Engineering human PEG10-based nanoparticles for RNA self-packaging, delivery and cancer therapy.

PEG10 protein was recently uncovered to self-assemble and self-package its own mRNA into nanoparticles, but the particles require expensive transfection for production and have yet to be explored for cancer therapy. Here we develop a human PEG10-based nanoparticles (PBNPs) platform for cargo RNA self-packaging and delivery for cancer therapy. We design a process to improve the PBNPs production for 11.3-fold while reducing the cost. The PBNPs self-package mRNA of at least 7336 nucleotides and remain stable for 7 months. We engineer the PBNPs surface and tremendously improve mRNA delivery efficiencies to various cancer cells, particularly colon cancer cells (≈71%). We further reprogram the PBNPs to deliver an immunotherapeutic mRNA cocktail to colon cancer cells, which elicits T cell responses in vitro. In vivo co-administration of the engineered PBNPs and chemodrug in female mice synergizes immune responses and promotes anti-cancer efficacy, implicating the potential of PBNPs as an RNA delivery vehicle for immunotherapy.