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Control of Lipid Bilayer Phases of Cell-Sized Liposomes by Surface-Engineered Plasmonic Nanoparticles
journal contribution
posted on 2020-06-19, 16:33 authored by Tomohiro Nobeyama, Kazuki Shigyou, Hirotaka Nakatsuji, Hiroshi Sugiyama, Naoko Komura, Hiromune Ando, Tsutomu Hamada, Tatsuya MurakamiLiquid-ordered
(Lo)-phase domains, a cholesterol-rich area on lipid
bilayers, have attracted significant attention recently because of
their relevance to lipid rafts, the formation/collapse of which is
associated with various kinds of information exchange through the
plasma membrane. Here, we demonstrate that the formation/collapse
of Lo-phase domains in cell-sized liposomes, that is, giant unilamellar
vesicles (GUVs), can be controlled with bioactive plasmonic nanoparticles
and light. The nanoparticles were prepared by surface modification
of gold nanorods (AuNRs) using a cationized mutant of high-density
lipoprotein (HDL), which is a natural cholesterol transporter. Upon
the addition of surface-engineered AuNRs to GUVs with the mixed domains
of Lo and liquid-disorder (Ld) phases, the Lo domains collapsed and
solid-ordered (So)-phase domains were formed. The reverse phase transition
was achieved photothermally, with the AuNRs loaded with cholesterol.
During these transitions, the AuNRs appeared to be selectively localized
on the less fluidic domain (Lo or So) in the phase-mixed GUVs. These
results indicate that the phase transitions occur through the membrane
binding of the AuNRs followed by spontaneous/photothermal transfer
of cholesterol between the AuNRs and GUVs. Our strategy to develop
bioactive AuNRs potentially enables spatiotemporal control of the
formation/collapse of lipid rafts in living cells.