Search

This study aimed to elucidate whether the administration of parathyroid hormone (PTH) results in remodeling- or modeling-based bone formation in different regions of the murine femora, and whether the PTH-driven bone formation would facilitate osteoblastic differentiation into osteocytes. Six-week-old male C57BL/6J mice were employed to examine the distribution of alkaline phosphatase (ALP), PHOSPHO1, podoplanin, and calcein labeling in two distinct long bone regions: the metaphyseal trabeculae close to the chondro-osseous junction (COJ) and those distant from the COJ in three mouse groups, a control group receiving a vehicle (sham group) and groups receiving hPTH (1–34) twice a day (PTH BID group) or four times a day (PTH QID group) for two weeks. The sham group showed PHOSPHO1-reactive mature osteoblasts localized primarily at the COJ, whereas the PTH BID/QID groups exhibited extended lines of PHOSPHO1-reactive osteoblasts even in regions distant from the COJ. The PTH QID group displayed fragmented calcein labeling in trabeculae close to the COJ, whereas continuous labeling was observed in trabeculae distant from the COJ. Osteoblasts tended to express podoplanin and PHOSPHO1 independently in the close and distant regions of the sham group, while osteoblasts in the PTH-administered groups showed immunoreactivity of podoplanin and PHOSPHO1 together in the close and distant regions. Administration of PTH may accelerate remodeling-based bone formation in regions close to the COJ while predominantly inducing modeling-based bone formation in distant regions. PTH appeared to simultaneously facilitate osteoblastic bone mineralization and differentiation into osteocytes in both remodeling- and modeling-based bone formation. [ABSTRACT FROM AUTHOR]

Background: This study aimed to investigate the association between body composition (BC) specific parameters such as fat mass (FM) and lean body mass (LBM) and bone quality in obese and non-obese young Slovak adults (18–30 years) using bioelectrical impedance analysis and quantitative ultrasound while considering the factors of sex and obesity status; Methods: BC was evaluated using bioelectrical impedance analysis (InBody 770) and bone quality by the speed of sound (SOS) in radius using QUS (Sunlight MiniOmni) in 774 young Slovak young adults aged 18–30 years, categorized by sex and obesity status (body fat %, PBF, ≥28% for men and ≥20% for women); Results: In non-obese individuals, radial SOS correlated positively with FM parameters. Significant positive correlations with LBM, including skeletal muscle mass (SMM), were observed in non-obese men but not in women. Conversely, SOS correlated negatively with FM parameters in obese individuals, significantly only in women. The correlation of SOS with LBM in obese individuals was insignificant in both sexes. Age, visceral FM, FM in the arm, and vitamin D intake were identified as the main predictors of radial SOS in young adults, except in obese men. Conclusions: Findings indicate FM benefits bone tissue in non-obese individuals, while excessive adiposity deteriorates bone quality in obese individuals, necessitating tailored evaluations and interventions based on sex, obesity status, and specific predictors. [ABSTRACT FROM AUTHOR]

In this systematic review, the authors aimed to investigate the state of knowledge on in vivo evaluations of chitosan and nanometric hydroxyapatite (nanohydroxyapatite, nHAp) scaffolds for bone-tissue regeneration. In March 2024, an electronic search was systematically conducted across the PubMed, Cochrane, and Web of Science databases using the keywords (hydroxyapatite) AND (chitosan) AND (scaffold) AND (biomimetic). Methodologically, the systematic review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) protocol to the letter. Initially, a total of 375 studies were screened, and 164 duplicates were removed. A further 188 articles were excluded because they did not correspond to the predefined topics, and an additional 3 articles were eliminated due to the inability to obtain the full text. The final compilation included 20 studies. All publications indicated a potential beneficial effect of the scaffolds in in vivo bone defect repair. A beneficial effect of hydroxyapatite as a scaffold component was observed in 16 studies, including greater mechanical resistance, cellular differentiation, and enhanced bone damage regeneration. The addition of chitosan and apatite ceramics, which combined the strengths of both materials, had the potential to become a useful bone-tissue engineering material. [ABSTRACT FROM AUTHOR]

Bone tissue engineering (BTE) provides an alternative for addressing bone defects by integrating cells, a scaffold, and bioactive growth factors to stimulate tissue regeneration and repair, resulting in effective bioengineered tissue. This study focuses on repurposing chitosan from blue swimming crab (Portunus pelagicus) shell waste as a composite scaffold combined with HAP and COL I to improve biocompatibility, porosity, swelling, and mechanical properties. The composite scaffold demonstrated nearly 60% porosity with diameters ranging from 100–200 μm with an interconnected network that structurally mimics the extracellular matrix. The swelling ratio of the scaffold was measured at 208.43 ± 14.05%, 248.93 ± 4.32%, 280.01 ± 1.26%, 305.44 ± 20.71%, and 310.03 ± 17.94% at 1, 3, 6, 12, and 24 h, respectively. Thus, the Portunus pelagicus scaffold showed significantly lower degradation ratios of 5.64 ± 1.89%, 14.34 ± 8.59%, 19.57 ± 14.23%, and 29.13 ± 9.87% for 1 to 4 weeks, respectively. The scaffold supports osteoblast attachment and proliferation for 7 days. Waste from Portunus pelagicus shells has emerged as a prospective source of chitosan with potential application in tissue engineering. [ABSTRACT FROM AUTHOR]

BACKGROUND: Tumor necrosis factor-α is a broadly acting inflammatory cytokine that plays an important role in the immune inflammatory response of the body. The current study concluded that tumor necrosis factor-α has significant biological effects on a variety of bone tissue cells. OBJECTIVE: To summarize the expression and action pathways of tumor necrosis factor-α in osteoblastic and osteoclastic cells to further elucidate the regulatory role of tumor necrosis factor-α on bone tissue cells. METHODS: PubMed and CNKI were searched until March 2023, and the Chinese search terms included “tumor necrosis factor α, osteoblast, osteoclast, osteoclast, osteoprogenitor”; the English search terms included “TNF-α, osteoblast, osteoclast, osteocyte, osteoprogenitor cell”. The corresponding criteria were established according to the research needs, and the final literature was screened. Finally, 77 articles were included for review. RESULTS AND CONCLUSION: (1) Tumor necrosis factor-α is participating in regulating the recruitment, appreciation, and differentiation of osteoprogenitor cells, but leads to osteoprogenitor cell stripping and death under specific environments. It also participates in bone resorption directly or indirectly through secreted enzymes. (2) Tumor necrosis factor-α can increase the level of inflammatory factors in the environment by activating relevant signaling pathways in osteoclast lineage cells or directly induce the generation of osteoclasts in specific environments. (3) Tumor necrosis factor-α can inhibit osteogenic differentiation by activating nuclear factor-κB signaling pathway, inhibiting the expression of transcription factors such as RUNX2 and Osterix, and inducing apoptosis and necrotizing apoptosis in osteoblasts. (4) Tumor necrosis factor-α inhibits osteogenesis and promotes osteoclastogenesis by activating the nuclear factor-κB signaling pathway in osteocytes and inducing cytokines such as RANKL, SOST, and DKK1, while enhancing apoptosis of the osteocytes, as well as bone resorption around the apoptotic bone tissue. (5) Taken together, the effect of tumor necrosis factor-α in bone tissue is mainly to inhibit osteogenesis and promote osteoclastosis. The biological effect of tumor necrosis factor-α in bone tissue cells is usually dependent on the activation of tumor necrosis factor receptor and nuclear factor-κB signaling pathways. (6) The interaction of tumor necrosis factor-α with other tissue cell types surrounding bone tissue and its role in bone immune regulation still deserve attention in future studies. [ABSTRACT FROM AUTHOR]

