3-Bromopyruvate-Loaded Ti3C2 MXene/Cu2O Nanosheets for Photoacoustic Imaging-Guided and Hypoxia-Relieving Enhanced Photothermal/Chemodynamic Therapy

Biodegradable MXene Quantum Dots with High Near-Infrared Photothermal Performance for Cancer Treatment

Photothermal therapy (PTT) offers significant potential in cancer treatment due to its short, simple, and less harmful nature. However, obtaining a photothermal agent (PTA) with good photothermal performance and biocompatibility remains a challenge. MXenes, which are PTAs, have shown promising results in cancer treatment. This study presents the preparation of Ti3C2 MXene quantum dots (MXene QDs) using a simple hydrothermal and ultrasonic method and their use as a PTA for cancer treatment. Compared to conventional MXene QDs synthesized using only the hydrothermal method, the ultrasonic process increased the degree of oxidation on the surface of the MXene QDs. This resulted in the presence of more hydrophilic groups such as hydroxyl groups on the MXene QD surfaces, leading to excellent dispersion in the aqueous system and biocompatibility of the prepared MXene QDs without the need for surface modification. The MXene QDs showed great photothermal performance with a photothermal conversion efficiency of 62.5%, resulting in the highest photothermal conversion efficiency among similar materials reported thus far. Both in vitro and in vivo experiments have proved the potent tumor inhibitory effect of the MXene QD-mediated PTT, with minimal harm to mice. Therefore, these MXene QDs hold a significant promise for clinical applications.

Free Radicals Generated in Perfluorocarbon-Water (Liquid-Liquid) Interfacial Contact Electrification and Their Application in Cancer Therapy

Electron transfer during solid-liquid contact electrification has been demonstrated to produce reactive oxygen species (ROS) such as hydroxyl radicals (•OH) and superoxide anion radicals (•O2-). Here, we show that such a process also occurs in liquid-liquid contact electrification. By preparing perfluorocarbon nanoemulsions to construct a perfluorocarbon-water "liquid-liquid" interface, we confirmed that electrons were transferred from water to perfluorocarbon in ultrasonication-induced high-frequency liquid-liquid contact to produce •OH and •O2-. The produced ROS could be applied to ablate tumors by triggering large-scale immunogenic cell death in tumor cells, promoting dendritic cell maturation and macrophage polarization, ultimately activating T cell-mediated antitumor immune response. Importantly, the raw material for producing •OH is water, so the tumor therapy is not limited by the endogenous substances (O2, H2O2, etc.) in the tumor microenvironment. This work provides new perspectives for elucidating the mechanism of generation of free radicals in liquid-liquid contact and provides an excellent tumor therapeutic modality.

CeO2 and Glucose Oxidase Co-Enriched Ti3C2Tx MXene for Hyperthermia-Augmented Nanocatalytic Cancer Therapy

Foreseen as foundational in forthcoming oncology interventions are multimodal therapeutic systems. Nevertheless, the tumor microenvironment (TME), marked by heightened glucose levels, hypoxia, and scant concentrations of endogenous hydrogen peroxide could potentially impair their effectiveness. In this research, two-dimensional (2D) Ti3C2 MXene nanosheets are engineered with CeO2 nanozymes and glucose oxidase (GOD), optimizing them for TME, specifically targeting cancer therapy. Following our therapeutic design, CeO2 nanozymes, embodying both peroxidase-like and catalase-like characteristics, enable transformation of H2O2 into hydroxyl radicals for catalytic therapy while also producing oxygen to mitigate hypoxia. Concurrently, GOD metabolizes glucose, thereby augmenting H2O2 levels and disrupting the intracellular energy supply. When subjected to a near-infrared laser, 2D Ti3C2 MXene accomplishes photothermal therapy (PTT) and photodynamic therapy (PDT), additionally amplifying cascade catalytic treatment via thermal enhancement. Empirical evidence demonstrates robust tumor suppression both in vitro and in vivo by the CeO2/Ti3C2-PEG-GOD nanocomposite. Consequently, this integrated approach, which combines PTT/PDT and enzymatic catalysis, could offer a valuable blueprint for the development of advanced oncology therapies.