93-O17O is a chalcogen-containing cationic lipidoid.1,2It has been used in the generation of lipid nanoparticles (LPNs). LPNs containing 93-O17O localize to the spleen after intravenous injection into mice.1LPNs containing 93-O17O have been used for the delivery of Cre recombinase and ribonucleoproteins for genome editing in mice and for the intratumoral delivery of cGAMP to enhance cross-presentation of tumor antigens.3,2