BACKGROUND: Exercise is an effective method for preventing and treating osteoporosis, but it is unclear whether its effect on postmenopausal osteoporosis is related to changes in bone autophagy levels. OBJECTIVE: To observe the effects of exercise via cellular autophagy on the morphology and mechanical properties of bone tissue in ovariectomized rats, and to explore the mechanism of exercise on bone mass in ovariectomized rats from the perspective of autophagy. METHODS: A rat model of postmenopausal osteoporosis was established, and a 24-week moderate-intensity exercise was used for intervention. After the experiment, serum estradiol levels were measured by ELISA, and bone mineral density and bone microstructure of the cortical and trabecular bone were detected by micro-CT. The biomechanical indicators of the tibia were tested by a three-point bending test. Autophagosomes were observed by transmission electron microscopy. The expression of LC3 and ATG7 proteins was analyzed by western blot. RESULTS AND CONCLUSION: The serum estradiol level in the ovariectomized group was significantly lower than that of the sham-operation group and ovariectomized+exercise group (P < 0.01). The body mass of rats in each group increased, and the order was the ovariectomized group > the ovariectomized+exercise group > the sham-operation group > the sham-operation+exercise group. The bone mineral density and bone mass of rats in all groups significantly increased (P < 0.01), but the increase in the ovariectomized group was significantly lower than that of the other groups, and the increase in the ovariectomized+exercise group was significantly higher than that of the ovariectomized group. Compared with the sham-operation group, the bone mineral density of the tibial cancellous bone in the sham-operation+exercise group was significantly increased (P < 0.01), while the bone mineral density in the ovariectomized and ovariectomized+exercise groups was significantly decreased (P < 0.01). Compared with the ovariectomized+exercise group, the ovariectomized group showed significantly lower bone volume fraction, number of trabeculae, and bone mineral density of cancellous bone (P < 0.05), extremely significantly lower trabecular thickness (P < 0.01), and significantly higher mean trabecular pattern factor, trabecular separation, and structural model index (P < 0.01). Compared with the ovariectomized group, the LC3-II/LC3-I ratio and the relative expression of ATG7 protein significantly increased in the ovariectomized+exercise group (P < 0.05). Compared with the sham-operation and ovariectomized groups, the number of autophagosomes increased in the sham-operation+exercise and ovariectomized+exercise groups, respectively. To conclude, moderate-intensity treadmill exercise can improve the bone microstructure and biomechanical properties of the tibial cancellous bone and increase bone mass in ovariectomized rats by increasing serum estradiol levels and bone autophagy levels. [ABSTRACT FROM AUTHOR]

Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aimed to develop Janus-, cross-network-, and coaxial-structured piezoelectric–conductive polymer nanofibers through electrospinning to mimic the piezoelectricity of bone and facilitate the conduction of electrical signals in bone tissue repair. These nanofibers were constructed using the piezoelectric polymer polyvinylidene fluoride, and the conductive fillers reduced graphene oxide and polypyrrole. The influence of structural features on the electroactivity of the fibers was also explored. The morphology and components of the various structural samples were characterized using SEM, TEM, and FTIR. The electroactivity of the materials was assessed with a quasi-static d33 meter and the four-probe method. The results revealed that the piezoelectric–conductive phases were successfully integrated. The Janus-structured nanofibers demonstrated the best electroactivity, with a piezoelectric constant d33 of 24.5 pC/N and conductivity of 6.78 × 10−2 S/m. The tensile tests and MIP measurements showed that all samples had porosity levels exceeding 70%. The tensile strength of the Janus and cross-network structures exceeded that of the periosteum (3–4 MPa), with average pore sizes of 1194.36 and 2264.46 nm, respectively. These properties indicated good mechanical performance, allowing material support while preventing fibroblast invasion. The CCK-8 and ALP tests indicated that the Janus-structured samples were biocompatible and significantly promoted the proliferation of MC3T3-E1 cells. [ABSTRACT FROM AUTHOR]

Background and Objectives: Various materials are used to perform post-mastoidectomy mastoid obliteration (MO) to reduce the risk of recurrent infections, stasis of secretions, or caloric dizziness. Autologous materials used as fillers for MO tend to be insufficient owing to shrinkage over time or inadequate volume of these substances. Synthetic materials are unsatisfactory for MO because of the risk of rejection and extrusion. We investigated the safety and effectiveness of bone allografts for post-mastoidectomy MO. Subjects and Methods: We reviewed the medical records of patients who underwent mastoidectomy with MO between January 2013 and January 2021. In the MO group, bone allografts were additionally used to fill the residual mastoid cavity. In the canal wall down (CWD) group, all patients underwent CWD mastoidectomy with use of additional inferiorly based mucoperiosteal flaps. Results: The study included the MO group (23 ears) and the CWD group (53 ears). In the MO group, compared with the preoperative status, we observed a decrease in the tendency of the air-bone gap postoperatively. Compared with the CWD group, the total complication rate showed a decreasing tendency in the MO group. Conclusions: No patient showed post-MO shrinkage of the grafted bone allograft or otorrhea. Further large-scale studies are warranted to confirm the advantages of bone allografts for MO, including maintenance with time and sufficient amount. [ABSTRACT FROM AUTHOR]

Microgravity, the near absence of gravity experienced in space, is a major health concern for astronauts, leading to significant bone loss. This weakens their skeletal system, impacting performance during missions and hindering post-mission rehabilitation. To address this challenge, this paper explores the potential of advanced cellular research and regenerative medicine for mitigating bone loss in astronauts. We analyze the biological mechanisms affecting bone turnover markers and their implications for space travel. By examining key studies on the effects of spaceflight on bone structure in rodents and humans, we highlight the complex relationship between bone density and the microgravity environment. While acknowledging limitations like limited spaceflight simulators and the early stage of extraterrestrial research facilities, we propose a strategic shift towards advanced cellular research specifically tailored to microgravity. This approach focuses on understanding how microgravity disrupts bone formation and resorption at the cellular level. Tailor-made cellular laboratories are crucial for this research. These specialized labs would simulate microgravity and incorporate advanced technology to study the behavior and function of bone-forming cells (osteoblasts) and stem cells under these conditions. By investigating cellular mechanisms and potential therapeutic targets, this research holds promise for developing novel bone regeneration strategies for astronauts. This could involve stimulating bone formation or promoting the activity of stem cells to repair and strengthen bones in space. The success of this approach relies on collaboration between clinical applications and molecular signaling research. It also underscores the need for a skilled team of scientist-astronauts to conduct in vivo bone regeneration research under microgravity conditions. This multifaceted approach has the potential to not only improve astronaut health and well-being, but also pave the way for a sustainable human presence in space. Furthermore, advancements in cellular therapies for bone health under microgravity could have applications on Earth for treating conditions like osteoporosis. [ABSTRACT FROM AUTHOR]

Abstract The acquisition of bone models to perform simulations is a complex and expensive process. The hierarchical structure of bones is very complex, so that studies are mainly focused on the larger scales of bones. The objective of this work is to perform a fracture simulation at the microscale level. For this purpose, the first part of the process focuses on segmenting a bone model and selecting an area of it to generate a representation of the microstructures that make up the bone tissue from a microscopic point of view. The second part is dedicated to carry out a fracture simulation in the microscopic bone model. The developed algorithm follows a statistical approach and solves the main problems of the traditional approach (FEM) to perform a bone fracture simulation. The method returns the path that a fracture follows and demonstrates how bone structures affect fracture growth. The parameters used are configurable and can be adapted for specific cases. In addition, users can reproduce as many clinical cases as desired within seconds without have to manually segment images obtained from a microscope. The data obtained may be exported to obtain synthetic images that could be used to generate datasets for machine learning tasks or other purposes.

