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Assembly and Characterization of Polyelectrolyte Complex Micelles
Published on: March 2, 2020
Composition and properties of complexes between spherical polycationic brushes and anionic liposomes
Andrey V Sybachin1, Olga V Zaborova, Matthias Ballauff
1Department of Chemistry, MV Lomonosov Moscow State University, Moscow, Russian Federation. sybatchin@mail.ru
Langmuir : the ACS Journal of Surfaces and Colloids
|November 6, 2012
Summary
Spherical polycationic brushes effectively adsorb anionic liposomes, forming stable complexes. Liposome charge and cardiolipin content influence complex stability and dissociation in varying salt concentrations.
Area of Science:
- Colloid and Surface Science
- Materials Science
- Biophysics
Background:
- Spherical polycationic brushes (SPBs) are synthesized by grafting cationic monomers onto polystyrene beads.
- Anionic liposomes, composed of phosphatidylcholine (PC) and cardiolipin (CL(2-)), were prepared with varying CL(2-) fractions (0.05-0.4 mol).
Purpose of the Study:
- To investigate the adsorption of anionic liposomes onto SPBs.
- To characterize the resulting SPB-liposome complexes and their stability.
- To explore the influence of liposome charge and salt concentration on complex formation and integrity.
Main Methods:
- Electrophoretic mobility measurements to determine surface charge.
- Dynamic light scattering (DLS) for aggregate size analysis.
- Fluorescence labeling to quantify adsorbed liposomes.
- Cryo-transmission electron microscopy (cryo-TEM) for morphological characterization.
Main Results:
- SPB-liposome complexation resulted in a charge reversal from positive to negative.
- Complex formation led to multicomplex aggregates, with maximum size at charge equivalence.
- Liposome adsorption per SPB decreased with increasing CL(2-) content due to electrostatic repulsion.
- Complex dissociation was dependent on CL(2-) content and NaCl concentration; higher CL(2-) increased salt stability.
Conclusions:
- SPBs can adsorb anionic liposomes while preserving liposome integrity, unlike other surfaces.
- The cardiolipin content in liposomes critically controls complex stability and salt tolerance.
- These findings offer insights into designing stable colloidal complexes for potential applications.
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