PEG lipids, also known as PEGylated lipid, is a class of PEG derivatives that is attached with a lipid moiety such as DMG or DSPE. PEG lipid has been used extensively to improve circulation times for liposome encapsulated (LNP) drugs and reduce non-specific uptakes.
PEG lipids such as PEG2000-DMG (Figure 1) can have multiple effects on the properties of lipid nanoparticles. The amount of PEG lipids can affect particle size. PEG lipids can further contribute to particle stability by decreasing particle aggregation, and the optimization of PEG prolong the blood circulation time of nanoparticles by reducing clearance mediated by the kidneys and the mononuclear phagocyte system.