The Shape Parameter of Liposomes and DNA-Lipid Complexes Determined by Viscometry Utilizing Small Sample Volumes

• Published in: Biophysical journal Vol. 85; no. 2; pp. 1223 - 1232
• Main Authors: Sun, Y., Li, X., Düzgüneşν, N., Takaoka, Y., Ohi, S., Hirota, S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.08.2003; Biophysical Society
• Subjects: Capillary Action; Deoxyribonucleic acid; DNA; DNA - chemistry; DNA - ultrastructure; Drug Delivery Systems - methods; Equipment Design; Equipment Failure Analysis - instrumentation; Equipment Failure Analysis - methods; Gene therapy; Lipids - chemistry; Liposomes - chemistry; Macromolecular Substances; Materials Testing - instrumentation; Materials Testing - methods; Membrane Fluidity; Microchemistry - instrumentation; Microchemistry - methods; Microfluidics - instrumentation; Microfluidics - methods; Molecular Conformation; Particle Size; Reproducibility of Results; Sample Size; Sensitivity and Specificity; Supramolecular Assemblies; Viscosity
• ISSN: 0006-3495; 1542-0086
• DOI: 10.1016/S0006-3495(03)74558-5

A minicapillary viscometer utilizing <0.5 ml of sample at a volume fraction of <0.1% is described. The calculated a/b of DPPC/DPPG multilamellar liposome was 1.14 as prolate ellipsoids and a/ b of dioleoylpropyltrimethyl ammonium methylsulfate-DNA complex at a charge ratio of 4:1 (+/−) was 3.7 as prolate ellipsoids or 4.9 as oblate ellipsoids. The deviation of shape from perfect sphere is thus expressed quantitatively in more than two significant figures. In these measurement, the necessary amount of DNA is <0.5 mg.