Insertion of poly(ethylene glycol) derivatized phospholipid into pre-formed liposomes results in prolonged in vivo circulation time

FEBS Lett. 1996 May 20;386(2-3):243-6. doi: 10.1016/0014-5793(96)00452-8.


Transfer of MPEG(1900)-DSPE from micellar phase to pre-formed liposomes imparts long in vivo circulation half-life to an otherwise rapidly cleared lipid composition. MPEG(1900)-DSPE transfers efficiently and quickly in a time and temperature dependent manner. There is negligible content leakage and a strong correlation between assayed mol% MPEG(1900)-DSPE, liposome diameter increase, and pharmacokinetic parameters such as distribution phase half-life. Since a biological attribute (liposome clearance rate) can be modified by the insertion process, it suggests a simple and economical way to impart site-specific targeting to a variety of liposome delivery systems. This method is also a convenient way to measure the 'brush' thickness of such conjugates directly.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dose-Response Relationship, Drug
  • Liposomes / pharmacokinetics*
  • Male
  • Phosphatidylethanolamines / pharmacokinetics*
  • Polyethylene Glycols / pharmacokinetics*
  • Rats
  • Rats, Sprague-Dawley
  • Solubility


  • Liposomes
  • N-carbamylmethoxypoly(ethylene glycol)-1,2-distearoyl-sn-glycero-3-phosphoethanolamine
  • Phosphatidylethanolamines
  • Polyethylene Glycols