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Differentiating cremated non-human bones from human ones in archaeological contexts is a challenging task. This analysis aims at proposing a rather solid criterion based on an osteoarchaeological sample. In this work, the main issues of taxonomic identification of cremated remains are analysed and a research methodology tested on an Italian protohistoric sample is proposed. The 314 subjects composing the sample come from 298 tombs of the Golasecca Civilization (1st millennium BC in north-eastern Italy). On a morphological basis, 246 bone fragments were selected from which as many thin sections were obtained for a histomorphological evaluation. From the analyses, we identified the presence of animals in burials, whereas a mere morphometric analysis was not able to recognize them. Furthermore, the taxonomic identification has allowed us to propose new hypotheses on the funerary rite of Golasecca linked to the zooarchaeological remains. [ABSTRACT FROM AUTHOR]

The membranes are an important biomaterial that contribute to osteopromotion. This study aimed to evaluate the osteopromotive potential of collagen membranes associated with Hydroxyapatite (HA) in critical size calvaria rat's defects. Ninety-six Albinus Wistar rats were divided into four groups: (CG) negative control: clot only (CG); positive control: porcine collagen membrane (BG); fish collagen membrane associated with HA (CP); bovine collagen membrane associated with HA (CB), analyzed at 7, 15, 30, and 60 postoperative days. At 30 days, membrane integrity was observed in the CB and fragments in the CP and BG groups were dispersed in the center of the defect. At 60 days, BG demonstrated better results with no statistical difference for the CP group (p = 0.199) and a statistically significant difference for the CB group (p = 0.013). The inflammatory profiles of the BG and CP groups were similar. Immunohistochemistry demonstrated at 60 days moderate osteopontin staining for the BG and CP groups, light staining for the CB, and intense osteocalcin staining for the BG, while the CB and CP groups demonstrated moderate staining. Microtomography revealed the highest mean bone volume (14.247 mm3) in the BG, followed by the CB (11.850 mm3), and CP (9.560 mm3) group. The collagen membranes associated with HA demonstrated an osteopromotive potential. [ABSTRACT FROM AUTHOR]

The treatment of bone defects remains one of the major challenges in modern clinical practice. Nowadays, with the increased incidence of bone disease in an aging population, the demand for materials to repair bone defects continues to grow. Recent advances in the development of biomaterials offer new possibilities for exploring modern bone tissue engineering strategies. Both natural and synthetic biomaterials have been used for tissue repair. A variety of porous structures that promote cell adhesion, differentiation, and proliferation enable better implant integration with increasingly better physical properties. The selection of a suitable biomaterial on which the patient's new tissue will grow is one of the key issues when designing a modern tissue scaffold and planning the entire treatment process. The purpose of this article is to present a comprehensive literature review of existing and novel biomaterials used in the surgical treatment of bone tissue defects. The materials described are divided into three groups—organic, inorganic, and synthetic polymers—taking into account current trends. This review highlights different types of existing and novel natural and synthetic materials used in bone tissue engineering and their advantages and disadvantages for bone defects regeneration. [ABSTRACT FROM AUTHOR]

Assessment of the state of bone tissue during biopsy examination of the material of patients with degenerative or traumatic diseases is a very urgent task of modern medicine. Such an assessment makes it possible to characterize the regenerative processes at the site of the bone defect and to choose the most effective treatment strategies. Currently, in the study of bone tissue, methods of X-ray examination and survey histological staining are used. Such methods do not allow a highly sensitive analysis of individual components of the cellular substance. One approach to solving this problem can be the use of Raman spectroscopy. In contrast to infrared spectroscopy, Raman spectroscopy records in the optical range, which ensures high sensitivity and ease of use. Raman spectroscopy is a non-contact, non-destructive testing method suitable for working with substances in any phase. In this scientific work, a study of the distribution of hydroxyapatite in a section of the regenerative material of the parietal bone of the rat skull is carried out. As a result, it was shown that the Raman spectroscopy method can be used to determine the characteristics of the formation, mineralization, and maturation of bone tissue, to identify loci with maximum and minimum mineralization. [ABSTRACT FROM AUTHOR]

Objective: assessment of clinical-hematological and metabolic-biochemical parameters of the of bone tissue and hormonal regulation depending on the serum iron content and radiation dose values in children living on radiologically contaminated territories after the ChNPP accident in Ukraine. Materials and methods. Children (n = 271) living on radiologically contaminated territories (RCT) of Ukraine were involved in the study. Three study groups were formed according to the serum iron level (SIL), namely group I with SIL 10.0-22.0 μmol/l (n = 92), group II with SIL 23.0-34.0 μmol/l (n = 144), and group III with SIL above 35.0 μmol/l (n = 35). Diseases in the family tree, bodyweight at birth, complaints on osalgia, bone fractures, jaw anomalies, dental caries, and obesity were accounted. Morphometric parameters of erythrocytes and hemogram elements were analyzed. Creatinine, alkaline phosphatase, calcium, total protein, iron, cholesterol, bilirubin, and transaminases were assayed in blood serum. The urine content of the 19 free amino acids, serum content of the free thyroxine (FT4), pituitary thyroid-stimulating hormone (TSH), and cortisol were assayed both with bone tissue density. Individual radiation doses were calculated. Results. In 12.9 % of cases the SIL was > 35.0 μmol/l. Relatives with endocrine diseases were often present in the family tree of children with SIL > 23.0 μmol/l. There were increased urine content of the free amino acids (p < 0.05) and signs of protein degradation under high SIL. Contents of amino acids involved in collagen synthesis and antioxidant status (alanine, serine, glutamine, aspartic acid) and iron metabolism (arginine, leucine) were assayed at the highest levels ( p< 0.05). Urinary levels of valine, lysine, and methionine, which are associated with iron metabolism, were decreased (p< 0.05). An inverse correlation (rs = -0.58; p< 0.01) was established between the serum TSH and cortisol levels regardless of the SIL. Serum TSH level directly correlated with urine content of amino acids involved in collagen synthesis. An inverse correlation (rs = -0.55; p < 0.001) was established between the serum TSH level and urine content of tyrosine that is essential for the thyroid hormone (triiodothyronine and thyroxine) synthesis. Cortisol was found having a negative effect on protein synthesis. Inverse correlation was established between the serum cortisol level and urine content of the free amino acids essential for collagen synthesis. There was no depend& ence of the average radiation dose values on the SIL. An inverse correlation was determined between the patient's radiation dose and SIL > 35.0 μmol/l (rs = -0.29; p< 0.05). Conclusions. The increased SIL in children living on RCT may occur due to both a genetic predisposition and the acquired factors driving protein and mineral metabolism of bone and their hormonal regulation. [ABSTRACT FROM AUTHOR]

With the development of nanotechnology, nanomaterials are widely applied in different areas. Some nanomaterials are designed to be biocompatible and can be used in the medical field, playing an important role in disease treatment. Exosomes are nanoscale vesicles with a diameter of 30–200 nm. Studies have shown that exosomes have the effect of angiogenesis, tissue (skin, tendon, cartilage, et al.) repair and reconstruction. Nano-hydrogels are hydrogels with a diameter of 200 nm or less and can be used as the carrier to transport the exosomes into the body. Some orthopedic diseases, such as bone defects and bone infections, are difficult to handle. The emergence of nano-hydrogels coated exosomes may provide a new idea to solve these problems, improving the prognosis of patients. This review summarizes the function of nano-hydrogels coated exosomes in bone tissue repair, intending to illustrate the potential use and application of nano-hydrogels coated exosomes in bone disease.

