Gold nanoparticle-loaded multifunctional Ti3C2Tx MXene nanosheets fabricated by in situ reduction to effectively enhance their catalase-like activity for tumor therapy

Abstract

Designing novel, high-performance nanozymes is essential for developing biocatalytic therapeutics, a promising therapeutic approach. In this work, gold nanoparticles (Au NPs)-loaded Ti₃C₂T_x MXene nanosheets (Ti₃C₂T_x-Au) are prepared by in situ reduction and then modified with polyethylene glycol (PEG) to obtain a multifunctional anticancer cascade enzyme system, Ti₃C₂T_x-Au-PEG (TANP). The photothermal properties of Ti₃C₂T_x in the near-infrared (NIR) region allow for its use in photothermal therapy (PTT). The complexation of Au NPs with Ti₃C₂T_x significantly enhances the catalase-like (CAT) activity of TANP, while incubating the glucose oxidase (GOx)- and peroxidase (POD)-like properties of TANP. The strong CAT-like property of TANP allows it to decompose the H₂O₂ overexpressed in cancer cells into O₂, which alleviates hypoxia. It can also be used for glucose catabolism in cancer cells, i.e., GOx-like induced starvation therapy. H₂O₂, one of the glucose degradation products, can be supplied to TANP to generate O₂ and POD-like induced reactive oxygen species (ROS) generation to kill cancer cells. Density functional theory (DFT) calculations provide possible reasons for the enhanced CAT-like activity of Ti₃C₂T_x-Au. Photothermal can enhance enzyme activity and can also be combined with biocatalytic therapy to achieve good therapeutic effects.