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Egg phosphatidylcholine liposomes incorporating hydrophobically modified chitosan: pH-sensitive release
1School of Biotechnology and Bioengineering and Institute of Bioscience and Biotechnology Kangwon National University, 192-1, Hyoja 2-Dong, Chunchon, Kangwon-Do 200-701, Korea.
Journal of Nanoscience and Nanotechnology
|March 31, 2011
Summary
Hydrophobically modified chitosan (HmCh) was used to create pH-sensitive egg phosphatidylcholine (EPC) liposomes. These novel liposomes demonstrate controlled release, with release rates increasing significantly at lower pH levels.
Area of Science:
- Biomaterials Science
- Drug Delivery Systems
- Nanotechnology
Background:
- Liposomes are versatile drug delivery vehicles.
- Chitosan is a biocompatible polysaccharide with potential for modification.
- Developing pH-sensitive liposomes is crucial for targeted drug release.
Purpose of the Study:
- To prepare and characterize egg phosphatidylcholine (EPC) liposomes incorporating hydrophobically modified chitosan (HmCh).
- To investigate the pH-responsive release properties of these novel liposomes.
- To establish the relationship between HmCh content and liposome release characteristics.
Main Methods:
- Liposomes were prepared using egg phosphatidylcholine (EPC) and hydrophobically modified chitosan (HmCh) via sonication.
- Pentyl chains were covalently attached to chitosan to immobilize it on liposome surfaces.
- Proton NMR spectroscopy was used to determine the degree of chitosan modification.
- Fluorescence quenching was employed to assess liposome formation yield.
- In vitro release studies were conducted across a range of pH conditions.
Main Results:
- High yields of liposome formation were achieved when the HmCh to EPC ratio was below 1:5.
- The modified liposomes exhibited minimal release in neutral and alkaline conditions.
- Significant pH-dependent release was observed starting at pH 6.5, with increased release at lower pH.
- The extent of pH-sensitive release was directly correlated with the amount of HmCh incorporated.
Conclusions:
- Hydrophobically modified chitosan effectively functionalizes EPC liposomes, imparting pH-sensitivity.
- These HmCh-EPC liposomes demonstrate tunable, pH-responsive drug release capabilities.
- The developed liposomes hold promise for targeted drug delivery applications in acidic environments.
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