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.

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.

Several rheumatologic diseases are primarily distinguished by their involvement of bone tissue, which not only serves as a mere target of the condition but often plays a pivotal role in its pathogenesis. This scenario is particularly prominent in chronic inflammatory arthritis such as rheumatoid arthritis (RA) and spondyloarthritis (SpA). Given the immunological and systemic nature of these diseases, in this review, we report an overview of the pathogenic mechanisms underlying specific bone involvement, focusing on the complex interactions that occur between bone tissue’s own cells and the molecular and cellular actors of the immune system, a recent and fascinating field of interest defined as osteoimmunology. Specifically, we comprehensively elaborate on the distinct pathogenic mechanisms of bone erosion seen in both rheumatoid arthritis and spondyloarthritis, as well as the characteristic process of aberrant bone formation observed in spondyloarthritis. Lastly, chronic inflammatory arthritis leads to systemic bone involvement, resulting in systemic bone loss and consequent osteoporosis, along with increased skeletal fragility.

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.

Algae have shown numerous advantages as biofunctional and bioactive material sources. The development of biosynthetic or synthetic materials has enabled algal-derived macromolecules and their derivatives to be used in biomedical applications. This review examines and analyzes the most recent developments in the production of biomaterials from algal-derived macromolecules and their composites and their potential applications in bone and cardiovascular tissue engineering. Several macromolecules derived from algal polysaccharides, including sulfated polysaccharides, fucoidans, and fucans, have been developed for cartilage, intervertebral disc, bone, and skeletal muscle transplants because of their stable structures. Alginates, fucoidans, chitin, porphyrin, and other algal polysaccharide derivatives have been investigated for engineering blood vessels, heart valves, and even the liver. One advantage of algal-derived macromolecules and composites is their safe immunity properties. This review also highlights cutting-edge developments in applying algal-derived macromolecules with a broader biomedical scope to encourage in-depth research into their potential as biomaterial scaffolds in medical applications.

Background: 3D-printing has shown potential in several medical advances because of its ability to create patient-specific surgical models and instruments. In fact, this technology makes it possible to acquire and study physical models that accurately reproduce patient-specific anatomy. The challenge is to apply 3D-printing to reproduce the porous structure of a bone tissue, consisting of compact bone, spongy bone and bone marrow. Methods: An interesting approach is presented here for reproducing the structure of a bone tissue of a femur by 3D-printing porous structure. Through the process of CT segmentation, the distribution of bone density was analysed. In 3D-printing, the bone density was compared with the density of infill. Results: The zone of compact bone, the zone of spongy bone and the zone of bone marrow can be recognized in the 3D printed model by a porous density additive manufacturing method. Conclusions: The application of 3D-printing to reproduce a porous structure, such as that of a bone, makes it possible to obtain physical anatomical models that likely represent the internal structure of a bone tissue. This process is low cost and easily reproduced.

Background. Bone health is relevant for patients of all age groups. Special attention is paid to childhood and adolescence, since it is during this period that bone mass is actively accumulated, which depends on the structural and functional state of the bone tissue of an adult. The purpose of this study was to determine the features of the structural and functional state of bone tissue in children during the second growth spurt based on the analysis of markers of bone modeling, the level of 25(OH)D and the indicators of ultrasound densitometry and DXA. Materials and methods. 205 children aged 9–17 years were examined. They divided into three groups depending on the presence and intensity of growth spurts. Examination included: general clinical examination with an assessment of the levels of physical and sexual development, determine of the levels of 25(OH)D, glycosaminoglycans, chondroitin sulfates and alkaline phosphatase, ultrasound densitometry and DXA. Results. 83.9 % of children had vitamin D deficiency, 16.1 % of children had insufficiency. A decrease in BMD according to UD data was diagnosed in 48.0 % (n = 24) of children with growth spurt, in 60.87 % (n = 28) of children with intense growth spurt, and in 39.45 % (n = 43) of children without growth spurt. According to DXA data, BMD reduction was confirmed in 56.25 % (n = 18) of 32 examined children: children with growth spurt — 38.9 % (n = 7), children with intense growth spurt — 50.0 % (n = 9), children without growth spurt — 11.1 % (n = 2). The level of chondroitin sulfates in children with growth spurt and intense growth spurt is significantly higher than in children without growth spurt, which indicates the instability of metabolic processes. At the same time, the level of total glycosaminoglycans is significantly lower in the group of children with growth spurt and intense growth spurt than in the group of children without growth spurt, which indicates the intensity of metabo­lic processes in children of these groups. Conclusions. 100 % of children had insufficiency and deficiency of vitamin D. A decrease in BMD is more often diagnosed in children during an intense growth spurt and does not have a reliable relationship with the level of vitamin D, in contrast to children without a growth spurt. Children with growth spurts and intense growth spurts had an imbalance in the le­vel of chondroitin sulfates and glycosaminoglycans, which indicates the instability and activity of bone tissue growth processes.

Introduction: The current study, for the first time, suggests nature-made pollen grains (PGs) of Pistacia vera L. as a potential candidate for using as scaffolding building blocks with encapsulation capability of bioactive compounds, such as bone morphogenetic protein 4 (BMP4). Methods: A modified method using KOH (5%, 25ºC) was developed to produce nonallergic hollow pollen grains (HPGs), confirmed by energy dispersive X-ray (EDX) analysis, field emission scanning electron microscopy (FESEM), and DNA and protein staining techniques. The in-vitro study was conducted on human adipose-derived mesenchymal stem cells (hAD-MSCs) to investigate the applicability of HPGs as bone scaffolding building blocks. Cytocompability was evaluated by FESEM, MTT assay, and gene expression analysis of apoptotic markers (BAX and BCL2). The osteoconductive potential of HPGs was assessed by alkaline phosphatase (ALP) activity measurement and gene expression analysis of osteogenic markers (RUNX2 and osteocalcin). Results: Findings demonstrated that HPGs can be considered as biocompatible compounds increasing the metabolic activities of the cells. Further, the bioactive nature of HPGs resulted in suitable cellular adhesion properties, required for a potent scaffold. The investigation of apoptotic gene expression indicated a reduced BAX/BCL2 ratio reflecting the protective effect of HPGs on hAD-MSCs. The increased ALP activity and expression of osteogenic genes displayed the osteoconductive property of HPGs. Moreover, the incorporation of BMP4 in HPGs initiated a synergistic effect on osteoblast maturation. Conclusion: Owing to the unique compositional and surface nanotopographical features of the Pistacia vera L. HPG, this microscale architecture provides a favorable microenvironment for the bottom-up remodeling of bone.

