as good biological activity, anti-inflammatory properties and osteoinductive properties. These multi-functional synergistic effects will become a new field of clinical application and also point out the direction for the development of new functions of biomedical metals. [ABSTRACT FROM AUTHOR]

BACKGROUND: Biodegradable microspheres, which release the functional modification factors encapsulated in them through self-degradation, can improve the drug solubility, half-life and other properties. They are widely used in the research of bone defect repair and regeneration. OBJECTIVE: To review and summarize the application of biodegradable microspheres in bone regeneration, the advantages and disadvantages of various materials used to prepare microspheres, as well as the new technology and modification methods of microspheres. METHODS: CNKI, Wanfang, PubMed, Elsevier, and Web of Science database were retrieved using “biodegradable microsphere, nanoparticle, bone regeneration, osteogenic” as English and Chinese keywords. RESULTS AND CONCLUSION: In the research of bone regeneration, the materials used to prepare biodegradable microspheres include inorganic materials, natural polymer materials and synthetic polymer materials. The preparation methods include ionic gel, solvent evaporation, spray drying, phase separation, and sol-gel method. Although the microspheres have excellent biocompatibility and bone conductivity, the osteogenic properties of most of the materials are still not ideal. Many ways are used to modify the microspheres, such as loading osteogenic factor, anti-infective factor and angiogenic factor, making it possible to functionalize the microspheres. The optimization of microsphere processing technology, the construction of composite microspheres and composite scaffolds, and the introduction of new efficient modification factors all provide new ideas for the application of microsphere in bone regeneration. [ABSTRACT FROM AUTHOR]

BACKGROUND: The oblique lateral approach interbody fusion is used more and more clinically. There are more and more biomechanical studies on the oblique lateral approach interbody fusion and internal fixation. OBJECTIVE: To summarize the research progress of the biomechanics of the oblique lateral approach interbody fusion and internal fixation in recent years so as to provide important reference value for the clinical application of the oblique lateral approach interbody fusion for the treatment of lumbar degenerative diseases. METHODS: In CNKI, Wanfang, PubMed, and Web of Science databases, “oblique lateral interbody fusion, oblique and anterior lumbar interbody fusion, finite element analysis, biomechanics, lumbar interbody fusion” were selected as the key words, and 45 articles were finally included for review. RESULTS AND CONCLUSION: (1) There are few studies on the biomechanics of oblique lateral approach interbody fusion, mainly including the comparison of lumbar interbody fusion with other approaches, stability comparison of different internal fixation methods, postoperative adjacent segmental degeneration, different types of fusion apparatus and so on. (2) The biomechanical stability of the oblique lateral approach is not significantly different from that of the lateral approach, which is better than other approaches. (3) Oblique lateral approach interbody fusion combined with bilateral pedicle screw fixation has the best biomechanical stability, and it is recommended that clinicians apply this technique as the first choice for oblique lateral approach interbody fusion. (4) Comparative studies of biomechanics between oblique lateral approach interbody fusion and anterior approach interbody fusion are insufficient, and there are few clinical outcomes comparisons, and further research is needed. [ABSTRACT FROM AUTHOR]

BACKGROUND: Studies have shown that a large amount of inflammatory factors produce in the occurrence of osteoarthritis, and antibodies against inflammatory factors have recently become a research hotspot. OBJECTIVE: To summarize the latest research progress of monoclonal antibodies for the treatment of osteoarthritis, and to provide references for the clinical treatment of osteoarthritis. METHODS: A computer search of CNKI, WanFang, PubMed and Web of Science databases was conducted for relevant articles published from January 2006 to May 2020. The key words were “osteoarthritis; monoclonal antibody; inflammatory factors.” After consulting related articles, a total of 69 articles were finally included for result analysis. RESULTS AND CONCLUSION: Osteoarthritis is an inflammatory and degenerative disease. Compared with traditional non-steroidal anti-inflammatory drugs, monoclonal antibodies have shown good effects in the treatment of osteoarthritis pain due to their good targeting and low side effects. Some monoclonal antibodies will increase the risk of joint replacement in patients, so the choice of drugs should vary from person to person. As research continues to deepen, more monoclonal antibodies against different targets will be produced, providing more options for clinical treatment of osteoarthritis. [ABSTRACT FROM AUTHOR]

