Journal of Materials Chemistry B最新文献

Owing to their high aspect ratio of length to diameter, large surface area, large pore size, and high molecular orientation, electro-spun (e-spun) nanofibrous mats have been explored as effective nanomaterials for various applications, including wound dressings and healing materials. Of particular interest are poly(vinyl alcohol) (PVA) e-spun nanofibers that are required to be crosslinked with covalent organic bonds to retain their structural integrity in wound environments. However, conventionally crosslinked PVA nanofibers present critical drawbacks, typically including the uncontrolled release of encapsulated drug molecules. Herein, we report a robust approach that centers on the integration of boronic ester (BE) chemistry into the design of PVA e-spun nanofibers crosslinked through the formation of degradable BE crosslinks. A new phenyldiboronic acid with an ethylene spacer, which is biocompatible and has a lower pK_a value, is proved to be an effective crosslinker to fabricate BE-crosslinked PVA e-spun nanofibrous materials. In response to multiple stimuli such as reactive oxygen species, alkaline pH, and glucose (common features of wounds), the fibers degrade through the cleavage of BE bonds or transesterification, confirmed by our model spectroscopic study with a small molecular boronic ester. Such wound-induced degradation ensures the controlled/enhanced release of antibiotics active against both Gram-positive and Gram-negative bacteria. These results, combined with their non-hemolysis and non-cytotoxicity properties, demonstrate that the approach is versatile for the fabrication of well-defined BE-crosslinked PVA e-spun nanofibers that are dimensionally stable but degrade to release antibiotics in wounds, thus exhibiting a great promise as smart wound dressing materials.

Reactive oxygen species (ROS) play a dual role in human physiology, acting as essential signaling molecules at physiological levels while driving oxidative damage and disease pathogenesis when overproduced. This review systematically examines the molecular mechanisms of ROS-induced tissue injury and the evolution of antioxidant materials. Conventional antioxidants and emerging nano-antioxidants are discussed here, with particular focus on nanozyme-engineered nanomaterials mimicking natural enzyme activities. This article details design strategies for metal-based, carbonaceous, and polymeric nanozymes, their catalytic ROS scavenging mechanisms (including superoxide dismutase-, catalase-, and peroxidase-like activities), and therapeutic applications in inflammatory diseases, organ protection, and chronic disorders. Through a comparative analysis of material performance and biological effects, we highlight the advantages of nanozymes in terms of stability, multifunctionality, and targeted delivery. Current challenges regarding biocompatibility optimization, in vivo fate prediction, and clinical translation are critically discussed. This work provides strategic insights for developing next-generation antioxidant nanomaterials with enhanced therapeutic precision and safety profiles.

Traditional tumor treatments focus on treating the location of the lesion, while immunogenic cell death (ICD) triggers systemic anti-tumor immunity and inhibits tumor metastasis. Therefore, there is a need to develop an inducer that amplifies ICD. Here, methotrexate (MTX) and MoO₂ were loaded into a Cu²⁺-doped iron-based targeted metal–organic framework Fe–NH₂-MIL-101 with nano-enzymatic activity to establish a novel ICD amplifier. The photothermal agent MoO₂ generates heat under near-infrared (NIR) light excitation, inducing tumor ablation. Simultaneously, the released Mo⁺ combines with Fe²⁺ and Cu⁺ in the system, synergistically enhancing electron transfer efficiency based on the bimetallic system. Combined with thermal effects, this approach cooperatively elevates glutathione peroxidase (GPx)-like and peroxidase (POD)-like activities. This catalytic cascade depletes glutathione through Fenton-like reactions while amplifying hydroxyl radical (˙OH) generation, thereby remodeling the tumor microenvironment (TME), potentiating chemodynamic therapy (CDT), and triggering ICD. The chemotherapeutic agent MTX not only exerts direct cytotoxic effects but also serves as an inducer of ICD. In vitro and in vivo experiments have shown that the resulting synergistic treatment model based on the combination of CDT, photothermal therapy (PTT), and chemotherapy guided by T₂-MRI imaging will amplify the ICD effect, enhance tumor treatment, and is expected to achieve the prevention of metastasis and recurrence of tumors and to realize the integration of tumor diagnosis, treatment, and prevention.

