Gambinossi Filippo, Sefcik Lauren S, Wischerhoff Erik, Laschewsky Andre, Ferri James K
Department of Chemical and Biomolecular Engineering, Lafayette College , 740 High Street, Easton18042, Pennsylvania, United States.
ACS Appl Mater Interfaces. 2015 Feb 4;7(4):2518-28. doi: 10.1021/am507418m. Epub 2015 Jan 20.
Adhesion control in liquid-liquid-solid systems represents a challenge for applications ranging from self-cleaning to biocompatibility of engineered materials. By using responsive polymer chemistry and molecular self-assembly, adhesion at solid/liquid interfaces can be achieved and modulated by external stimuli. Here, we utilize thermosensitive polymeric materials based on random copolymers of di(ethylene glycol) methyl ether methacrylate (x = MEO2MA) and oligo(ethylene glycol) methyl ether methacrylate (y = OEGMA), that is, P(MEO2MAx-co-OEGMAy), to investigate the role of hydrophobicity on the phenomenon of adhesion. The copolymer ratio (x/y) dictates macromolecular changes enabling control of the hydrophilic-to-lipophilic balance (HBL) of the polymer brushes through external triggers such as ionic strength and temperature. We discuss the HBL of the thermobrushes in terms of the surface energy of the substrate by measuring the contact angle at water-decane-P(MEO2MAx-co-OEGMAy) brush contact line as a function of polymer composition and temperature. Solid supported polyelectrolyte layers grafted with P(MEO2MAx-co-OEGMAy) display a transition in the wettability that is related to the lower critical solution temperature of the polymer brushes. Using experimental observation of the hydrophilic to hydrophobic transition by the contact angle, we extract the underlying energetics associated with liquid-liquid-solid adhesion as a function of the copolymer ratio. The change in cellular attachment on P(MEO2MAx-co-OEGMAy) substrates of variable (x/y) composition demonstrates the subtle role of compositional tuning on the ability to control liquid-liquid-solid adhesion in biological applications.
液-液-固系统中的粘附控制对于从自清洁到工程材料生物相容性等一系列应用来说都是一项挑战。通过使用响应性聚合物化学和分子自组装技术，可以实现并通过外部刺激调节固/液界面处的粘附。在此，我们利用基于二（乙二醇）甲基醚甲基丙烯酸酯（x = MEO2MA）和低聚（乙二醇）甲基醚甲基丙烯酸酯（y = OEGMA）的无规共聚物的热敏聚合物材料，即P（MEO2MAx-co-OEGMAy），来研究疏水性在粘附现象中的作用。共聚物比例（x/y）决定了大分子变化，从而能够通过离子强度和温度等外部触发因素来控制聚合物刷的亲水-亲脂平衡（HBL）。我们通过测量水-癸烷-P（MEO2MAx-co-OEGMAy）刷接触线处的接触角作为聚合物组成和温度的函数，根据底物的表面能来讨论热刷的HBL。接枝有P（MEO2MAx-co-OEGMAy）的固体支持聚电解质层表现出与聚合物刷的低临界溶液温度相关的润湿性转变。通过接触角对亲水到疏水转变的实验观察，我们提取了与液-液-固粘附相关的潜在能量学作为共聚物比例的函数。在可变（x/y）组成的P（MEO2MAx-co-OEGMAy）底物上细胞附着的变化证明了组成调节在生物应用中控制液-液-固粘附能力方面的微妙作用。
