Journal of biomedical materials research. Part B, Applied biomaterials最新文献

To compare the osseointegration properties of two different types of nitrogen-containing bisphosphonate (N-BP)-coated dental implants in an experimental in vivo sheep model. In total, eight sheep were divided into two groups receiving implants at two time points. Each animal received four types of implants, AddBIO STL implants coated with Zoledronate (Zol) and AddBIO STL implants coated with Ibandronate and Pamidronate (IbaPam) as test groups and uncoated AddBIO STL implants (UC) and Straumann original SLA implants (SSLA) as controls. Implants were placed in the metatarsus bilaterally, and healing times were either 10 or 28 days. Implant stability quotient (ISQ) was measured at baseline and at euthanasia. Removal torque (RT) was assessed post-mortem, followed by histomorphometric analysis to evaluate bone-to-implant contact (BIC) and bone area (BA). The differences between implants were evaluated using paired t-tests. The significance level was set at p value < 0.05 After 10 days, Zol implants presented significantly higher RT (Ncm mean ± SD) values 26.0 (± 18.0) than IbaPam implants 8.3 (± 14.9) (p = 0.011). SSLA implants demonstrated significantly higher RT values 34.6 (± 22.2) than Zol and IbaPam-coated implants (p = 0.048) and Zol-coated implants showed significantly higher RT values than UC implants 12.0 (± 7.6) than UC implants (p = 0.015). No significant differences in RT were detected at 28 days. No differences were observed among the groups regarding ISQ, BIC, or BA at either time point. Zoledronate-coated implants exhibited enhanced early mechanical stability compared to ibandronate/pamidronate-coated implants. However, this advantage was eradicated after 28 days, suggesting that the early anabolic effect of zoledronate may be time-limited.

The development of functional materials for osteoporosis is essential for effective bone remodeling. In this context, the extraction of biocompatible implantable biomaterials from bio-waste emerges as a valuable strategy, addressing both environmental challenges and promoting human health. The objective of this work was to evaluate the physicochemical properties of the added-value by-product biomaterial (SS-90), extracted from sardine scales (Sardina Pilchardus) and combined with chitosan (SS-90-CH). Besides, the efficacy of both biomaterials for bone regeneration was evaluated through in vitro and in vivo tests. The physicochemical characteristics of the biomaterials were demonstrated by ICP-OES, TGA, XRD, FTIR, and SEM-EDS analyses. Their characteristic features were compared with pure commercial hydroxyapatite (HA_syn) and associated with chitosan (HA_syn-CH). ICP-OES analysis evidenced the presence of Ca, P, Mg, Na, Sr, and Zn in SS-90 with a molar ratio (Ca/P) of 1.84 near to that of synthetic hydroxyapatite (1.67). The FTIR spectrum confirmed the presence of carbonate and phosphate functional groups in SS-90, which is similar to healthy rat bone (HRB). In vitro, SS-90 and SS-90-CH biomaterials demonstrated no cytotoxicity, maintaining cell viability between 80% and 100% for SaOS-2, L929, and LIG cells after 72 h of incubation. Furthermore, these biomaterials were implanted into bone defects in femoral condyles of osteoporotic rats to evaluate their effectiveness in bone fracture repair under osteoporotic conditions. Physicochemical, biochemical, and histological studies conducted at different time intervals after implantation indicated that the biomaterials could effectively promote bone regeneration. In conclusion, the present study highlights that SS-90 and SS-90-CH biomaterials are promising solutions for repairing bone defects or fractures under osteoporotic conditions, combining the valorization of marine bio-waste with biomedical applications.

Drug delivery to the central nervous system (CNS) is primarily hindered by the blood–brain barrier (BBB). To address this, mucoadhesive formulations have been designed to prolong residence time at the application site. In this study, we comprehensively characterized the physicochemical and mucoadhesive properties of hyaluronic acid tyramine (HATA) photocrosslinked hydrogels using rheological methods, nanoindentation, contact angle goniometry, and advanced confocal microscopy. A novel parameter, photon count per pixel, was introduced through confocal microscopy to assess hydrogel stability and mucoadhesion on ex vivo porcine olfactory tissues. Crosslinked hydrogels (1% and 2% w/v) exhibited stable mucoadhesive properties, ranging between 16.5 and 18 photon counts per pixel, whereas uncrosslinked counterparts typical of classical nasal formulations showed significant photon count losses (71% and 50% for 1% and 2% HATA, respectively). Nanoindentation analysis revealed a correlation between photoirradiation time, effective Young's modulus, and mucoadhesion, identifying 1 min of irradiation as optimal across all concentrations tested. The optimized hydrogels demonstrated mucoadhesive forces of 0.263, 0.412, and 0.701 mN mm⁻², corresponding to Young's modulus values of 1995, 2465, and 2985 Pa for 1%, 2%, and 3% w/v HATA, respectively. These results highlight the importance of crosslinking for enhancing hydrogel stability and mucoadhesion. Additionally, BSA-labeled rhodamine served as a model protein drug in low-swelling hydrogels for drug release studies, laying the foundation for further optimization in targeted nasal drug delivery systems.

