Structure‐Governed MXene Quantum Dots for Cancer Theranostics: From Quantum Confinement to Tumor‐Selective Catalytic and Photothermal Activation

ABSTRACT MXene quantum dots (MQDs) have recently emerged as a compelling class of nanomaterials for cancer theranostics, owing to their confined electronic structure, multifunctional activation mechanisms, and favorable in vivo performance. In this review, the structure‐governed behavior of MQDs is systematically examined and interpreted, highlighting how their quantum‐scale architecture influences therapeutic functionality. The chemical and physical origins of functional diversity in MQDs are discussed, with an emphasis on dimensional miniaturization, electronic confinement, and structure–property relationships beyond biological contexts. Building on this foundation, recent advances in tumor‐selective catalytic and photothermal activation of MQDs are analyzed, highlighting Fenton‐like redox processes, near‐infrared photothermal conversion, and synergistic therapeutic modalities supported by in vivo evidence. Particular attention is given to tumor microenvironment modulation, spatiotemporal control, and imaging‐guided activation strategies that distinguish MQDs from conventional nanotherapeutics. Finally, key challenges related to clinical advancement, manufacturing scalability, safety evaluation, and regulatory considerations are evaluated. By integrating fundamental structure‐driven insights with therapeutic and clinical perspectives, MQDs are positioned as a versatile and promising platform for next‐generation precision cancer theranostics.