Highly effective inhibition of lung cancer growth and metastasis by systemic delivery of siRNA via multimodal mesoporous silica-based nanocarrier

Lung cancer has been the leading type of cancers with regard to mortality and mobility. New versions of RNAi-based therapy are greatly required to tackle the challenges of lung cancer. In this study, we developed a novel siRNA delivery vector based on our magnetic mesoporous silica nanoparticles (M-MSNs) platform. This nanocarrier was constructed by loading siRNAs into the mesopores of M-MSNs, followed by polyethylenimine (PEI) capping, PEGylation and fusogenic peptide KALA modification. The resultant delivery system exhibited prolonged half-life in bloodstream, enhanced cell membrane translocation and endosomal escapablity, and favorable tissue biocompatibility and biosafety. Systemic application of vascular endothelial growth factor (VEGF) siRNA via this nanocarrier resulted in remarkable tumor suppression, both in subdermal and orthotopic lung cancer models, while tumor metastasis was also significantly reduced, overall leading to improved survival. In addition, the magnetic core of the particles and the functionalized fluorescence markers conveniently enabled in vivo imaging of target tissues. Taken together, this M-MSNs-based siRNA delivery vehicle has shown very favorable applicability for cancer therapy. (C) 2014 Elsevier Ltd. All rights reserved.