DSPE-PEG2000 is a synthetic PEGylated lipid derivative of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine. DSPE-PEG2000 has been found to display a better anchoring ability than short-chain PEG lipids in membranes and thereby increase LNP circulation time. PEG-modified lipids are typically added to phospholipid vesicles used for drug delivery to provide a steric coating on the surface of the membrane to hinder clearing of the particles by the reticuloendothelial system (RES). This prolongs the circulating plasma half-life of the drug. The plasma half-life of the drug can be "tuned" from several hours to days depending on the size of the PEG and fatty acids attached to the lipid anchor.
Polyethylene glycol (PEG)-lipids have been the polymer-lipid conjugate of choice for lipid formulations for decades. PEG-lipids are used increase systemic circulation times, mediate indirect targeting capabilities, promote LNP self-assembly, control size and aid in storage stability. Particles containing PEG-lipids are able to bypass the reticulo-endothelial system, giving them their nickname - “stealth agents”. The DSPE lipid anchor has 2 saturated 18-carbon chains. DSPE-PEG2000 is the most common lipid-PEG conjugate used in drug delivery for small molecules, as it has been employed as a stealth agent in liposomal delivery systems.
Functions include:
- Increased half life when administered systemically
- Aids in storage ability
- Helps obtain small particle sizes.