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

Oral diseases such as dental caries, periodontitis, and oral cancer remain significant global health challenges due to their high prevalence and potential for severe complications. Conventional diagnostic and therapeutic methods face limitations including insufficient tissue penetration, low spatial resolution, radiation risks, and the emergence of antibiotic resistance. Near-infrared II (NIR-II, 1000–1700 nm) theranostic agents offer deep tissue penetration, high-resolution imaging, and low tissue autofluorescence, enabling precise diagnosis, and targeted treatment integration. This review summarizes the design and development of various NIR-II platforms, including fluorescent probes, photothermal and photodynamic agents, and multifunctional nanomaterials. Key applications in dentistry include early caries detection, guidance for root canal therapy, monitoring of periodontal inflammation, dental implant evaluation, and oral cancer diagnosis and therapy. NIR-II agents enhance antimicrobial efficacy via photothermal and photodynamic effects, promote tissue regeneration, and reduce systemic side effects. Despite promising advances, challenges such as biosafety concerns, limited retention in the dynamic oral environment, and difficulties in imaging mineralized dental tissues remain. Strategies including biodegradable and biomimetic materials, stimuli-responsive delivery systems, and standardized clinical protocols are critical to overcoming these barriers. Looking forward, interdisciplinary collaboration and technological innovation are expected to accelerate clinical translation of NIR-II theranostics, driving a paradigm shift toward precision, minimally invasive dentistry. This emerging approach holds great potential to improve oral health outcomes by enabling safer, more effective, and personalized dental care.

This study investigated the biomechanical efficacy of conventional and 3D-printed scaffold-augmented fixation methods for a large 6 cm osseous femoral defect. Finite element analyses were conducted to compare four conventional techniques: single plate, intramedullary nail, combined plate and nail, and double plate. These were then evaluated with the addition of three porous Ti-6Al-4V scaffold designs (Weaire–Phelan, Diamond, and Voronoi) with 70% porosity. Models were subjected to peak physiological loading from gait, simulating a 106 kg patient. Performance was assessed based on implant stress and the volume fraction of the fracture callus experiencing osteogenic strains (0.005%–2.5%). Results showed that conventional single-implant methods were mechanically insufficient; the single plate failed at 20% of the physiological load and the nail at 90%. These methods also produced suboptimal osteogenic environments, with an osteogenic volume fraction < 16%. In contrast, combined conventional methods (plate and nail, double plate) withstood 100% of the load with significantly lower stresses and promoted highly osteogenic environments, with an osteogenic volume fraction > 95%. The integration of 3D-printed scaffolds transformed the single-implant constructs, enabling them to withstand 100% physiological load and increasing their osteogenic volume fraction to over 90%. Scaffolds also substantially reduced stress on the primary implants in all configurations. The plate and nail fixation augmented with a scaffold emerged as the most robust strategy, reducing conventional implant stresses to approximately 140 MPa while maintaining an exceptional osteogenic volume fraction > 99%. These findings highlight the quantitative potential of 3D-printed scaffolds to improve treatment outcomes for large bone defects.

The objective of this study was to optimize the composition and loading of silver-doped mesoporous silica nanoparticles (Ag/MSNs) within the poly(methyl methacrylate) (PMMA) denture base to enhance mechanical properties, antifungal activity, and maintain biocompatibility. Silica nanoparticles (SBA-15) were synthesized and functionalized with either diaminosilane (PC1200) or gamma-methoxysilane (γ-MPTS) coupling agents prior to silver impregnation. The functionalized and unmodified SBA-15 were then loaded with silver nanoparticles via chemical reduction. These Ag/MSN-modified PMMA composites were fabricated at different nanoparticle loadings (0.1, 0.5, 1, and 1.5 wt%) and characterized for their physical, mechanical, antimicrobial, and biocompatibility properties. The incorporation of Ag/MSNs significantly improved the mechanical properties and antimicrobial activity of the PMMA-based dental prosthesis material without compromising biocompatibility. The modification of Ag/MSNs particles by both types of coupling agents fortified the material's mechanical properties, sustained water solubility and release of silver nanoparticles, thereby providing better biocompatibility for the synthesized nanocomposites. This phenomenon was more pronounced in the amino-silane coupling agents equipped with diamine groups. The findings of this study demonstrated that an increase in the concentration of Ag/MSNs particles in the PMMA polymers up to 1.5 wt% resulted in the deterioration of the mechanical properties, reducing water sorption and solubility, but enhancement of antifungal activity. A concentration of 0.5 wt% silver-doped mesoporous silica nanoparticles modified by amino-silane or gamma-methoxysilane coupling agents can be considered the optimal concentration for incorporation into PMMA denture bases, resulting in enhanced mechanical and antifungal properties while preserving biocompatibility.

