Polydopamine-supported lipid bilayers

Abstract

We report the formation of lipid membranes supported by a soft polymeric cushion of polydopamine. First, 20nm thick polydopamine films were formed on mica substrates. Atomic force microscopy imaging indicated that these films were also soft with a surface roughness of 2nm under hydrated conditions. A zwitterionic phospholipid bilayer was then deposited on the polydopamine cushion by fusion of dimyristoylphosphatidylcholine (DMPC) and dioleoylphosphatidylcholine (DOPC) vesicles. Polydopamine films preserved the lateral mobility of the phospholipids as shown by fluorescence microscopy recovery after photobleaching (FRAP) experiments. Diffusion coefficients of ~5.9 and 7.2μm2 s-1 were respectively determined for DMPC and DOPC at room temperature, values which are characteristic of lipids in a free standing bilayer system. © 2012 by the authors.