TY - JOUR
T1 - Correlation of AFM and SFA Measurements Concerning the Stability of Supported Lipid Bilayers
AU - Benz, Marcel
AU - Gutsmann, Thomas
AU - Chen, Nianhuan
AU - Tadmor, Rafael
AU - Israelachvili, Jacob
N1 - Funding Information:
This work was funded by the Swiss National Science Foundation, the National Science Foundation, through the Materials Research Science and Engineering Centers program (award no. DMR 9988640), the Materials Research Laboratory (MRL) program (award no. DMR00-80034), the National Institutes of Health (award no. 8R01EB00380-09 and GM65354), the NASA/URETI on Bio Inspired Materials (award no. NCC-1-02037), and the Deutsche Forschungsgemeinschaft (project GU 568/2-1).
PY - 2004/1/1
Y1 - 2004/1/1
N2 - Phospholipid bilayers were studied by means of atomic force microscopy (AFM) and a surface force apparatus (SFA). The stability of the supported bilayers was described by the amount of irregularities in the topography of the membrane by means of AFM and by the occurrence of hemifusion in the SFA, which is an indicator of defective bilayers. The bilayers, composed of lipids having the same headgroup but different chain lengths in the two leaflets, were prepared by Langmuir-Blodgett deposition and transferred at different surface pressures. The topography of the supported bilayers in aqueous solution, as imaged by AFM, revealed an increasing number of defects in the supported lipid membranes with decreased deposition pressure of the outer lipid layer. These defects, which appeared in the form of monolayer and bilayer (self-assembled) thick holes within the membrane, were energetically favorable over an evenly depleted bilayer. We found that the quantity of these defects (holes of ≤0.5 μm diameter and covering up to 30% of the surface area) correlated well with the stability of the bilayers as measured by SFA, a truly complementary instrument.
AB - Phospholipid bilayers were studied by means of atomic force microscopy (AFM) and a surface force apparatus (SFA). The stability of the supported bilayers was described by the amount of irregularities in the topography of the membrane by means of AFM and by the occurrence of hemifusion in the SFA, which is an indicator of defective bilayers. The bilayers, composed of lipids having the same headgroup but different chain lengths in the two leaflets, were prepared by Langmuir-Blodgett deposition and transferred at different surface pressures. The topography of the supported bilayers in aqueous solution, as imaged by AFM, revealed an increasing number of defects in the supported lipid membranes with decreased deposition pressure of the outer lipid layer. These defects, which appeared in the form of monolayer and bilayer (self-assembled) thick holes within the membrane, were energetically favorable over an evenly depleted bilayer. We found that the quantity of these defects (holes of ≤0.5 μm diameter and covering up to 30% of the surface area) correlated well with the stability of the bilayers as measured by SFA, a truly complementary instrument.
UR - http://www.scopus.com/inward/record.url?scp=1142286435&partnerID=8YFLogxK
U2 - 10.1016/S0006-3495(04)74162-4
DO - 10.1016/S0006-3495(04)74162-4
M3 - Article
AN - SCOPUS:1142286435
SN - 0006-3495
VL - 86
SP - 870
EP - 879
JO - Biophysical Journal
JF - Biophysical Journal
IS - 2
ER -