An ionizable cationic lipid (pKa 7.12) intravenous administration of LNPs containing (S)-C12-200 and encapsulating mRNA encoding Cre recombinase increase the percentage of tdTomato hepatocytes endothelial cells and Kupffer cells in the livers of Ai14 mice greater than (R)-C12-200-containing and Cre mRNA-encapsulating LNPs