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

Exosomes, nanoscale extracellular vesicles, have garnered substantial interest in biomedical research owing to their critical roles in intercellular communication, diagnostics, and regenerative therapeutics. Among biomolecules investigated in regenerative medicine, exosomes are one of the most intensively researched. While no clinical trials have yet been conducted to assess their regenerative efficacy in human dental applications, a rapidly growing body of preclinical research highlights their therapeutic potential in oral and maxillofacial regeneration. Dental tissue-derived exosomes, most notably from dental pulp stem cells, periodontal ligament stem cells, gingival fibroblasts, and stem cells from exfoliated deciduous teeth, have shown the ability to promote regeneration of bone, the periodontal ligament and other supporting tissues. Moreover, these exosomes have demonstrated potential roles in modulating orthodontic tooth movement and alleviating temporomandibular joint disorders. Preclinical studies included in this review consistently reported improved bone regeneration outcomes, such as increased bone volume, mineralization, and osteogenic marker expression following exosome application. Importantly, exosomes have also exhibited potent immunomodulatory effects, notably through inhibition of inflammation in bone defects and periodontitis models. The therapeutic versatility of exosomes is further reflected in their application across several fields of dentistry, such as periodontitis therapy, pulp regeneration, alveolar bone regeneration, and immune regulation. The majority of the studies highlighted the anti-inflammatory, pro-angiogenic, and osteoinductive features of exosomes, derived from diverse cellular sources. These promising preclinical outcomes collectively indicate that exosome-based therapies hold strong potential for translation into clinical dental practice, offering a novel, cell-free, and biologically targeted strategy to craniofacial tissue regeneration.

Photoaging is a skin damage process resulting from prolonged ultraviolet (UV) exposure. Poly-l-lactic acid (PLLA), as a common injectable filler in skin esthetics and anti-aging, is reported to be capable of promoting the synthesis of collagen. However, the potential mechanism remains unclear. This study focused on clarifying the potential molecular mechanisms by which PLLA promotes collagen synthesis in UV-induced skin photoaging. Hs68 cells exposed to UVB (30 mJ/cm²) were employed to simulate skin photoaging. PLLA at different concentrations (100–800 μg/mL) was used to treat cells. The expression of c-Jun, c-Fos, ERK, JNK, and p38 mitogen-activated protein kinase (MAPK) was accomplished by the qPCR. The ROS level and the activities of MMP-1 and MMP-13 were assessed by corresponding kits. The AP-1 activity was evaluated by the dual-luciferase reporter system. Inhibition of MAPK was accomplished by transfection of specific inhibitors. PLLA significantly enhanced the cell viability and reduced ROS production in UVB-exposed Hs68 cells. PLLA contributed a lot to counteracting MMPs activation and collagen degradation induced by UVB exposure. Inhibiting the MAPK pathway not only reduced AP-1 activity but also weakened the activities of MMP-1 and MMP-13. Additionally, the pronounced decline in cell viability and collagen production, as well as the excessive ROS and cell damage, could be ameliorated by inhibiting MAPKs. PLLA significantly alleviated the photoaging of Hs68 cells induced by UVB and effectively promoted the production of collagen via the MAPK/AP-1 pathway.

Peripheral nerve injuries (PNIs) are challenging to treat and call for advanced biomaterial-based approaches to support effective regeneration. This study explores the potential of a novel plant-based regenerative biomaterial, Astragalus microcephalus extract (AMEx)-functionalized zinc oxide nanoparticles (ZnO NPs) in promoting sciatic nerve repair in a rat model. ZnO NPs were synthesized via chemical and green methods, with AMEx acting as a capping and reducing agent. Comprehensive characterization (XRD, SEM, DLS, Zeta potential, UV-Vis DRS, FTIR, TGA) confirmed the structural and optical properties of the nanomaterials. The neuroregenerative potential was assessed in rats through histological and behavioral analyses, including sciatic function index (SFI), walking track analysis, and the hot plate test. A total of 35 animals were divided into five groups (n = 7 each), and treatments (5 mg/kg ZnO or AMEx/ZnO; 40 mg/kg AMEx) were administered for 1 week. AMEx/ZnO treatment significantly enhanced myelin sheath formation, reduced fibrosis and vacuolization, and improved motor coordination compared to controls. Myelin sheath thickness increased by approximately 35%–40% relative to the negative control, and muscle atrophy was reduced by ~25%–30%, indicating superior structural recovery. Behavioral assessments revealed superior functional recovery, with the AMEx/ZnO group exhibiting significantly improved SFI values from week 4 onward (p < 0.05) and the shortest pain-response latencies in the hot plate test by week 8 (~40%–50% faster than the negative control; p < 0.05). The observed therapeutic benefits were attributed to bioactive phytochemicals in AMEx, which modulated oxidative stress, inflammation, and neurotrophic signaling, facilitating structural integrity and neuroprotection. This study underscores the potential of AMEx/ZnO as an innovative regenerative biomaterial for peripheral nerve repair, leveraging the synergistic effects of phytochemicals and ZnO NPs. By integrating nanotechnology and bioactive plant compounds, AMEx/ZnO offers a biocompatible, neuroprotective, and pain-modulating approach to nerve regeneration. The significant improvements in SFI, pain latency, myelin sheath thickness, and muscle mass provide strong support for its therapeutic promise. Future studies should further elucidate its molecular mechanisms to advance clinical translation in biomaterial-based nerve regeneration therapies.

This follow-up in vitro study aimed to determine how collagen-coated substrates modulate the response of human fibroblasts to femtosecond laser irradiation—using our previously published uncoated-glass data as control—with particular focus on cell viability, morphology, and autofluorescence of metabolic cofactors. Human fibroblasts cultured on collagen-coated glass plates were exposed to an 800 nm, 90 fs laser (320 mW average power, 0.07 cm² spot) for 5, 20, or 100 s, delivering radiant exposures of 22.6, 90.6, and 452.9 J/cm² (photon densities 6.4 × 10¹⁸, 2.6 × 10¹⁹, and 1.3 × 10²⁰ photons/cm²), respectively. Cell viability, morphology, and autofluorescence were assessed by laser-scanning microscopy at 0, 1, 25, and 45 h post-irradiation. Compared to uncoated glass, collagen-coated substrates showed markedly accelerated and more severe damage, particularly after 100 s exposure, including extensive cellular swelling, cytoplasmic granularity, and pyknotic nuclei. Autofluorescence intensity increased dramatically on collagen-coated surfaces, with spectral signatures consistent with elevated contributions from endogenous flavins, lipopigments, and porphyrins. These findings demonstrate that the presence of a collagen extracellular matrix substantially enhances fibroblast susceptibility and metabolic stress responses to femtosecond laser irradiation, highlighting a critical role of the substrate in ultrafast laser–cell interactions relevant to laser-based therapeutics, tissue remodeling, and wound healing.

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.