BACKGROUND: The repair of cartilage defects such as ears, noses, throats, trachea and joints has always been one of the difficulties faced by clinical treatment. The emergence of cartilage tissue engineering has become a popular development direction for cartilage repair, in which seed cells are used to construct tissue engineered cartilage key. OBJECTIVE: This article intends to review the characteristics of various types of seed cells, their application in cartilage tissue engineering, and existing problems, and to bring new ideas to clinical transformation. METHODS: The first author searched the relevant articles of CNKI, Wanfang, PubMed, Scopus and Web of Science databases, using “seed cells; tissue engineering; chondrocytes; stem cells; co-cultivation” as the Chinese and English search terms. Finally, 70 articles that met the criteria were selected for review. RESULTS AND CONCLUSION: (1) Current experimental research on cartilage tissue engineering has achieved a lot of results, but the problem of selecting seed cells is still a big problem. Chondrocytes, various types of mesenchymal stem cells, embryonic stem cells, and induced pluripotent stem cells have different degrees of advantages, but also face different challenges. (2) The discovery, development and application of various seed cells have promoted the progress of cartilage tissue engineering. Among them, the method of co-culture of chondrocytes and stem cells is currently a popular and promising seed choice for research. [ABSTRACT FROM AUTHOR]

BACKGROUND: Keloid is a benign skin tumor with excessive proliferation of fibroblasts and deposition of collagen after trauma. Vascular occlusion, inflammation, fibroblast proliferation and collagen secretion in keloid tissues all lead to tissue hypoxia, which plays an important role in the pathogenesis and prognosis of keloids. OBJECTIVE: To review the research progress of hypoxia-inducible factor 1 alpha (HIF-1α) in the tumor-like characteristics of keloid. METHODS: CNKI, VIP, WanFang, PubMed, Biosos Preview, and Web of Science databases were searched for relevant articles from their inception to November 2020. The retrieval key words were “keloids, HIF-lα; radioresistance” in Chinese and English, respectively. After reading the title, abstract and full text, 104 articles that met the selection criteria were finally selected. RESULTS AND CONCLUSION: The hypoxic microenvironment inhibits the degradation of HIF-1α, and increased HIF-1α induces several biological behaviors in keloid tissue similar to malignant tumors, including epithelial-mesenchymal transition, angiogenesis, glycolysis, radioresistance, and recurrence after radiation. These pathophysiological processes in turn exacerbate tissue hypoxia and increase HIF-1αexponentially, thereby forming a vicious circle. Current treatments for keloids mainly focus on surgical resection combined with radiotherapy. HIF-1α targeting therapies, such as hyperbaric oxygen therapy, can significantly improve the hypoxic environment of keloid tissue, promote wound healing, and reverse the tumor-like properties of keloid fibroblasts. However, there are few studies on the treatment of keloids with hyperbaric oxygen therapy combined with radiotherapy, and the clinical treatment of keloids with HIF-1α as the target is still under exploration. [ABSTRACT FROM AUTHOR]

BACKGROUND: Polycationic chitosan drug carriers have shown good prospects in improving the effectiveness, utilization and security of existing drug delivery methods. OBJECTIVE: To review the research progress of chitosan-based nano drug carriers in recent years. METHODS: Computer was utilized to retrieve recently published articles in PubMed, CNKI and Elsevier Science Direct databases with key words “chitosan, nano, drug delivery, carrier” in Chinese and English. The time of publication was limited from 1994 to October 2020. The articles were primarily screened by reading and analyzing to exclude duplicate and low-relevance articles, and finally 54 articles were selected for result analysis. RESULTS AND CONCLUSION: At present, the research of chitosan as a drug delivery carrier has made significant progress. Both in vitro cell experiments and animal experiments have confirmed that it has a good drug encapsulation rate and can effectively release drugs, with the help of chitosan’s good bioadhesive properties, it can achieve drug delivery across the barrier (such as the blood-brain barrier), and achieve targeted drug delivery to a certain extent. According to different needs, the chitosan-based composites are different in molecular weight, shape, particle size distribution, encapsulation efficiency and drug loading. Even if it coated with the same drug, due to different manufacturing process or operation, there may also be differences in drug encapsulation rate, drug loading and release rate. Therefore, most of these carriers cannot be mass-produced at present. There is still a lot of work to be done for the chitosan-based nanomedicine carrier in a wide range of clinical applications, but in future research, its excellent biomedical properties may further expand its application potential. [ABSTRACT FROM AUTHOR]

