Zhejiang da xue xue bao. Yi xue ban = Journal of Zhejiang University. Medical sciences最新文献

Myocardial infarction is a cardiovascular disease with high morbidity and mortality rates. Hydrogel biomaterials mimicking the extracellular matrix have recently been shown to demonstrate excellent biocompatibility, low immunogenicity, favorable biodegradability, and multifunctionality, showcasing significant potential for treatment of myocardial infarction. Hydrogels can provide mechanical support to the damaged myo-cardium, alleviating pathological remodeling. Moreover, their porous structure makes them ideal carriers for localized and sustained drug delivery. Hydrogels derived from various matrices-including polysaccharides, polypeptides, proteins, decellularized extracellular matrix, and synthetic polymers-exhibit distinct properties in terms of biocompatibility, mechanical performance, and drug delivery capacity. These hydrogels support tissue regeneration and enable targeted release of diverse therapeutics, meeting the various therapeutic demands for myocardial repair. In the infarcted myocardial microenvironment, endogenous signals such as low pH, specific enzyme expression, and elevated levels of reactive oxygen species can trigger responsive drug release from hydrogels, while external physical stimuli-such as ultrasound, light, and magnetic fields-can also be employed to precisely control the release process, thereby enhancing therapeutic efficacy and reducing systemic side effects. This review summarizes recent advances in hydrogel-based drug delivery systems for treatment of myocardial infarction, focusing particularly on the characteristics and advantages of different hydrogel materials for myocardial repair. Furthermore, the responsive drug release behavior of hydrogels is analyzed in the context of the cardiac injury microenvironment, providing a reference for future research.

The tumor microenvironment (TME) is a critical determinant of tumor initiation, progression, and therapeutic response, and serves as the basis for designing precise delivery strategies. Its marked heterogeneity underscores the need for a more comprehensive understanding of its composition and function. In addition to the extensively studied classical TME, emerging evidence highlights the significant roles of the tumor mechanical microenvironment and the tumor microbial microenvironment in modulating treatment efficacy. These non-classical dimensions not only independently influence tumor behavior but also interact dynamically with classical TME components. Mechanical cues within the TME, including matrix stiffness and solid stress, significantly affect drug distribution and treatment efficacy, suggesting that mechanical remodeling represents a potential strategy to enhance therapeutic outcomes. Concurrently, tumor-associated microbiota and their metabolites participate in immune regulation and metabolic reprogramming, contributing to tumor development and offering novel therapeutic targets. Moreover, recent advances have broadened our understanding on the multilayered regulatory landscape of the TME through the investigation of previously underappreciated factors such as neural regulation, metabolic niche dynamics, spatiotemporal heterogeneity, and epigenetic modulation. This review systematically summarizes the characteristics of these diverse TME dimensions and highlights recent progress in targeted delivery strategies, to facilitate the development of more personalized and effective anticancer therapies.

Objectives: To fabricate an injectable composite microsphere hydrogel reinforced with silk fibroin/hyaluronic acid microspheres, achieving synergistic enhance-ment of mechanical robustness and biofunctionality.

Methods: Methacrylated hyaluronic acid (HAMA) and thiolated silk fibroin (TSF) were synthesized. Monodisperse microspheres generated via microfluidics were UV-cured (420 nm) through thiol-ene click reaction. These microspheres were embedded in a TSF/HAMA matrix to form photo-cured composites. The grafting rate of TSF and HAMA was characterized by H1-NMR; particle size distribution of microsphere hydrogels in soybean oil was observed by optical microscopy; gel point of composite microsphere hydrogels was determined by advanced extensional rheometer; microscopic morphology of microsphere hydrogels was observed by scanning electron microscopy; elemental distribution of microsphere hydrogels was detected by X-ray energy dispersive spectroscopy; tunability of composite microsphere hydrogels was observed by inverted confocal microscopy; mechanical properties of composite microsphere hydrogels were tested by compression testing; swelling ratio, degradation rate and water retention rate of composite microsphere hydrogels were measured by gravimetric method. Cytotoxicity of the composite microsphere hydrogels was determined by Calcein-AM/propidium iodide dual staining and CCK-8 assay; cell migration capability was observed by scratch assay.

Results: The grafting rates of HAMA and TSF was 48.03% and 17.99%, respectively. Microsphere hydrogels with particle sizes of (43.3±1.2), (78.1±3.0), and (130.8±1.9) μm were prepared. The gel time of the composite microsphere hydrogels was 48-115s. The laser confocal imaging confirmed dynamic regulation characteristics of the composite microsphere hydrogels. The compressive strength of the composite microsphere hydrogels reached 22.7 kPa and maintained structural integrity at 40% strain after 20 compression cycles. The composite microsphere hydrogels exhibited differential deswelling behaviors in simulated physiological environments, and reducing microsphere particle size could significantly enhance its stability under moist conditions. The degradation rate of the composite microsphere hydrogels was (49.1±0.9)% after 200 h, and water retention rate was maintained at 40%-60% after 96 h. Biocompatibility assays confirmed >95% cell viability and unimpaired cell migration abilities.

