Lipid Exchange Rates of Conventional and Polymer Stabilized Liposomes
Abstract
Polymer-stabilized liposome systems consisting of polyethylene glycol bound lipids (PEG-lipids) and conventional (nonpolymer stabilized) liposomes were compared in terms of their inter-membrane lipid migration rates. In order to monitor the exchange of lipids between the membranes, 1 -hexadecanoyl-2-(1- pyrenedecanoyl)-sn-glycero-3 -phosphocholine (PY-PC), a phospholipid with pyrene attached to the hydrophobic tail, was used to label the liposome. Labeled and unlabeled liposome systems were mixed and fluorescence spectroscopy was used to examine the lipid transfer. More specifically, the relative employed to deduce the exchange kinetics. After labeled and unlabeled liposome systems were mixed, the E/M ratio for PY-PC in a polymer stabilized liposome system decreased by 66% over a period of 80 minutes, while the E/M for PY-PC in a conventional liposome system decreased 70% in less than 2 minutes. This suggests that the exchange rate for lipids in polymer stabilized liposome systems is much slower than that of conventional liposome systems. In addition, the exchange rates for both conventional and polymer stabilized liposome systems are accelerated at an elevated temperature.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2002
- Accession Number
- ADP014415
Entities
People
- Awad Ahmed
- Gregory Slack
- Nicole Heldts
- Yuzhuo Li
Organizations
- Clarkson University