BACKGROUND: With the improvement of the medical level and people’s higher requirements for the quality of life, the quality and requirements for cartilage repair in the clinic are getting more and more, but traditional repair methods cannot regenerate cartilage with good biological properties. OBJECTIVE: To review the research progress of autologous chondrocyte implantation in recent years, and to analyze its development process, basic science, indications, contraindications, surgical techniques, clinical efficacy and limitations, and look forward to the development trend of this field. METHODS: A computer-based online search of CNKI, PubMed, Web of Science databases, and Google Scholar was performed to retrieve papers published during 1990-2020 with the search terms “autologous chondrocyte implantation, cartilage defect, techniques, clinical effect, indications, contraindications, defect size, treatment after initial failure, return to sports, age, magnetic resonance imaging, limitation” in English and Chinese. The document types include treatise, reviews, case reports, and meta-analysis. A total of over 1 000 papers were retrieved, and 52 of them were included in the final analysis. RESULTS AND CONCLUSION: Autologous chondrocyte transplantation first appeared for the treatment of knee cartilage defects in the late 1980s. The first generation of autologous chondrocyte transplantation used periosteal patches to seal the cultured chondrocytes in the defect. Due to the proliferation of periosteal grafts, second-generation autologous chondrocyte transplantation used collagen membrane patches instead of periosteal patches. The third generation of autologous chondrocyte transplantation used three-dimensional culture technology to improve cell delivery, allowing minimally invasive implantation, which could regenerate normal cartilage structure with accelerating patient recovery. Autologous chondrocyte transplantation was an effective method to treat high tibia or femoral cartilage defects, but it must solve the problems consisting of coronal force line, ligament laxity, and meniscus injury. Because of the graft needing a long time to mature, patients needed a specific rehabilitation plan to return to the sport, which assisted the injured patients in restoring strength and neuromuscular coordination as much as possible before the graft was fully mature. [ABSTRACT FROM AUTHOR]

BACKGROUND: Human amniotic epithelial cells have a wide range of biological functions and can be used in the treatment of many diseases, such as conjunctival injury, burn, pulmonary fibrosis and heart disease. Human amniotic epithelial cells have been tested in the field of obstetrics and gynecology and achieved remarkable results, which is expected to become a new disease treatment, and is worthy of in-depth research and exploration. OBJECTIVE: To review the research progress, application status and development prospect of human amniotic epithelial cells on some diseases in the field of gynecology and obstetrics. METHODS: Key words “human amniotic epithelial cells”, “tumor” and “obstetrics and gynecology” were used to search PubMed and Web of Science databases, and Wanfang and CNKI Chinese databases were searched with key words “human amniotic epithelial cells”, “gynecological tumor” and “obstetrics and gynecology”. A total of 40 articles were included according to the inclusion and exclusion criteria. RESULTS AND CONCLUSION: (1) Human amniotic epithelial cells reverse abnormal vascular structure and function and induce apoptosis of endometrial carcinoma. (2) Human amniotic epithelial cells can inhibit apoptosis of granulosa cells induced by chemotherapy and restore fertility. (3) Human amniotic epithelial cells can treat uterine adhesion and improve fertility. (4) Human amniotic epithelial cells can treat recurrent spontaneous abortion. It is believed that with the further research, the function of human amniotic epithelial cells will be more widely developed and utilized. [ABSTRACT FROM AUTHOR]