Multiple endocrine neoplasia type 1 (MEN1) is a rare, inherited cancer syndrome characterized by the development of multiple endocrine and non-endocrine tumors. MEN1 patients show a reduction of bone mass and a higher prevalence of early onset osteoporosis, compared to healthy population of the same age, gender, and ethnicity. During the monitoring and follow-up of MEN1 patients, the attention of clinicians is primarily focused on the diagnosis and therapy of tumors, while the assessment of bone health and mineral metabolism is, in many cases, marginally considered. In this study, we retrospectively analyzed bone and mineral metabolism features in a series of MEN1 patients from the MEN1 Florentine database. Biochemical markers of bone and mineral metabolism and densitometric parameters of bone mass were retrieved from the database and were analyzed based on age ranges and genders of patients and presence/absence of the three main MEN1-related endocrine tumor types. Our evaluation confirmed that patients with a MEN1 diagnosis have a high preval ence of earlyonset osteopenia and osteoporosis, in association with levels of serum and urinary markers of bone turnover higher than the normal reference values, regar dless of their different MEN1 tumors. Fifty percent of patients younger than 26 years manifested osteopenia and 8.3% had osteoporosis, in at least one of the measured bone sites. These data suggest the importance of including biochemical and instrumental monitoring of bone metabolism and bone mass in the routine medical evaluation and follow-up of MEN1 patients and MEN1 carriers as important clinical aspects in the management of the syndrome.

The aim of this article is to analyze the genetic and immunological mechanisms of the development of fracture consolidation disorders at the present scientific stage.Materials and methods. The search for literary sources was carried out in the open electronic databases of scientific literature PubMed and eLIBRARY. Search depth – 10 years.Results. The review analyzes the literature data on the current state of the study of the molecular genetic mechanisms of reparative regeneration including the development of fracture consolidation disorders. The mechanisms of the most important links of pathogenesis which most often lead to various violations of the processes of bone tissue repair are considered.Conclusion. The process of bone tissue repair is multifaceted, and many factors are involved in its implementation, however, we would like to note that the leading role in the course of reparative regeneration is played by a personalized genetically programmed response to this pathological condition. Nevertheless, despite the undeniable progress of modern medicine in studying the processes of bone recovery after a fracture, there are still many “white” spots in this issue, which dictates the need for further comprehensive study in order to effectively treat patients with impaired consolidation.

Background: There is still little understanding of the associations between physical fitness variables and bone health in children taking into account key confounders.Aim: The aim of this study was to analyze the associations between performance in tests of speed, agility, and musculoskeletal fitness (power of the upper and lower limbs) with bone mass of different regions in children, considering the adjustment to maturity-offset, lean percentage, and sex.Methods: Cross-sectional study design: the sample consisted of 160 children aged 6–11 years. The physical fitness variables tested were 1) speed, assessed with the running test at a maximum speed of 20 m; 2) agility, assessed through the 4×4-m square test; 3) lower limb power, assessed using the standing long jump test, and 4) upper limb power, assessed using the 2-kg medicine ball throw test. Areal bone mineral density (aBMD) was obtained from the analysis of body composition by dual-energy X-ray absorptiometry (DXA). Simple and multiple linear regression models were performed using the SPSS software.Results: In the crude regression analyses, the results indicated a linear relationship between all the physical fitness variables and aBMD in all body segments, but maturity-offset, sex, and lean mass percentage seemed to have an effect on these relationships. Except for the upper limb power, the other physical capacities (speed, agility, and lower limb power) were associated with aBMD in at least three body regions in the adjusted analyses. These associations occurred in the spine, hip, and leg regions, and the aBMD of the legs presented the best association magnitude (R2).Conclusion: There is a significant association between speed, agility, and musculoskeletal fitness, specifically the lower limb power and aBMD. That is, the aBMD is a good indicator of the relationship between fitness and bone mass in children, but it is essential to consider specific fitness variables and skeletal regions.

Bioengineered porous bone tissue materials based on additive manufacturing technology have gradually become a research hotspot in bone tissue-related bioengineering. Research on structural design, preparation and processing processes, and performance optimization has been carried out for this material, and further industrial translation and clinical applications have been implemented. However, based on previous studies, there is controversy in the academic community about characterizing the pore structure dimensions of porous materials, with problems in the definition logic and measurement method for specific parameters. In addition, there are significant differences in the specific morphological and functional concepts for the pore structure due to differences in defining the dimensional characterization parameters of the pore structure, leading to some conflicts in perceptions and discussions among researchers. To further clarify the definitions, measurements, and dimensional parameters of porous structures in bioengineered bone materials, this literature review analyzes different dimensional characterization parameters of pore structures of porous materials to provide a theoretical basis for unified definitions and the standardized use of parameters.

This paper reviewed the research status of the microstructure of scaffold pores from five aspects, including the pore shape, pore size, porosity, surface roughness, and connection pathways of bone tissue engineering scaffolds. The pore shape of the scaffold with a gradient structure was found to be closer to those of the natural bone. The rough surface can improve the cell adhesion and proliferation of the scaffolds, and the internal structure of the non-orthogonal connection pathway can provide a dynamic growth space for later bone regeneration. [ABSTRACT FROM AUTHOR]

Tissue engineering is nowadays a powerful tool to restore damaged tissues and recover their normal functionality. Advantages over other current methods are well established, although a continuous evolution is still necessary to improve the final performance and the range of applications. Trends are nowadays focused on the development of multifunctional scaffolds with hierarchical structures and the capability to render a sustained delivery of bioactive molecules under an appropriate stimulus. Nanocomposites incorporating hydroxyapatite nanoparticles (HAp NPs) have a predominant role in bone tissue regeneration due to their high capacity to enhance osteoinduction, osteoconduction, and osteointegration, as well as their encapsulation efficiency and protection capability of bioactive agents. Selection of appropriated polymeric matrices is fundamental and consequently great efforts have been invested to increase the range of properties of available materials through copolymerization, blending, or combining structures constituted by different materials. Scaffolds can be obtained from different processes that differ in characteristics, such as texture or porosity. Probably, electrospinning has the greater relevance, since the obtained nanofiber membranes have a great similarity with the extracellular matrix and, in addition, they can easily incorporate functional and bioactive compounds. Coaxial and emulsion electrospinning processes appear ideal to generate complex systems able to incorporate highly different agents. The present review is mainly focused on the recent works performed with Hap-loaded scaffolds having at least one structural layer composed of core/shell nanofibers. [ABSTRACT FROM AUTHOR]

