Journal of Materials Chemistry B最新文献

To address the rapid systemic clearance and limited targeting efficiency of particulate drug delivery systems, localized drug delivery systems combining injectable hydrogels and nanoparticles have emerged as a promising alternative. This study introduces a photo-responsive multi-scale composite hydrogel platform for localized delivery of chemotherapeutic agents. In this study, doxorubicin-loaded photothermal nanoparticles (DOX@polydopamine@P(NIPAAm-co-AM), abbreviated as DPN) are prepared via a free radical polymerization route. Subsequently, they are incorporated into a thermosensitive PLGA–PEG–PLGA matrix to obtain the composite hydrogel (termed DPNP). The injectable DPNP hydrogel rapidly undergoes gelation as the temperature rises to the physiological level and forms an in situ depot at the targeted tissue due to the thermoresponsive sol–gel transition of the PLGA–PEG–PLGA matrix. Upon exposure to near-infrared light, polydopamine generates heat that induces a volume-phase transition of the DPN nanogels, thereby producing a precisely light-triggered release profile. The drug release rate can reach 87%. In the absence of light, the system maintains a sustained basal release rate. Overall, we have successfully developed a localized and spatiotemporally regulated drug delivery system capable of rapid NIR-triggered release coupled with sustained long-term release. The tumor suppression rate was 98.77%, providing a promising platform for precision-controlled cancer therapy.

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.

Detonation-derived nitrogen-enriched detonation soot is reported herein as a promising candidate for non-enzymatic glucose sensing. The intrinsic impurities and heteroatom composition present within detonation soot act as electrocatalytic centers, facilitating efficient glucose oxidation. These findings highlight the potential of detonation-synthesized nanodiamonds as cost-effective and stable electrode materials for glucose sensing applications.

Gd-based contrast agents (GBCAs) with high relaxivity and favorable in vivo profiles are greatly desired yet present formidable challenges, especially on the molecular side. Here, we report a macrocyclic GBCA (namely Gd-IN-DO3A) characterized by the presence of an isonicotinate group (IN) tethered asymmetrically to the macrocyclic DO3A scaffold with the pyridine-N coordinated to the Gd³⁺ center. Our studies reveal that it shows an assembly-dissociable feature with human serum albumin (HSA) by moderate non-covalent interactions at Sudlow site II, showing a binding fraction of ∼50%, a binding constant (K_a) of 316 M⁻¹ and a dissociation constant (K_D) of 5.24 µM. This dynamic GBCA-HSA adduct ensures a high r₁ relaxivity of ∼23.75 mM⁻¹ s⁻¹ in 4.5% HSA (∼8.29 mM⁻¹ s⁻¹ in water) and enables favorable pharmacokinetic properties, with a blood half-life (t_1/2) of ∼3.2 h, desirable biodistribution and excretion, and superior lesion imaging performance. These results suggest that developing novel GBCAs bearing an assembly-dissociable feature with albumin via moderate non-covalent interactions could serve as a compensation approach for enhanced magnetic resonance imaging and in vivo profiles.

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.

Surface-enhanced Raman scattering (SERS) is a powerful analytical technique for molecular detection, offering high sensitivity and label-free identification. However, achieving reproducible and highly efficient SERS substrates remains a challenge. In this study, we developed a silver nanoparticle (AgNP)-embedded silk fibroin film as a multifunctional SERS platform. An in situ light-mediated reduction method was employed to synthesize AgNPs within a silk fibroin matrix, ensuring uniform nanoparticle distribution and strong plasmonic activity. Silver nanoclusters were observed to be formed in the silk matrix at lower concentrations of silver nitrate in silk fibroin solution. These nanoclusters acted as hotspots for SERS activity of the formed films and for the detection of protein biomarkers. The biocompatibility, optical properties, and wettability of the silk silver films were systematically characterized, demonstrating their potential for biosensing applications. Notably, the integration of AgNPs within the silk film enhanced SERS signals due to strong plasmonic coupling and nanoparticle–matrix interactions. To explore their biomedical utility, specifically in tissue engineering, where it is important to achieve temporal control over biomolecules for manipulating cell growth, proliferation and differentiation, we evaluated the platform for the detection of bone morphogenetic protein-2 (BMP-2), a critical biomarker in osteogenesis and cancer diagnostics. The silk silver films exhibited ultrasensitive and specific SERS responses, enabling the detection of BMP-2 at low concentrations. The synergy between the plasmonic properties of AgNPs and the biocompatibility of silk provides a versatile and tunable platform for biosensing, particularly in disease diagnostics and biomedical applications. This study highlights the potential of silk silver films as next-generation SERS substrates for early biomarker detection in real time for advancing tissue engineering applications.

