Peptide-assembled siRNA nanomicelles confine MnOx-loaded silicages for synergistic chemical and gene-regulated cancer therapy

Abstract

Chemodynamic therapy (CDT) is a promising therapeutic approach for in situ cancer treatment, but it is still hindered by inefficient single-modality treatment and the weak targeted delivery of reagents into mitochondria (the main site of intracellular ROS production). Herein, to obtain a multimodal strategy, peptide-assembled siRNA nanomicelles were prepared to confine ultrasmall MnOx in small silica cages (silicages), which is convenient for synergistic chemical and gene-regulated cancer therapy. Given the free energy and versatility of small silicages, as well as the excellent Fenton-like activity of ultrasmall MnOx, MnOx-inside-loaded silicages (10 nm) were prepared for CDT delivery to mitochondria. Subsequently, to obtain a synergistic CDT and gene silencing treatment, the peptide-mediated assembly of siRNA and MnOx-loaded silicages were employed to obtain silicage@MnOx-siRNA nanomicelles (SMS NMs). After multiple modifications, sequential cancer cell-targeted delivery, GSH-controlled reagent release of siRNA and mitochondria-targeted delivery of MnOx-loaded silicages were successfully achieved. Finally, by both in vitro and in vivo experiments, SMS NMs were confirmed to be effective for synergistic chemical and gene-regulated cancer therapy. Our findings expand the applications of silicages and initiate the development of multimodal CDT.