Aluminium contamination is often found in daily life unintentionally, including in drinking water and food appliances. Aluminium intoxication impairs the balance between reactive oxygen species (ROS) and antioxidant levels, which produces oxidative stress and apoptosis. In bone tissue, it has been reported in previous studies to alter mineral deposition and cellular composition. However, the effects of gradually increased dose and exposure periods have not been explored extensively. We examined later, using induced oral AlCl3 on 27 male Wistar rodents aged 2-3 months. These animals were randomized equally into 3 groups, control (placebo), Al-1 (oral AlCl3, 64 mg/kg of body weight/day for 67 days, then the dose was doubled to 128 mg/kg of body weight/day for 20 days) and Al-2 (oral AlCl3, 128mg/kg of body weight/day for 67 days then the dose was doubled to 256mg/kg of body weight/day for 20 days). The means of osteocyte, osteoblast, osteoclast cell nuclei, and diaphysis trabecular density of the right femoral bone tissue were calculated from the longitudinal slices using Cell Sense, Adobe Photoshop, and ImageJ software after being stained with HE. Data were analyzed using Kruskal-Wallis or one-way ANOVA to seek significant differences with a significance level of p<0.05. In Al-2, osteocytes were significantly lower than other groups (p=0.024), whereas osteoclasts were significantly higher than Al-1 (p=0.001). There were no significant differences in the osteoblasts (p=0.102) and the trabecular bone density (p=0.094). In this study, upgraded and prolonged oral AlCl3 induction caused impaired cellular components in the long bone diaphysis of male rodents' femur. [ABSTRACT FROM AUTHOR]

Purpose of Review: To revisit the bone tissue mechanotransduction mechanisms behind the bone tissue response to mechanical loading and, within this context, explore the possible negative influence of regular swimming practice on bone health, particularly during the growth and development period. Recent Findings: Bone is a dynamic tissue, responsive to mechanical loading and unloading, being these adaptative responses more intense during the growth and development period. Cross-sectional studies usually report a lower bone mass in swimmers compared to athletes engaged in weigh-bearing sports. However, studies with animal models show contradictory findings about the effect of swimming on bone health, highlighting the need for longitudinal studies. Summary: Due to its microgravity characteristics, swimming seems to impair bone mass, but mostly at the lower limbs. It is unkown if there is a causal relationship between swimming and low BMD or if other confounding factors, such as a natural selection whithin the sport, are the cause. [ABSTRACT FROM AUTHOR]

Objective: Implantology represents the gold standard for oral rehabilitation, unfortunately, often, despite there are no local contraindications to this type of rehabilitation, there are uncertainties regarding the general health of our patients. Many patients nowadays take bisphosphonate drugs, often without first seeking advice from an oral surgeon or a dentist. The purpose of this review is precisely to highlight any contraindications to this type of treatment reported in the literature, in patients who take or have taken bisphosphonate drugs. Methods: For this study the scientific information sources were consulted using as search terms “(“bisphosphonate AND “dental implant”)”, obtaining 312 results, these were subsequently skimmed according to the inclusion and exclusion criteria, and further evaluated their relevance to the study and the presence of requested outcomes. Results: Only 9 manuscripts (RCTs, Multicentric studies and Clinical Trials) were included in this review, as they respected the parameters of this review, they were analyzed and it was possible to draw important results from them. Surely from this study it is understood that the use of bisphosphonate drugs does not represent an absolute contraindication to implant therapy, it is evident how adequate pharmacological prophylaxis, and an adequate protocol reduce the risks regarding implant failures. Furthermore, the values of marginal bone loss over time seem, even if not statistically significant, to be better in implant rehabilitation with bisphosphonate drugs association. Only a few molecules like risedronate, or corticosteroids, or some conditions like smoking or diabetes have shown a high risk of surgical failure. Conclusion: Although this study considered different studies for a total of 378 patients and at least 1687 different dental implants, showing better results in some cases for dental implant therapy in cases of bisphosphonate intake, further clinical, randomized and multicentric studies are needed, with longer follow-ups, to fully clarify this situation which often negatively affects the quality of life of our patients and places clinicians in the face of doubts. [ABSTRACT FROM AUTHOR]

Bone is a highly hierarchical complex structure that consists of organic and mineral components represented by collagen molecules (CM) and hydroxyapatite crystals (HAC), respectively. The nanostructure of bone can significantly affect its mechanical properties. There is a lack of understanding how collagen fibrils (CF) in different orientations may affect the mechanical properties of the bone. The objective of this study is to investigate the effect of interaction, orientation, and hydration on atomic models of the bone composed of collagen helix (CH) and HAC, using molecular dynamics simulations and therefrom bone-related disease origins. The results demonstrate that the mechanical properties of the bone are affected significantly by the orientation of the CF attributed to contact areas at 0° and 90° models. The molecular dynamics simulation illustrated that there is significant difference (p < 0.005) in the ultimate tensile strength and toughness with respect to the orientation of the hydrated and un-hydrated CF. Additionally, the results indicated that having the force in a longitudinal direction (0°) provides more strength compared with the CF in the perpendicular direction (90°). Furthermore, the results show that substituting glycine (GLY) with any other amino acid affects the mechanical properties and strength of the CH, collagen–hydroxyapatite interface, and eventually affects the HAC. Generally, hydration dramatically influences bone tissue elastic properties, and any change in the orientation or any abnormality in the atomic structure of either the CM or the HAC would be the main reason of the fragility in the bone, affecting bone pathology. [ABSTRACT FROM AUTHOR]

The design of magnetic composite scaffolds with superior properties has the potential to construct a targeted delivery platform with hyperthermia. In this study, strontium hexaferrite (SrFe 12 O 19 , SrM) magnetic nanoparticles (MNPs) were obtained by the chemical precipitation method. Non-toxic cross-linked biogels were prepared for adhesive ceramic scaffolds, and chitosan/polyvinylalcohol (CS/PVA)-bonded SrM magnetic nanoscaffolds were successfully prepared by 3D gel printing (3DGP) method. The effects of PVA physical cross-linking and in situ formed SiO 2 on the properties of CS-bonded scaffolds were evaluated, and the compressive strengths were increased from 6.13 ± 2.45 MPa to 8.80 ± 2.02 MPa and 17.18 ± 2.15 MPa, respectively. The results showed that the saturation magnetization of SiO 2 /CS/PVA/SrM composite scaffolds was 59.96 emu/g. In vitro immersion experiments showed that the degradation rates of SiO 2 /CS/PVA/SrM scaffolds were 4.90% after 28 days, and the in situ SiO 2 improved the deposition of calcium salts on the scaffolds. The experiments showed that the SrM magnetic scaffolds could not only concentrate magnetic fields to improve the efficiency of targeting deposition but also achieve a weak targeting process without external magnetic field assistance. In vitro cell proliferation test showed that MC3T3-E1 cells had good adhesion and proliferation on the surface of SiO 2 /CS/PVA/SrM scaffolds, which indicated that the scaffolds may be used for bone repairing. [ABSTRACT FROM AUTHOR]

