A 3D network structured reduced graphene oxide/PtRu alloyed composite catalyst in-situ assembled via particle-constructing method

Au@Pd nanozyme-mediated catalytic therapy: a novel strategy for targeting tumor microenvironment in cancer treatment

BACKGROUND

Breast cancer, with its high morbidity and mortality rates, is a significant global health burden. Traditional treatments-surgery, chemotherapy, and radiotherapy-are widely used but come with drawbacks such as recurrence, metastasis, and significant side effects, including damage to healthy tissues. To address these limitations, new therapeutic strategies are being developed. Peroxidases (POD) can catalyze excess H2O2 in the tumor microenvironment to generate reactive oxygen species (ROS), which induce cancer cell apoptosis by disrupting redox homeostasis and modulating apoptosis-related proteins. However, natural enzymes face challenges like poor stability, high cost, and sensitivity to environmental conditions, limiting their application in breast cancer treatment. Nanozymes, nanomaterials with enzyme-like activity, offer a promising alternative by overcoming these limitations.

METHODS

In this study, we successfully prepared Au@Pd nanozymes with peroxidase activity by depositing metallic Pd on Au nanoparticles (Au NPs) synthesized using a trisodium citrate reduction method and ascorbic acid reduction. The in vitro validation was conducted through a series of experiments, including ROS detection, flow cytometry, CCK-8 assay, DNA damage assessment, live/dead cell staining, Western blot (WB), and qPCR. Tumor treatment was performed via tail vein injection of the drug, followed by HE staining of the treated tissues and biochemical analysis of the blood.

RESULTS

Au@Pd nanozymes can effectively accumulate at the tumor site through the EPR effect and exert peroxidase-like activity, catalyzing the excess H2O2 in the tumor microenvironment to produce ROS. This triggers apoptosis pathways and DNA damage, leading to the downregulation of the anti-apoptotic protein Bcl-2, upregulation of the pro-apoptotic protein Bax, and induction of apoptosis-related genes, demonstrating strong anti-tumor effects.

CONCLUSIONS

This study developed an efficient nanozyme-mediated catalytic therapy strategy targeting the tumor microenvironment for the treatment of breast cancer cells.

Dicyanamide Anion-Based Ionic Liquid-Functionalized Graphene-Supported Pt Catalysts for Boosting Methanol Electrooxidation

As an environmentally friendly energy technology, direct methanol fuel cells (DMFCs) meet the needs of sustainable development. Herein, novel dicyanamide anion-based (N(CN)₂^-) ionic liquid (IL)-functionalized reduced graphene oxide (rGO)-supported Pt catalysts are synthesized via a facile one-pot room temperature reduction method, which show a boost in methanol oxidation performance compared with Pt/rGO. The mass activities of the as-prepared Pt/emimN(CN)₂/rGO (863.6 mA mg^-1_Pt) and Pt/epyN(CN)₂/rGO (524.9 mA mg^-1_Pt) are about five and three times higher than that of Pt/rGO (178.6 mA mg^-1_Pt), and about six and four times higher than that of Pt/C (140.2 mA mg^-1_Pt), respectively. The participation of ILs significantly improves the CO poisoning resistance, stability, and activity for methanol oxidation of catalysts. The relationship between the structures and conductivities of diverse ILs and the performance of Pt catalysts are studied systematically. These findings may offer a promising prospect of ILs in DMFCs.