Thermoresponsive PEG-Based Polymer Layers: Surface Characterization with AFM Force Measurements

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• 作者：Stefanie Kessel ; Stephan Schmidt ; Renate Mller ; Erik Wischerhoff ; Andr Laschewsky ; Jean-Franois Lutz ; Katja Uhlig ; Andreas Lankenau ; Claus Duschl ; Andreas Fery
• 刊名：Langmuir
• 出版年：2010
• 出版时间：March 2, 2010
• 年：2010
• 卷：26
• 期：5
• 页码：3462-3467
• 全文大小：784K
• 年卷期：v.26,no.5(March 2, 2010)
• ISSN：1520-5827

文摘

Thermoresponsive polymer-coated surfaces based on poly(2-(2-methoxyethoxy)ethyl methacrylate-co-oligo(ethylene glycol) methacrylate) [P(MEO₂MA-co-OEGMA)] allow switching between cell attachment and detachment. Here, we investigate the temperature-dependent surface interactions between the polymer coating and a colloidal probe in an aqueous medium by means of atomic force microscopy (AFM) force−distance measurements. The analysis of the adhesion forces from AFM retraction curves indentifies two kinds of regimes for the copolymer at temperatures below and above the lower critical solution temperature (LCST). Whereas at 25 °C the surface interactions with the polymer in the swollen state are dominated by repulsive forces, at 37 °C the surface interactions switch to attractive forces and a stronger adhesion is detected by AFM. Running several heating/cooling cycles repeatedly shows that switching the surface properties provides reproducible adhesion force values. Time-dependent measurements give insight into the switching kinetics, demonstrating that the cell response is coupled to the polymer kinetics but probably limited by the cellular rearrangements.