– mPEG2000-DSPE is used in COVID 19 mRNA vaccines. It is a PEGylated derivative of 1,2-distearoyl-sn-glycero-3-PE . Formulations containing DSPE-MPEG(2000) have been used to prepare liposomes with long circulation time for the delivery of anticancer and antimalarial agents.. mPEG2000-DSPE has also been widely used as hydrophilic surface modifying agent for a variety types of hydrophobic nanoparticles, including recently reported lipid nanoparticle mRNA vaccines.