This investigation addresses the pressing concern of tumor hypoxia, a phenomenon that significantly compromises the efficacy of photodynamic therapy (PDT) and chemotherapy in oncological treatment. This investigation presents a novel polymersome-based system, denoted as IR808/DOX@Psome/MnO₂, which concurrently mitigates tumor hypoxia and enables triple-modal therapy, encompassing PDT, chemodynamic therapy (CDT), and chemotherapy, alongside dual-modality imaging capabilities for precise cancer treatment. Activated by the acidic and glutathione-rich tumor microenvironment (TME), MnO₂ nanoenzymes first catalyze the conversion of H₂O₂ to O₂, which reduces hypoxia and generates cytotoxic hydroxyl radicals (˙OH) and enhances CDT. The concurrent release of IR808 and doxorubicin (DOX) ensures spatiotemporally synchronized triple-modal therapy. It not only improves the efficacy of photodynamic therapy but also reverses chemotherapy resistance by inhibiting the drug efflux pathway. Furthermore, the system's activatable magnetic resonance imaging (MRI) and fluorescence imaging capabilities facilitate real-time visualization of tumor targeting and therapy progression, addressing a significant unmet need in precision oncology. The modular design of the platform permits customization with various therapeutic agents, thereby expanding its relevance to other diseases associated with hypoxia.

Combined photothermal and photodynamic therapy is a promising strategy for the treatment of triple-negative breast cancer (TNBC) as it can accurately target tumor tissues and improve therapeutic efficacy. However, its efficacy is still insufficient owing to the heat resistance resulting from the upregulation of heat shock protein 90 (HSP90) and diminished reactive oxygen species (ROS) levels due to the accumulation of its client protein hypoxia-inducible factor-1α (HIF1α). Herein, SNX2112 (HSP90 inhibitor) and IR825 (photosensitizer) are loaded into a pH-responsive nano-micelle for efficient photothermal and photodynamic therapy. SNX2112 inhibits HSP90 activity to reduce heat resistance for enhanced photothermal therapy. Furthermore, HIF1α accumulation is reduced to increase ROS production to amplify photodynamic therapy efficacy. Consequently, the combined therapy enhanced by inhibiting HSP90-HIF1α effectively suppresses tumor growth via synergistic effects, with high photothermal conversion and ROS productivity under mild temperature (42 °C). Furthermore, using SNX2112 improves the efficacy of the combined photothermal and photodynamic therapy, showing its eminent potential in TNBC treatment.

Accelerating wound healing poses a significant challenge in clinical practice, necessitating the exploration of innovative strategies. The development of biomaterials with tissue repair and regenerative properties represents a forefront approach to addressing this challenge; however, the functional characteristics and application methods of these materials remain limited. In this context, a novel bioactive micro carrier (Bio-MC) was developed from egg white hydrogel microspheres (EWMs) which served as a bio-niche incorporating adipose-derived stem cells (ADSCs). This formulation capitalizes on the intrinsic tissue reparative capabilities of stem cells, allowing for the sustained release of multiple growth factors. These factors, via paracrine signaling, promote the proliferation and migration of neighboring cells, thereby creating an environment that supports wound healing. Upon application to wound sites, Bio-MCs exhibited significant effectiveness in enhancing the healing process by promoting tissue regeneration, increasing collagen deposition, and facilitating vascularization. The paracrine signaling mediated by Bio-MCs has the potential to exert lasting beneficial effects on cells in a comprehensive and physiologically relevant manner. In comparison to conventional growth factor treatments, the Bio-MC offers enhanced application versatility and functional attributes, indicating substantial promise in the field of tissue repair and regeneration and representing a noteworthy advancement in the clinical management of wounds.

