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Triggerable plasmalogen liposomes: improvement of system efficiency
D H Thompson1, O V Gerasimov, J J Wheeler
1Department of Chemistry, Purdue University, West Lafayette, IN 47907-1393, USA.davethom@chem.purdue.edu
Biochimica Et Biophysica Acta
|February 21, 1996
Summary
This study introduces a photoactivated liposome system for triggered release of hydrophilic materials. Near-infrared light triggers plasmalogen liposomes to release contents and fuse, showing potential for photodynamic therapy applications.
Area of Science:
- Biochemistry
- Materials Science
- Photochemistry
Background:
- Liposome membrane permeability is crucial for drug delivery.
- Plasmalogen photooxidation affects membrane permeability in biological systems.
- Controlled release systems are needed for targeted therapies.
Purpose of the Study:
- To develop a photoactivated liposome system for triggered release.
- To investigate the mechanism of light-induced membrane changes.
- To evaluate the potential of this system in photodynamic therapy.
Main Methods:
- Preparation of semi-synthetic plasmenylcholine liposomes with encapsulated calcein and sensitizers.
- Irradiation of liposomes with 630-820 nm light in the presence of sensitizers (zinc phthalocyanine, tin octabutoxyphthalocyanine, bacteriochlorophyll a).
- Analysis of membrane permeability, release rates, and membrane fusion using techniques like 31P-NMR and TEM.
Main Results:
- Photoactivation increased liposome membrane permeability and promoted membrane fusion.
- Bacteriochlorophyll a sensitization achieved rapid release (100% in <20 min) with 800 nm light.
- Plasmenylcholine liposomes showed significantly faster release than egg lecithin liposomes.
Conclusions:
- Photoactivated plasmenylcholine liposomes offer a versatile system for triggered release.
- The observed membrane fusion capabilities are advantageous for therapeutic applications.
- This system is a promising adjunct to biochemical targeting in photodynamic therapy.