Abstract Background Sports practice during adolescence is important to enhance bone development, although it may provide different effects depending on the mechanical impact present in the sport. Besides, resistance training (RT) may also induce bone changes directly (via muscle contractions) and indirectly (via myokines). However, there have been no studies analyzing the longitudinal influence of engaging in sport with and without added mechanical load. Thus, this study aims to analyze the combined effects of sports participation and resistance training on areal bone mineral density (aBMD) accrual in adolescent athletes participating in swimming and impact sports for 12-months. Methods This was a 12-month longitudinal study. The sample comprised 91 adolescents (21 females) aged 10 to 18 years, engaged in impact sports (basketball, tennis, track & field, baseball and gymnastics, n = 66) and non-impact sport (swimming, n = 25). The sample was divided according to resistance training participation: impact sports only (n = 45), impact sports + resistance training (n = 21), swimming-only (n = 17) and swimming + resistance training (n = 8). aBMD and soft tissues were measured using dual-energy X-ray absorptiometry. Generalized linear models analysis was used for the resistance training (RT) x type of sport interaction in predicting aBMD changes overtime, adjusting for maturation, sex and baseline aBMD. Results After 12-months, all groups showed a significant increase in aBMD, except for the swimming groups (regardless of resistant training), which showed a significant loss in spine aBMD (-0.045 [-0.085 to -0.004] g/cm2 in swimming-only and − 0.047 [-0.073 to -0.021] g/cm2 in swimming + RT). In comparisons between groups, only swimming + RT group, compared with swimming-only group presented higher upper limbs aBMD (0.096 g/cm2 [0.074 to 0.118] in swimming + RT vs. 0.046 [0.032 to 0.060] g/cm2 in swimming only; p

In this study, 3D porous multicomponent bioceramic scaffolds were fabricated. Hydroxyapatite (HA) and carbonate-substituted hydroxyapatite (CHA) synthesized from Asian moon scallop shell (Amusium pleuronectes) served as the bioceramics, whereas alginate and chitosan served as the polymeric components. The study was focused on determining whether the presence of polyvinyl alcohol (PVA) in the scaffold exerted an impact. When PVA was not included, the morphological examination revealed that the samples exhibited porous structures characterized by effective pore interconnectivity and a substantial pore size. X-ray diffraction and scanning electron microscopic analyses indicated that the inclusion of PVA led to a decrease in the crystallinity, pore size, and porosity of the scaffolds. Those containing PVA exhibited porosity levels in the range of 56%–60%, and pore sizes ranged from 42 to 90 µm. These properties may provide advantages for the scaffold with respect to the ability for cell migration and cell attachment, thus enhancing new bone formation. Moreover, the compositions of HA and chemically modified HA (CHA) within the scaffold influenced the crystallinity and uniformity of the scaffold morphology. This finding suggests the potential for crafting a customized porous bioceramic scaffold based on specific compositions.

The bone regeneration process is complex and challenging and requires the application of biomaterials to promote adequate tissue growth and repair. Biomaterials traditionally used are produced with biocompatible and bioinert metal alloys, not presenting any response in the recipient tissue, whether negative, such as inflammation and infections, or positive, such as rapid and effective healing of the injured tissue. Using biomaterials with an active compound adsorbed in their structure allows a direct interaction between the material and the injured tissue, and consequent modulation of biological responses to promote bone formation. Such biomaterials can facilitate the adhesion of osteoprogenitor cells and other important biological factors for bone tissue regeneration and remodeling. This review explores the importance of considering adsorption during biomaterials production and understanding the bone regeneration process. In addition, focus is given to biomaterials produced from biopolymers based on cellulose and hydroxyapatite, as well as mechanisms of bone regeneration. Challenges remain for optimizing these processes, and the adsorption properties of different materials must be carefully investigated to guarantee adequate interaction with bone tissues and cells. Furthermore, the development of strategies to control the release of adsorbed components is crucial to obtain efficient and targeted bone tissue regeneration. [ABSTRACT FROM AUTHOR]

Background: Erectile dysfunction (ED) stands out as one of the most prevalent sexual disorders in men, with its incidence progressively escalating with age. As delineated by the International Consultation Committee for Sexual Medicine on Definitions/Epidemiology/Risk Factors for Sexual Dysfunction, the prevalence of ED among men under 40 years is estimated to be within the range of 1–10%. The aim of this study was to determine the relationship between the concentration of bioelements (Zn, Cu, Fe, Cr, Mg, and Mn) in the serum and bone tissue and the concentration of selected hormones in men with and without erectile dysfunction. Materials and methods: The retrospective cohort study included 152 men who underwent total hip arthroplasty for hip osteoarthritis at the Department of Orthopaedic Traumatology and Musculoskeletal Oncology at the Pomeranian Medical University in Szczecin. Certain exclusion criteria were applied to ensure the integrity of the study. These included individuals with diabetes, a history of cancer, alcohol abuse, liver or kidney failure, New York Heart Association (NYHA) class III or IV heart failure, and those taking medications that affect bone metabolism, such as mineral supplements, neuroleptics, chemotherapeutic agents, immunosuppressants, corticosteroids, or antidepressants. Patients with hypogonadism or infertility were excluded from the study. Results: The study showed an association between bioT concentrations and Cu concentrations in both patients with and without erectile dysfunction. A correlation between bioactive testosterone and Cr concentrations was also observed in both groups. Patients with erectile dysfunction showed a relationship between bioT concentration and Zn concentration, TT concentration and Mn concentration, FT concentration and Zn concentration, and E2 concentration and Cr concentration. An analysis of elemental concentrations in bone tissue showed an association between FT and Mg and Mn concentrations, but only in patients with erectile dysfunction. In patients without erectile dysfunction, a correlation was observed between FT and Cu concentrations. A correlation was also observed between bioT concentrations and Mg, Mn, and Zn concentrations, but only in patients with erectile dysfunction. In patients without erectile dysfunction, a correlation was observed between bioT and Cu concentrations. Conclusions: Studying the relationship between the concentration of bioelements (Zn, Cu, Fe, Cr, Mg, and Mn) in the serum and bone tissue and the concentration of selected hormones in men may be important in explaining the etiology of the problem. The study of the concentration of Zn and Cu in bone tissue and serum showed that these two elements, regardless of the place of accumulation, may be related to the concentration of androgens in men. [ABSTRACT FROM AUTHOR]

Biocompatible and bioactive composite scaffolds are essential in bone tissue regeneration because of their bioactivity and multilevel porous assemblies. There is a high demand for three-dimensional (3D) scaffolds to treat bone regeneration defects, trauma, and congenital skeletal abnormalities in the current scenario. The main objective of this review is to collect all the possible information concerning synthetic and natural polymer-Bioglass (BG)-based scaffold materials and systematically present them to summarize the importance and need for these materials. The importance of the bone tissue engineering field has been highlighted. Given the current challenges, a comprehensive description of materials fabrication and patterns in scaffold structures is required. This review also includes the most crucial aspect of this study: why are polymeric materials mixed with BG materials? Individually, both BG and polymeric materials lack specific essential characteristics to enhance the scope of these materials. However, preparing the composites of both ensures the researchers that composites of polymers and BG have improved properties that make them versatile materials for bone tissue engineering applications. This study deals with the individual drawbacks of the inorganic BGs, synthetic polymers, and the deficiencies of natural polymers. This study has also included a brief description of various scaffold fabricating techniques. Finally, this study revealed that by manufacturing and developing novel composite materials-scaffolds bearing the capability to repair, heal, and regenerate accidentally damaged or badly injured bones, many occasional problems can be solved in vivo and in vitro. Moreover, this review demonstrated that natural polymeric materials present many advantages over synthetic bone grafts. Yet, synthetic biomaterials have one additional attractive feature, as they have the flexibility to be designed according to the desired demands. These features make them the best choice for a wide range of bone tissue engineering projects for orthopedic surgeons. [ABSTRACT FROM AUTHOR]

