Journal of Materials Science: Materials in Medicine最新文献

Osseointegration is essential for successful implant treatment. However, the underlying molecular mechanisms remain unclear. In this study, we focused on decorin (DCN), which was hypothesized to be present in the proteoglycan (PG) layer at the interface between bone and the titanium oxide (TiOx) surface. We utilized DCN RNA interference in human bone marrow mesenchymal stem cells (hBMSCs) to investigate its effects on PG layer formation, proliferation, initial adhesion, cell extension, osteogenic capacity, fibrotic markers, and immunotolerance to TiOx in vitro. After 14 days of cultivation, we observed no PG layer was detected, and the osteogenic capacity was suppressed in DCN-depleted hBMSCs. Furthermore, the conditioned medium upregulated the expression of M1 macrophage markers in human macrophages. These results suggest that endogenous DCN plays a crucial role in PG layer formation and that the PG layer alters inflammation around Ti materials.

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The number of patients with bone defects caused by trauma and diseases has been increasing year by year. The treatment of bone defects remains a major challenge in clinical practice. Bone scaffolds are increasingly favored for repairing bones, with triply periodic minimal surface (TPMS) scaffolds emerging as a popular option due to their superior performance. The aim of this review is to highlight the crucial influence of pore structure on the properties of TPMS bone scaffolds, offering important insights for their innovation and production. It briefly examines various elements that influence the properties of TPMS bone scaffolds, such as pore shape, porosity, pore diameter, and curvature. By analyzing these elements, this review serves as a valuable reference for upcoming research and practical implementations in the field of bone tissue engineering.

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Wound dressing development is an area of active research. Traditional dressings lack antibacterial activity, biocompatibility, and tissue regeneration. Alginate is a heavily investigated polymer employed as wound dressings and can be combined with a wide range of additives. Herein, we report the preparation of alginate gel using the crosslinking technique as potential wound dressing, with insight investigation of the influence of employing single, two, or three cross-linkers: Strontium (Sr), zinc oxide (ZnO), and gentamicin sulfate. Rheology was used to confirm the gel’s preparation, where the samples’ viscosity curves show decreased viscosity with increased shear rate, indicating pseudoplastic flow. The linear viscoelastic region shows constant G’ and G” within the sample structure. In this study, we used three gels with different mixtures of ingredients: Gels A, B, and C contain sodium alginate (1% w/v) and 0.5 mL of Sr nitrate (4% w/v). However, Gels B and C contain 0.25 mL of ZnO (0.5% w/v). Gel C also includes 0.1 mL of gentamicin (1% w/v). The study examined the effectiveness of Gel A, B, and C on wound healing, calculating the reduction of wound area after seven, 14, and 20 days of a single topical treatment. Gel A, B, and C significantly reduced wound area, while Gel B and C showed a significant reduction. The zone of inhibition was used to detect the gels’ efficacy against microorganisms. The study found zinc deposition in the liver and bone, with Gel B and C showing higher levels. The study also found significant overexpression of MIP α and MIP β in tissues and downregulation of CCL2, IL8, and TGF β, explaining wound healing with minimal scar formation.

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Tooth extraction is physiologically followed by resorption of alveolar bone. Surgical method which aims to minimise this reduction in alveolar bone with a goal to provide enough bone volume for dental implant insertion is called socket preservation. The purpose of this article was to asses clinical, histomorphometric and histological results of socket preservation conducted with natural bovine bone substitute with hyaluronate. Three patients with one or more hopeless teeth in posterior region planned for extraction and implant placement were included in these case reports. After atraumatic extractions, empty sockets were filled with the bovine xenograft with hyaluronate, and then covered with collagen sponge. After 4–7.5 months the samples for biopsy were taken and then implants were inserted. The augmented sites healed uneventfully and without any complications. The histological specimens demonstrated new bone formation and osteoclastic activity around the biomaterial, as well as blood vessels in soft tissue. Histomorphometrically, formation of new bone averaged 24.8% ± 4.7% (mean ± standard deviation) in bone biopsies taken from the center of the augmented site, while the residual biomaterial averaged 52.7% ± 4.9% and the soft tissue averaged 22.6% ± 4%. In conclusion, the natural bovine bone substitute with hyaluronate demonstrated excellent osteoconductive potential for bone regeneration.