Silicon nitride (Si₃N₄) is reported to exhibit antibacterial properties and support osteoblast maturation, while polyetherketoneketone (PEKK) is considered to potentially have antibacterial and osseointegrative properties while offering favorable manufacturability through extrusion-based additive manufacturing compared to traditional ceramics manufacturing. Incorporating silicon nitride into PEKK is hypothesized to enhance its bioactivity while maintaining processability, making Si₃N₄-PEKK composites promising for medical implants. Our objective was to determine optimal fused filament fabrication (FFF) parameters for PEKK and Si₃N₄-PEKK. Taguchi optimization (L9 array, n = 5) was performed on PEKK and 15 vol.% Si₃N₄-PEKK to assess the impact of printing parameters (layer height: 0.1, 0.2, and 0.3 mm; nozzle temperature (PEKK/Si₃N₄-PEKK): 340/380, 370/400, and 400/420; bed temperature: 130°C, 150°C, and 170°C; and chamber temperature: 110°C, 130°C, and 150°C) on ultimate tensile strength (UTS). Z-directional tensile specimens were printed on a medical FFF printer. Specimens underwent tensile testing according to ASTM D638. Signal/noise ratios for UTS were calculated and ANOVA (Minitab 21.4.2) was used to assess statistical significance (p < 0.05). Layer height had the greatest impact on UTS for both PEKK and Si₃N₄-PEKK. Optimal nozzle and chamber temperatures were 400°C and 130°C, respectively, while the optimal layer height was 0.1 mm for both materials. The optimal bed temperature for PEKK and Si₃N₄-PEKK was 150°C and 170°C, respectively. For PEKK, differences in all parameters were significant except for bed temperature, while for Si₃N₄-PEKK all parameters were significant except for nozzle temperature. The specimens with optimum statistically significant parameters showed the highest UTS for both PEKK (91 ± 2 MPa) and Si₃N₄-PEKK (76 ± 3 MPa). Layer height is the most influential printing variable for both PEKK and Si₃N₄-PEKK. The optimal PEKK printing condition has a comparable UTS, while Si₃N₄-PEKK achieved 84% of the injection-molded value for neat PEKK.

An ideal meniscus substitute should possess a remarkable resemblance to the native meniscus, which includes structural integrity, biocompatibility, mechanical strength, and durability. Understanding the meniscus anatomy, microarchitecture, and biomechanical properties of the meniscus can help in developing innovative designs, and advancements for addressing meniscus injuries and replacement. Emphasis is made on the promising application of decellularized extracellular matrix (dECM) as a source material for bioink in meniscus 3D printing. This paper examines the criteria required for dECM bioink, including immunogenicity, ECM composition, printability, biocompatibility, biomechanical properties, types of cross-linkers, and their potential applications. By comprehensively addressing these factors, researchers can optimize dECM bioink for 3D printing and develop meniscus substitutes that closely mimic the native meniscus. In conclusion, this review highlights the most promising approaches for 3D printing the meniscus, drawing on the insights gained from the analysis of meniscus anatomy, biomechanics, and dECM bioink characteristics.

The study explores the potential of zeolites as carriers for controlled trimethoprim (TMP) release. Zeolites of types X and Y were ion-exchanged with lanthanum (La³⁺) and cerium (Ce³⁺) ions and characterized to evaluate their efficacy in TMP sorption and delivery. Although type X zeolites were ineffective, type Y zeolites demonstrated significant TMP retention, with CeY adsorbing 0.95 mg (58%) and LaY adsorbing 0.78 mg (49%) of TMP per gram. Characterization techniques, including nitrogen adsorption/desorption, FT-IR, EDS, and SEM, confirmed TMP adsorption within the zeolite structure without altering its morphology. TMP release studies conducted in simulated body fluid (pH 7.4) and acidic conditions (pH 5) revealed sustained release profiles, with CeY outperforming LaY in both environments. The results highlight the potential of CeY and LaY zeolites as carriers for TMP, enabling controlled drug delivery while minimizing burst release. These findings offer a promising approach to improving antibiotic treatment and combating antibiotic resistance development.

This study aims to examine the effect of the chitosan/polyethylene oxide (Cs/PEO) scaffold on sciatic nerve regeneration and neural tissue angiogenesis in adult male rats. Thirty two rats were divided into normal, control, sham and Cs/PEO groups. In the control, sham and Cs/PEO groups, the sciatic nerve was severed in the middle region of the thigh, and epineuria was sutured. After 8 weeks, the functional recoveries, the nerve conduction velocity (NCV), the nerve fiber number, the largest nerve fiber area (LNFA), the largest axon area (LAA) and the number of blood vessels were evaluated. Nerve fiber numbers showed a statistically significant increase in the Cs/PEO, control and sham relative to the normal group. The mean size of the LAA and blood vessels indicated a significant increase in the Cs/PEO group in comparison with the others and the normal group, respectively. The study demonstrated that nerve regeneration with epineural sutures and Cs/PEO could prevent fatal neuron changes and promote angiogenesis following sciatic nerve injury particularly in the first 2 weeks, which rescue some neurons in this initial vital time of injury. However, the Cs/PEO scaffold alone may not be sufficiently effective in sciatic nerve regeneration over a long time period.