Bone infections are a serious problem to cure, as systemic administration of antibiotics is not very effective due to poor bone vascularization. Therefore, many drug delivery systems are investigated to solve this problem. One of the potential solutions is the delivery of antibiotics from poly(L-actide-co-glycolide) (PLGA) nanoparticles suspended in the gellan gum injectable hydrogel. However, the loading capacity and release kinetics of the system based on hydrophilic drugs (e.g., gentamycin) and hydrophobic polymers (e.g., PLGA) may not always be satisfying. To solve this problem, we decided to use hydrophobized gentamycin obtained by ion-pairing with dioctyl sulfosuccinate sodium salt (AOT). Herein, we present a comparison of the PLGA nanoparticles loaded with hydrophobic or hydrophilic gentamycin and suspended in the hydrogel in terms of physicochemical properties, drug loading capacity, release profiles, cytocompatibility, and antibacterial properties. The results showed that hydrophobic gentamycin may be combined in different formulations with the hydrophilic one and is superior in terms of encapsulation efficiency, drug loading, release, and antibacterial efficacy with no negative effect on the NPs morphology or hydrogel features. However, the cytocompatibility of hydrophobic gentamycin might be lower, consequently more extensive study on its biological properties should be provided to evaluate a safe dose. [ABSTRACT FROM AUTHOR]

Minerals in bones, including calcium and phosphorus, make them hard and dense. To maintain bone density (or bone mass), the body must be supplied with sufficient calcium and other minerals and must produce adequate amounts of several hormones such as parathyroid hormone, growth hormone, calcitonin, estrogen, and testosterone. A sufficient supply of vitamin D is necessary for the absorption of calcium from food and its incorporation into the bones. Vitamin D is absorbed from the diet and is also produced in the skin using sunlight. This process is known as remodeling. In this process, small areas of bone tissue are continuously removed and new bone tissue is deposited. Remodeling affects the shape and density of bones. In youth, bones increase in width and length as the body grows. Later in life, bones may sometimes grow wider, but do not continue to grow longer. [ABSTRACT FROM AUTHOR]

3D cell culture systems based on biological scaffold materials obtainable from both animal and human tissues constitute very interesting tools for cell therapy and personalised medicine applications. The white adipose tissue (AT) extracellular matrix (ECM) is a very promising biomaterial for tissue engineering due to its easy accessibility, malleability and proven biological activity. In the present study, human dental pulp stem cells (hDPSCs) were combined in vitro with ECM scaffolds from porcine and human decellularised adipose tissues (pDAT, hDAT) processed as 3D solid foams, to investigate their effects on the osteogenic differentiation capacity and bone matrix production of hDPSCs, compared to single-protein-based 3D solid foams of collagen type I and conventional 2D tissue-culture-treated polystyrene plates. pDAT solid foams supported the osteogenic differentiation of hDPSCs to similar levels to collagen type I, as assessed by alkaline phosphatase and alizarin red stainings, reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and osteocalcin/bone gamma-carboxyglutamate protein (BGLAP) immunostaining. Interestingly, hDAT solid foams showed a markedly lower capacity to sustain hDPSC osteogenic differentiation and matrix calcification and a higher capacity to support adipogenesis, as assessed by RT-qPCR and oil red O staining. White ATs from both human and porcine origins are relatively abundant and available sources of raw material to obtain high quality ECM-derived biomedical products. These biomaterials could have promising applications in tissue engineering and personalised clinical therapy for the healing and regeneration of lesions involving not only a loss of calcified bone but also its associated soft non-calcified tissues.

Osteoid osteoma (OO) is a relatively common, benign bone-forming tumour, which mainly occurs on the long tubular bones of the limbs in adolescents. Usually, the OO is classified based on its localisation. Night-time pain is the major symptom of OO, which is commonly relieved using non-steroidal anti-inflammatory drugs, while surgery is required only for those patients with severe pain or in case of failure of previous conservative treatments. Our case report describes a 56-year-old male basketball player who self-referred to our outpatient physical therapy with a shoulder pain complaint. Considering the anamnesis and the physical examination, the physical therapist referred the patient to an orthopaedic surgeon, who suggested a detailed imaging investigation. The peculiarity of this clinical case is the overlapping of two clinical presentations: the symptomatology of the OO and the concurrent mechanical disorder due to a rotator cuff tendinopathy.

[Display omitted] • Revolutionizing healthcare, 3D bioprinting pioneers the creation of artificial skin, bone, and blood vessels. • Solutions for treating skin and bone defects, as well as cardiovascular diseases. • Transformative technology where personalized tissues and organs can be printed on demand, paving the way for advanced treatments and improved patient outcomes. Tissue engineering and regenerative medicine field, which focuses on creating functional tissue constructs resembling native tissue to repair or replace damaged tissues or organs, has undergone rapid evolution in recent decades. Particularly, there has been a surge of interest in utilizing tissue engineering for treating cardiovascular diseases, utilizing both natural and synthetic blood vessels. Additionally, advancements in bio-printing hold promise for generating human-engineered tissues like bone and skin for clinical applications. However, traditional tissue engineering methods, involving the scaffolds used, growth factors, and cells, have faced challenges in fabricating complex 3D shapes and achieving in vivo organ regeneration, making them less feasible for clinical use due to logistical and economic constraints. Various techniques, such as Electrospinning, Molding, Cell Sheet Rolling, and Decellularization, have been explored, but they have limitations, prompting the investigation of 3D bioprinting techniques. The advantages of 3D bioprinting over other biofabrication techniques are manifold. Firstly, the technique enables the advanced and precise layer-by-layer assembly of cells and biomaterials. Secondly, the utilization of a 3D bioprinter to create replicas based on medical images allows for the fabrication of complex tissues. Thirdly, the construction of tissue models through layering provides control over the precise placement of biomaterials and cells. Additionally, the use of 3D bioprinting allows for significant advancements in bioink modification, resulting in more accurate tissue replicas for practical in vivo tissue regeneration. Furthermore, 3D bioprinting enables the printing of tissues from undifferentiated stem cells obtained from the patient, reducing the risk of tissue rejection in native vessels. This paper reviews the applications of 3D bioprinting in engineered human tissues such as skin, bones and artificial blood vessels for cardiovascular diseases treatments. It provides an overview of 3D bioprinting technology and strategies, including ink-jet printing, extrusion printing, and stereolithography. The review then focuses on the applications of 3D bioprinting in constructing various tissues and organs, including cardiac, skin, and bone, discussing the steps involved and the technological requirements based on recent review and research articles. Finally, the review underscores the merits of the 3D bioprinting technique and outlines its current state while providing insights into future innovations aimed at skin tissue, bone tissue and blood vessels bioprinting. It explores potential advancements in polymer and biomaterial usage, cell sources, oxygen provision to cells, hydrogel and scaffold utilization, integration of machine learning, combining 3D bioprinting with 4D bioprinting, and addressing the expenses associated with 3D bioprinting, along with recommended cost mitigation methodologies. [ABSTRACT FROM AUTHOR]

