Synthesis of an end-group functionalized polyethylene glycol-lipid conjugate for preparation of polymer-grafted liposomes

Bioconjug Chem. Jul-Aug 1993;4(4):296-9. doi: 10.1021/bc00022a008.


Synthesis of a distearoylphosphatidylethanolamine-polyethylene glycol (DSPE-PEG) conjugate, bearing a hydrazide group at the unattached end of the polymer chain, was achieved using a new heterobifunctional polymeric reagent. The heterobifunctional PEG derivative carrying on one end a reactive succinimidyl carbonate (SC) group and at the other terminal a tert-butyloxycarbonyl (Boc) protected hydrazide group was prepared by an efficient four step process from readily available PEG-2000. The SC-end group of the polymer reacted readily with the amino group of DSPE forming a stable urethane attachment between lipid and PEG. Acidolytic removal of the Boc group yielded a hydrazide-PEG-lipid conjugate suitable for preparation of polymer-grafted liposomes. Taking advantage of the well-documented chemical versatility of hydrazide groups, various biologically relevant ligands can be linked to this type of functionalized liposomes.

MeSH terms

  • Cholesterol / chemistry
  • Cross-Linking Reagents / chemistry
  • Ethylamines / chemistry
  • Indicators and Reagents
  • Lipids / chemistry*
  • Liposomes / chemical synthesis*
  • Molecular Weight
  • Phosphatidylcholines / chemistry
  • Phosphatidylethanolamines / chemistry
  • Polyethylene Glycols / chemistry*


  • Cross-Linking Reagents
  • Ethylamines
  • Indicators and Reagents
  • Lipids
  • Liposomes
  • Phosphatidylcholines
  • Phosphatidylethanolamines
  • 1,2-distearoylphosphatidylethanolamine
  • Polyethylene Glycols
  • Cholesterol
  • triethylamine