Patterning adjacent supported lipid bilayers of desired composition to investigate receptor-ligand binding under shear flow
Patterning adjacent supported lipid bilayers of desired composition to investigate receptor-ligand binding under shear flow
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DOI：
10.1021/la0489099
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发表时间：
2004-11-09
期刊：
影响因子：
3.9
通讯作者：
Wong, JY
中科院分区：
文献类型：
--
作者：
Burridge, KA;Figa, MA;Wong, JY
为了实现有效的靶向，含有药物或成像剂的载体必须具有促进与靶结合但同时阻止快速免疫系统清除的表面性质。在这里，我们描述了一种通用的技术，允许同时比较的载体表面组合物在相同的流动条件下的结合性能的影响。模拟脂质体递送载体表面的支撑脂质双层的平行泳道使用囊泡融合方法在经由标准软光刻技术产生的微流体通道中形成。将囊泡储备溶液预混合并注入由可逆密封到载玻片上的聚（二甲基硅氧烷）（PDMS）印模形成的泳道中，以产生不同组成的相邻泳道。在去除印模之后，在将图案化的基底组装到流动室中用于结合研究之前，使用牛血清白蛋白（BSA）的吸附层来防止双层扩散。该方法的优点包括从无限数量的脂质类型中容易且快速地制备具有所需组成的双层、特征尺寸的选择、时间稳定的特征和低非特异性结合。数十微米量级的特征尺寸允许在一个视场中分析多种成分，从而减少实验数量，确保相同的流动条件，并能够同时纳入对照。我们表明，脂质和配体之间的长聚（乙二醇）（PEG）系链（MW 2000）的存在下，结果在更高的分离阻力相比，一个短的六碳间隔。
To achieve efficient targeting, carriers containing either drugs or imaging agents must have surface properties that promote binding to targets yet at the same time block rapid immune system clearance. Here we describe a versatile technique that allows simultaneous comparison of the effects of carrier surface composition on binding properties under identical flow conditions. Parallel lanes of supported lipid bilayers that mimic the surface of liposomal delivery vehicles are formed using the vesicle fusion method in microfluidic channels created via standard soft lithography techniques. Vesicle stock solutions are premixed and injected into lanes formed by a poly(dimethylsiloxane) (PDMS) stamp reversibly sealed to a glass slide to create adjacent lanes of distinct composition. After removing the stamp, an adsorbed layer of bovine serum albumin (BSA) is used to prevent bilayer spreading before assembling the patterned substrate into a flow chamber for binding studies. Advantages of this method include easy and rapid preparation of bilayers with desired compositions from an unlimited number of lipid types, choice of feature size, time-stable features, and low nonspecific binding. Feature sizes on the order oftens of microns allow multiple compositions to be analyzed in one field of view, thereby reducing the number of experiments, ensuring identical flow conditions, and enabling simultaneous incorporation of controls. We show that the presence of a long poly(ethylene glycol) (PEG) tether (MW 2000) between the lipid and ligand results in higher detachment resistances as compared to a short six-carbon spacer.