2-B-S23-4 〇真栄城 正寿 Maeki Masatoshi 北海道大・工・応用化学部門 Hokkaido University RNA and DNA delivery technology using lipid nanoparticles (LNPs) has reached the practical application stage, including its use in mRNA vaccines. To date, 21 bp siRNA (Onpattro) and 4300 nucleotides mRNA vaccines for COVID-19 have been commercialized; however, the decrease in transfection efficiency with the increase in the size of the delivered RNA and DNA is a major challenge. In particular, compared with RNA transfection, plasmid DNA (pDNA) transfection requires multiple steps, including cellular uptake, endosomal escape, nuclear translocation, transcription, and translation. The low transfection efficiency of large pDNA is a critical limitation in the development of artificial cells and functionalization of cells. In this study, we report polymer-lipid hybrid nanoparticles for large-sized pDNA transfection. We demonstrated that positively charged pDNA-polycation core nanoparticle-loaded LNPs showed a four-fold higher transfection efficiency of 15 kbp pDNA than that of the conventional LNPs. Based on the assessment of the size and internal structure of polymer-lipid nanoparticles, hemolysis assay, and cellular uptake, we propose a strategy to enhance large-sized pDNA transfection using LNPs. This strategy will accelerate the delivery of large-sized pDNA in vivo and the development of artificial cells.