Glioblastoma multiforme, the most aggressive brain malignancy, exhibits poor prognosis and intrinsic resistance to standard therapies, often limited by systemic toxicity and suboptimal efficacy. Berberine, a bioactive isoquinoline alkaloid, exhibits potent anti-glioma activity; however, its clinical utility is hindered by rapid metabolism, low bioavailability, and poor penetration across the blood–brain barrier. To overcome these challenges, we designed folic acid-functionalized BSA nanoparticles for targeted and sustained delivery of berberine to glioma cells. Folic acid modification facilitated receptor-mediated endocytosis via overexpressed folate receptors in glioblastoma cells, enhancing specificity and therapeutic potency. FA–BER–BSA NPs were synthesized via desolvation method using EDC instead of glutaraldehyde to mitigate potential human and environmental toxicity. The resulting nanoparticles exhibited a spherical morphology with an average diameter of 120–140 nm, as confirmed by FESEM and TEM analyses. Comprehensive physicochemical characterization, conducted through XRD, DSC, FTIR, and UV-vis spectroscopy, confirmed the successful conjugation of folic acid to the nanoparticles. In vitro studies in LN229 cells demonstrated that FA–BER–BSA NPs exhibited higher cytotoxicity compared to BER-BSA NPs, accompanied by enhanced inhibition of cell migration, ROS generation, nuclear condensation, mitochondrial membrane potential disruption, apoptosis induction, and cell cycle arrest. Fluorescence microscopy and flow cytometry confirmed efficient internalization of FA–BER–BSA NPs in (FR)+ LN229 cells and 3D tumor spheroids, with negligible effects on (FR)− HaCaT cells. Notably, FA–BER–BSA NPs significantly suppressed the growth of 3D spheroids compared to BER. These findings highlight the potential of the nanoparticles as a promising targeted therapeutic agent for glioblastoma, offering enhanced tumor-specific delivery and improved anticancer efficacy.

The hypoxic and immunosuppressive tumor microenvironment (TME) significantly impedes reactive oxygen species (ROS) generation and suppresses the release of tumor-associated antigens, thereby limiting the induction of immunogenic cell death (ICD) and compromising therapeutic outcomes. Reprogramming this immunosuppressive TME is therefore crucial for effective cancer treatment. In this study, we developed a heterojunction-engineered MXenzyme-based platform (NbMR@EDM) to address this challenge. By leveraging the exceptional photothermal conversion capability and multi-enzymatic activities of Nb₂C MXene, and further enhancing its physiological stability and catalytic performance through in situ loading of MnO_x and metal-polyphenol encapsulation, we constructed a robust nanoplatform for synergistic photothermal/enzymatic/immunotherapy. This system effectively catalyzes the generation of a cytotoxic ROS storm within tumor cells, while its catalase-like activity alleviates tumor hypoxia and augments type-II photodynamic therapy. Subsequently, the induced ICD, together with the released TLR7/8 agonist R848, promotes dendritic cell maturation and enhances T-cell infiltration, ultimately reversing the immunosuppressive TME. This work provides a promising strategy for TME reprogramming and demonstrates significant antitumor efficacy in triple-negative breast cancer, highlighting its broad potential in advancing cancer immunotherapy.