Retraction of ‘Biocompatible dextran-coated gadolinium-doped cerium oxide nanoparticles as MRI contrast agents with high T₁ relaxivity and selective cytotoxicity to cancer cells’ by A. L. Popov et al., J. Mater. Chem. B, 2021, 9, 6586–6599, https://doi.org/10.1039/D1TB01147B.

Biomaterials could influence the production and composition of cell derived extracellular vesicles (EVs), including osteoblast-derived EVs (OB-EVs), which are essential for cell-to-cell communication and hold potential for bone regeneration. Despite their promise, methods for enhancing OB-EVs yields, especially from 3D highly porous microfibrous polymeric scaffolds, remain limited. In this study, we cultured mouse osteoblasts cell line MC3T3-E1 on 3D melt electrowritten (MEW) medical grade polycaprolactone (mPCL) scaffolds and 2D tissue culture plates (TCPs) to compare EV yield, subtypes (small EVs, microvesicles, apoptotic bodies), and proteome profile using liquid chromatography coupled with Tandem mass spectrometry (LC/MS-MS). Our results revealed that OB cultured on MEW mPCL scaffolds significantly increased small EVs yield, with increased particles of small EVs and reduced apoptotic bodies. Notably, two 30 × 30 mm, 0.8 mm-thick MEW mPCL scaffolds (5.07 × 10⁸ sEVs per scaffold) produced the same sEVs yield comparable to that of a T175 TCP flask (9.37 × 10⁸ sEVs per flask). The LC-MS/MS results showed that MEW mPCL sEVs were enriched for 34 proteins associated with tight junction, cell adhesion, gap junction, proteasome, apoptosis and complement pathways. Key proteins such as tubulin superfamily members, myosin heavy chain 9, ezrin, complement 3, CD9, Decorin, and Biglycan were identified, all potentially contributing to tissue repair and regeneration. These findings suggest that 3D MEW mPCL scaffolds not only enhanced OB-sEVs production but also enriched sEVs-protein profiles, particularly those involved in cell–cell junctions and phagosome secretion, suggesting their strong potential in bone tissue engineering.

Valvular heart disease (VHD) is a leading cause of cardiovascular morbidity and mortality. Polymeric heart valves (PHVs) offer potential solutions for treating VHDs but are limited by issues like thrombosis, calcification, and inflammation. Surface modification with antifouling coatings has been explored to mitigate those complications, but these coatings often exhibit poor stability and mechanical mismatch with elastomer substrates. Here, we report a fiber-reinforced zwitterionic elastomer composite for PHVs that simultaneously achieves antifouling surfaces and robust mechanical properties. This approach generates zwitterionic surfaces in situ and incorporates orthogonally aligned electrospun fibers for mechanical reinforcement. The resulting composite integrates excellent anticoagulant and antifouling properties with anisotropic mechanics, mimicking the structure and function of natural heart valve leaflets. It maintained chemical and mechanical integrity during 60-day serum immersion and withstood 100 million cycles in accelerated fatigue testing. In vivo evaluation using a rat subcutaneous implantation model revealed remarkable anti-inflammatory and anti-calcification effects.

Nanozyme-mediated catalytic therapy has emerged as a promising strategy for antitumor treatment, but it is imperative to further improve the catalytic efficiency of nanozymes to achieve potentiated antitumor efficacy. Single-phase high-entropy (HE) nanozymes with desirable enzyme-like catalytic activity and photothermal properties are appealing for enhancing the efficacy of catalytic therapy but have remained synthetically challenging. As a proof-of-concept demonstration, we herein prepared a single-phase HE Prussian blue analogue (HEPBA) using a conventional coprecipitation method. The HE mixing state enabled an exceptionally high photothermal conversion efficiency of 95.3% and a notable photothermally enhanced peroxidase-like catalytic activity. Therefore, the HEPBA-mediated photothermally enhanced catalytic therapy led to potentiated antitumor efficacy in both 4T1 and CT26 tumor-bearing mouse models. Thus, this work provides a rational and flexible platform for convenient and green preparation of biocompatible HE nanozymes and offers new perspectives on the use of HE nanozymes to improve the efficacy of catalytic therapy.