Journal of Materials Chemistry B最新文献

Various protein species exhibit great potential in industrial and therapeutic applications; however, these applications are still limited owing to their fragility to high temperatures. In this work, a biomimetic mineralization strategy was used to construct a condensed protein–calcium phosphate hybrid structure to improve the thermostability of proteins. The mineral ion precursor used in the conventional method was replaced with a biomimetic nanocluster of calcium phosphate capped with triethylamine to provide an extra linking site on the phosphate end of the mineral. A higher protein concentration could be integrated into this new hybrid, forming a homogeneous system of condensed structures. The spectrum of the hybrid indicated enhanced hydrogen bond interactions between the protein and mineral, resulting in improved thermostability of the incorporated protein. Applying this method, lysozyme and catalase could maintain more than 75% of their enzyme activity after heating to 120 °C, and this new hybrid mineral outperformed the conventional biomineralization strategy for long-term preservation of proteins. This research presents an alternative biomimetic platform for protein preservation and provides insights into protein–mineral interactions, paving the way for better control and modification of proteins in the future.

g-C₃N₄, as a novel photocatalytic antibacterial material, has been widely studied due to its broad-spectrum antibacterial properties, strong photocatalytic activity, excellent chemical and thermal stability, high versatility, and low cost. However, there is still a lack of comprehensive summaries regarding its antibacterial applications. This article reviews the preparation methods, antibacterial principles, and enhancement strategies of g-C₃N₄, and discusses its current status and prospects in antibacterial applications. Firstly, the principles of preparing g-C₃N₄ using methods such as thermosetting polymerization, solvothermal synthesis, electrochemical deposition, chemical vapor deposition, and microwave-assisted synthesis are introduced. Then, starting from the antibacterial mechanisms of g-C₃N₄, strategies for enhancing antibacterial performance through surface modification, elemental doping, and constructing heterojunctions are discussed. Additionally, the antibacterial applications of g-C₃N₄ in fields such as water purification, wound infection, textiles, and packaging materials are summarized, showcasing its broad application prospects. We believe that this review will open new avenues for the development of g-C₃N₄ antibacterial materials and expand their use into a wider range of applications.

Developing an effective hydrogel dressing to protect against bacterial infection and exhibit synchronously integrated mechanical robustness and self-healing properties is highly desirable for infected wound healing in clinical practice. Inspired by the extracellular matrix (ECM), we constructed a dynamic and nondynamic synergy network to prepare a natural polymer-based composite hydrogel dressing for infected wound healing. The aldehyde groups of oxidized hyaluronic acid were bonded with amino groups of carboxymethyl chitosan and polyacrylamide (PAAm) via the Schiff base reaction to form a dynamic crosslinked network, mimicking the dynamically reversible glycosaminoglycan network in the ECM. A nondynamic PAAm network was created via UV-irradiated free radical polymerization, analogous to the covalently crosslinked collagen network in the ECM. The elaborate dynamic and nondynamic synergy network enabled the resultant hydrogel dressing to exhibit high mechanical strength and fatigue resistance, excellent self-healing properties and the remarkable antibacterial activity. An in vivo Staphylococcus aureus-infected full-thickness wound model revealed that our natural polymer-based composite hydrogel dressing significantly reduced inflammation and promoted the formation of granulation tissues and angiogenesis to achieve accelerated infected wound healing. This study offers a valuable reference for designing and fabricating multifunctional hydrogel dressings for treating wound infection.

