Janzen J, Song X, Brooks D E
Department of Pathology, University of British Columbia, Vancouver, Canada.
Biophys J. 1996 Jan;70(1):313-20. doi: 10.1016/S0006-3495(96)79572-3.
The electrophoretic mobilities of liposomes incorporating a polyethylene glycol (PEG) headgroup coupled to cholesterol for PEG of average chain index 3.0, 13.2, and 22.3 have been determined as a function of PEG-cholesterol mole fraction between 5% and 40% and ionic strength between 2 and 200 mM. The liposome compositions were 40 mole % cholesterol plus PEG-cholesterol, 10 mole % 1,2-dipalmitoyl-sn-glyerco-3-phosphoglycerol, and 50 mole % egg phosphatidylcholine. The mobilities were fit to a model in which the PEG forms a surface layer of polymer subject to viscous drag arising from electroosmotic flow within this layer. The model provides estimates of the average layer thickness that are comparable to those determined from contemporary models of surface-attached polymer.
已测定了含有与胆固醇偶联的聚乙二醇（PEG）头基的脂质体的电泳迁移率，其中PEG的平均链指数分别为3.0、13.2和22.3，测定结果是PEG-胆固醇摩尔分数在5%至40%之间以及离子强度在2至200 mM之间时的函数。脂质体组成包括40摩尔%的胆固醇加PEG-胆固醇、10摩尔%的1,2-二棕榈酰-sn-甘油-3-磷酸甘油以及50摩尔%的鸡蛋磷脂酰胆碱。迁移率符合一个模型，在该模型中，PEG形成聚合物表面层，该表面层会受到此层内电渗流产生的粘性阻力影响。该模型提供的平均层厚度估计值与从当代表面附着聚合物模型确定的值相当。
