A Layered Ferrous Silicate for Ion-Exchange-Driven Chemodynamic Therapy
Nanoparticle-based therapeutics have been intensively explored for tumor treatment. However, developing convenient and specific strategies that do not rely on exogenous energy-guided activation remains challenging. Herein, an ion-exchange-driven chemodynamic therapy is proposed based on the TME K+-mediated cation exchangeability of layered ferrous silicates (LFSs). LFSs were prepared by a facile "in situ 3D-to-2D structural transformation" strategy through valence bond transition from SiO–H–OSi to Fe–O, providing extensive convenience compared to conventional exfoliation methods. The structure-activity relationship and mechanism between surrounding TME ions and the cation exchange behavior of LFSs were revealed by both experimental investigation of the cation-exchange process and DFT calculations of the adsorption hydration behavior. As a result, the interlayered Fe ions were selectively and preferentially exchanged by TME K+ rather than surrounding TME Na+, Mg2+, Ca2+, or Cl−, thereafter activating specific Fenton reaction together with TME H+, H2O2, and glutathione, demonstrating highly precise catalytic therapeutic efficacy both in vitro and in vivo. This study proposes an original tumor-specific therapy modality with high precision and safety through taking advantage of ionic exchangeability of layered silicate, and provides enlightenment to reverse the TME K+ disorder.