A Smart Nanocomposite Based on Mo₂C MXene for Active Targeted Photothermal-Chemotherapy of Cancer in NIR-II Biowindows

As a novel cancer treatment method, photothermal therapy (PTT) is considered an up-and-coming candidate for cancer treatment owing to its low invasiveness and ease of implementation. Nevertheless, single PTT in the first transparency (NIR-I, 750-1000 nm) biowindows is often insufficient to eliminate tumor cells due to light scattering and absorption at the tumor site. Therefore, the rational design of multifunctional nanocomposites for multimodal combination therapies based on PTT is attractive for improving treatment efficacy while reducing drug resistance and adverse reactions. Herein, we report a smart multifunctional nanocomposite DOX-Mo₂C-PAA/Apt-M (DMPM) based on molybdenum carbide (Mo₂C) MXene for active targeted photothermal-chemotherapy in the second transparency (NIR-II, 1000-1350 nm) biowindows. This nanocomposite effectively absorbed light and converted it into heat, achieving a photothermal conversion efficiency of 38.64% under NIR-II laser irradiation. Meanwhile, the DMPM nanocomposite exhibited pH and laser dual-stimuli-triggered doxorubicin (DOX) release in the tumor microenvironment. Furthermore, DMPM could effectively target MCF-7 solid tumors, significantly improving therapeutic efficacy. <i>In vitro</i> and <i>in vivo</i> studies confirmed that DMPM triggered significant cellular killing and tumor eradication without systemic toxicity. Our work not only presents a new approach for multimode cancer treatment but also expands the application of Mo₂C MXene in the biomedical field.