Effective mRNA Delivery by Condensation with Cationic Nanogels Incorporated into Liposomes.

The challenge in effective delivery of mRNA has been a major hurdle in their development as therapeutics. Herein, we present that the incorporation of cationic nanogels as the condensing material for mRNA into liposomes enables stable and enhanced mRNA delivery to cells in vitro. We prepared dextran-based nanogel particles, which were surface functionalized with oligoarginine peptide (DNPR9) and complexed with mRNA for incorporation into liposomes (LipoDNPR9). The use of DNPR9 with the liposomes resulted in enhanced internalization, as well as a 4-fold increase in transfection of luciferase mRNA when treated with A549 cells in vitro, compared to control liposomes. The enhancement in transfection efficiency was also observed in various cell lines while causing low cytotoxicity. The versatility of the strategy was also investigated by applying DNPR9 for mRNA condensation to ionizable lipid particles, which resulted in an ∼55% increase in transfection. The current development based on nanogel-incorporated liposomes introduces an effective platform for mRNA delivery, while the condensation strategy using DNPR9 can be widely applied for various lipid-based formulations to enhance their efficacy.