Journal of Materials Chemistry B最新文献

Effective intervention during the early phases of alkali burns is crucial for preventing progressive ocular damage and persistent inflammation, necessitating multifunctional solutions beyond single-component therapies. In this study, we developed a thermosensitive hydrogel based on L-arginine-modified hydroxybutyl chitosan (HBC_Arg). The hydrogel remains liquid at room temperature for easy application and undergoes thermosensitive gelation upon reaching the ocular surface temperature, ensuring prolonged retention and enhanced drug efficacy. The L-arginine modification enables the hydrogel to release nitric oxide (NO), which plays a critical role in modulating immune responses and controlling excessive inflammation. Additionally, EPL@MnO₂ nanosheets were encapsulated within the hydrogel for extended-release and enhanced scavenging of reactive oxygen species (ROS), reducing oxidative stress and mitigating alkali burn-induced damage. In a rat ocular alkali burn model, the composite HBC_Arg/MnO₂ hydrogel significantly suppressed inflammation, promoted re-epithelialization, enhanced stromal healing, and prevented corneal vascularization and opacity. This multifunctional hydrogel offers a promising advanced therapeutic strategy for treating acute ocular alkali burns, providing potential improvements in visual outcomes and overall quality of life.

The pathogenesis of Parkinson's disease (PD) is closely linked to the dysregulation of the clearance mechanism responsible for degrading misfolded proteins and malfunctioning organelles. Thus, maintaining a balance in autophagy is essential for managing PD. 17β-Estradiol (E2) is a specific calpain inhibitor, where the latter is upregulated in the PD brain and is responsible for inducing apoptosis. However, its peripheral toxicity and hydrophobicity hinder the investigation of its therapeutic potential. To address this, a neuroprotective and biocompatible chitosan nanoparticle, conjugated with DRD3 (Ab-ECSnps), is engineered to enable active targeting. The nanoformulation with immense potential for inhibiting calpain downregulates caspase 3-mediated apoptosis in the rotenone-treated PD model. Neuroprotection conferred by the nanoformulation is not solely due to apoptosis inhibition. Interestingly, the study reveals that the simultaneous induction of SIRT1- and LAMP2-mediated autophagy enhances autophagic flux, as supported by the upregulation of beclin, VPS34, and an increase in the number of lysosomes. The nanoformulation also clears pathological pSer129-synuclein and protects substantia nigra dopaminergic neurons in rotenone-induced Parkinson's disease models. This non-invasive, dopaminergic neuron-targeted delivery system, with its excellent biocompatibility, maintains a balance between apoptosis and autophagy, making it a promising approach for treating and preventing Parkinson's disease.

The widespread use of antibiotics to combat bacterial infections has now introduced significant new risks, particularly the continuous evolution of antibiotic-resistant strains. Consequently, the development of non-antibiotic antibacterial materials with high efficacy has become a major focus of research. Inspired by the morphology of sea urchins, we developed novel spiky microparticles (SMPs) fabricated using a natural fatty acid mixture (lauric acid and stearic acid) loaded with hemin chloride and silver nanoparticles (Ag NPs). The SMPs exhibited excellent photothermal and photodynamic properties. Under mild photothermal conditions (<45 °C), the SMPs achieved bactericidal rates exceeding 99.999% against Escherichia coli (E. coli) and over 99.9% against tetracycline-resistant enteroinvasive Escherichia coli (E. coli EIEC) within 10 min. Under near-infrared (NIR) light irradiation, there was a significant increase in the production of reactive oxygen species (ROS), ultimately achieving rapid and highly efficient bacterial eradication. Thus, we propose that SMPs synergistically disrupt bacterial cell membranes due to their urchin-inspired spiky structure and photothermal effects. Moreover, in a mouse model of bacterial wound infection, the SMPs demonstrated outstanding antibacterial efficacy. SMPs promoted wound tissue healing and suppressed the production of inflammatory cytokines, without inducing significant cytotoxicity. Therefore, this study presents a novel non-antibiotic tool for antibacterial therapy that offers a promising alternative approach for future clinical applications in treating bacterial infections.

