Related Experiment Video
Updated: Jul 19, 2026
09:45
On-Chip Octanol-Assisted Liposome Assembly for Bioengineering
Published on: March 17, 2023
Complexation of phosphocholine liposomes with polylysine. Stabilization by surface coverage versus aggregation.
Dmitry Volodkin1, Vincent Ball, Pierre Schaaf
1Institut National de la Santé et de la Recherche Médicale, Unité 595, Faculté de Chirurgie Dentaire, 11 rue Humann, 67085 Strasbourg Cedex, France. Dmitry.Volodkin@medecine.u-strasbg.fr
Biochimica Et Biophysica Acta
|November 7, 2006
Summary
Complexation of poly-L-lysine (PLL) with liposomes can lead to charge inversion or aggregation. Controlling experimental conditions allows for tunable aggregation, forming stable colloids for applications like drug delivery.
Area of Science:
- Colloid and Surface Science
- Materials Science
- Biotechnology
Background:
- Liposomes are widely used as drug delivery vehicles.
- Polycations can interact with liposomes to modify their properties.
- Understanding these interactions is crucial for developing advanced delivery systems.
Purpose of the Study:
- To investigate the complexation between linear poly-L-lysine (PLL) and phosphocholine liposomes.
- To determine how experimental conditions influence complexation outcomes (charge inversion vs. aggregation).
- To explore the potential for controlling aggregate formation for specific applications.
Main Methods:
- Dynamic Light Scattering (DLS) for size analysis.
- Microelectrophoresis for surface charge determination.
- Differential Scanning Calorimetry (DSC) for thermal analysis.
Main Results:
- Complexation resulted in either charge inversion (stabilization) or aggregation, dependent on experimental variables.
- Aggregation was controllable, leading to the formation of stable, micron-sized aggregates.
- DSC confirmed physical adsorption on the vesicle surface without disturbing lipid organization.
Conclusions:
- The study elucidates multivariable aspects of liposome-polycation complexation.
- A procedure for fabricating polycation-stabilized vesicles was optimized.
- These findings support the development of novel colloidal systems for drug delivery.
Related Concept Videos
01:19Complexation Equilibria: The Chelate Effect
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
01:09Colloidal precipitates
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...
01:29The Colloidal State
The formation of a colloidal system is exemplified by an aqueous solution containing Cl− ions is introduced to another containing Ag+ ions, resulting in the precipitation of solid AgCl as extremely tiny crystals. Instead of settling out as a filterable precipitate, these crystals remain suspended in the liquid, showcasing a colloidal system.A colloidal system involves colloidal particles within the approximate range of 1 to 1000 nm in at least one dimension, dispersed in a medium called the...