Introduction: High + Gz loads, the gravitational forces experienced by the body in hypergravity environments, can lead to bone loss in pilots and astronauts, posing significant health risks. Materials and methods: To explore the effect of treadmill exercise on bone tissue recovery, a study was conducted on 72 male Wistar rats. These rats were subjected to four weeks of varying levels of periodic high + Gz loads (1G, 8G, 20G) experiments, and were subsequently divided into the treadmill group and the control group. The treadmill group underwent a continuous two-week treadmill experiment, while the control group rested during this period. The mechanical properties, microstructure, and molecular markers of their tibial bone tissue were measured using three-point bending, micro-CT, and PCR. Results: The results showed that treadmill exercise improved the elastic modulus, ultimate deflection, and ultimate load of rat bone tissue. It also increased the number, density, and volume fraction of bone trabeculae, and decreased their separation. Moreover, treadmill exercise enhanced osteogenesis and inhibited osteoclastogenesis. Conclusion: This study demonstrates that treadmill exercise can promote the recovery of bone tissue in rats subjected to high + Gz loads, providing a potential countermeasure for bone loss in pilots and astronauts. [ABSTRACT FROM AUTHOR]

Simple Summary: Examination of the nutritional mineral composition of carp (Cyprinus carpio) tissues revealed that both edible (fillet) and inedible parts of fish (spine and bones) can be good sources of compounds with functional or beneficial influence on human health. Due to the high mineral content, carp bones and spine can be used as a natural calcium source in food and feed or as a supplement. Therefore, C. carpio bone by-products could be utilized taking into account the principles of a circular economy and can be even exploited by the food industry on a larger scale, facilitating better promoting by-products of this widely cultured fish species. The aim of the study was to compare the content of major components, selected elements and heavy metals in the fillet, spine and bones of a carp (Cyprinus carpio). Moreover, the extent to which a prepared portion of carp tissue (100 g of fillet and 10 g of carp spine or bones) met the requirements for analyzed elements in adults (women and men) and children was calculated. The proximate composition (total protein, total lipid, ash, moisture) and mineral content of the fish samples were determined. The nutrient composition presented fluctuations among the different tissues. Moisture was the main constituent in the fillet and in the spine with 77.8% and 56.0%, respectively, whereas in bones, the main ingredient was ash (36.2%). All carp tissues were good sources of protein, with 16.5%, 21.0% and 17.0% in spine, bones and fillet, respectively. The most abundant main elements were the potassium in the fillet (4005 mg kg−1) and calcium in the bones (116,463 mg kg−1). The most abundant trace elements were iron in fillet and zinc in bones and spine. Carp meat can be considered a safe foodstuff in terms of concentrations of Hg, Pb and Cd, as the levels of these contaminants were less than FAO and European Commission maximum guidelines. [ABSTRACT FROM AUTHOR]

Obesity, type 2 diabetes mellitus (T2DM) and osteoporosis are serious diseases with an ever-increasing incidence that quite often coexist, especially in the elderly. Individuals with obesity and T2DM have impaired bone quality and an elevated risk of fragility fractures, despite higher and/or unchanged bone mineral density (BMD). The effect of obesity on fracture risk is site-specific, with reduced risk for several fractures (e.g., hip, pelvis, and wrist) and increased risk for others (e.g., humerus, ankle, upper leg, elbow, vertebrae, and rib). Patients with T2DM have a greater risk of hip, upper leg, foot, humerus, and total fractures. A chronic pro-inflammatory state, increased risk of falls, secondary complications, and pharmacotherapy can contribute to the pathophysiology of aforementioned fractures. Bisphosphonates and denosumab significantly reduced the risk of vertebral fractures in patients with both obesity and T2DM. Teriparatide significantly lowered non-vertebral fracture risk in T2DM subjects. It is important to recognize elevated fracture risk and osteoporosis in obese and T2DM patients, as they are currently considered low risk and tend to be underdiagnosed and undertreated. The implementation of better diagnostic tools, including trabecular bone score, lumbar spine BMD/body mass index (BMI) ratio, and microRNAs to predict bone fragility, could improve fracture prevention in this patient group. [ABSTRACT FROM AUTHOR]

The review of modern literature presents data on the prevalence of obesity and osteoporosis in Ukraine and the world. These diseases are associated with severe and persistent symptoms, slow recovery, and a significant negative impact on patients' quality of life. Melatonin is a hormone with enormous biological functions. As a widely available and versatile molecule in vivo, it has powerful antioxidant and anti-inflammatory properties in various bone diseases, has an effect on the restoration of damaged tissues, helps to reduce the amount of visceral adipose tissue and improves eating behavior. However, the informational analysis of the problem showed that there are still many unsolved questions regarding the optimal dosage and timing of melatonin administration, as well as the study of any possible side effects during its longterm administration. At the same time, the study of the effect of melatonin on the state of the bone system in obesity can contribute to a deeper understanding of the pathogenesis of both osteopenic and metabolic syndromes for the development of new methods of treatment and prevention. [ABSTRACT FROM AUTHOR]

Background: Sports practice during adolescence is important to enhance bone development, although it may provide different effects depending on the mechanical impact present in the sport. Besides, resistance training (RT) may also induce bone changes directly (via muscle contractions) and indirectly (via myokines). However, there have been no studies analyzing the longitudinal influence of engaging in sport with and without added mechanical load. Thus, this study aims to analyze the combined effects of sports participation and resistance training on areal bone mineral density (aBMD) accrual in adolescent athletes participating in swimming and impact sports for 12-months. Methods: This was a 12-month longitudinal study. The sample comprised 91 adolescents (21 females) aged 10 to 18 years, engaged in impact sports (basketball, tennis, track & field, baseball and gymnastics, n = 66) and non-impact sport (swimming, n = 25). The sample was divided according to resistance training participation: impact sports only (n = 45), impact sports + resistance training (n = 21), swimming-only (n = 17) and swimming + resistance training (n = 8). aBMD and soft tissues were measured using dual-energy X-ray absorptiometry. Generalized linear models analysis was used for the resistance training (RT) x type of sport interaction in predicting aBMD changes overtime, adjusting for maturation, sex and baseline aBMD. Results: After 12-months, all groups showed a significant increase in aBMD, except for the swimming groups (regardless of resistant training), which showed a significant loss in spine aBMD (-0.045 [-0.085 to -0.004] g/cm2 in swimming-only and − 0.047 [-0.073 to -0.021] g/cm2 in swimming + RT). In comparisons between groups, only swimming + RT group, compared with swimming-only group presented higher upper limbs aBMD (0.096 g/cm2 [0.074 to 0.118] in swimming + RT vs. 0.046 [0.032 to 0.060] g/cm2 in swimming only; p < 0.05) and whole body less head (WBLH) aBMD (0.039 [0.024 to 0.054] g/cm2 in swimming + RT vs. 0.017 [0.007 to 0.027] g/cm2 swimming-only; p < 0.05). Conclusion: Despite the significant gain in aBMD in all groups and body sites after 12-months, except for the spine site of swimmers, the results indicate that participation in RT seems to improve aBMD accrual in swimmers at the upper limbs and WBLH. [ABSTRACT FROM AUTHOR]

In this work, hybrid materials within the polydimethylsiloxane–silica (PDMS–SiO2) system, synthesized via the sol–gel method, were developed and characterized for their potential to incorporate and release the bioactive compound resveratrol (RES). RES was incorporated into the materials with a high loading efficiency (>75%) using the rotary evaporator technique. This incorporation induced the amorphization of RES, resulting in enhanced solubility and in vitro release when compared to the free polyphenolic compound. The release profiles displayed pH dependence, exhibiting notably faster release at pH 5.2 compared to pH 7.4. The gradual release of RES over time demonstrated an initial time lag of approximately 4 h, being well described by the Weibull model. In vitro cytotoxicity studies were conducted on human osteosarcoma cells (MG-63), revealing a concentration-dependent decrease in cell viability for RES-loaded samples (for concentrations >50 µg mL−1). [ABSTRACT FROM AUTHOR]

