Biodegradable and Excretable 2D W1.33C i-MXene with Vacancy Ordering for Theory-Oriented Cancer Nanotheranostics in Near-Infrared Biowindow

MXenes, a new class of two-dimensional (2D) nanomaterials, have shown enormous potential for biological applications. Notably, the development of 2D MXenes in nanomedicine is still in its infancy. Herein, a distinct W1.33C i-MXene with multiple theranostic functionalities, fast biodegradation, and satisfactory biocompatibility is explored. By designing a parent bulk laminate in-plane ordered (W2/3Y1/3)(2)AlC ceramic and optionally etching aluminum (Al) and yttrium (Y) elements, 2D W1.33C i-MXene nanosheets with ordered divacancies are efficiently fabricated. Especially, theoretical simulations reveal that W1.33C i-MXene possesses a strong predominance of near-infrared (NIR) absorbance. The constructed ultrathin W1.33C nanosheets feature excellent photothermal-conversion effectiveness (32.5% at NIR I and 49.3% at NIR II) with desirable biocompatibility and fast degradation in normal tissue rather than in tumor tissue. Importantly, the multimodal-imaging properties and photothermal-ablation performance of W1.33C-BSA nanosheets are systematically revealed and demonstrated both in vitro and in vivo. The underlying mechanism and regulation factors for the W1.33C-BSA nanosheets-induced hyperthermia ablation are also revealed by transcriptome and proteome sequencing. This work offers a paradigm that i-MXenes achieve the tailoring biomedical applications through composition and structure design on the atomic scale.

Automated summary

MXenes are a new class of 2D nanomaterials showing great potential in biological applications. This study explores a unique W1.33C i-MXene with multiple theranostic functionalities, fast biodegradation, and satisfactory biocompatibility. The constructed ultrathin W1.33C nanosheets exhibit excellent photothermal-conversion effectiveness and fast degradation in normal tissues, showcasing potential for tailored biomedical applications.