The results of a comprehensive study of the patterns of structural and functional changes in bone tissue samples after combined (ozone + radiation) sterilization are presented. The study used a different approach to the sterilization process with selective ozone or radiation exposure and an integral, combined one, based on a combined ozone–oxygen treatment of bone samples at the first stage and radiation at the second. The methods of IR spectroscopy, scanning electron microscopy with a prefix for elemental analysis, atomic force microscopy, and mechanical analysis with determination of elastic-plastic properties (Vickers microhardness index) were used in the work. It is shown that the ozone exposure used at the first stage of the combined sterilization process of bone implants does not lead to negative consequences with respect to their properties and characteristics. The results obtained serve as a scientific and methodological basis for the further improvement and optimization of sterilization technologies (including combined). They also offer a comprehensive justification of the parameters of sterilization regimes to ensure the safety of using bone implants during reconstructive operations, minimizing structural and functional changes in bone matter, and creating effective health-saving technologies and the possibility of using them for various biomedical applications.

The effects of combination treatments using the selective androgen receptor modulators (SARMs) ostarine (OST) or ligandrol (LIG) with treadmill exercise (TE) were studied in healthy adult rats. Fifteen-week-old male Wistar rats were divided into groups (n = 10/group). Experiment 1 consisted of (1) Control group: sedentary rats receiving vehicle; (2) OST: sedentary rats receiving OST; (3) TE: training rats receiving vehicle; (4) OST + TE: training rats receiving OST. Experiment 2 consisted of (1) LIG: sedentary group receiving LIG; (2) LIG + TE: training group receiving LIG. The TE regime was as follows: 25 m/min, 5° elevation, 40 min, five times/week, and the sedentary regime was 5 min, three times/week. OST and LIG were administered subcutaneously (0.4 mg/kg body weight/day, five times/week). After eight weeks, bone samples underwent microcomputed tomographical, biomechanical, histological, and ashing analyses. All the treatments had weak effects on the bone structure without affecting bone biomechanics. The OST + TE improved bone structure, while the LIG + TE had unfavorable effects. In serum, OST, OST + TE, and LIG + TE altered cholesterol and lipoprotein levels; TE did not change the serum parameters. The SARM treatments had no clear bone benefit, and the serum effects can be considered as side effects. TE represents a safe treatment. Because SARMs are increasingly applied in gyms along with physical activities, attention should be paid to possible side effects.

In the search for effective biomaterials for bone repair, magnesium phosphate cements (MPCs) are nowadays gaining importance as bone void fillers thanks to their many attractive features that overcome some of the limitations of the well-investigated calcium-phosphate-based cements. The goal of this review was to highlight the main properties and applications of MPCs in the orthopedic field, focusing on the different types of formulations that have been described in the literature, their main features, and the in vivo and in vitro response towards them. The presented results will be useful to showcase the potential of MPCs in the orthopedic field and will suggest novel strategies to further boost their clinical application.

Racing pigeons are potential carriers of zooanthroponic diseases, since they can travel considerable distances during their flight. The study of the formation features of the pigeon skeleton’s hematopoietic function on different levels of its structural organization with the determination of the relationship between the growth and development of hematopoietic components and the processes of osteohistogenesis is necessary to understand the immunity of pigeons, especially during the early stages of their development when young animals are in the greatest risk of disease, especially during processes of osteogenesis and haematopoiesis in chicks. The bones of the axial and peripheral skeleton of one-day-old, 5-, 10-, 15-, 20-, and 25-day-old pigeons (n = 5) were examined. The presence and degree of development of dia- and epiphyseal ossification centers (EOCs), their relative area (RA) and X-ray density in the organs of universal hematopoiesis were determined on radiographs made on an x-Ray-TW-102 x-ray machine with an Alpha 4600 receiver using the MultiVox Dicom Viewer program. It was established that in day-old pigeons the rudiments of the studied bones are completely built by cartilaginous tissue, have low radiographic density, and fuzzy contours on radiographs. On the 10th day of life, the axial skeleton of pigeon cubs has formed EOCs of head and a tubercle on the 5th rib (third «true rib»), while in the bones of the peripheral skeleton there is an enchondral EOC of the diaphysis. The spongy and compact bone structure (BS) of the bones were fuzzy. The body of the rib and the epiphyses of the limbs’ tubular bones were cartilaginous. The X-ray density of the humerus at this age remains unchanged, and the tibial-metatarsal increases by 1.5 times, reaching 12 HU. In 15-day-old chicks, the RA of the EOC in the skeleton was moderately increased due to an increase in the RA of previously formed EOCs at the age of 10 days, the appearance of individual EOCs in the body of 5th rib, and in the tubular bones of the limbs, the enchondral EOCs of the proximal and distal epiphyses. In the diaphysis of the extremities tubular bones, a strip-like compact BS was clearly distinguished, and in the epiphyses, a small-sized spongy BS. The X-ray density of the bones almost doubled, reaching 19–21 HU. In 20-day-old pigeons, the processes of osteohistogenesis in the skeleton were almost completed, in the studied bones, all the main and additional EOCs were well expressed, their RA increased sharply. X-ray density of bones did not change. For 25-day-old pigeons in the skeleton, there was a slight increase in RA of the EOC, a process of complete synostosis of the bones was characteristic. From the moment of the appearance of the EOC in 10-day-old chicks until they reach the age of 25 days, the bones of the axial skeleton and the skeleton of the limbs were formed by 95–100% of BS, and their X-ray density was increased almost 2.5 times, reaching 19–26 HU.

Background. The endocrine system occupies a leading place not only in the regulation of growth and development mechanisms, but also in compensation reactions when the body is exposed to extreme factors. Coordinated hormonal regulation contributes to the correct response of the macroorganism adaptive processes, aimed at restoring and maintaining homeostasis. A cascade of endocrine changes accompanies the processes of both physiological and reparative regeneration of bone tissue at all its stages. The aim of the study was to analyze the currently known mechanisms of hormonal regulation of physiological and reparative bone tissue regeneration. Materials and Methods. The search and analysis of scientific literary sources was carried out in the electronic databases PubMed and eLIBRARY. Search depth 10 years. Results. The review considers both fundamental aspects and new data on the main histogenetic mechanisms of osteogenesis hormonal regulation. The ways and points of interaction of the endocrine and skeletal systems are highlighted, the main functions of hormones in the participation of bone remodeling in different age periods are determined. Conclusion. In violations of physiological regulation, hormonal imbalance is assigned a key role, while under conditions of reparative osteogenesis, the role of qualitative and dynamic changes in the endocrine system has been studied insufficiently. Hormonal regulation of reparative regeneration to date has no clear assessment criteria and requires further research.

