1,2-Distearoyl-sn-Glycero-3-Phosphoethanolamine-hydrazone- poly(ethylene glycol) (DSPE-hydrazone-PEG, DSPE-HZ-PEG) is a linear phospholipid PEG conjugate which has both hydrophilicity and hydrophobicity. Hydrazone bond can be cleaved at acidic pH.
DSPE-Hydrazone-PEG can be used to prepare pH sensitive liposomes or solid lipid particles for drug delivery. pH sensitive liposomes are lipid compositions that can be destabilized when the external pH is changed; usually from a neutral or slightly alkaline pH to an acidic pH. They are designed to circumvent delivery of liposome contents to the lysosomes of cells following internalization of the vesicle via the endocytic pathway.
Pegylated phospholipids are excellent liposome or micelle formation materials that can be used for drug delivery. Pegylation of phospholipids significantly improves the blood circulation time and stability for encapsulated drugs. These materials can also be used for targeted drug delivery by modifying their surfaces with targeting ligands such as antibodies, peptides.