Intelligent design of iron-doped LDH nanosheets for cooperative chemo-chemodynamic therapy of tumors

Chemodynamic therapy (CDT) has received increasing attention due to its unique tumor microenvironment (TME) responsiveness and minimal adverse side effects, but the therapeutic effect of CDT alone is always limited due to the low Fenton or Fenton-like reaction efficiency at tumor sites. Herein, Fe-doped layered double hydroxide (LDH) nanosheets were synthesized to load the anticancer drug epigallocatechin-3-O-gallate (EGCG) and then conjugated with boronic acid-modified hyaluronic acid for targeted and cooperative chemo-chemodynamic therapy of tumors. The formed LDH-EGCG-HA nanoplatforms could specifically target tumor cells overexpressing CD44 receptors, quickly release iron ions and EGCG in the TME, and efficiently generate toxic hydroxyl radicals with the acceleration of Fe3+/Fe2+ cycling in the Fenton reaction by EGCG. The cooperative cancer cell inhibition effect through chemotherapy and chemodynamic therapy was achieved by the significant upregulation of caspase-3 and p53 expression to induce cell apoptosis, and the deactivation of xCT and GPX-4 to inhibit GSH synthesis and reduce lipid peroxides for reinforced ferroptosis. In vivo experiments further verified that the intelligently designed LDH-EGCG-HA nanoplatforms had a superior biocompatibility with normal organs with an excellent inhibition efficacy towards tumors overexpressing CD44 receptors by targeted chemo-chemodynamic therapy.