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

Tissue engineering is a new alternative for the recovery from bone injuries. Nanomaterials are often combined with scaffolds to improve structure, bioactivity, stability, adhesion, and compatibility. Carbon dots (CDs), which are fluorescent carbon nanomaterials with diameters of less than 10 nm, are powerful allies. In this study, we aimed to develop chitosan-gelatin/hydroxyapatite scaffolds and CDs for use in bone tissue engineering. First, we developed two types of CDs based on gelatin and heat-treated them at 200°C for 3 h (CDA) or 4 h (CDB). Both systems were characterized, and CDA exhibited better quantum yield and cytotoxic behavior. Therefore, we selected CDA for the scaffolds. Scaffolds without (CG/HA) and with CDA (CG/HA/CDA) displayed suitable porosities and degradation rates. Based on in vitro tests, we observed that the CD-containing scaffolds presented an excellent cell adhesion rate (94–100%), an indirect cytotoxicity viability of approximately 75%, and a direct cytotoxicity viability of at least 100% at all analyzed times (p < 0.05). Furthermore, alkaline phosphatase (ALP) expression suggested the formation of more mature osteoblasts in CG/HA/CDA. Its association with CDA promotes bioactivity, stability, cell adhesion, and compatibility. We also highlighted the ability of CG/HA/CDA to emit fluorescence for monitoring cell growth during tissue regeneration. These results demonstrated that CDA is highly biocompatible and supports cell growth, which can induce bone tissue regeneration and help treat bone diseases.

Preventing bacterial infections on Ti-based medical products is crucial, driving the need for durable antibacterial surfaces with enhanced mechanical strength and photocatalytic activity. This study introduces an anodization process for fabricating a hard barrier-type TiO₂ layer on a Ti substrate with visible-light-responsive photocatalytic activity. The core technology involves using an electrolyte comprising nitrate and ethylene glycol maintained at a high temperature to improve the layer hardness and photocatalytic performance. The layer characteristics, including thickness, crystallinity, and density, sensitively varied with increasing electrolyte temperature. For instance, raising the temperature to 100°C increased the layer thickness and density. By contrast, the thickness decreased beyond 100°C, leading to the deterioration of photocatalytic performance. Using ethylene glycol containing 100 mM nitrate maintained around 100°C was appropriate for maximizing layer hardness and photocatalytic performance. The resulting monolithic TiO₂ layer exhibited a hardness of ~450 HV, approximately twice that of the Ti substrate. Moreover, it effectively reduced the number of living Escherichia coli to ~4/100 under ultraviolet (UV) light and ~4/10 under visible light after 4 h of illumination. These results provide a guideline for obtaining a semi-permanent antibacterial medium through anodization.

This study synthesized and characterized amoxicillin-functionalized Ag/AgCl nanoparticles (Amoxicillin@Ag/AgCl NPs) for biomedical applications. The nanoparticles were prepared via a coprecipitation method and functionalized with amoxicillin to enhance therapeutic potential. Characterization techniques (X-ray diffraction [XRD], Fourier-transform infrared (FTIR), scanning electron microscopy [SEM], and UV–Vis) confirmed successful functionalization and improved physicochemical properties. The crystallite size increased from 17.29 ± 3.44 to 20.47 ± 4.17 nm, while the bandgap widened from 2.33 to 2.40 eV, indicating enhanced electronic interactions. Antioxidant activity was significantly improved, with 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging reaching 97.87% and β-carotene bleaching inhibition at 95.47% (175 μg/mL). The antibiofilm efficacy was notable, with inhibition rates of 90.24% for E. coli (250 μg/mL), 81.47% for S. typhimurium (175 μg/mL), and 87.68% for B. subtilis (250 μg/mL). In enzymatic inhibition studies, Amoxicillin@Ag/AgCl NPs showed neuroprotective potential, inhibiting acetylcholinesterase (AChE) (93.74% at 160 μg/mL) and butyrylcholinesterase (BChE) (97.41% at 80 μg/mL), highlighting their potential in Alzheimer's treatment. Additionally, they exhibited anti-inflammatory effects, inhibiting lipoxygenase (LOX) by 90.47% (120 μg/mL). To the best of our knowledge, this is the first report on the synthesis of Amoxicillin@Ag/AgCl NPs that simultaneously demonstrate strong antioxidant, antibiofilm, neuroprotective, and anti-inflammatory properties, underscoring their novelty as next-generation nanomedicines.

