Composition and structure of mixed phospholipid supported bilayers formed by POPC and DPPC

TY - JOUR

T1 - Composition and structure of mixed phospholipid supported bilayers formed by POPC and DPPC

AU - Åkesson, Anna Karin Louise

AU - Lind, Tania Kjellerup

AU - Ehrlich, Nicky

AU - Stamou, Dimitrios

AU - Wacklin, Hanna

AU - Cardenas Gomez, Marite

PY - 2012/5/28

Y1 - 2012/5/28

N2 - In this paper we present a systematic study of the morphology and composition of supported lipid bilayers (SLBs) formed by vesicle fusion using a wide variety of surface sensitive techniques that give information about the lateral as well as vertical structure and bilayer fluidity. SLBs of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1,2-dipalmitoyl-sn- glycero-3-phosphocholine (DPPC) mixtures at five different bulk vesicle compositions were formed in such a way that the phase separation boundaries were crossed. For all compositions studied, the SLBs were systematically enriched with POPC compared to the nominal vesicle composition. Nevertheless, gel-fluid domain coexistence was observed for SLB compositions in which phase separation was expected based on the bulk phase diagram. The probable causes for the compositional difference in the SLBs are discussed in terms of the phase behaviour of the mixture and its effect on the membrane formation process by vesicle fusion.

AB - In this paper we present a systematic study of the morphology and composition of supported lipid bilayers (SLBs) formed by vesicle fusion using a wide variety of surface sensitive techniques that give information about the lateral as well as vertical structure and bilayer fluidity. SLBs of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1,2-dipalmitoyl-sn- glycero-3-phosphocholine (DPPC) mixtures at five different bulk vesicle compositions were formed in such a way that the phase separation boundaries were crossed. For all compositions studied, the SLBs were systematically enriched with POPC compared to the nominal vesicle composition. Nevertheless, gel-fluid domain coexistence was observed for SLB compositions in which phase separation was expected based on the bulk phase diagram. The probable causes for the compositional difference in the SLBs are discussed in terms of the phase behaviour of the mixture and its effect on the membrane formation process by vesicle fusion.

U2 - 10.1039/c2sm00013j

DO - 10.1039/c2sm00013j

M3 - Journal article

SN - 1744-683X

VL - 8

SP - 5658

EP - 5665

JO - Soft Matter

JF - Soft Matter

IS - 20

ER -