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Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by π-π Stacking Interactions
Published on: October 10, 2016
Contrasting behavior of zwitterionic and cationic polymers bound to anionic liposomes
A A Yaroslavov1, T A Sitnikova, A A Rakhnyanskaya
1Department of Chemistry, M. V. Lomonosov Moscow State University, Leninskie Gory, Moscow 119992, Russia. yaroslav@genebee.msu.ru
Langmuir : the ACS Journal of Surfaces and Colloids
|June 7, 2007
Summary
Zwitterionic polymers interact differently with anionic liposomes based on their structure. Shorter polymers show no interaction, while longer ones exhibit varying degrees of binding and aggregation, offering insights into polymer-liposome interactions.
Area of Science:
- Polymer Chemistry
- Materials Science
- Biophysical Chemistry
Background:
- Zwitterionic polymers possess both positive and negative charges, influencing their interactions with biological membranes.
- Anionic liposomes, particularly those containing cardiolipin, serve as model systems for studying membrane interactions.
- Understanding polymer-membrane interactions is crucial for developing drug delivery systems and biomaterials.
Purpose of the Study:
- To synthesize zwitterionic polymers with varying chain lengths by quaternizing polyvinylpyridine.
- To investigate the interaction of these zwitterionic polymers with anionic liposomes containing cardiolipin.
- To compare the behavior of zwitterionic polymers with a polycation and elucidate structure-dependent interactions.
Main Methods:
- Polymer synthesis via quaternization of polyvinylpyridine with bromoacids.
- Liposome preparation using egg lecithin or dipalmitoylphosphatidylcholine and cardiolipin.
- Characterization using light scattering, electrophoretic mobility, fluorescence, and differential scanning calorimetry.
Main Results:
- Zwitterionic polymers did not induce cardiolipin flip-flop, unlike a polycation.
- Polymer interactions with liposomes varied with the alkyl chain length (n) of the bromoacid.
- n=1 showed no interaction; n=2 exhibited reversible electrostatic binding and aggregation; n=3 showed strong irreversible binding and aggregation; n=5 showed reversible binding without significant aggregation.
Conclusions:
- The length of the alkyl chain in zwitterionic polymers significantly dictates their interaction with anionic liposomes.
- Zwitterionic polymers offer tunable interactions with liposomes, distinct from polycations.
- These findings provide molecular insights into the design of zwitterionic polymers for specific biomaterial applications.
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