Conclusions: The TSF/HAMA composite microsphere hydrogel developed in this study has characteristics of rapid fabrication, adjustable mechanical properties, enhanced environmental stability and excellent biocom-patibility, thus providing a new material solution for tissue repair and regenerative medicine.

Adoptive cell transfer (ACT) shows significant efficacy against hema-tological malignancies but is limited in solid tumors due to poor homing, immunosuppre-ssion, and potential toxicity. Biomaterials spanning from nano- to macroscales-including nanoparticles, microspheres/micropatches, and hydrogels-offer unique advantages for ex vivo cell engineering, in vivo delivery, and modulation of the tumor microenvironment. Specifically, nanoparticles enable gene delivery, artificial antigen-presenting cell engi-neering, and immune microenvironment remodeling. Microspheres/micropatches improve immune cell expansion, targeted activation, and localized retention. Hydrogels enhance ACT via in situ genetic engineering, 3D culture support, and cytokine co-delivery. This review summarizes advances in biomaterial-enhanced ACT, highlighting their potential to improve delivery efficiency, amplify antitumor responses, and reduce toxicity. These insights may accelerate the clinical translation of ACT for solid tumors.

Neutrophils, as the most abundant immune cells in the human body, possess the inherent ability to rapidly migrate to sites of inflammation and infection. Novel drug delivery systems leveraging neutrophils capitalize on their natural targeting and phagocytic capabilities to achieve precise drug delivery. Efficient drug loading into neutrophils within neutrophil-based delivery systems can be achieved through physical adsorption, chemical conjugation, and phagocytosis. Design strategies emphasize carrier selection and targeting ligand design to enhance delivery precision. Compared to traditional drug delivery systems, neutrophil-based systems offer significant advantages, including excellent biocompatibility and strong tissue penetration. These properties can significantly improve drug bioavailability and reduce adverse reactions associated with non-target tissue accumulation. However, these systems also face several challenges that require resolution, such as difficulties in cell collection and preservation, the need for stability optimization, challenges in large-scale production, and a lengthy clinical translation cycle. In disease treatment applications, neutrophil-based drug delivery systems enable precise delivery of anti-cancer drugs to tumor sites, potentially disrupting immunosuppression of the tumor microenvironment and enhancing therapeutic efficacy. For brain diseases, their unique ability to cross the blood-brain barrier facilitates effective drug delivery. In chronic inflammatory diseases, neutrophil-based systems can precisely deliver anti-inflammatory agents to mitigate inflammation. Performance enhancements for neutrophil-based systems can be achieved by the development of novel nanomaterials and optimization of targeting ligand affinity, thereby improving the accuracy and efficiency of drug delivery. This review comprehensively explores the design strategies, advantages, challenges, and future directions of neutrophil-based drug delivery systems. It summarizes research progress in disease treatment applica-tions, aiming to offer key insights for the development of novel drug delivery systems and advance precision medicine and targeted therapy.

Nano-drug delivery systems offer significant benefits, including high specific surface area, structural and functional diversity, and surface modifiability. When formulated as inhalable nano-formulation, these can not only enable precise pulmonary drug delivery but also improve pulmonary bioavailability and enhance thera-peutic efficacy. Currently, there are four types of inhalable nano-formulations for the treatment of respiratory diseases. Inhalable liquid preparations exhibit facile manufactur-ability and broad applicability yet demonstrate compromised stability during aerosolization. Through structure optimization, surface modification, dispersion medium optimization and device improvement, the atomization stability of nano-drug has been enhanced. Pressurized metered-dose inhalers loaded with nano-drugs face technical challenges: conventional propellants may dissolve nano-carriers, whereas co-solvents like ethanol compromise delivery efficiency. Thus, it is necessary to develop novel propellants that provide thermodynamic stability and optimal delivery performance. Nano-drug formulations in dry powder inhalers exhibit relatively favorable physical stability, however, pulmonary delivery efficiency and nanoparticles integrity during processing remain problematic. Pulmonary delivery efficiency can be improved by employing strategies such as blending excipients to promote the re-dispersibility of nanoparticle agglomerates, optimizing the design of microcarrier, and innovating preparation processes. In contrast, soft mist inhalers are an ideal option for pulmonary delivery of nano-drugs owing to their gentle and efficient atomization properties to maintain nano-drug integrity. This review summarizes the inhalable nano-formulations and focuses on challenges and proposed strategies encoun-tered in integrating nano-drug delivery systems and inhalation drug delivery systems. It aims to provide references for the future development of inhalable nano-formulations.