Effective treatment of abdominal hernia with synthetic implants requires a prosthetic material biologically and mechanically compatible with the tissue. The mechanical compatibility is particularly important because the human abdominal wall is a complex multilayer structure and its properties may have individual characteristics that are not fully known. To address this issue, we propose a novel approach to optimal implant design for hernia repair by modifying locally the implant thickness to adapt it to the applied loads. Compatibility criteria are translated to an objective function that is to be minimized in the optimization procedure. The objective function is designed to equalize and minimize forces at the tissue-implant interface and minimize implant deflection. This reduces vulnerability to failure without hindering functionality. The input data are taken from in vivo tests on human subjects performed using digital image correlation and applied to a computational model of the implant defined by means of the Finite Element Method. The results show that the material distribution varies across models with different properties in two perpendicular directions (i.e., orthotropy) and across individuals, suggesting the potential for patient-specific design of the implant and a patient-specific approach to hernia repair. This approach takes into account abdominal wall heterogeneity and anisotropy, which in practice may help to reduce the ventral hernia recurrence rate.

This study evaluated the effects of boron nanoparticles (BNPs) on the mechanical properties of two silicone elastomers, A-2000 and A-2006. Tensile, tear, hardness, and elongation tests were conducted in accordance with ASTM and ISO standards. A total of 180 specimens were prepared, comprising control groups without BNPs and experimental groups containing 1 and 3 wt% BNPs. Tensile and tear strength tests were performed using a device with a 1 kN capacity at a crosshead speed of 100 mm/min; hardness was measured using Shore A tests, and Atomic Force Microscopy (AFM) was employed to assess surface roughness. Tensile testing revealed that the A-2000 control group exhibited the highest tensile strength, with significant reductions observed in both BNP-incorporated subgroups. In A-2006, tensile strength decreased significantly with 1 wt% BNPs but partially recovered at 3 wt%. Tear strength in A-2000 significantly decreased at 1 wt% but returned to control levels at 3 wt%, whereas no statistically significant differences were observed among the A-2006 subgroups. Hardness significantly increased with 3 wt% BNPs in A-2000 and with both 1 and 3 wt% BNPs in A-2006. Regarding elongation, A-2000 showed no significant change compared with the control, although the 1 and 3 wt% groups differed significantly from each other. In A-2006, both 1 and 3 wt% BNP groups showed significant reductions in elongation compared with the control. Overall, A-2000 exhibited superior tensile and tear strength, while A-2006 demonstrated greater elongation capacity. These findings indicate that BNP incorporation depends on both the elastomer type and concentration, with potential trade-offs between improved hardness and decreased flexibility. Both A-2000 and A-2006 remain viable options for maxillofacial prostheses, although optimization of BNP concentration is essential to balance strength, durability, and flexibility.

In an effort to improve bone response, predictably regenerate lost tissue, and provide an anatomically pleasing ridge contour for biomechanically favorable and prosthetically driven implant placement, guided bone regeneration (GBR) procedures have been indicated. This study provides the first direct in vivo comparison of the biocompatibility of an experimental porcine-derived collagen membrane (CMI, Regenity Biosciences, Paramus, NJ, USA) and a commercially available bovine-derived collagen membrane (CopiOs, ZimVie, Palm Beach Gardens, FL, USA) in a beagle mandibular model for the purposes of GBR. Four bilateral defects of 10 mm × 10 mm through the mandibular thickness were placed in each of n = 16 adult beagle dogs. Defects were filled with a deproteinized porcine-derived particulate graft and were covered either with CMI or CopiOs to allow compartmentalized healing. Animals were euthanized after 4, 8, 12, or 16 weeks post-operatively (n = 4 beagles/time point). Bone regenerative capacity, graft, and soft tissue presence were evaluated by histomorphometric and microtomographic analyses. Outcome variables were compared using a mixed model analysis with fixed factor variables of time and material. Qualitatively, no histomorphological differences in healing were observed between the membrane groups at any time point. Histomorphometrically, CMI and CopiOs presented statistically significant differences in bone (mean ± SD: 38.27% ± 15.20 vs. 17.43% ± 15.49, respectively, p = 0.016) and soft tissue presence (mean ± SD: 50.88% ± 11.83 vs. 68.21% ± 16.98, respectively, p = 0.026) at 8 weeks. These results might influence treatment timing in clinical practice, by enabling early implant placement or shorter healing intervals. No significant differences were detected in these parameters at any other healing time point (p > 0.05). CMI and CopiOs showed no signs of adverse immune response and led to similar trends in bone regeneration after 16 weeks of permitted healing. Both membranes minimized soft tissue infiltration and maintained defect stability over the observed healing periods without adverse events such as inflammation and/or foreign body reaction.