Resin composites have become the preferred restorative material in modern dentistry due to their superior esthetics, improved physical properties, and advancements in curing technologies. To enhance their clinical performance, manufacturers continuously refine the resin matrix and optimize filler particle size and shape, improving both mechanical strength and optical characteristics. Evaluating optical properties is crucial for predicting the performance of resin composites over time, particularly in maintaining color, gloss, translucency, and overall appearance. Translucency refers to a material's ability to transmit and scatter light. This in vitro study evaluated changes in color, translucency, and gloss of nine commercially available flowable resin composites following artificial accelerated aging (AAA) and staining. Specimens were subjected to AAA and staining in black tea, coffee, and red wine. Using a spectrophotometer, color and translucency measurements were performed before and after the AAA and staining. Gloss measurements were performed using a small-area glossmeter before and after the AAA and staining. A two-way ANOVA was used to compare the effects of material and treatment, followed by Tukey's post hoc multiple comparison test to assess differences among levels within each variable (α = 0.05). A statistically significant interaction was observed between materials and procedures (p < 0.05) for color changes. All tested composites displayed translucency parameter changes within clinically acceptable limits. Gloss retention percentage upon treatments remained high across all composites tested. AAA and staining significantly influenced the color stability, translucency, and gloss retention of tested flowable resin composites, and were material- and procedure-dependent.

Guided bone regeneration (GBR) is essential in implant dentistry for managing bone deficiencies. Despite its high success rate, complications like wound dehiscence, membrane exposure, and infection can compromise outcomes. These issues are influenced by patient health, surgical technique, and the implanted biomaterials. Membrane exposure may lead to significant bone loss and jeopardise treatment success. A resorbable magnesium membrane has been recently introduced for GBR, but soft tissue healing complications have not yet been reported. This case series reviews four instances of wound dehiscence to assess its impact on clinical outcomes. Four patients underwent GBR using a magnesium membrane before implant placement. Each followed a similar protocol: defects were filled with bovine and autologous bone, then covered with the magnesium membrane. Membrane exposure occurred in all cases, varying from small to large. However, none experienced pain or signs of infection, and no additional treatment was required. Implant placement proceeded as planned, with no notable bone loss. Despite varying degrees of exposure, the magnesium membrane prevented infection, pain, or significant bone loss. It effectively maintained a barrier between tissues, suggesting its potential to reduce complications from exposure. Larger studies are needed to validate these findings.

Permanent implants, which are primarily used to treat fractures, are either removed during a subsequent procedure or remain in the body after being surgically inserted. Bioabsorbable implants are designed to be reabsorbed by the body, minimizing the risk of chronic infections or foreign body reactions. The qualification of a novel zinc-silver alloy containing 3.3 wt% silver (ZnAg3) as a bioabsorbable implant was investigated in this in vivo study on New Zealand white rabbits. The osteointegration of ZnAg3 pins and MAGNEZIX pins, which served as controls, was evaluated histomorphometrically and histologically at 4, 8, and 16-week intervals. The implant area and the osteoid area were measured in order to assess the degradation of the material as well as the bone formation. The histological evaluation included a cell count of osteogenic cells and a descriptive evaluation of the histological images. The animal trial was accompanied by frequent blood, urine, and X-ray tests. The results showed adequate degradation of ZnAg3 with an implant area of 93.92% ± 5.85% at week 16 and a sufficient number of osteogenic cells, allowing progressive osteointegration. In comparison, the MAGNEZIX pin degraded significantly faster and, after 16 weeks, diminished to 77.54% ± 13.59% of the original implant area. Furthermore, harmful hydrogen gas pockets were found, which correlated with reduced bone formation, represented by a lower cell count of osteoblasts after 4 weeks. ICP-OES measurements performed on the animals' blood samples did not reveal any increased metal ion concentrations above the tolerable level. Thus, ZnAg3 pins showed excellent results compared to MAGNEZIX pins, which are in clinical use as bioabsorbable implants.