Ferrite nanoparticles, known for their enzyme-like catalytic activity, have gained significant attention as innovative nanozymes for various catalysis medicine applications. However, the relationship between catalytic activity and ultrasmall ferrite nanoparticle composition remains unclear, which hinders the development of ferrite-based nanozymes with high catalytic performance. Here, we have synthesized a series of ultrasmall ferrite nanozymes for studying their composition dependent peroxidase (POD)-like activity. Initially, their size and surface charge were regulated to assess their impact on POD-like activity. The results indicate that smaller ferrite nanozymes with a negative charge exhibited superior activity when using TMB as the substrate. Subsequently, we examined the ultrasmall ferrite nanozymes with the same size and surface charge but different compositions (CoFe₂O₄, MnFe₂O₄, and γ-Fe₂O₃), and comprehensively investigated the effect of composition on POD-like activity. The results show that the POD-like activity is closely related to the composition of the ultrasmall ferrite nanozymes and the activity order towards TMB is found to be CoFe₂O₄ > MnFe₂O₄ > γ-Fe₂O₃. By comparing the catalytic performance of nanoparticles with different compositions, the influence of composition on their activity is elucidated. Furthermore, we determined that the optimal pH and temperature for the POD-like catalytic activity of ultrasmall CoFe₂O₄ nanozyme were pH = 4–4.5 and 30 °C. Under these optimal catalytic conditions, the ultrasmall CoFe₂O₄ nanozymes exhibited a higher POD-like activity, resulting in increased tumor cell staining intensity. This suggests that ultrasmall CoFe₂O₄ nanozymes may serve as a viable alternative to horseradish peroxidase for immunohistochemical staining applications. This work provides experimental evidence for designing efficient ultrasmall ferrite catalysts for nanozyme catalysis medicine applications.

Parkinson's disease (PD) poses a formidable neurodegenerative challenge, particularly with a burgeoning aging demographic. The pathological hallmarks of PD—the degeneration of dopaminergic neurons and formation of Lewy bodies from α-synuclein (α-Syn) aggregates—underscore the need for innovative diagnostic and therapeutic strategies. Nanozymes, with their enzyme-like activities and antioxidant features, offer a triad of benefits: early biomarker diagnosis, penetration of the blood–brain barrier (BBB) for targeted delivery, and intervention in core pathological mechanisms. This review navigates the strategic application of nanozymes in PD, evaluating their clinical potential against the backdrop of existing challenges. We explore their role in identifying early biomarkers, facilitating targeted drug delivery across the BBB, and addressing the central pathogenic processes of PD. The discussion concludes with considering the hurdles in integrating nanozymes into clinical practice and prospects for future development.

Photodynamic therapy (PDT) has emerged as a promising treatment for drug-resistant bacterial infections by avoiding the abuse of antibiotics. However, most PDTs rely on reactive oxygen species (ROS) generated via a type II process, which limits the antimicrobial effect in a hypoxic microenvironment. Herein, we reported phycocyanin functionalized selenium nanoparticles (Se@PC NPs) for type I photodynamic antibacterial therapy and wound healing. Se@PC NPs can generate hydroxyl radicals and superoxide radicals under visible light irradiation, effectively disrupting the bacterial membrane structure and demonstrating sterilization against Gram-positive and Gram-negative bacteria. Notably, in vivo experiments and histological tests have demonstrated that Se@PC NPs effectively eliminate bacteria, regulate proinflammatory cytokines against bacteria-induced inflammation, promote collagen deposition, and accelerate wound healing. Consequently, this study provides a strategy for the design of highly effective type I photosensitizers for photodynamic antibacterial therapy.

The clinical success of metal-based anticancer agents can be achieved by developing not only an efficient metallodrug but also a suitable drug delivery system (DDS). Although spatiotemporal delivery, enhancing the efficacy, and alleviating toxicity are achievable, modifying the mechanism of action of metallodrugs using a nano DDS remains scarce. With all this in mind, a series of cyclometalated ruthenium(II) half-sandwich complexes of the type [(η⁶-p-cymene)Ru(L)Cl] Ru(1)–Ru(4), where L is 2-phenylquinoline (L1), 2-(thiophen-2-yl)quinoline (L2), 4-methyl-2-phenylquinoline (L3), or 2,4-diphenylquinoline (L4), have been isolated and characterized by analytical and spectroscopic methods. Ru(1) and Ru(2) have been structurally characterized, and their coordination geometries around the ruthenium(II) are described as pseudo-octahedral geometry. Only the Ru(1) complex, which exhibited substantial cytotoxicity in non-cancerous cells and low cytotoxicity in breast cancer cells, is encapsulated into a hybrid nanosystem comprising phospholipid and polydiacetylene. The Ru(1)-entrapped nanoassembly (PDL-Ru(1)) is found to show pH-induced emission and higher release of the complex in a simulated tumor environment than in a physiological environment. Even though such a halochromic character failed to benefit cell imaging, the nanocarrier-mediated delivery has been proven to improve the cytotoxicity of Ru(1) in breast cancer cells, modulate the mode of cell death, and reduce toxicity in normal cells. Zebrafish embryo toxicity studies revealed that polydiacetylene-lipid nanoassembly could be useful for in vivo biocompatibility applications of ruthenodrug candidates.

