Related Experiment Videos
Cationic cage-like complexes formed by DC-cholesterol, Quil-A, and phospholipid
Dirk G Lendemans1, Julia Myschik, Sarah Hook
1School of Pharmacy, University of Otago, Dunedin, New Zealand.
Journal of Pharmaceutical Sciences
|June 30, 2005
Summary
Researchers created cationic, cage-like complexes by replacing cholesterol with a DC-CHOL derivative. Formulation buffer, specifically TRIS, significantly influenced the formation of these positively charged particles.
Area of Science:
- Biochemistry
- Materials Science
- Nanotechnology
Background:
- Classic immunostimulating complexes (ISCOMs) are anionic and utilize cholesterol.
- Developing cationic ISCOM-like structures is of interest for novel applications.
Purpose of the Study:
- To synthesize and characterize novel cationic, cage-like complexes.
- To investigate the influence of formulation components, particularly buffer systems, on particle formation.
Main Methods:
- Lipid-film hydration method used to prepare colloidal dispersions.
- Characterization via transmission electron microscopy and laser Doppler electrophoresis.
- Analysis of formulations using pseudo-ternary phase diagrams.
Main Results:
- Cationic, cage-like particles formed with 3beta-[N-(N',N'-dimethylaminoethane)-carbamoyl]-cholesterol (DC-CHOL), phosphatidylcholine, and Quil-A.
- Particle formation was highly dependent on the buffer system; TRIS buffered saline (TBS) promoted cage-like structures with positive zeta-potential.
- Phosphate buffered saline (PBS) resulted in significantly reduced formation of these cationic structures.
Conclusions:
- The formation of cationic, cage-like particles is critically dependent on the presence of TRIS in the hydration buffer.
- These positively charged structures can be purified using differential centrifugation.
- The study demonstrates a method for creating ISCOM-like structures with tunable charge via component modification and buffer selection.