Relevance. Magnets have long been used to treat various diseases, especially in inflammatory processes. According to existing historical data, magnetotherapy was already used in ancient times by the Chinese, Egyptians and Greeks. Different magnetic field strengths affect cells in different ways, with medium-strength magnetic fields being the most widely used. The review presents a brief history and current state of the issue of using a magnetic field in bone tissue regeneration. Modern knowledge about the mechanisms of physiological and reparative regeneration, restoration of bone tissue is clarified, and modern areas of bone tissue engineering are considered, taking into account the characteristics of microcirculation and the effect of a magnetic field on the physiology of bone tissue and reparative regeneration. One of the key findings of the review is that the magnetic field improves bone tissue repair by influencing the metabolic behavior of cells. Studies show that magnetotherapy promotes the activation of cellular processes, accelerates the formation of new bone tissue and improves its quality. It is also noted that the magnetic field has a positive effect on microcirculation, improving the blood supply to tissues and facilitating a better supply of nutrients to the site of injury. This contributes to faster wound healing and early rehabilitation of patients. Conclusion. Magnetotherapy is one of the effective physical and rehabilitation methods of treatment that will become increasingly important in modern medicine. However, further research is needed to better understand the mechanisms of action of a magnetic field on bone tissue and to determine the optimal parameters for its application.

The goal of this work is the flaw-free, industrial-scale production of biological additive manufacturing of tissue constructs (Bio-AM). In pursuit of this goal, the objectives of this work in the context of extrusion-based Bio-AM of bone tissue constructs are twofold: (1) detect flaw formation using data from in-situ infrared thermocouple sensors; and (2) prevent flaw formation through preemptive process control. In realizing the first objective, data signatures acquired from in-situ sensors were analyzed using several machine learning approaches to ascertain critical quality metrics, such as print regime, strand width, strand height, and strand fusion severity. These quality metrics are intended to capture the process state at the basic 1D strand-level to the 2D layer-level. For this purpose, machine learning models were trained to classify and predict flaw formation. These models predicted print quality features with accuracy nearing 90%. In connection with the second objective, the previously trained machine learning models were used to preempt flaw formation by changing the process parameters (print velocity) during deposition—a form of feedforward control. With the feedforward process control, strand width heterogeneity was statistically significantly reduced, reducing the strand width difference between strand halves to less than 50 µm. Using this integrated process monitoring, detection, and control approach, we demonstrate consistent, repeatable production of Bio-AM constructs. [ABSTRACT FROM AUTHOR]

Dental implants are becoming an increasingly important part of modern dental treatment. Developing an optimal implant surface design can improve osseointegration. Promising to increase the rate of osseointegration is the use of extracorporeal shock wave therapy, which has proven itself for the treatment of fractures, bone defects, and bone tissue regeneration during surgery and arthroplasty. This work aims at a numerical investigation of the effects of low-energy shock wave therapy of various intensities on the mechanical behavior of dental implants and surrounding bone tissues, taking into account the physiological characteristics in the area of dental implant placement. Modeling was carried out using the method of movable cellular automata. The results of computer simulation showed that the conditions for the regeneration of bone tissues at the near-contact zone with the implant of the jaw segment are created by a shock wave with intensity greater than 0.1 mJ/mm2. [ABSTRACT FROM AUTHOR]

Objectives: Conducting a scoping review (SR) to assess scientific evidence for topical simvastatin’s impact on alveolar bone regeneration and determine its level of support for clinical applications. Materials and methods: This SR followed the PRISMA-ScR and OSF registries protocol; systematic searching was conducted on MEDLINE/PubMed, Cochrane, Embase, Scopus, Web of Science, and LILACS, to identify relevant articles until June 2023. Inclusion criteria covered clinical trials, case series, prospective and retrospective studies, along with in vivo investigations, involving participants of any sex and age. Results: Out of 1312 identified studies, 20 (9 in vivo, 11 RCTs) met inclusion criteria. RCTs focused on third molar extraction, in vivo on mandibular incisor surgery. The majority of RCTs employed a collagen sponge and a simvastatin concentration of 10mg; conversely, most in vivo studies favored polylactide-co-glycolide and a 2 mg simvastatin concentration. RCTs had 3-month follow-ups; in vivo, studies extended to 8 weeks. Seven RCTs assessed pain outcomes, simvastatin did not significantly affect pain in six studies. Among four RCTs on postoperative swelling, only two observed a significant increase in the simvastatin group. In general, positive bone formation and the absence of adverse effects directly linked to topical simvastatin were observed across the study models. Conclusions: Intra-alveolar simvastatin post-tooth extraction has been to be shown to be effective and safe for preserving alveolar bone, with varied concentrations and carriers, with no significant adverse effects. Clinical relevance: This review provides critical insights into the effects of simvastatin on alveolar bone regeneration, informing potential benefits and possible challenges associated with its post-extraction application. OSF Registry protocol: osf.io/q3bnf [ABSTRACT FROM AUTHOR]

A rat model of coal combustion-contaminated fluorine-aluminum co-toxicity was replicated using coal-dried corn from the diseased area as the main feed along with AlCL3 added to the drinking water. This study successfully established a rat model of coal-fired fluorine-aluminum co-toxicity by measuring fluorine and aluminum loading and urinary excretion and analyzing the results of dental fluorosis. Measurement and analysis of the isolated bone mineral density of the femur and tibia in rats with fluorine-aluminum co-toxicity were achieved by the application of an X-ray bone densitometer. Scanning electron microscopy was also applied to observe the morphological changes in the ultrastructure of the cancellous bone of the femur and the morphometric parameters of the bone of the upper end of the tibia of the rats during fluorine-aluminum co-toxicity. This study showed that: (1) the bone density and morphometric indicators of the high fluorine-aluminum group and high aluminum group were consistently reduced, mainly characterized by malacic skeletal fluorosis and (2) the changes in the bone tissue and morphometry in the high fluorine-aluminum group were more significant than those in the high aluminum group, suggesting a possible superimposed effect during fluorine-aluminum co-toxicity. [ABSTRACT FROM AUTHOR]

Objetive. To determine the effect of metformin (MET) treatment on adipogenic predisposition of bone marrow progenitor cells (BMPC), bone marrow adiposity and bone biomechanical properties. Materials and methods. 20 young adult male Wistar rats were sorted into four groups. Each of the groups received the following in drinking water: 100% water (C); 20% fructose (F); metformin 100 mg/kg wt/day (M); or fructose plus metformin (FM). After five weeks the animals were sacrificed. Both humeri were dissected to obtain BMPC, and both femurs were dissected to evaluate medullary adiposity (histomorphometry) and biomechanical properties (3-point bending). BMPC were cultured in vitro in adipogenic medium to evaluate RUNX2, PPAR-γ and RAGE expression by RT-PCR, lipase activity and triglyceride accumulation. Results. The fructose-rich diet (group F) caused an increase in both triglycerides in vitro, and medullary adiposity in vivo; being partially or totally prevented by co-treatment with metformin (group FM). No differences were found in femoral biomechanical tests in vivo, nor in lipase activity and RUNX2/PPAR-γ ratio in vitro. DRF increased RAGE expression in BMPC, being prevented by co-treatment with MET. Conclusions. Metabolic syndrome induced by a fructose-rich diet increases femoral medullary adiposity and, in part, the adipogenic predisposition of BMPC. In turn, this can be totally or partially prevented by oral co-treatment with MET.. [ABSTRACT FROM AUTHOR]

