(515e) Lipid Bilayer Assembly On Colloidal Platelets

Colloidal suspensions of single sheet α?Zirconium phosphate (α?ZrP) platelets have been shown to undergo disordered isotropic (I) to nematic (N) phase transition as the particle volume fraction of the samples increases. Similar to other inorganic and organic/biological liquid crystals such as discotic phospholipid particles (bicelles), alignment of these plate-like particles can be induced by applying external magnetic field. This can be validated through solution NMR studies and magnetic field induced birefringence. In this talk, we will present the preparation of a novel type of liposome-particle hybrid, where lipid coated platelets are formed by vesicle fusion. The experimental concept will be demonstrated first by the formation of supported lipid bilayer on a planar zirconium phosphate surface using fluorescence microscopy. Assembly of lipid bilayers on suspended particle surfaces will then be achieved by electrostatic interactions between positively charge α?ZrP and negatively charged liposomes. Surface charges on the resulting lipid coated platelets can be easily tuned by varying lipid compositions; particle size can also be easily modified by variation of synthesis conditions. These robust lipid-particle assemblies offer great potential for biophysical applications involving membrane proteins, especially in the area of NMR based protein structure determination.