BACKGROUND: With the development of bone tissue engineering, the role of scaffold materials has become more and more important. Polycaprolactone and its composite materials have also increasingly attracted researchers to become one of the research highlights in this field. OBJECTIVE: To introduce the basic properties and synthesis methods of polycaprolactone, to summarize the research status of polycaprolactone and its composite materials in the field of bone tissue engineering, and to prospect the future development and research direction. METHODS: These articles published from 1950 to 2020 in Web of Science database were retrieved by using the search terms “PCL, PCL composites, bone tissue engineering, scaffold, bone, PCL synthesis”, taking “and” as the logical combination relationship. Totally 253 articles were initially obtained, and finally 52 articles were reviewed and analyzed after careful reading and selection. RESULTS AND CONCLUSION: (1) Pure polycaprolactone materials have certain shortcomings in bone tissue engineering. Due to their easy chemical modification and physical modification, polycaprolactone composite undoubtedly has become one of the candidate materials for bone tissue engineering scaffolds. (2) Due to the excellent solubility and thermal properties of polycaprolactone, it can be applied to a variety of scaffold preparation technologies. The appropriate scaffold preparation technology can be selected according to the application site. A variety of scaffold preparation technologies also broaden the application field of polycaprolactone, and there are also developed some novel technologies, so scaffold preparation technology should also attract the attention researchers. (3) For the modification direction of polycaprolactone, the modification of inorganic substances and natural or synthetic polymers has received extensive attention. (4) In terms of experimental research methods, researchers should pay attention to introducing more kinds of experimental cells and experimental models in accordance with clinical needs. [ABSTRACT FROM AUTHOR]

BACKGROUND: Biological three-dimensional (3D) printing technology has been extensively utilized in numerous fields of biomedicine. However, not many cases have been successfully transformed into clinical trials. It is still in the development stage in precision medicine. This technology reveals great potential in realizing individualized medical treatment, changing the existing treatment process, and helping pharmaceutical and medical companies develop more accurate drugs. Furthermore, it is expected to accomplish the closed-loop from individualized information collection and diagnosis to individualized medical product preparation and precise treatment scheme. OBJECTIVE: To analyze the current research and hotspots of biological 3D printing technology in precision medicine. METHODS: Web of Science and Wanfang databases were searched for literature on 3D printing technology in precision medicine published from January 2015 to August 2020. The retrieval results received scientific quantitative analysis through big data analysis tools, mathematical statistics, computer semantic analysis, visualization software, and database analysis and retrieval. RESULTS AND CONCLUSION: (1) The amount of studies on 3D printing technology in the field of precision medicine gradually increases from 2015 to 2020. (2) The United States has the largest amount of publications, and its cooperation with other countries also occupies a core position. The research in China is also active in this field. (3) The institution that published the most papers in the world in the past five years is the University of California system, while the Chinese Academy of Sciences and Shanghai Jiao Tong University are the Chinese institutions with the highest number of publications. (4) Biofabrication and Chinese Journal of Tissue Engineering Research are the journals with the largest number of publications in the world and in China, respectively. (5) The hotspots of biological 3D printing technology in precision medicine mainly include bioinks, microfluidics, orthopedics, tissue/organ regeneration, and drug development. The research results published in Chinese journals are mainly concentrated in the fields of orthopedics, tissue engineering, clinical teaching, and medical models. (6) As one of the most revolutionary and influential advanced tools, biological 3D printing has achieved some accomplishments in regenerative medicine and organ transplantation. It has become an excellent scientific research tool in tissue engineering, stem cells, and cancer, and has created a way for precision medicine from medical imaging, preoperative plan to implant design and manufacture through digital tools. [ABSTRACT FROM AUTHOR]

