Fabrication, GSH-responsive drug release, and anticancer properties of thioctic acid-based intelligent hydrogels

Biotinylated Self-Assembled Cytarabine Nano-Prodrug with Enhanced Targetability and Anticancer Efficacy: An In Vitro Study

In this study, we developed a tumor-target biotinylated cytarabine (Ara-C) prodrug linked through a disulfide bond (Bio-SS-Ara). To enhance its delivery, Bio-SS-Ara was found to be able to self-assemble into uniform nanoparticles (BSSA NPs) with an average particle size of 230 nm, a PDI of 0.265, a critical micelle concentration (CMC) of 5.89 μg/mL, and a zeta potential of -15 mV. BSSA NPs showed good storage stability over 6 weeks. In a glutathione-rich environment, the drug release of BSSA NPs was more rapid than that of BCCA NPs. Concentration-dependent size analysis suggested that BSSA NPs were formed through a dynamic, reversible assembly process. Cellular uptake studies showed significantly increased internalization of BSSA NPs compared to free Ara-C, with enhancements of 4.13-fold in HeLa cells and 3.13-fold in A549 cells. Cytotoxicity assays demonstrated enhanced efficacy, reducing the IC50 by 67.9% in HeLa and 45.2% in A549 cells. The migration rate of HeLa cells was reduced to 14% after BSSA NPs treatment, in comparison with Ara-C treatment, and nuclear shrinkage and fragmentation were observed, indicating the potential of BSSA NPs to limit tumor progression and induce apoptosis. Importantly, no hemolysis was observed in BSSA NPs-treated groups, confirming their good biocompatibility. These findings suggest that BSSA NPs represent a promising strategy for targeted cancer therapy, combining enhanced drug delivery, antitumor efficacy, and biocompatibility.

High α-lipoic acid-loaded hollow mesoporous prussian blue nanozymes for targeted therapy of nasopharyngeal carcinoma in mice

This study successfully constructs a tumor-targeting α-lipoic acid-loaded hollow mesoporous prussian blue nanozyme (AHPRzyme) for targeted therapy of nasopharyngeal carcinoma in mice. In these nanozymes, Arg-Gly-Asp (RGD) acts as a targeting ligand, enabling effective targeting of tumor cells. Additionally, AHPRzyme exhibits multiple anti-tumor mechanisms: ① The prussian blue nanozymes in AHPRzyme have catalase (CAT) activity, which decomposes H2O2 in human nasopharyngeal carcinoma CEN2 cells into non-toxic H2O, reducing H2O2 levels and minimizing damage to normal cells. The released O2 helps alleviate the hypoxic environment of the tumor, inhibiting lactate production due to hypoxia and consequently suppressing tumor growth. ② The prussian blue nanozymes also have peroxidase (POD) activity, which catalyzes H2O2 in tumor cells to generate ·OH, a reactive oxygen species, leading to tumor cell apoptosis. ③ The α-lipoic acid structure in AHPRzyme contains disulfide bonds that react with GSH, depleting excess glutathione (GSH) in tumor cells, disrupting the oxidative stress balance within the cells, and making them more sensitive to reactive oxygen species, thereby increasing tumor cell apoptosis. In summary, AHPRzyme can inhibit tumor cell growth and promote tumor cell apoptosis by improving the tumor microenvironment, achieving the goal of anti-nasopharyngeal carcinoma therapy.

Redox-sensitive hydrogel based on hyaluronic acid with selenocystamine cross-linking for the delivery of Limosilactobacillus reuteri in a DSS-induced colitis mouse model

Disrupted gut microbiota homeostasis is an important cause of inflammatory colitis. Studies have shown that effective supplementation with probiotics can maintain microbial homeostasis and alleviate colitis. Here, to increase the viability of probiotics in the harsh gastrointestinal environments and enable targeted delivery, a redox-sensitive selenium hyaluronic acid (HA-Se) hydrogel encapsulating probiotics was developed. HA was modified with selenocystamine dihydrochloride and crosslinked by an amide reaction to generate a redox-sensitive hydrogel with stable mechanical properties, a low hemolysis rate and satisfactory biocompatibility. The HA-Se hydrogel exhibited suitable sensitivity to 10 mM GSH or 100 μM H2O2. The encapsulation of Limosilactobacillus reuteri (LR) in the HA-Se hydrogel (HA-Se-LR) significantly increased the survival rate of the probiotics in simulated gastric and intestinal fluid. HA-Se-LR administration increased the survival rate of mice with dextran sulfate sodium (DSS)-induced colitis, significantly alleviated oxidative stress and inflammation, and increased the effect of LR on microbiota α diversity. These results indicate that the HA-Se hydrogel constructed in this study can be used as a delivery platform to treat colitis, expanding the targeted applications of the natural polymer HA in disease treatment and the administration of probiotics as drugs to alleviate disease symptoms.

