Banquy Xavier, Lee Dong Woog, Kristiansen Kai, Gebbie Matthew A, Israelachvili Jacob N
Canada Research Chair in Bio-Inspired Materials, Faculté de Pharmacie, Université de Montréal , C.P. 6128, Succursale Centre-ville, Montréal, Québec H3T1J4, Canada.
Biomacromolecules. 2016 Jan 11;17(1):88-97. doi: 10.1021/acs.biomac.5b01216. Epub 2015 Dec 14.
Using the surface forces apparatus (SFA), interaction forces between supported lipid bilayers were measured in the presence of polyethylene glycol and two other commercially available pegylated triblock polymers, Pluronic F68 and F127. Pluronic F68 has a smaller central hydrophobic block compared to F127 and therefore is more hydrophilic. The study aimed to unravel the effects of polymer architecture and composition on the interactions between the bilayers. Our keys findings show that below the critical aggregation concentration (CAC) of the polymers, a soft, weakly anchored, polymer layer is formed on the surface of the bilayers. The anchoring strength of this physisorbed layer was found to increase significantly with the size of the hydrophobic block of the polymer, and was strongest for the more hydrophobic polymer, F127. Above the CAC, a dense polymer layer, exhibiting gel-like properties, was found to rapidly grow on the bilayers even after mechanical disruption. The cohesive interaction maintaining the gel layer structure was found to be stronger for F127, and was also found to promote the formation of highly structured aggregates on the bilayers.
使用表面力仪（SFA），在聚乙二醇以及另外两种市售的聚乙二醇化三嵌段聚合物（普朗尼克F68和F127）存在的情况下，测量了支撑脂质双层之间的相互作用力。与F127相比，普朗尼克F68的中央疏水嵌段较小，因此更具亲水性。该研究旨在揭示聚合物结构和组成对双层之间相互作用的影响。我们的主要发现表明，在聚合物的临界聚集浓度（CAC）以下，双层表面形成了一个柔软、弱锚定的聚合物层。发现该物理吸附层的锚定强度随着聚合物疏水嵌段尺寸的增加而显著增加，对于疏水性更强的聚合物F127来说最强。在CAC以上，即使在机械破坏后，也发现一个表现出凝胶状特性的致密聚合物层在双层上迅速生长。发现维持凝胶层结构的内聚相互作用对于F127更强，并且还发现其促进了双层上高度结构化聚集体的形成。