Introduction. According to the literature, oxidative stress is described as one of the main factors in the pathogenesis of chronic suppurative otitis media, supporting the inflammatory process at the local level. The transition of inflammatory mediators to the systemic level is associated with the risk of developing ear purulent-destructive complications. The study of the products of lipid peroxidation in comparison with morphological changes in the structures of the temporal bone will justify the tactics of the operation.Aim. Comparison of the levels of lipid peroxidation products at the local and systemic levels in chronic suppurative otitis media, depending on the nature of pathomorphological changes in the structures of the temporal bone.Materials and methods. A prospective study of 130 patients with chronic suppurative otitis media at the age of 20-62 years with a verified diagnosis of chronic suppurative otitis media, admitted for surgical treatment, was carried out. To study the indicators of oxidative stress at the systemic level, the blood serum of patients was used; at the local level, the bone biomaterial obtained from patients during the surgical treatment of chronic suppurative otitis media was used. The quantitative determination of the primary, secondary and final products of peroxidation was carried out in the groups of patients with separate registration of lipoperoxides in the heptane and isopropanol phases of the lipid extract by spectrophotometry.Results and discussion. In the observation of patients with morphological signs of purulent destruction of the temporal bone, not only a local level of inflammation activity, but also a systemic level of an unfavorable outcome was revealed in two variants: osteoproliferation or osteonecrosis of the bone tissue of the temporal bone in chronic purulent otitis media with a constant threat to the patient's life due to intracranial purulent complications.Conclusion. The appearance in low concentrations of lipid peroxidation products in serum in patients with chronic purulent otitis media substantiates the need for a behind-the-ear approach in reconstructive-sanitizing otosurgery even with minimal clinical manifestations and CT scan data, since at the preclinical level it confirms the osteonecrotic type of bone remodeling with the risk of delayed death.

Psammomatoid juvenile ossifying fibroma (PJOF) is a benign fibro-osseous lesion that mainly affects the paranasal sinuses and periorbital bones. It may cause significant esthetic and functional impairment. Herein, we describe the diagnosis and surgical approach of an extensive PJOF arising in the frontal sinus of a young male. After complete lesion removal and histopathological confirmation, the bone defect was repaired with a customized polymethylmethacrylate implant. PJOF may present aggressive clinical behavior. The excision of extensive PJOF in the orbitofrontal area can result in significant esthetic defects. Polymethacrylate implants restore functionally and esthetically the involved area.

This literature review presents data on the influence of serotonin on the metabolism of bone tissue. The mechanisms by which serotonin affects the formation and resorption of bone, depending on the site of synthesis (central or peripheral), as well as the cells and receptor subtypes that are activated, have been considered. A number of issues for further research are highlighted, in particular, the dose-response relationship and side effects during chronic and long-term treatment with various selective serotonin reuptake inhibitors. [ABSTRACT FROM AUTHOR]

Bioactive glass (BG) is a frequently used biomaterial applicable in bone tissue engineering and known to be particularly effective when applied in nanoscopic dimensions. In this work, we employed the scalable reactive laser fragmentation in liquids method to produce nanosized 45S5 BG in the presence of light‐absorbing Fe and Cu ions. Here, the function of the ions was twofold: (i) increasing the light absorption and thus causing a significant increase in laser fragmentation efficiency by a factor of 100 and (ii) doping the BG with bioactive metal ions up to 4 wt%. Our findings reveal an effective downsizing of the BG from micrometer‐sized educts into nanoparticles having average diameters of <50 nm. This goes along with successful element‐specific incorporation of the metal ions into the BG, inducing co‐doping of Fe and Cu ions as verified by energy‐dispersive X‐ray spectroscopy (EDX). In this context, the overall amorphous structure is retained, as evidenced by X‐ray powder diffraction (XRD). We further demonstrate that the level of doping for both elements can be adjusted by changing the BG/ion concentration ratio during laser fragmentation. Consecutive ion release experiments using inductively‐coupled plasma mass spectrometry (ICP‐MS) were conducted to assess the potential bioactivity of the doped nanoscopic BG samples, and cell culture experiments using MG‐63 osteoblast‐like cells demonstrated their cytocompatibility. The elegant method of in situ co‐doping of Fe and Cu ions during BG nanosizing may provide functionality‐advanced biomaterials for future studies on angiogenesis or bone regeneration, particularly as the level of doping may be adjusted by ion concentrations and ion type in solution. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) show a bright application prospect in the field of biomedicine and energy materials due to their unique recyclable, modifiability, structure of cation and anion adjustability, as well as excellent physical and chemical properties. Dissolving silk fibroin (SF), from different species silkworm cocoons, with ILs is considered an effective new way to obtain biomaterials with highly enhanced/tailored properties, which can significantly overcome the shortcomings of traditional preparation methods, such as the cumbersome, time-consuming and the organic toxicity caused by manufacture. In this paper, the basic structure and properties of SF and the preparation methods of traditional regenerated SF solution are first introduced. Then, the dissolving mechanism and main influencing factors of ILs for SF are expounded, and the fabrication methods, material structure and properties of SF blending with natural biological protein, inorganic matter, synthetic polymer, carbon nanotube and graphene oxide in the ILs solution system are introduced. Additionally, our work summarizes the biomedicine and tissue engineering applications of silk-based materials dissolved through various ILs. Finally, according to the deficiency of ILs for dissolving SF at a high melting point and expensive cost, their further study and future development trend are prospected. [ABSTRACT FROM AUTHOR]

The relationship between cardiovascular diseases and iron disorders has gained increasing attention; however, the effects of hypotensive drugs on iron metabolic alterations in hypertension are not well understood. The purpose of this study was to investigate iron metabolic changes after prazosin treatment of spontaneously hypertensive rats (SHRs) and Wistar–Kyoto (WKY) rats. Our second objective was to examine the effects of hypertension and anti‐hypertensive drugs on bone formation and resorption. SHRs and WKY rats were randomized into either prazosin‐treated groups (WKY + PZ and SHR + PZ) or untreated groups (WKY and SHR). After 7 days of intragastric prazosin administration, the rats were sacrificed for analysis; blood samples and organs (the duodenum, liver, kidneys, spleen, and femur) were collected. Both WKY + PZ and SHR groups exhibited iron deficiency in the serum and liver. Prazosin increased the iron levels in the bone tissue of SHRs. Prazosin stimulated the expression of hepcidin mRNA in the liver of SHRs and inhibited the expression of this iron‐regulatory hormone in WKY rats. FPN1 expression in the duodenum was increased significantly in SHRs, however markedly decreased after prazosin treatment. The expression of TLR4 and Ctsk was enhanced in the bone tissue of SHRs, whereas CLC‐7 expression was inhibited. Both hypotension and hypertension can lead to iron deficiency. Treatment with prazosin restored iron homeostasis in SHRs. The inverse impacts of prazosin on hepatic hepcidin expression in SHRs versus WKY rats indicates differing iron regulatory mechanisms between hypertensive and normal animals. The osteoclast activity was found to be enhanced in SHRs. Further study is needed to address whether the changes in osteoblast and osteoclast activity in SHRs correlates with the effects on iron metabolism. [ABSTRACT FROM AUTHOR]

