Lipid PEG Linkers, also referred to as PEGylated lipids, have become a popular focus in drug delivery. These amphiphilic molecules feature a hydrophilic polyethylene glycol (PEG) component linked to a hydrophobic lipid tail, which produces a distinct structure that can dissolve in both water and lipids. This quality makes it an appealing alternative for enhancing the stability, pharmacokinetics, and bioavailability of various therapeutics, including small molecules, proteins, and peptides. Lipid PEG has two main properties that contribute to its potential as a drug delivery system: biocompatibility and the ability to self-assemble into stable structures such as liposomes or micelles. Pam3Cys = N-Palmitoyl-S-[2,3-bis (palmitoyloxy) - (2RS) -propyl]-R-cysteinyl. The Pam3cys building block with an attached PEG chain is a new type of watersoluble adjuvants and PEG lipids at the same type. It features 3 palmitoyl lipid tails with a cystein core. The hydroxy group on one side of this PEG crosslinker is able to undergo esterification reactions with acids for reversible pegylation. It also enables further derivatization or replacement with other reactive functional groups.