Van Alstine J M, Malmsten M, Brooks D E
Department of Chemistry, University of Alabama, Huntsville, 35899, USA.
J Chromatogr B Biomed Appl. 1996 May 17;680(1-2):145-55. doi: 10.1016/0378-4347(95)00393-2.
Surface localized poly(ethylene glycol) (PEG) amphiphiles of type C16:0-EO151 and C18:2-EO151 were studied via ellipsometry at macroscopic, flat methylated silica (MeSi), phosphatidic acid (PA), and phosphatidylcholine (PC) surfaces. At these surfaces the amphiphiles adsorb similarly, in a non-cooperative manner, achieving a plateau (approximately 0.1 PEG chains/nm2) well below amphiphile critical micelle concentration (CMC). The resultant PEG-enriched layers were 10-15 nm thick, with a polymer concentration (approximately 0.07 g/cm3) greater than the PEG-enriched phase of many dextran, PEG aqueous two-phase systems. PEG-amphiphile adsorption (mg/m2) at hydrophobic and phospholipid flat surfaces correlated with changes in the partition (log K) of PC liposomes in such two-phase systems. PEG-amphiphile adsorption at macroscopic surfaces appears to represent a balance between hydrophobic attraction and repulsive intra-chain interactions which promote chain elongation normal to the surface.
通过椭偏测量法，在宏观的、平整的甲基化二氧化硅（MeSi）、磷脂酸（PA）和磷脂酰胆碱（PC）表面研究了C16:0 - EO151型和C18:2 - EO151型的表面定位聚乙二醇（PEG）两亲物。在这些表面上，两亲物以非协同方式类似地吸附，在远低于两亲物临界胶束浓度（CMC）的情况下达到一个平稳状态（约0.1个PEG链/纳米²）。所得富含PEG的层厚度为10 - 15纳米，聚合物浓度（约0.07克/立方厘米）高于许多葡聚糖、PEG水相双相体系中富含PEG的相。在疏水和平坦磷脂表面的PEG - 两亲物吸附量（毫克/平方米）与PC脂质体在这种双相体系中的分配变化（log K）相关。在宏观表面的PEG - 两亲物吸附似乎代表了疏水吸引力和促进链垂直于表面伸长的链内排斥相互作用之间的平衡。