BACKGROUND: The self-renewal and differentiation potential of stem cells make it a research hotspot in the medical field. Its immune regulation and neuroprotective effects make stem cells applications in multiple sclerosis and optic neuromyelitis spectrum diseases favored by clinicians. OBJECTIVE: To summarize the research progress of stem cells in multiple sclerosis and optic neuromyelitis spectrum diseases in recent years. METHODS: The PubMed and Web of Science databases were searched for documents related to stem cell therapy for multiple sclerosis and optic neuromyelitis spectrum diseases published in recent years. Search terms are "stem cells, multiple sclerosis, MS, EAE, neuromyelitis optica spectrum diseases, neuromyelitis optica, NMO, NMODS". According to inclusion and exclusion criteria, 75 related articles were included for careful reading and comprehensive analysis. RESULTS AND CONCLUSION: Compared with past immunosuppressive therapies, stem cell transplantation has great potential for the treatment of multiple sclerosis and optic neuromyelitis spectrum diseases. However, cell selection, donor source, transplantation time, route, post-transplantation long-term safety and effectiveness limit clinical applications. [ABSTRACT FROM AUTHOR]

BACKGROUND: Delayed fracture healing and nonunion are common complications in clinic. The mechanism of brain injury promoting fracture healing is the focus of current research. OBJECTIVE: To summarize the latest research progress on the mechanism of promoting fracture healing by traumatic brain injury, and provide theoretical basis for clinical application. METHODS: The first author searched CNKI, Wanfang, VIP, PubMed, Embase and Web of Science databases from January 2009 to March 2020. Search terms were "traumatic brain injury, fracture healing, bone marrow mesenchymal stem cells, fat stem cells, cytokines, hormones, neuropeptides, genes" in Chinese and English. Totally, 63 articles that met the inclusion criteria were selected. RESULTS AND CONCLUSION: Fracture healing is a complex and orderly pathological process, involving a variety of pathophysiological mechanisms and many factors affect bone regeneration. Large numbers of clinical studies have shown that traumatic brain injury can promote healing of fracture, but there is no systematic conclusion on the specific mechanism of fracture repair. Moreover, the current research is aimed at detection of the role of one or several factors alone. There are gaps in systematic research and dynamic detection of all relevant factors. Therefore, in the future clinical research, we should observe the expression of related factors at different time points during post-traumatic bone regeneration, and further explore the action mechanism of their interaction, so as to provide sufficient theoretical basis for clinical fracture nonunion, delayed fracture healing, heterotopic ossification and guide clinical treatment. [ABSTRACT FROM AUTHOR]