Stimulus-responsive drug delivery systems (SRDDS) are advanced mechanisms that release drugs in response to specific bodily microenvironments or signal receptors, triggering targeted physiological reactions. These systems integrate the chemical properties of drugs with the organism's environment and immune response, modulating the metabolic and growth conditions of target cells or organs to exert therapeutic effects. Initially focused on anti-inflammatory and antioxidant functions via enzymes like SOD and CAT, SRDDS have evolved with advancements in tumor microenvironment research and bioinformatics, becoming a cornerstone for precision medicine and solid tumor treatment. The integration of omics studies, particularly proteomics, has further expanded SRDDS applications, providing precise targets for new drug development and enhancing personalized treatments for hematologic malignancies. Biocompatible nanomaterials, with their excellent stability, have emerged as ideal carriers for SRDDS, enabling precise drug delivery through targeted interactions with membrane proteins. This combination of nanotechnology and proteomics represents a technological revolution, offering significant practical value in the precise treatment of diseases.

Hydrogel microneedles (HMNs) are promising transdermal delivery systems. We prepared HMNs using a mixture of poly(vinyl alcohol) (PVA), sacran, and quaternised sacran (Q-sacran) crosslinked with citric acid (CA). The impact of the polymer composition, crosslinking time, and annealing temperature on the HMN properties was studied. Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA) revealed the formation of networks composed of polymers containing CA and the corresponding HMNs. The highest swelling degree of HMNs was 440 ± 23%. Mechanical testing confirmed that HMNs were strong enough to penetrate the skin. The PVA/sacran HMNs were durable with a maximum force of 43 ± 1.2 N. These HMNs penetrated the Parafilm®-simulated skin up to 630–760 μm, while PVA/Q-sacran HMNs exhibited a penetration depth of 500 μm. The biocompatibility of HMNs was confirmed through cytotoxicity assays using L929 fibroblasts and B16F1 melanoma cells. The doxorubicin-loaded HMNs exhibited a controlled release profile and a potent anticancer activity against B16F1 melanoma cells. This work suggests that the PVA/sacran and PVA/Q-sacran HMNs can be used as new tools for transdermal drug delivery as mechanically tunable and biocompatible systems.

Current knee osteoarthritis (KOA) treatments mainly provide symptom relief rather than cartilage repair. While regenerative medicine using stem cell therapy holds promise for tissue regeneration and joint function restoration, a significant challenge lies in the efficient and minimally invasive delivery of stem cells to target sites and ensuring high regenerative efficacy. This challenge stems from issues such as cell leakage and reduced cellular activity post-transplantation. In this study, we report the development of an injectable polysaccharide hydrogel (termed Ald-HA/Suc-CS), which is compatible with cells and tissues, and will be suitable to support the proliferation of human adipose-derived stem cells (hADSCs) for cartilage regeneration. The hydrogel is formed on-site at the defect site of articular cartilage by mixing two injectable polymer solutions at physiological temperature post-injection. During the gelation process, hADSCs contained in one of the polymer solutions are encapsulated in the hydrogel. The hydrogel is tailored to create a desired microenvironment with mechanical properties, pore size, and degradation rate suitable for supporting hADSC viability and function. We demonstrated that nearly all of the encapsulated hADSCs remained viable 14 days post-injection and exhibited increased expression of chondrogenic differentiation genes compared to those cultured on 2D surfaces. This hydrogel holds great promise to improve the efficacy of KOA treatment and is potentially applicable to other cell-based therapies.