Research in photodynamic therapy (PDT) primarily focuses on enhancing light penetration depth, improving oxygen supply, and optimizing photosensitizer delivery. Notably, the delivery efficiency of the photosensitizer is crucial for therapeutic efficacy. Carboxyl-substituted phthalocyanines, as important photosensitizing molecules, possess unique chemical modification sites that enable direct targeted delivery or integration into diverse delivery systems. Their synthesis predominantly employs mixed- or cross-condensation, selective synthesis, and axial modification strategies to introduce carboxyl groups. However, their inherent hydrophobicity significantly hinders effective delivery. To address this limitation, modifications with peptides or quaternary ammonium salt derivatives may facilitate precise delivery to tumor cells and pathogens. With advances in nanotechnology, carboxyl-substituted phthalocyanines can serve as key photosensitizer modules, effectively integrated into nanomaterials such as biomacromolecules, inorganic metals, and polymers for both active and passive delivery. Recently, researchers have exploited the π-π stacking and other intermolecular forces among carboxyl-substituted phthalocyanine molecules to drive their self-assembly into nano-micelles, enabling carrier-free delivery or co-delivery with other therapeutic agents for synergistic effects. This review systematically outlines the synthesis strategies for carboxyl-substituted phthalo-cyanines. Taking mono-carboxyl-substituted zinc phthalocyanine as a model molecule, the performance of three delivery modalities were compared: single-molecule targeted delivery, nanocarrier-encapsulated delivery, and carrier-free self-assembled delivery, in terms of PDT efficacy, biocompatibility, and imaging-guided tracing capabilities, to provide a systematic technical framework for the rational design of novel modular photosensitizers and to advance the clinical translation of PDT in precision oncology and anti-infective therapy.

Messenger RNA (mRNA) therapeutics involve delivering in vitro transcribed mRNA into specific cells to produce target proteins for the treatment or prevention of diseases. However, the development of mRNA therapeutics relies largely on mRNA delivery systems. Lipid nanoparticles (LNPs) represent the most widely used mRNA carriers in clinical applications. Composed of ionizable lipids, zwitterionic phospholipids, cholesterol, and polyethylene glycol-lipids, LNPs can address critical challenges in mRNA drug development, such as poor in vivo stability and the difficulty in crossing biological barriers. Ultimately, LNPs enable safe, efficient, and targeted mRNA delivery to the liver, lung, spleen, and other organs. This review outlines the roles of the four lipid components in LNPs for mRNA delivery. It then introduces targeted mRNA delivery to various organs/tissues such as the liver, lung, spleen, pancreas, bone marrow, and placenta, using strategies such as antibody modification, lipid structure alteration, and specialized administration routes. Additionally, this review discusses the applications and challenges of LNP-based mRNA therapeutics in disease treatment, aiming to provide insights for the clinical translation of mRNA therapies and for further innovations in LNP delivery systems.

Objectives: To investigate the effect of in vitro cultured calculus bovis (ICCB) on cerebral ischemia/reperfusion injury (CIRI) and its mechanism.

Methods: A CIRI rat model and a cell model were induced by middle cerebral artery occlusion (MCAO) in Sprague Dawley rats and oxygen glucose deprivation/reperfusion (OGD/R) in BV2 cells, respectively. The CIRI rat model was evaluated using the modified neurological severity score (mNSS), brain water content, and cerebral infarction volume after 1.5 h of ischemia followed by 72 h of reperfusion. Histopathological changes in the cortex and hippocampal CA1 region were observed with hematoxylin and eosin staining. Microglial polarization and NOD-like receptor thermal protein domain associated protein (NLRP) 3 inflammasome expression in the cortex were examined by immunofluorescence. BV2 cell viability was measured via MTT assay after treatment with ICCB and Nigericin. The expressions of NLRP3, ASC, caspase-1 proteins and inflammatory cytokines were detected with Western blotting in OGD/R treated BV2 cells (0.5 h OGD+24 h reperfusion) and in cells pretreated with Nigericin for 24 h.

Results: ICCB treatment significantly improved neurological function, reduced cerebral infarct volume and brain water content, and mitigated pathological damage in the cortical and hippocampal CA1 regions of rats subjected to CIRI (all P<0.05). ICCB promoted the transition of cortical microglia from M1 to M2 phenotypes and suppressed NLRP3 activation in microglial cells (all P<0.01). ICCB significantly down-regulated the expression of NLRP3, ASC, and caspase-1 proteins, and reduced the secretion of IL-18 and IL-1β in BV2 cells of OGD/R model (all P<0.01). In addition, Nigericin significantly reversed the salvage effect of ICCB on model cells (both P<0.01) and the modulation of inflammatory cytokines (P<0.05).

Conclusions: ICCB exerts a protective effect against CIRI by mitigating neuroinflammation, through the reduction of M1 microglial polarization, promotion of M2 conversion, and suppression of the NLRP3/ASC/caspase-1 signaling pathway.