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In recent years, the incidence of cartilage defects has increased dramatically, and its etiology is complex and varied. Osteochondritis dissecans (OCD), as one of the main etiologies, damages both cartilage and bone tissues and can progress to severe osteoarthritis, which has been one of the difficult problems for clinicians. The vigorous development of material science and tissue engineering provides new ideas for the treatment of OCD, in which the selection of scaffold materials is particularly important. In this study, true-bone-ceramics (TBC), which has good mechanical strength and osteoconductivity, and type I collagen (COL1), which has excellent biocompatibility, were chosen as scaffold materials to co-construct the TBC/COL1 scaffold for osteochondral repair. In order to ensure the most appropriate collagen coating concentration, three experimental groups (1, 5, 12 mg/ml) were set up. Through the physicochemical property test, biocompatibility analysis and in vivo implantation experiments of composite scaffolds, 12 mg/ml TBC/COL1 scaffolds present the best repair effect among the three groups.

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Hydroxyapatite (HAp)-coated bone implants are frequently used for orthopaedic or dental implants since they offer high biocompatibility and osteoconductivity. Yet, problems such as infections, e.g. periprosthetic joint infections, occur when implanting foreign material into the body. In this study, HAp coatings were produced via high-velocity suspension flame spraying (HVSFS). This method allows for the production of thin coatings. We investigated the effects of different gas parameters on the coating properties and on the biocompatibility, which was tested on the human osteosarcoma cell line MG63. Furthermore, Copper (Cu) was added to achieve antibacterial properties which were evaluated against standard microorganisms using the airborne assay. Three gas parameter groups (low, medium, and high) with different Cu additions (0 wt.%, 1 wt.% and 1.5 wt.%) were evaluated. Our findings show that porosity as well as hardness can be controlled through gas parameters. Furthermore, we showed that it is possible to add Cu through external injection. The Cu content in the coating as well as the release varies with different gas parameters. Both antibacterial efficacy as well as biocompatibility are affected by the Cu content. We could significantly reduce the amount of colony-forming units (CFU) in all coatings for E. coli, CFU for S. aureus was reduced by adding 1.5 wt.% of Cu to the coating. The biocompatibility testing showed a cytotoxicity threshold at a Cu-release of 14.3 mg/L in 120 hours. Based on our findings, we suggest medium gas parameters for HVSFS and the addition of 1 wt.% Cu to the coating. With these parameters, a reasonable antibacterial effect can be achieved while maintaining sufficient biocompatibility.

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Hydrogels are currently widely used in regenerative medicine and wound repair due to their superior biocompatibility, reliable mechanical strength, and good morphological memory. We aimed to prepare a self-expanding hydrogel that can be used as a skin expander for the repair of large soft skin tissue defects. Self-expanding hydrogels were prepared by chemical cross-linking, which consisted of water-soluble chitosan (CS), acrylamide (AM), methylene bisacrylamide (NMBA), etc. Five groups of in vitro experiments, including (CS-AM) of 0% (pure AM group), 13.9%, 27.8%, 41.7%, and 55.6%, were conducted to determine mechanical properties, swelling properties, cytotoxicity, etc. In the rat model, both a tight skin area (neck) and a loose skin area (back) were selected for expansion with hydrogels. A total of 27.8% of the CS-AM samples expanded stably under the skin of the rats, achieving 370% expansion in the tight zone and 490% expansion in the flaccid zone. Subcutaneous histopathological examination suggested that the inflammation index of the pericolloid tissue was lower in the CS-AM group than in the pure AM group. Our results demonstrate that self-expanding CS-AM hydrogels have great potential for application as skin expanders.

