Scrutiny of the failure of lipid membranes as a function of headgroups, chain length, and lamellarity measured by scanning force microscopy.

A fast, quantitative, and unambiguous screening of material properties of biomembranes using scanning force microscopy in pulsed force mode on lipid membranes is presented. The spatially resolved study of breakthrough force, breakthrough distance, adhesion, stiffness, and topography of lipid membranes as determined simultaneously by digitalized pulsed force mode provides new insight into the structure-function relationship of model membranes, which are systematically analyzed by varying chain length, lipid headgroup, and lamellarity. For this purpose, a novel unbiased analysis method is presented. A strong correlation between adhesion and breakthrough events is found on lipid bilayers and multilayers and discussed in terms of structural stability and chemical and physical interactions. Our findings indicate that multilamellar 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoserine is mechanically strengthened with respect to material failure by calcium ions in solution.