Today, the construction of scaffolds promoting the differentiation of stem cells is an intelligent innovation that accelerates the differentiation toward the target tissue. The use of calcium and phosphate compounds is capable of elevating the precision and efficiency of the osteogenic differentiation of stem cells. In this research, osteoconductive electrospun poly (ɛ-caprolactone) (PCL) - poly (vinyl alcohol) (PVA) hybrid nanofibrous scaffolds containing modified cockle shell (CS) nanopowder were prepared and investigated. In this regard, the modified CS nanopowder was prepared by grinding and modifying with phosphoric acid, and it was then added to PVA nanofibers at different weight percentages. Based on the SEM images, the optimum content of the modified CS nanopowder was set at 7 wt %, since reaching the threshold of agglomeration restricted this incorporation. In the second step, the PVA-CS7 nanofibrous sample was hybridized with different PCL ratios. Concerning the hydrophilicity and mechanical strength, the sample named PCL50-PVA50-CS7 was ultimately selected as the optimized and suitable candidate scaffold for bone tissue application. The accelerated hydrolytic degradation of the sample was also studied by FTIR and SEM analyses, and the results confirmed that the mineral deposits of CS are available approximately 7 days for mesenchymal stem cells. Moreover, Alizarin red staining illustrated that the presence of CS in the PCL50-PVA50-CS7 hybrid nanofibrous scaffold may potentially lead to an increase in calcium deposits with high precipitates, authenticating the differentiation of stem cells towards osteogenic cells.

Abstract The objective of the current study was to carry out a survey of the main anatomopathological alterations in raising quails and evaluate possible interference of these in the bone tissue. To obtain the data, 23 quails were collected from farm in the central Serrana region of Espírito Santo. Necropsies with macroscopic descriptions, microbiological, coproparasitological, radiographic and histomorphometric tests were carried out. It was done data descriptive analysis and average comparision using Student T test. It was found that they presented lesions predominantly in the digestive system, followed by urinary and reproductive, and muscular system, were the altered color of the liver (47%) was the most frequent lesion. In the parasitological exams, it was found oocysts of Eimeira sp. (39.13%). In the microbiological exams, it was detected predominantly Escherichia coli (83%). Moderate osteopenia in quails, but the percentage of trabecular bone on bones was similar between healthy and diseased quails, without bone changes in histology. Microscopically, it was observed lung congestion as predominant lesion. It is concluded that there was predominance of alterations in the digestive system and mild parasitic infection; and although there was moderate level of osteopenia, there wasn’t bone change as a result of the observed infections.

3D printing, or additive manufacturing, has transformed various industries with its layer-by-layer fabrication approach. In medicine, 3D printing, or biofabrication, has seen significant advancements, particularly in the creation of patient-specific medical models and custom-made drug tablets. Bioprinting, a key aspect of biofabrication, encompasses three approaches: biomimicry, autonomous self-assembly, and microtissues, each with its unique advantages and disadvantages. This comprehensive review explores the merits and limitations of these bioprinting approaches and outlines the three main phases of the entire bioprinting process: pre-processing, processing, and post-processing. By enhancing patients’ quality of life, reducing healthcare costs, and tapping into the global medical device market, biofabrication technologies hold immense promise for the future of medicine. This literature review focuses on the applications of 3D printing technologies in creating medical devices, including bone tissues, joint tissues, 3D printed tablets, and medical models.

Introduction. Ensuring control over regenerative processes by using the patient's blood is a unique concept of an autogenous transplant product, a universal and safe method of application that contains growth factors and cytokines stored in the fibrin matrix and provides stimulating properties of tissue regeneration through the processes of angiogenesis, proliferation, cell migration, and extracellular matrix synthesis. The aim. To substantiate the effectiveness of the protocol for collecting, preparing, and forming autocellular mesoconcentrate products in the analysis of the results of their electron microscopic examination. Materials and methods. Based on our own clinical experience of using the Endoret-PRGF technique (Human Technology, BTI, Spain) to collect, prepare, and form autocellular transplant products rationally, we used the method of morphological study of objects using a stream of electrons that passed through thin films under high voltage, allowing us to study the structure of these objects at the macromolecular and subcellular levels – transmission electron microscopy, which contributed to the study of the density (number of occurrences in 10 μm2 ), diameter (Ø) of the formed fibrin fibers in the PRGF – F1 and F2 fractions of mesoconcentrate products, namely, isolating membranes (M) and obturating blocks (B). An equally important step in PRGF technology is to follow the step-by-step instructions for preparing and using autocellular transplants. Results. Protocol for the collection, preparation, and formation of autocellular transplants using the KMU15 kit (Human Technology, BTI) for the application of the Endoret – PRGF technique, platelet-rich plasma, as a unique and first scientifically proven technique recognized worldwide and patented by the Institute of Human Biotechnology, Spain. The results of the clinical application of mesoconcentrate products, namely isolating membranes widely used in targeted tissue regeneration and obturating blocks, confirm their biological effectiveness. The results of the median (Me) and interquartile range (IQR) during the statistical analysis were obtained, where F1-M = 0.196 (0.176; 0.286) compared to F1-B = 0.344 (0.325; 0.394); F2-M = 0.180 (0.168; 0.214) - F2-B = 0.254 (0.202; 0.338), which gives us the right to assert the reliability of the data set and confirms the quantitative characterization of interfraction differences, and, accordingly, the quality in the sequence of protocol stages. Conclusions. The protocol for the efficiency of autocellular graft collection and formation is synchronized with the analysis of electron microscopic images characterizing the density and diameter of fibrin fibers, which differ in the fractional products of the mesoconcentrate and are higher in the obturating blocks than in the isolating membranes, indicating its completeness and compliance.

This article describes the role of resonance frequency analysis (RFA) as an indicator of the quality of primary implant stability, which is the basis of the goal and confirmed by the results of a clinical case – odontological implantation on edentulous segments of atrophied bone tissue on the right side of the mandible, taking into account the topographic features of its canal, using ultra-short (h = 5.5 mm) implants. Aim. To highlight the role of resonance frequency analysis during surgical interventions using short (ultrashort) implants in predicting their primary stability and preserving the normal morphology of the mandibular bone tissue. Materials and methods. The primary stability of 17 dental implants in seven patients was determined using the Penguin Instruments (RFA) technique in declarative units of measurement – the implant stability quotient (ISQ). Values in the range of 75 ISQ meant that the implant had adequate primary stability and could receive and distribute the immediate load on the bone tissue of the edentulous segment. Results. Following the stages of preparation, 17 ultra-short (h = 5.5 mm × b = 4.0 mm) implants were placed on the edentulous segments of the mandible without an incisional osteotomy path according to the patient rehabilitation protocol. We used the method of resonance frequency analysis to obtain a value of high primary stability of two short subcortical implants in the projection of tooth 4.7 – 92 ISQ and the projection of tooth 4.6 – 90 ISQ. On the 3rd day of the clinical stage of fixation of the supraconstruction, RFA measurements were performed, the values of which showed a significant decrease in the stability quotient of the installed implants in the projection of tooth 4.7 – 61 ISQ and in tooth 4.6 – 74 ISQ. This result made it necessary to revise the rehabilitation plan, adjust the medical prescription sheet and decide to postpone the placement of the all-milled restorative structure on the implants. Conclusions. The RFA study indicates not only the primary stability of implants but also a full-fledged stage-bystage clinical prognosis of the further functionality of a prosthetic structure based on short implants with proper preservation of the morphological functionality of bone tissue.