The combination of histological and biomolecular analyses provides deep understanding of different biological processes and is of high interest for basic and applied research. However, the available analytical methods are still limited, especially when considering bone samples. This study compared different fixation media to identify a sufficient analytical method for the combination of histological, immuno-histological and biomolecular analyses of the same fixed, processed and paraffin embedded bone sample. Bone core biopsies of rats' femurs were fixed in different media (RNAlater + formaldehyde (R + FFPE), methacarn (MFPE) or formaldehyde (FFPE)) for 1 week prior to decalcification by EDTA and further histological processing and paraffin embedding. Snap freezing (unfixed frozen tissue, UFT) and incubation in RNAlater were used as additional controls. After gaining the paraffin sections for histological and immunohistological analysis, the samples were deparaffined and RNA was isolated by a modified TRIZOL protocol. Subsequently, gene expression was evaluated using RT-qPCR. Comparable histo-morphological and immuno-histological results were evident in all paraffin embedded samples of MFPE, FFPE and R + FFPE. The isolated RNA in the group of MFPE showed a high concentration and high purity, which was comparable to the UFT and RNAlater groups. However, in the groups of FFPE and R + FFPE, the RNA quality and quantity were statistically significantly lower when compared to MFPE, UFT and RNAlater. RT-qPCR results showed a comparable outcome in the group of MFPE and UFT, whereas the groups of FFPE and R + FFPE did not result in a correctly amplified gene product. Sample fixation by means of methacarn is of high interest for clinical samples to allow a combination of histological, immunohistological and biomolecular analysis. The implementation of such evaluation method in clinical research may allow a deeper understanding of the processes of bone formation and regeneration. [ABSTRACT FROM AUTHOR]

The undamaged structure and functionality of the skeleton are a prerequisite for ensuring the quality of human life. The introduction of the latest treatment methods and prosthetics in traumatic surgery, oncology, cranial surgery, and dentistry form a demand for biomaterials with functionalized properties. The growth of new bone tissue is a cellregulated process based on creating a specific bone morphology, which combines the organic matrix and its inorganic content. The inorganic component of human bones and teeth is calcium deficiency hydroxyapatite (cdHA), with a molar ratio of Ca/P ranging from 1.5 to 1.67. The combination of cdHA and natural polymers in the material allows the incorporation of proteins and growth factors into the polymer matrix. It promotes biocompatibility and the growth of new bone tissue. This review considers the critical role of the porosity parameter of biomaterials (BM) in their use for bone regeneration. Porosity is an essential characteristic of BM and guarantees the interaction of the material with cells in bone formation, promoting vascularization and the process of biosorption of synthetic graft when it is replaced by newly formed native bone. At the same time, the degree of porosity should correlate with mechanical stability to maintain the structural integrity of BM in the process of hard tissue regeneration. Processes involving cells and proteins during BM implantation with both high (70–80 %) and low (≤ 45 %) degrees of porosity are considered. Data on existing methods of obtaining BM in porous scaffolds are given. The specified degree of porosity is provided by chemical (cross-linking) and physical (sublimation) methods. The effects of pores of different sizes and shapes on bone formation and vascularization are considered. It is shown that porosity is an influential factor influencing the mechanical properties of scaffolds, in particular, the stiffness of BM - a parameter that affects the proliferation of osteoblasts by regulating cell adhesion in the scaffold structure. The influence of the biopolymer component (Sodium Alginate - AN) on the porosity and swelling of hybrid apatite-biopolymer (HA/AN) composites, in which nanometric needle crystallites represent HA, is analyzed in detail. [ABSTRACT FROM AUTHOR]

This work aimed to study the rate and quality of maturation of the mineral component of retained teeth 3.8, 4.8 and lower jaw fragment of a human in connective tissue dysplasia in different periods of postpartum ontogenesis. The study involved 102 men (76 with connective tissue dysplasia and 26 without connective tissue dysplasia) divided into groups by age: 31–40, 41–50, 51–60 years. One tooth 3.8, 4.8 and a fragment of the alveolar part of the lower jaw in the projection of teeth 3.8, 4.8 0.5*0.5 cm in size were extracted from each examinee for medical indications. Low optical density values are observed at the age of 41–50 years, at the age of 51–60 years, indicating decreased mineral density and the presence of total areas of hypomineralization from the age 31–40 years in connective tissue dysplasia. At the age of 41–50, 51–60 years, at the boundary of connective tissue structures and periosteum, a pronounced sclerosis and deformation of delineation elements were observed; at the age of 31–40 years, the indicated changes were less pronounced. At the age of 31–40 years, the level of bone plate dissection has a local character, after 40 years, it has a generalized character. Progressive osteoporosis of the mandible and incomplete amelogenesis are an obstacle to the correct and harmonious teething of the lower wisdom teeth after the age of 30. [ABSTRACT FROM AUTHOR]

Alumina is a polymorphic bioceramic that has been extensively investigated for application in bone regeneration. Dense a-alumina has been considered a suitable biomaterial for dental and orthopedic implants due to its superior mechanical properties. However, its use is limited due to its high inertia in a biological environment. Recent investigations have focused on its distinct phases and surface characteristics through the control of morphology, physical properties, and chemical composition to enhance bioactivity. This article presents a brief review of the developments in porous a-alumina and amorphous-?-alumina transition. Most studies have shown that composites and alumina coated with bioactive materials, high surface area, and hydroxylated surface can significantly improve biological properties. Cellular responses such as fixation, growth, and proliferation, as well as biomineralization, are the main studies to validate improvements in bioactive properties. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the mediating effect of muscle mass on the relationship between training load and bone density in adolescent swimmers. Methods: A cross-sectional study involving 87 control and 22 swimmers aged 10-19 years (overall sample: n = 109). Swimmers had a minimum of 1 year of competition in regional and national championships, and control adolescents reported 1 year without any organized sport. Bone density was the main outcome (dual-energy X-ray absorptiometry), which was measured in upper limbs, lower limbs, spine, and whole body. Monthly training load was the independent variable, while the mediation effect of lean soft tissue was assessed. Maturity offset, age, inflammation, and vitamin D intake were treated as covariates. Results: Swimmers had lower bone density than controls; there was a significant and positive relationship between training load and muscle mass. In boys, training load presented a negative correlation with bone density in lower limbs [r = -.293; 95% confidence interval (CI), -.553 to -.034]. In girls, training load was negatively related to bone mineral density in lower limbs (r = .563; 95% CI, -.770 to -.356) and whole body (r = -.409; 95% CI, -.609 to -.209). Conclusion: Training load had a negative relationship on bone density of swimmers of both sexes, independently of the positive effect of lean soft tissue on bone density. [ABSTRACT FROM AUTHOR]