laboratoire de physique statistique
 
 
laboratoire de physique statistique

Publications

Rechercher
Martine BEN AMAR 


JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 


1
P U B L I C A T I O N S



 
2009
Local Membrane Mechanics of Pore-Spanning Bilayers - Mey, Ingo and Stephan, Milena and Schmitt, Eva K. and Mueller, Martin Michael and Ben Amar, Martine and Steinem, Claudia and Janshoff, Andreas
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 1317031-7039 (2009) 
LPS


Abstract : The mechanical behavior of lipid bilayers; spanning the pores of highly ordered porous silicon substrates was scrutinized by local indentation experiments as a function of surface functionalization, lipid composition, solvent content, indentation velocity, and pore radius. Solvent-containing nano black lipid membranes (nano-BLMs) as well as solvent-free pore-spanning bilayers were imaged by fluorescence and atomic force microscopy prior to force curve acquisition, which allows distinguishing between membrane-covered and uncovered pores. Force indentation curves on pore-spanning bilayers attached to functionalized hydrophobic porous silicon substrates reveal a predominately linear response that is mainly attributed to prestress in the membranes. This is in agreement with the observation that indentation leads to membrane lysis well below 5\% area dilatation. However, membrane bending and lateral tension dominate over prestress and stretching if solvent-free supported membranes obtained from spreading giant liposomes on hydrophilic porous silicon are indented. An elastic regime diagram is presented that readily allows determining the dominant contribution to the mechanical response upon indentation as a function of load and pore radius.