The repair of severe bone defects remains a major clinical challenge. While our team has developed a Si-CaP material with significant potential for bone defect repair, its limitations in application convenience and poor degradability have hindered practical use. This study addresses these issues by creating an injectable light-curable P24–Si-CaP/GelMA (P-Si/G) composite hydrogel, further enhancing Si-CaP's osteogenic capacity through P24 peptide grafting. The composite material integrates P24–Si-CaP bio-ceramic powder (with surface-modified osteogenic peptide) into a GelMA hydrogel matrix. Experimental results demonstrate that when the Si-CaP/GelMA mass ratio is 20%, the hydrogel exhibits optimal gel-forming capability, mimics the inorganic/organic ratio of natural bone, and maintains excellent mechanical strength. Comprehensive characterization confirmed successful peptide conjugation, resulting in superior porosity and enhanced hydrophilicity. In vitro experiments showed that P-Si/G hydrogel significantly promotes the migration and osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs), evidenced by increased alkaline phosphatase activity, mineralization, and enhanced expression of osteogenic genes, with no observed cytotoxicity. In a rat cranial defect model, micro-CT and histological analysis revealed that the P-Si/G hydrogel group achieved significantly higher new bone formation and near-complete defect closure after 8 weeks of implantation compared to control, pure GelMA, and Si-CaP/GelMA groups, demonstrating in vivo safety. Comprehensive research demonstrates that the P24–Si-CaP/GelMA composite hydrogel exhibits outstanding biocompatibility, osteogenic induction, and bone-conducting properties, making it a highly promising injectable scaffold material for bone tissue engineering.

Skin injuries are common health concerns, with excessive reactive oxygen species (ROS) accumulation and inflammation in the wound area hindering the healing process. This underscores the urgent need for wound dressings with antioxidant and anti-inflammatory properties. In this study, inspired by the concept of waste valorization, carbon dots (CDs) were synthesized from corn stalks via a hydrothermal method. The results demonstrated that the CDs exhibited in vitro antioxidant activity and promoted the proliferation and migration of oxidative-damage fibroblasts. In vivo experiments further revealed that CDs reduced early-stage ROS accumulation, downregulated inflammation, and accelerated acute wound healing by promoting angiogenesis. Moreover, CDs effectively blocked the Toll-like receptor 4 (TLR4)-mediated nuclear factor kappa B (NF-κB) signaling pathway by promoting the dephosphorylation of IκBα and inhibiting the nuclear translocation of the p65 protein, thereby reducing the expression of pro-inflammatory cytokines. This study integrates agricultural waste utilization with biomedical material development, providing a dual solution to both the environmental issues associated with straw burning and the advancement of novel medical nanomaterials. It offers a strategic approach to agricultural pollution management and medical material innovation, strongly promoting the synergy between green chemistry and sustainable medicine.

Biocompatible shape-memory polymers are promising next-generation tissue engineering biomaterials that possess low toxicity, tunable mechanical strength, and programmable movement and actuation properties. To develop low cost, biocompatible and controllable shape-memory polymers, in this work, we prepared Poly(lactide-co-trimethylene carbonate) copolymers (PDTs) by incorporating flexible trimethylene carbonate (TMC) segments into the rigid poly(DL-lactide) (PDLLA) backbone via ring-opening copolymerization. The polymerization conditions were optimized through a systematic orthogonal experimental design. Compared with brittle PDLLA (initial elongation at break: ∼7%), the introduction of TMCs resulted in a significant improvement in the flexibility and ductility (elongation at break for PDT: 27.6–1288%). The thermal shape-memory/recovery rate of PDTs after cyclic deformation is more than 95%, the adjustable thermomechanical properties (T_g: 41.54–10.14 °C) enable their programmable thermal shape-memory function. Moreover, the introduction of TMCs could alleviate local acid degradation of PDLLA, improve the hydrophilicity (water contact angle reduced from 97.75° to 62.25°), and maintain excellent cytocompatibility (meet the medical grade standard). The results showed that PDT copolymers possess tunable elasticity, acid degradation resistance, and enhanced bioactivity, making them promising biocompatible thermal shape-memory elastomers for cell culture scaffold application towards tissue engineering.

Chirality is ubiquitous in nature, from the macroscopic to the microscopic. Natural bone has good hardness and toughness. It is composed of collagen and minerals and has chiral structures from the atomic scale to the macroscopic scale. It plays an important role in regenerative medicine. The design of bone-inspired bioscaffolds focuses on the surface roughness, three-dimensional structure and layered structure of the scaffold in order to build a microenvironment that is closest to the biological bone structure. However, the current bone repair materials do not reflect chiral structures. Therefore, this work selected lanthanum-doped hydroxyapatite/chitosan as the raw material, and added different percentages (10%, 30%, 50%, 70%, and 90%) of poly(L-lactide) (PLLA) to synthesize PLLHC-0, PLLHC-1, PLLHC-3, PLLHC-5, PLLHC-7 and PLLHC-9 chiral scaffold materials. Cell experiments have demonstrated that the cell survival rate and the relative activity of ALP at days 1, 7, and 14 in the PLLHC-5 scaffold group are 99.4%, 7.06, 8.64, and 11.84, respectively. In animal models, micro-CT analysis at 8 weeks showed that the BV/TV (%) of PLLHC-5 at 4 and 8 weeks reached 89.33% and 95.13%, which were significantly higher than those in other groups. All PLLHC-X scaffolds exhibited gradual degradation in vivo, while strongly promoting new bone formation and effective bone tissue repair. These results demonstrate that the PLLHC-5 scaffold exhibits the strongest osteogenic capability and represents a promising novel material for bone regeneration.