Disulfiram-loaded CuO2 nanocarriers for enhanced synergistic chemodynamic chemotherapy

Disulfiram (DSF) metabolites exhibit antitumor properties when bound to Cu2+. This combination also promotes the generation of reactive oxygen species (ROS), ultimately leading to tumor cell death. In this study, CuO2 served as a carrier for DSF, forming a dual-drug delivery system with Cu2+ and DSF encapsulated in polydopamine (PDA). In the final delivery system, CuO2 (DSF-CuO2@PDA) was hydrolyzed at the tumor site, releasing both Cu2+ and H2O2. Cu2+ reacts with DSF metabolites to form Bis(diethyldithiocarbamate)-Cu (CuET), which triggers a Fenton-like reaction that generates ROS. Chemotherapy and chemodynamic therapy exhibited significant tumor-suppressive capabilities, with an inhibition rate of 61 %. In addition, the DSF-CuO2@PDA complex demonstrated superlative tumor-targeting ability and biocompatibility.

Advances in Hydrogels of Drug Delivery Systems for the Local Treatment of Brain Tumors

The management of brain tumors presents numerous challenges, despite the employment of multimodal therapies including surgical intervention, radiotherapy, chemotherapy, and immunotherapy. Owing to the distinct location of brain tumors and the presence of the blood-brain barrier (BBB), these tumors exhibit considerable heterogeneity and invasiveness at the histological level. Recent advancements in hydrogel research for the local treatment of brain tumors have sought to overcome the primary challenge of delivering therapeutics past the BBB, thereby ensuring efficient accumulation within brain tumor tissues. This article elaborates on various hydrogel-based delivery vectors, examining their efficacy in the local treatment of brain tumors. Additionally, it reviews the fundamental principles involved in designing intelligent hydrogels that can circumvent the BBB and penetrate larger tumor areas, thereby facilitating precise, controlled drug release. Hydrogel-based drug delivery systems (DDSs) are posited to offer a groundbreaking approach to addressing the challenges and limitations inherent in traditional oncological therapies, which are significantly impeded by the unique structural and pathological characteristics of brain tumors.

Nanotechnological Approaches to Enhance the Potential of α-Lipoic Acid for Application in the Clinic

α-lipoic acid is a naturally occurring compound with potent antioxidant properties that helps protect cells and tissues from oxidative stress. Its incorporation into nanoplatforms can affect factors like bioavailability, stability, reactivity, and targeted delivery. Nanoformulations of α-lipoic acid can significantly enhance its solubility and absorption, making it more bioavailable. While α-lipoic acid can be prone to degradation in its free form, encapsulation within nanoparticles ensures its stability over time, and its release in a controlled and sustained manner to the targeted tissues and cells. In addition, α-lipoic acid can be combined with other compounds, such as other antioxidants, drugs, or nanomaterials, to create synergistic effects that enhance their overall therapeutic benefits or hinder their potential cytotoxicity. This review outlines the advantages and drawbacks associated with the use of α-lipoic acid, as well as various nanotechnological approaches employed to enhance its therapeutic effectiveness, whether alone or in combination with other bioactive agents. Furthermore, it describes the engineering of α-lipoic acid to produce poly(α-lipoic acid) nanoparticles, which hold promise as an effective drug delivery system.

Injectable smart stimuli-responsive hydrogels: pioneering advancements in biomedical applications

Hydrogels have established their significance as prominent biomaterials within the realm of biomedical research. However, injectable hydrogels have garnered greater attention compared with their conventional counterparts due to their excellent minimally invasive nature and adaptive behavior post-injection. With the rapid advancement of emerging chemistry and deepened understanding of biological processes, contemporary injectable hydrogels have been endowed with an "intelligent" capacity to respond to various endogenous/exogenous stimuli (such as temperature, pH, light and magnetic field). This innovation has spearheaded revolutionary transformations across fields such as tissue engineering repair, controlled drug delivery, disease-responsive therapies, and beyond. In this review, we comprehensively expound upon the raw materials (including natural and synthetic materials) and injectable principles of these advanced hydrogels, concurrently providing a detailed discussion of the prevalent strategies for conferring stimulus responsiveness. Finally, we elucidate the latest applications of these injectable "smart" stimuli-responsive hydrogels in the biomedical domain, offering insights into their prospects.