Majewski J, Wong J Y, Park C K, Seitz M, Israelachvili J N, Smith G S
Manuel Lujan, Jr. Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Biophys J. 1998 Nov;75(5):2363-7. doi: 10.1016/S0006-3495(98)77680-5.
The structure of softly supported polymer-cushioned lipid bilayers, prepared in two different ways at the quartz-solution interface, were determined using neutron reflectometry. The polymer cushion consisted of a thin layer of branched, cationic polyethyleneimine (PEI), and the bilayers were formed by adsorption of small unilamellar dimyristoylphosphatidylcholine (DMPC) vesicles. When vesicles were first allowed to adsorb to a bare quartz substrate, an almost perfect bilayer formed. When the polymer was then added to the aqueous solution, it appeared to diffuse beneath this bilayer, effectively lifting it from the substrate. In contrast, if the polymer layer is adsorbed first to the bare quartz substrate followed by addition of vesicles to the solution, there is very little interaction of the vesicles with the polymer layer, and the result is a complex structure most likely consisting of patchy multilayers or adsorbed vesicles.
通过中子反射测量法确定了在石英 - 溶液界面以两种不同方式制备的软支撑聚合物缓冲脂质双层的结构。聚合物缓冲层由一层薄的支化阳离子聚乙烯亚胺(PEI)组成,双层由小单层二肉豆蔻酰磷脂酰胆碱(DMPC)囊泡吸附形成。当囊泡首先被允许吸附到裸露的石英基板上时,形成了几乎完美的双层。然后当将聚合物添加到水溶液中时,它似乎在该双层下方扩散,有效地将其从基板上抬起。相比之下,如果首先将聚合物层吸附到裸露的石英基板上,然后向溶液中添加囊泡,则囊泡与聚合物层的相互作用非常小,结果是形成一个很可能由斑驳的多层或吸附的囊泡组成的复杂结构。