MXene Wrapped Magnetic Mesocrystals for Durable Redox Catalytic Cancer Therapy and Responsive MRI

ABSTRACT Multifunctional platforms capable of sustaining regenerative redox catalysis while providing imaging feedback offer a promising strategy for image‐guided oxidative cancer therapy. Here we report conformally wrapped Fe 3 O 4 ‐Ti 3 C 2 T x MXene core‐shell hybrid nanoparticles (FTHNPs), in which ultrathin MXene nanosheets effectively encapsulate crystallographically aligned magnetic mesocrystals to form an electronically coupled heterostructure. Controlled electrostatic and geometrical co‐assembly of polyacrylate coated Fe 3 O 4 mesocrystals with polyethyleneimine‐modified MXene enables conformal wrapping with maximized interfacial contact and suppressed edge‐associated wrinkling. The engineered heterointerface facilitates directional electron transfer, supporting sustained near‐infrared (NIR)‐activated redox cycling and amplified reactive oxygen species (ROS) generation. Concurrently, the Fe 3 O 4 core provides T 2 ‐weighted magnetic resonance imaging (MRI) contrast for noninvasive spatiotemporal monitoring of nanoparticle localization and catalytic activation. NIR irradiation of FTHNPs induces potent oxidative cytotoxicity across both 2D monolayer and 3D spheroid prostate cancer models. Redox activation is accompanied by measurable modulation of T 2 contrast, permitting MRI‐based tracking of catalytic activity. In vivo periodic NIR‐triggered treatment achieves significant tumor growth suppression under concurrent MRI surveillance. These findings establish an interfacial electron‐transfer–engineered MXene‐magnetic heterostructure as a platform for MRI‐guided, persistent redox catalytic cancer nanomedicine.