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Bioactive glasses are one of the most promising materials for applications in bone tissue engineering. In this study, the focus was on borosilicate bioactive glasses with composition 47.12 SiO₂ - 6.73 B₂O₃ - 21.77-x-y CaO - 22.65 Na₂O - 1.72 P₂O₅ - x MgO - y SrO (mol%). These compositions are based on silicate S53P4 bioactive glass, from where 12.5% of SiO₂ is replaced with B₂O₃, and additionally, part of CaO is substituted for MgO and/or SrO. The impact of ion release, both as extract and in direct contact, on human adipose-derived stem cells’ (hADSCs) viability, proliferation, ECM maturation, osteogenic commitment and endothelial marker expression was assessed. Osteogenic media supplements were utilized with the extracts, and in part of the direct cell/material culturing conditions. While it has been reported in other studies that boron release can induce cytotoxicity, the glasses in this study supported cells viability and proliferation. Moreover, borosilicate’s, especially with further Mg/Sr substitutions, upregulated several osteogenic markers (such as RUNX2a, OSTERIX, DLX5, OSTEOPONTIN), as well as angiogenic factors (e.g., vWF and PECAM-1). Furthermore, the studied glasses supported collagen-I production even in the absence of osteogenic supplements, when hADSCs were cultured in contact with the glasses, suggesting that while the bioactive glass degradation products are beneficial for osteogenesis, the glasses surface physico-chemical properties play a significant role on hADSCs differentiation. This study brings critical information on the impact of bioactive glass compositional modification to control glass dissolution and the subsequent influence on stem cells proliferation and differentiation. Furthermore, the role of the material surface chemistry on promoting cell differentiation is reported.

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Stainless steel and titanium-based alloys have been the gold standard when it comes to permanent implants and magnesium-based alloys have been the best option for bioresorbable alloys. Ti-6Al-4V, Ti-64, with its 110 GPa Young’s Modulus is the most commonly employed alloy to manufacture biomedical implants used for treatment of fractures of skeleton. Recently, researchers have developed a new low-cost and toxic Vanadium-free alternative to this alloy, Ti-3Mo-0.5Fe at.%, namely TMF8. This alloy has a 25% lesser Young’s Modulus compared to Ti-6Al-4V and also demonstrated acceptable mechanical properties while possessing better cell proliferation results. The lower Young’s Modulus can aid in lowering stress shielding effects while its cytocompatibility could enhance healing. This work, therefore, tries to use finite element analyses to compare these two alloys (Ti-64 and TMF8) from a practical structural point of view to analyse the advantages and disadvantages of this new alloy and how a low-cost biocompatible alternative (TMF8) can actually prove to be a more viable option. The analyses confirm that TMF8 shows almost similar biomechanics performance to Ti-64 alloy (and in acceptable range) in bone plate fixation of mandibular angular fracture treatment.

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New methods for producing surfaces with suitable biocompatible properties are desirable due to increasing demands for biomedical devices. Stainless steel 316 L and cp- titanium specimens were coated with thin films of alumina and hafnia deposited using the atomic layer deposition method at two temperatures, 180 and 260 °C. The morphology of the films was analysed using scanning electron microscopy, and their surface energies were determined based on drop contact angle measurements. Biocompatibility assays performed using mesenchymal stem cells were evaluated by incubating the specimens and then exposing their extracts to the cells or directly seeding cells on the specimen surfaces. No detrimental effect was noticed for any of the specimens. Antibacterial properties were tested by directly incubating the specimens with the bacteria Staphylococcus aureus. Overall, our data show that all prepared films were biocompatible. Alumina films deposited on cp-titanium at 260 °C outperform the other prepared and tested surfaces regarding antiadhesive properties, which could be related to their low surface energy.