Incorporation of dioleoyl N-(monomethoxy polyethyleneglycol succinyl)phosphotidylethanolamine (PEG-PE) into large unilamellar liposomes composed of egg posphatidylcholine:cholesterol (1:1) does not significantly increase the content leakage when the liposomes are exposed to 90% human serum at 37°C, yet the liposomes show a significant increase in the blood circulation half-life (t 1 2 = 5 h) as compared to those without PEG-PE(t 1 2 <30 min). The PEG-PE's activity to prolong the circulation time of liposomes is greater than that of the ganglioside GM 1 , awell-described glycolipid with this activity. Another amphipathic PEG derivative, PEG stearate, also prolongs the liposome circulation time, although its activity is less than that ofGM 1 . Amphipathic PEGs may be useful for the sustained release and the targeted drug delivery by liposomes. © 1990.
Klibanov, A. L., Maruyama, K., Torchilin, V. P., & Huang, L. (1990). Amphipathic polyethyleneglycols effectively prolong the circulation time of liposomes. FEBS Letters, 268(1), 235–237. https://doi.org/10.1016/0014-5793(90)81016-H