Relevance. Bone tissue regeneration and the development of methods for directed influence on the processes of bone healing are of the most urgent problems of modern medicine. Defects in the jaw bones are widespread, which in turn leads to the search for modern bone - replacing materials that meet the basic characteristics of the bone. Information was searched based on the PubMed and E-library databases, using the keywords: “bone tissue” AND “bone regeneration” AND “osteoplastic materials” AND “osteoinduction” AND “osteoconduction”. Autologous bone is considered the clinical gold standard and the most effective method of bone regeneration. It is the autograft that has three main characteristics: osteogenicity, osteoinductive and osteoconductive. The autograft has limitations due to the limited amount of bone tissue and the soreness of the donor site. A viable alternative to autologous bone is an allograft. The most widely used allograft is demineralized freeze - dried bone allograft (FDBA). The freeze - drying process promotes damage to osteoblasts, which limits its osteoinductive potential, but it is a profitable alternative in terms of convenience, abundance of choice and absence of pain due to the absence of additional surgical intervention. The main component of xenogeneic materials is collagen, which has the ability to resorb in tissues and stimulate regenerative processes. The material has osteoconductive properties and is capable of bone ingrowth, with the formation of a new bone directly from the xenomaterial bed with the deposition of bone cells on its surface. Subsequently, the xenomaterial undergoes resorption with complete replacement with new bone tissue. Alloplastic materials are fully synthetic materials synthesized from inorganic sources. Alloplastic materials have the property of osteoconduction, and when various growth factors are added to their composition, the property of osteoinduction is added to osteoconductive. The clinical use of bone substitutes is limited by their fragility as well as their unpredictable rate of resorption, which render these materials generally less favorable in clinical outcomes. Conclusion. Until now, a scientific search for various materials capable of replacing an autogenous transplant is being carried out. At the moment, none of the currently available materials has all the desired characteristics and the choice of materials directly depends on the specific clinical situation in the oral cavity.

Background: This study aimed to investigate the association between body composition (BC) specific parameters such as fat mass (FM) and lean body mass (LBM) and bone quality in obese and non-obese young Slovak adults (18–30 years) using bioelectrical impedance analysis and quantitative ultrasound while considering the factors of sex and obesity status; Methods: BC was evaluated using bioelectrical impedance analysis (InBody 770) and bone quality by the speed of sound (SOS) in radius using QUS (Sunlight MiniOmni) in 774 young Slovak young adults aged 18–30 years, categorized by sex and obesity status (body fat %, PBF, ≥28% for men and ≥20% for women); Results: In non-obese individuals, radial SOS correlated positively with FM parameters. Significant positive correlations with LBM, including skeletal muscle mass (SMM), were observed in non-obese men but not in women. Conversely, SOS correlated negatively with FM parameters in obese individuals, significantly only in women. The correlation of SOS with LBM in obese individuals was insignificant in both sexes. Age, visceral FM, FM in the arm, and vitamin D intake were identified as the main predictors of radial SOS in young adults, except in obese men. Conclusions: Findings indicate FM benefits bone tissue in non-obese individuals, while excessive adiposity deteriorates bone quality in obese individuals, necessitating tailored evaluations and interventions based on sex, obesity status, and specific predictors.

Bone tissue engineering (BTE) provides an alternative for addressing bone defects by integrating cells, a scaffold, and bioactive growth factors to stimulate tissue regeneration and repair, resulting in effective bioengineered tissue. This study focuses on repurposing chitosan from blue swimming crab (Portunus pelagicus) shell waste as a composite scaffold combined with HAP and COL I to improve biocompatibility, porosity, swelling, and mechanical properties. The composite scaffold demonstrated nearly 60% porosity with diameters ranging from 100–200 μm with an interconnected network that structurally mimics the extracellular matrix. The swelling ratio of the scaffold was measured at 208.43 ± 14.05%, 248.93 ± 4.32%, 280.01 ± 1.26%, 305.44 ± 20.71%, and 310.03 ± 17.94% at 1, 3, 6, 12, and 24 h, respectively. Thus, the Portunus pelagicus scaffold showed significantly lower degradation ratios of 5.64 ± 1.89%, 14.34 ± 8.59%, 19.57 ± 14.23%, and 29.13 ± 9.87% for 1 to 4 weeks, respectively. The scaffold supports osteoblast attachment and proliferation for 7 days. Waste from Portunus pelagicus shells has emerged as a prospective source of chitosan with potential application in tissue engineering.

In this systematic review, the authors aimed to investigate the state of knowledge on in vivo evaluations of chitosan and nanometric hydroxyapatite (nanohydroxyapatite, nHAp) scaffolds for bone-tissue regeneration. In March 2024, an electronic search was systematically conducted across the PubMed, Cochrane, and Web of Science databases using the keywords (hydroxyapatite) AND (chitosan) AND (scaffold) AND (biomimetic). Methodologically, the systematic review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) protocol to the letter. Initially, a total of 375 studies were screened, and 164 duplicates were removed. A further 188 articles were excluded because they did not correspond to the predefined topics, and an additional 3 articles were eliminated due to the inability to obtain the full text. The final compilation included 20 studies. All publications indicated a potential beneficial effect of the scaffolds in in vivo bone defect repair. A beneficial effect of hydroxyapatite as a scaffold component was observed in 16 studies, including greater mechanical resistance, cellular differentiation, and enhanced bone damage regeneration. The addition of chitosan and apatite ceramics, which combined the strengths of both materials, had the potential to become a useful bone-tissue engineering material.

The current paper highlights the active development of tissue engineering in the field of the biofabrication of living tissue analogues through 3D-bioprinting technology. The implementation of the latter is impossible without important products such as bioinks and their basic components, namely, hydrogels. In this regard, tissue engineers are searching for biomaterials to produce hydrogels with specified properties both in terms of their physical, mechanical and chemical properties and in terms of local biological effects following implantation into an organism. One of such effects is the provision of the optimal conditions for physiological reparative regeneration by the structural components that form the basis of the biomaterial. Therefore, qualitative assessment of the composition of the protein component of a biomaterial is a significant task in tissue engineering and bioprinting. It is important for predicting the behaviour of printed constructs in terms of their gradual resorption followed by tissue regeneration due to the formation of a new extracellular matrix. One of the most promising natural biomaterials with significant potential in the production of hydrogels and the bioinks based on them is the polymer collagen of allogeneic origin, which plays an important role in maintaining the structural and biological integrity of the extracellular matrix, as well as in the morphogenesis and cellular metabolism of tissues, giving them the required mechanical and biochemical properties. In tissue engineering, collagen is widely used as a basic biomaterial because of its availability, biocompatibility and facile combination with other materials. This manuscript presents the main results of a mass spectrometry analysis (proteomic assay) of the lyophilized hydrogel produced from the registered Lyoplast® bioimplant (allogeneic human bone tissue), which is promising in the field of biotechnology. Proteomic assays of the investigated lyophilized hydrogel sample showed the presence of structural proteins (six major collagen fibers of types I, II, IV, IX, XXVII, XXVIII were identified), extracellular matrix proteins, and mRNA-stabilizing proteins, which participate in the regulation of transcription, as well as inducer proteins that mediate the activation of regeneration, including the level of circadian rhythm. The research results offer a new perspective and indicate the significant potential of the lyophilized hydrogels as an effective alternative to synthetic and xenogeneic materials in regenerative medicine, particularly in the field of biotechnology, acting as a matrix and cell-containing component of bioinks for 3D bioprinting.

