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

In recent decades, death rates from microbial infections and cancer have been increasing. This increase is triggered by the limited effectiveness of existing treatments, such as the use of antibiotics, which are considered less effective due to the development of antibiotic resistance. Furthermore, cancer treatments such as chemotherapy have been reported to produce negative effects on the patient's body. Therefore, alternative treatments are urgently needed, such as developing drug delivery platforms and nanomaterial-based antimicrobial agents. This study aims to develop new hybrid nanocomposites, combining inorganic–organic materials, namely Fe₃O₄/HA/L-ac (L-ac = L-aspartic acid and HA = hydroxyapatite), as antimicrobial agents and drug delivery vehicles. In this case, Fe₃O₄, a well-known nanomaterial for antimicrobial agents and drug delivery vehicles, was optimized by combining it with HA and L-ac. The successful formation of nanocomposites was confirmed by X-ray diffraction and Fourier transform infrared spectroscopy. We found that the antimicrobial activity of the composites increased with increasing HA content. HA contributed to the formation of reactive oxygen species and released active ions from nanoparticles through the interaction between the active sites of proteins and antibacterial agents, causing cell lysis. The increased antimicrobial activity was also influenced by electrostatic interactions in the nanocomposite particles, which penetrated the membrane and damaged the microbial cells. As drug delivery vehicles for cancer treatment, the nanocomposites effectively released doxorubicin (DOX), achieving 70% release within the first 45 min and nearly 97%–99% overall. The increased release was associated with a proton exchange mechanism at the primary amine group of DOX. Therefore, the prepared Fe₃O₄/HA/L-ac hybrid nanocomposites possess high potential for dual applications as antimicrobial agents and drug delivery vehicles.

In this work, a green formulation of iron nanoparticles (FeNPs) using Lavandula angustifolia leaf extract was described. FeNPs were described using several spectroscopic approaches, and their efficacy in treating myocardial infarction was investigated. The nanoparticles were generated with a spherical shape. Isoproterenol was used to produce a myocardial infarction. Cardiac function was evaluated following treatment with FeNPs@L. angustifolia at various dosages using histochemical, biochemical, and electrocardiogram (ECG) studies. In vitro apoptosis and inflammatory responses in HCAECs were investigated. Real-time PCR was used to assess the activation of cytokines and PPAR-γ/NF-κB in response to lipopolysaccharide. In comparison to rats with myocardial infarction, FeNPs@L. angustifolia treatment greatly avoids typical ST-segment depression. Furthermore, FeNPs@L. angustifolia considerably reduces myocardial damage marker levels, lowers mortality rates, and improves ventricular wall infarction. Furthermore, in the heart of myocardial infarction mice, FeNPs@L. angustifolia decreased the proinflammatory cytokines. The normalization of phosphorylation gene expression may be linked to the positive effects of nanoparticles. FeNPs@L. angustifolia dramatically reduced the expression of inflammatory cytokines and cell death. Current data reports the cardioprotective effects of FeNPs@L. angustifolia on myocardial infarction caused by isoproterenol, which may be connected to the NF-κB signaling suppression and the PPAR-γ activation. In conclusion, the current study provides a modern remedial strategy for myocardial infarction treatment in a clinical context.

Traumatic spinal cord injury (TSCI) is a serious medical issue where there is a loss of sensorimotor function. Current interventions continue to lack the ability to successfully enhance these conditions; therefore, it is crucial to consider alternative effective strategies. Currently, we investigated the effects of collagen-based hydrogel (CbH) loaded with microspheres encapsulated with placental mesenchymal stem cells (PMSCs)-derived exosomes in the recovery of TSCI in rats. Sixty adult male Sprague–Dawley rats were randomly assigned into four groups (n = 15/group): TSCI (injury without treatment), CbH, Microsphere (exosomes encapsulated in microspheres), and CbH + Microsphere. At 48 h, 10 rats per group were sacrificed for immunohistochemical (caspase-3), molecular (cytokines), and biochemical (oxidative stress markers) analyses; the remaining five rats per group were used for stereological evaluations at day 14. Furthermore, behavioral assessment was performed pre-injury and on days 1, 3, 7, and 14 post-injuries. Results showed that the CbH + Microsphere group exhibited significantly reduced lesion volume and apoptosis, improved neuron preservation, and increased total volume compared to the TSCI group. Additionally, this group had higher levels of antioxidant enzymes (GSH, SOD, CAT) and IL-10, and lower levels of pro-inflammatory cytokines (TNF-α, IL-1β) and MDA. Functional recovery, as reflected by Basso-Beattie-Bresnahan (BBB) scores, was significantly better in the CbH + Microsphere group across all time points post-injury. In conclusion, our findings suggest that CbH encapsulated with microspheres containing PMSCs-derived exosomes could enhance the prevention of injury spreading and the enhancement of pathological and behavioral symptoms when delivered to the location of spinal cord injury.

3D printing has proven very beneficial in the medical field, especially in cardiovascular medicine, by providing cardiologists and cardiac surgeons with 3D models of patient anatomy for procedure planning. These models are helpful in providing visual aid but are typically simple in design and it is often unknown how the printed model's mechanical properties compare to cardiovascular tissue mechanical properties. Stratasys has developed tissue-mimicking materials; although there are almost no published characterization details on how these printed polyjet materials compare to published human cardiovascular tissue data. We compared J750 digital anatomy printer material properties to left human heart tissue properties using nonlinear elastic constitutive models. We mechanically tested 73 polyjet printer materials (Stratasys J750 DAP) and successfully created a database identifying which printer materials were the best “fit” for each cardiac region of interest. We found that all J750 DAP materials exhibited stiffer behavior than each cardiac tissue region. The top three materials that fit each cardiac region the best were SoftDM400, SolidInternalOrgans_FiberContraction6, and Liver_HighlyContractile, respectively.

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.