Biomimetic Cationic Nanoparticles Based on Silica: Optimizing Bilayer Deposition from Lipid Films

Abstract

The optimization of bilayer coverage on particles is important for a variety of biomedical applications, such as drug, vaccine, and genetic material delivery. This work aims at optimizing the deposition of cationic bilayers on silica over a range of experimental conditions for the intervening medium and two different assemblies for the cationic lipid, namely, lipid films or pre-formed lipid bilayer fragments. The lipid adsorption on silica in situ over a range of added lipid concentrations was determined from elemental analysis of carbon, hydrogen, and nitrogen and related to the colloidal stability, sizing, zeta potential, and polydispersity of the silica/lipid nanoparticles. Superior bilayer deposition took place from lipid films, whereas adsorption from pre-formed bilayer fragments yielded limiting adsorption below the levels expected for bilayer adsorption.

Keywords

• AEROSIL OX-50
• dioctadecyldimethylammonium bromide
• N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium chloride
• elemental analysis for in situ adsorption
• colloidal stability
• cationic bilayer fragments
• films of cationic lipids
• optimal bilayer adsorption from films