Preparation and properties of lipid bilayers supported on spherical hydrogel beads

Lipid bilayers supported on micron-sized spherical polyHEMA beads were prepared. The lipobeads coatings consisted of 100% DMPC, DMPC/cholesterol (70/30) or DMPC/DMPG (1:1). Coating of the beads was established by fluorescence microscopy, of a fluorophore-labeled lipid. The thermotropic phase behavior of the lipobead coating was similar to that of lipids in the absence of HEMA, based on 1H NMR studies. Cholesterol broadened the phase transition temperature of the lipids. 31P NMR under fast MAS conditions in the presence of a chemical shift reagent, Praseodymium (III), demonstrated that only a single bilayer was wrapped around each hydrogel bead. The successful coating of the hydrogel beads with lipid has opened many doors to future studies with applications to better understanding of membrane structure and functions, drug delivery; targeted drug release and NMR based diffusion studies in lipid bilayers.