title: Nanomechanical characterization of phospholipid bilayer islands on flat and porous substrates: a force spectroscopy study.
abstract: In this study, we compare for the first time the nanomechanical properties of lipid bilayer islands on flat and porous surfaces. 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) bilayers were deposited on flat (silicon and mica) and porous silicon (pSi) substrate surfaces and examined using atomic force spectroscopy and force volume imaging. Force spectroscopy measurements revealed the effects of the underlying substrate and of the lipid phase on the nanomechanical properties of bilayers islands. For mica and silicon, significant differences in breakthrough force between the center and the edges of bilayer islands were observed for both phospolipids. These differences were more pronounced for DMPC than for DPPC, presumably due to melting effects at the edges of DMPC bilayers. In contrast, bilayer islands deposited on pSi yielded similar breakthrough forces in the central region and along the perimeter of the islands, and those values in turn were similar to those measured along the perimeter of bilayer islands deposited on the flat substrates. The study also demonstrates that pSi is suitable solid support for the formation of pore-spanning phospholipid bilayers with potential applications in transmembrane protein studies, drug delivery, and biosensing.
authors: School of Chemistry, Physics and Earth Sciences, Flinders University, Sturt Road, Bedford Park, Adelaide, SA 5001, Australia.
authors: Matthew R
authors: MR
authors: Nussio
authors: Gerard
authors: G
authors: Oncins
authors: Ingrid
authors: I
authors: Ridelis
authors: Endre
authors: E
authors: Szili
authors: Joseph G
authors: JG
authors: Shapter
authors: Fausto
authors: F
authors: Sanz
authors: Nicolas H
authors: NH
authors: Voelcker
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry / Q000378:metabolism; D001696:Biomechanical Phenomena; D032701:Biomimetics; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism; D018625:Microscopy, Atomic Force; D036103:Nanotechnology; D010743:Phospholipids / Q000737:chemistry* / Q000378:metabolism; D016062:Porosity; D012825:Silicon / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000538:Aluminum Silicates; D008051:Lipid Bilayers; D010743:Phospholipids; C011934:mica; D012825:Silicon