Formation, stability, and mobility of one-dimensional lipid bilayers on polysilicon nanowires.
Curved lipid membranes are ubiquitous in living systems and play an important role in many biological processes. To understand how curvature and lipid composition affect membrane formation and fluidity, we have assembled and studied mixed 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) supported lipid bilayers on amorphous silicon nanowires grown around carbon nanotube cores with controlled wire diameters ranging from 20 to 200 nm. We found that lipid vesicles fused onto nanowire substrates and formed continuous bilayers for all DOPC-DOPE mixtures tested (with the DOPE content of up to 30%). Our measurements demonstrate that nanowire-supported bilayers are mobile, exhibit fast recovery after photobleaching, and have a low concentration of defects. Lipid diffusion coefficients in these high-curvature tubular membranes are comparable to the values reported for flat supported bilayers and increase slightly with decreasing nanowire diameter. A free space diffusion model adequately describes the effect of bilayer curvature on the lipid mobility for nanowire substrates with diameters greater than 50 nm, but shows significant deviations from the experimental values for smaller diameter nanowires.
Huang
Shih-Chieh J
SC
Chemistry, Materials, and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
Artyukhin
Alexander B
AB
Martinez
Julio A
JA
Sirbuly
Donald J
DJ
Wang
Yinmin
Y
Ju
Jiann-Wen
JW
Stroeve
Pieter
P
Noy
Aleksandr
A
D001709:Biotechnology / Q000379:methods; D004058:Diffusion; D004867:Equipment Design; D008051:Lipid Bilayers / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry; D018613:Microscopy, Confocal; D036103:Nanotechnology / Q000379:methods*; D053770:Nanowires / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000737:chemistry*; D010714:Phosphatidylethanolamines / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D013997:Time Factors
C410262:1,2-dioleoyl-glycero-3-phosphatidyl ethanolamine; D008051:Lipid Bilayers; D008055:Lipids; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; C017251:1,2-oleoylphosphatidylcholine; D012825:Silicon