BACKGROUND: Studies have indicated that femoral head necrosis is a refractory disease in orthopedics. To explore the research status and research focus in the field of osteonecrosis of the femoral head is beneficial to grasp the research direction, promote the development of the field of femoral head necrosis, and make it better serve the clinical practice. OBJECTIVE: To explore the development of research hotspots on osteonecrosis of the femoral head in the past 5 years and predict the future research focus in this field, and to provide reference for relevant researchers. METHODS: Base on the Science Citation Index Extended database of the Web of Science database, we search for literature on osteonecrosis of the femoral head from 2016 to 2020 with the theme of "osteonecrosis of the femoral head,” and the VOSviewer software was applied for visualization analysis, including keyword co-occurrence analysis, co-author analysis, institutional co-authoring analysis, country co-authoring analysis, and co-citation analysis. RESULTS AND CONCLUSION: Based on keyword co-occurrence analysis, current research on osteonecrosis of the femoral head is divided into four main categories: risk factors, diagnose and treatment, orthormorphia, cell biology, genetics heredity of osteonecrosis of the femoral head. Steriod-induced osteonecrosis of the femoral head, bone marrow mesenchymal stem cells, and osteogenic differentiation are recent research hotspots in the field of osteonecrosis of the femoral head. However, the pathogenesis and treatment methods of steroid-induced osteonecrosis of the femoral head have not yet been clarified, and the mechanism of action and therapeutic effects of mesenchymal stem cells are still unclear. Therefore, it is speculated that further excavation of the mechanism of femoral head necrosis and improvement of its treatment are important research contents in the future. To conclude, the mechanism of steroid-induced osteonecrosis of the femoral head and the therapy of bone marrow mesenchymal stem cells for osteonecrosis of the femoral head will be studied deeply around the process of osteogenic differentiation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Intertrochanteric fracture with medial wall injury is a common type of intertrochanteric fracture. Since the medial parietal cortex is responsible for the major mechanical conduction of the proximal femur, the classification and treatment of such injuries have been updated in clinical practice. OBJECTIVE: Through the analysis of the fracture classification, injury mechanism and mechanics of intertrochanteric fracture with medial wall injury, to summarize the different internal fixation treatment methods, thereby providing help for the treatment of this kind of fracture. METHODS: CNKI, WanFang, PubMed and Web of Science database were searched using “intertrochanteric fracture, femoral intertrochanteric fracture, medial wall, fracture fixation” in Chinese and English, respectively. According to the inclusion and exclusion criteria, eligible literatures were included for final analysis and review. RESULTS AND CONCLUSION: The medial parietal cortex of the intertrochanter bears the main pressure conduction of the proximal femur, and the calcar femorale is particularly important. The common fracture types include Evans type, Jensen type, AO/ATO type, Kyle type and Muller ME type, which are of guiding significance for fractures with medial wall injury. For the treatment of intertrochanteric fractures with medial wall injury in the elderly, there is no unified view on which internal fixation method is used. The best choice of internal fixation needs to be made according to the stability of the medial wall and the basic condition of elderly patients. However, for elderly patients with unstable medial wall injury, we should first restore the continuity of the cortex and bony support to the medial wall. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cancer is becoming more common worldwide, affecting one third of the world’s population, and its morbidity and mortality are high. With the deep understanding of the cancer molecular biology, new cancer treatment programs continue to appear, and monoclonal antibody targeted drug therapy and immunotherapy have brought new hope to cancer patients. However, the lack of good models has hindered our understanding of tumor biology and the discovery of real drug targets. Effective in vitro tumor models are of great significance for the biological screening of anticancer drugs.OBJECTIVE: To summarize the application and prospect of induced pluripotent stem cells in tumor diseases.METHODS: PubMed, Web of Science and CNKI databases were searched for the articles concerning the induced pluripotent stem cells. The keywords were “induced pluripotent stem cells, tumor diseases, gene editing, regenerative medicine” in English and Chinese, respectively. After screening based on the inclusion and exclusion criteria, the articles with high relevance were included for review RESULTS AND CONCLUSION: Induced pluripotent stem cells have the advantages of wide sources, direct isolation from human peripheral blood, and being induced to differentiate into tumor tissues in vitro. Thus, more and more induced pluripotent stem cells for disease modeling and drug screening are being explored. With the continuous development of gene editing technology (CRISPER/Cas9), gene editing of stem cells has become possible to treat tumor diseases. [ABSTRACT FROM AUTHOR]

BACKGROUND: The current diagnosis and study of depression lacks objective biological indicators. As an emerging non-invasive brain functional imaging technology, functional near infrared spectroscopy (fNIRS) may be a potential biomarker for the identification and diagnosis of depression. OBJECTIVE: To review the application of fNIRS technique in depression research and provide guidance for clinical research. METHODS: The keywords were “functional near-infrared spectroscopy, oxyhemoglobins, prefrontal cortex, depressive disorder.” The first author searched CNKI, WanFang, VIP, PuMed and Web of Science database from 1996 to 2020 in Chinese and English. Finally, 50 literatures were selected for review. RESULTS AND CONCLUSION: fNIRS signal may be a potential biomarker for depression. fNIRS technology is mainly used to study the cognitive dysfunction of depression based on the frontal lobe hemodynamic changes, which can be used for the differential diagnosis of depression. However, the current research on fNIRS is still in the exploratory stage, and there are still some defects in the existing research, which need to be further optimized and deepened in the future research. It can increase the study sample size and monitoring indicators, and integrate fNIRS with other technologies to improve the temporal and spatial resolution, so as to study the neural mechanism of depression systematically, comprehensively and accurately [ABSTRACT FROM AUTHOR]