A Serum Resistant Polymer with Exceptional Endosomal Escape and mRNA Delivery Efficacy for CRISPR Gene Therapy

Nanoparticle-based mRNA delivery offers a versatile platform for innovative therapies. However, most of the current delivery systems are limited by poor serum tolerance, suboptimal endosomal escape and mRNA delivery efficacy. Herein, a highly efficient mRNA-delivering material is identified from a library of fluoropolymers. The lead material FD17 shows exceptional serum stability and endosomal escape, enabling efficient mRNA delivery into various cell types, surpassing commercial mRNA delivery reagents such as Lipofectamine 3000. The formed mRNA nanoparticles adsorb abundant serum albumin on the surface, which facilitates cellular uptake via scavenger receptor-mediated endocytosis. FD17 enables the delivery of mRNAs encoding CRE, Cas9, and base editor hyCBE for efficient genome editing. The material mediates CRISPR/Cas9 gene therapy via intraocular injection effectively down-regulates vascular endothelial growth factor A in retinal pigment epithelial cells of mice, yielding promising therapeutic responses against laser-induced choroidal neovascularization. The discovered material in this study shows great promise for the development of mRNA therapeutics to combat a wide range of diseases.