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

Tracheal defects caused by trauma, malignancy, congenital anomalies, or prolonged intubation remain a significant clinical challenge, particularly for long-segment replacements where conventional solutions such as autologous tissue grafts, allografts, and synthetic implants have shown limited long-term success. Tissue-engineered tracheas (TETs) have emerged as a promising alternative by integrating advances in scaffold design, fabrication techniques, and biological augmentation. Recent progress in scaffold materials, including decellularized natural matrices, synthetic polymers, and hybrid composites, has led to the development of constructs that better mimic the structural and functional properties of the native trachea. Fabrication techniques such as 3D printing, electrospinning, and cell sheet engineering have enabled the production of anatomically precise and patient-specific grafts. In parallel, biological strategies aimed at promoting vascularization, accelerating epithelialization, and modulating immune responses have significantly improved graft integration and long-term functionality. Despite these advances, the clinical translation of TETs remains hindered by challenges related to achieving adequate vascularization, complete epithelialization, and immune modulation. Additionally, regulatory approval requires rigorous preclinical validation, standardized manufacturing protocols, and long-term safety assessments to ensure consistent clinical outcomes. As these challenges are addressed through ongoing research, TETs hold the potential to revolutionize the treatment of long-segment tracheal defects by providing functional, durable, and biologically integrated airway replacements.

Chronic wounds pose a significant health challenge that affects millions of people worldwide. Traditional treatments, such as antibiotics, have limitations, including the development of antibiotic resistance. Antimicrobial peptides (AMPs) are gaining attention due to their broad-spectrum antimicrobial activity, including against multidrug-resistant strains. TetraF2W-RR, a specific AMP, has shown promise in combating various bacteria, particularly when incorporated into wound dressings. Another emerging antimicrobial approach is photodynamic therapy (PDT), which utilizes photosensitizers (PS), such as chlorin e6 (Ce6), activated by light to destroy bacteria without inducing resistance. Ce6 offers advantages such as rapid photosensitization, selective accumulation in target areas, and minimal side effects, making it a favorable candidate for PDT in wound treatment. Furthermore, combining AMPs with PDT offers a combined approach for enhanced antibacterial activity. Although hydrogel dressings, particularly GelMA, provide an ideal environment for wound healing, GelMA lacks intrinsic antimicrobial properties and can promote bacterial growth. Therefore, combining GelMA with antimicrobial strategies is crucial. Herein, to investigate the influence of different strategies on antimicrobial efficiency, two distinct approaches were developed for the functionalization of GelMA with AMP and Ce6. This is the first comparative study of different AMP and PS conjugation strategies for enhancing PDT on hydrogels. In the first approach, the Ce6@AMP conjugate was immobilized onto GelMA (GelMA/Ce6@AMP). In the second approach, AMP and Ce6 were separately conjugated to GelMA via EDC/NHS chemistry (GelMA/AMP/Ce6). GelMA/Ce6@AMP hydrogels significantly lost their antibacterial activity, whereas GelMA/AMP/Ce6 hydrogels maintained strong antimicrobial and anti-biofilm effects, which clearly demonstrates the impact of conjugation strategy on antibacterial performance.

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.