Mesenchymal stem cell (MSC) transplantation has emerged as an effective approach for treating articular cartilage damage. However, unintended hypertrophy and fibrosis of the regenerated cartilage tissue markedly undermine the therapeutic effect. Herein, a two-factor delivery system, E₆₀TK, based on the elastin-like protein ELP (VPGIG₆₀, E₆₀), co-delivering transforming growth factor β1 (TGF-β1) and kartogenin (KGN), was established to regulate stem cells from human exfoliated deciduous teeth (SHED)-directed cartilage differentiation and prevent cartilage hypertrophy and fibrosis. MTT and Alcian blue staining outcomes demonstrated that the fusion protein E₆₀T composed of E₆₀ and TGF-β1 was capable of effectively facilitating the proliferation and chondrogenic differentiation of SHED cells. Transmission electron microscope (TEM) and DLS findings revealed that the recombinant protein E₆₀T could load KGN at physiological temperature to form nanoparticles E₆₀TK, with particle sizes 241.2 ± 46.1 nm. The results of immunofluorescence and immunohistochemistry following chondrogenic differentiation suggested that E₆₀TK could efficiently induce the chondrogenic differentiation of SHED and significantly suppress the expression of type X collagen. The hyaluronic acid methacrylamide (HAMA) hydrogel loading E₆₀TK, E₆₀TK–HAMA, exhibited excellent biocompatibility, presented an interconnected porous architecture, and was completely degraded within 2 weeks in vitro. In vivo experiments indicated that the E₆₀TK–HAMA hydrogel with SHED encapsulated could effectively promote the formation of new cartilage and inhibit hypertrophy. All these results signified that E₆₀TK was an effective system for regulating the directed chondrogenic differentiation of SHED.

In vitro tissue models are critical to our understanding of human cell functions and interactions, but their limited complexity can hinder translation to in vivo systems. Bioengineered 3D tissues are gradually improving the capabilities of in vitro models, but the highly complex spatial organization of the human central nervous system (CNS) represents a particular challenge. Many 3D CNS models are limited to single cell types, while multicellular models generally lack control of cell organization, failing to recapitulate the regional specificity of cells in vivo. Using the dorsoventral spinal cord axis as a representative system, we generated a modular 3D silk-collagen protein composite scaffold system for the co-culture of dorsal (sensory) and ventral (motor) spinal cord progenitors in spatially discrete regions. Imaging showed the differentiation and maturation of both cell populations in distinct compartments, while bulk RNA sequencing confirmed the presence of combined motor and sensory markers in dorsoventral co-cultures, suggesting the potential for enhanced biological function in vitro. While developed for spinal cord modeling, our fabrication approach is generalizable to other tissues and regions of the CNS, enabling spatial control of multiple tissue compartments. We anticipate that long-term culture with added supportive cell types will foster greater complexity and open avenues for future functional and translational applications.

Wound dressing provides a temporary barrier membrane against hemostasis and external infections, and subsequently serves as an induction template to guide tissue remodeling, highlighting the need for an efficient and streamlined design to accelerate the healing process. Herein, we report the development of a mechanically robust, biocompatible gelatin-based hydrogel dressing integrated with pH-responsive nanofibers for sustained and targeted antibiotic release. The nanofibers, fabricated via electrospinning and loaded with amoxicillin, exhibited pH-triggered release profiles responsive to acidic wound environments. A Schiff base reaction between aldehyde-modified guar gum and gelatin conferred enhanced mechanical strength without compromising biocompatibility. This hybrid structure enabled a dual-stage release mechanism, characterized by an initial release from the nanofibers and subsequent sustained diffusion from the hydrogel matrix. This sequential release profile resulted in a more than 10-fold extension of the release duration compared to the control. In a murine wound infection model, the composite dressing significantly accelerated healing, reducing the healing time by at least 50%. Additionally, it suppressed inflammatory cytokines and promoted collagen deposition. This study presents a practical strategy for developing multifunctional, bioresponsive wound dressings with customizable release behavior tailored to the dynamic wound microenvironment.