Enhancing mRNA therapy through iterative delivery

Clinical translation of therapeutic messenger RNA (mRNA) technologies, particularly in solid tumors, has been limited due to unavailability of effective delivery systems. Here, we describe an mRNA delivery system that overcomes current challenges by co-encapsulating gold nanoparticles (AuNPs) and mRNA within non-ionic surfactant vehicles (NSVs) to create "Aurniosoves" (AuNSVs). Through in vitro and in vivo studies, we demonstrate that AuNSVs improve vector accumulation and uptake within the tumor, resulting in enhanced protein expression and therapeutic efficacy. Mechanistically, these effects are the result of an iterative delivery process in which AuNSVs enter cells initially through clathrin-mediated endocytosis (CME) and release AuNPs into the cytoplasm. AuNPs subsequently adsorb and inactivate cellular trafficking regulators PP2A and Rab7, producing two effects: (i) rapid entry of additional AuNSVs through activation of caveolin-mediated endocytosis (CvME) and (ii) endosomal escape through inhibited endolysosomal fusion. We propose that AuNSVs be exploited as next-generation mRNA delivery systems.