Designing siRNA/Chitosan-Methacrylate Complex Nanolipogel for Prolonged Gene Silencing Effects

Abstract

Despite the great therapeutics potential, sustained release of small interfering RNA (siRNA) remains a challenge. Development of siRNA sustained release nanoparticle provides possibility to further enhance the therapeutic efficacy in gene-based therapy. Herein, we present a new system based on the encapsulation of siRNA/chitosan-methacrylate (CMA) complexes into liposomes to form UV crosslinkable Nanolipogels (NLGs) with sustained siRNA-release properties, both in vitro and inside cells. We demonstrated that the CMA nanogel in NLGs can enhance the encapsulation efficiency of siRNA and provide sustained release of siRNA up to 28 days. To understand the mechanism of cellular uptake, multiple endocytic inhibitors have been used to study the endocytosis pathways. This study proved that positively charged NLGs can enter the cells via multiple endocytosis pathways, facilitating the endosome escape and slowly releasing the siRNA into the cytoplasm. Transfection experiments confirmed that the crosslinked NLG delivery system provides effective transfection and prolonged silencing effect for up to 14 days. We expect that this sustained-release siRNA NLG platform would be of interest in both fundamental biological studies and in clinical applications to extend the use of siRNA-based therapies.