This study aimed to develop Janus-, cross-network-, and coaxial-structured piezoelectric–conductive polymer nanofibers through electrospinning to mimic the piezoelectricity of bone and facilitate the conduction of electrical signals in bone tissue repair. These nanofibers were constructed using the piezoelectric polymer polyvinylidene fluoride, and the conductive fillers reduced graphene oxide and polypyrrole. The influence of structural features on the electroactivity of the fibers was also explored. The morphology and components of the various structural samples were characterized using SEM, TEM, and FTIR. The electroactivity of the materials was assessed with a quasi-static d33 meter and the four-probe method. The results revealed that the piezoelectric–conductive phases were successfully integrated. The Janus-structured nanofibers demonstrated the best electroactivity, with a piezoelectric constant d33 of 24.5 pC/N and conductivity of 6.78 × 10−2 S/m. The tensile tests and MIP measurements showed that all samples had porosity levels exceeding 70%. The tensile strength of the Janus and cross-network structures exceeded that of the periosteum (3–4 MPa), with average pore sizes of 1194.36 and 2264.46 nm, respectively. These properties indicated good mechanical performance, allowing material support while preventing fibroblast invasion. The CCK-8 and ALP tests indicated that the Janus-structured samples were biocompatible and significantly promoted the proliferation of MC3T3-E1 cells.

A comprehensive study of deformation and destruction of compact bone tissue was carried out. Deformation of cylindrical samples was carried out in the mode of constant feed rate of the press plunger. During the experiments, deformation, changes in photon radiation on the surface of the samples and acoustic emission were recorded. It is shown that the initial accumulation of stresses on the relative axis of deformation for the occurrence of a crack on the lateral surface of the sample is the first link in the chain of formation of the micro-cut plane and an indicator of its orientation relative to the axis of the cylinder. The incipient plane of a macro-crack is a zone of increased local stresses, which stimulates the appearance of new microcracks in it. In this case, the exit of the microcrack to the lateral surface of the sample of compact bone tissue (human tibia) coincides in time with the registration of photoluminescence. [ABSTRACT FROM AUTHOR]

Zinc is a micronutrient of key importance for human health. An increasing number of studies indicate that zinc plays a significant role in bone tissue's normal development and maintaining homeostasis. Zinc is not only a component of bone tissue but is also involved in the synthesis of the collagen matrix, mineralization, and bone turnover. It has been demonstrated that zinc can stimulate runt-related transcription factor 2 (Runx2) and promote the differentiation of osteoblasts. On the other hand, zinc has been found to inhibit osteoclast-like cell formation and to decrease bone resorption by stimulating osteoclasts' apoptosis. Moreover, zinc regulates the RANKL/RANK/OPG pathway, thereby facilitating bone remodeling. To date, not all mechanisms of Zn activity on bone tissue are well understood and documented. The review aimed to present the current state of research on the role of zinc in bone tissue, its beneficial properties, and its effects on bone regeneration. Since calcium phosphates as bone substitute materials are increasingly enriched in zinc ions, the paper included an overview of research on the potential role of such materials in bone filling and regeneration. [ABSTRACT FROM AUTHOR]

Regenerative medicine offers a new solution by cell therapy and tissue engineering methods to improve irreparable bone damage. Engineered structures help to accelerate the natural recovery of the tissue because in some bone injuries, the lost tissue is extensive and it is not possible to recover naturally. This article provides an overview of common scaffolds in tissue engineering for bone tissue regeneration. Because bone is a hard and inflexible tissue, therefore, biological materials that are hard like bone should be used for scaffold design. From this category of materials, we can mention bioactive glasses, which when these glasses are placed in the simulated environment of the body, form a crystal layer of hydroxyapatite in contact with the body's physiological fluid. Choosing the right manufacturing method depends on the desired tissue structure. Considering the vital role of scaffolds in tissue engineering, several methods have been used to design and build good scaffolds for tissue engineering. Electrospinning is a common method for making scaffolding. In this technique, by changing the conditions, fibers from several microns to several nanometers can be created. Because the area ratio to the regional volume of the fibers obtained from electrospinning is high, this characteristic increases the connection and proliferation of cells on the scaffold. Therefore, the electrospun scaffold, which is a combination of bioactive glass and polymer, can provide the basis for the treatment of bone diseases. [ABSTRACT FROM AUTHOR]

Accurately printing customizable scaffolds is a challenging task because of the complexity of bone tissue composition, organization, and mechanical behavior. Graphene oxide (GO) and poly-L-lactic acid (PLLA) have drawn attention in the field of bone regeneration. However, as far as we know, the Fischer–Koch model of the GO/PLLA association for three-dimensional (3D) printing was not previously reported. This study characterizes the properties of GO/PLLA-printed scaffolds in order to achieve reproducibility of the trabecula, from virtual planning to the printed piece, as well as its response to a cell viability assay. Fourier-transform infrared and Raman spectroscopy were performed to evaluate the physicochemical properties of the nanocomposites. Cellular adhesion, proliferation, and growth on the nanocomposites were evaluated using scanning electron microscopy. Cell viability tests revealed no significant differences among different trabeculae and cell types, indicating that these nanocomposites were not cytotoxic. The Fischer Koch modeling yielded satisfactory results and can thus be used in studies directed at diverse medical applications, including bone tissue engineering and implants. [ABSTRACT FROM AUTHOR]

Simple Summary: Bone remodeling requires a delicate balance between bone-forming osteoblasts and bone-resorbing osteoclasts. However, in pathological conditions, bone remodeling is often deregulated and the uncoupling of osteoclast and osteoblast functions may alter the extent of bone loss. Although in chronic lymphocytic leukemia (CLL), patients' macroscopic skeletal involvement appears to be rarer than in other lymphoproliferative diseases, recent studies highlighted that the active crosstalk between leukemic B cells and bone tissue components may lead to the alteration of bone homeostasis already at early stages of the disease, becoming further evident in the advanced stages. Since the pathogenesis of bone involvement in CLL is not completely understood, this manuscript provides an overview of the clinical and biological data related to bone erosion in this disease. Chronic lymphocytic leukemia (CLL) is the most frequent leukemia in Western countries. Although characterized by the progressive expansion and accumulation of leukemic B cells in peripheral blood, CLL cells develop in protective niches mainly located within lymph nodes and bone marrow. Multiple interactions between CLL and microenvironmental cells may favor the expansion of a B cell clone, further driving immune cells toward an immunosuppressive phenotype. Here, we summarize the current understanding of bone tissue alterations in CLL patients, further addressing and suggesting how the multiple interactions between CLL cells and osteoblasts/osteoclasts can be involved in these processes. Recent findings proposing the disruption of the endosteal niche by the expansion of a leukemic B cell clone appear to be a novel field of research to be deeply investigated and potentially relevant to provide new therapeutic approaches. [ABSTRACT FROM AUTHOR]

The occurrence of fractures has emerged as one of the most prevalent injuries in the human body. In bone reconstruction surgery, after the implantation of porous hydroxyapatite materials, there is an initial infiltration of body fluids into the porous implant, followed by biomineralization-mediated apatite crystal formation and the subsequent ingrowth of bone cells. Despite extensive research efforts in this field, previous investigations have primarily focused on the formation of apatite crystals on exposed surfaces, with limited literature available regarding the formation of apatite crystals within the internal microstructures of bone implants. Herein, we demonstrate the occurrence of dynamic biomineralization within a three-dimensional porous hydroxyapatite/wollastonite (HA/WS) skeleton, leading to the abundant formation of nano-sized apatite crystals across diverse internal environments. Our findings reveal that these apatite nanocrystals demonstrate distinct rates of nucleation, packing densities, and crystal forms in comparison to those formed on the surface. Therefore, the objective of this study was to elucidate the temporal evolution of biomineralization processes by investigating the microstructures of nanocrystals on the internal surfaces of HA/WS three-dimensional porous materials at distinct stages of biomineralization and subsequently explore the biological activity exhibited by HA/WS when combined with cell investigation into apatite crystal biomineralization mechanisms at the nanoscale, aiming to comprehend natural bone formation processes and develop efficacious biomimetic implants for tissue engineering applications. The simultaneous examination of bone cell attachment and its interaction with ongoing internal nanocrystal formation will provide valuable insights for designing optimal scaffolds conducive to bone cell growth, which is imperative in tissue engineering endeavors. [ABSTRACT FROM AUTHOR]