Ernst Oliver, Lieske Antje, Jäger Magnus, Lankenau Andreas, Duschl Claus
Fraunhofer Institute for Biomedical Engineering, Am Mühlenberg 13, 14476 Potsdam, Germany.
Lab Chip. 2007 Oct;7(10):1322-9. doi: 10.1039/b708619a. Epub 2007 Aug 6.
The control of cell adhesion is crucial in many procedures in cellular biotechnology. A thermo-responsive poly(N-isopropylacrylamide)-poly(ethylene glycol)-thiol (PNIPAAm-PEG-thiol) copolymer was synthesized for the formation of self-assembled monolayers (SAM) that allow the control of adhesion of cells on gold substrates. The contact angle of water on these layers varies between 65 degrees at a temperature of 45 degrees C and 54 degrees at 25 degrees C. This behaviour is consistent with a transition of the polymer chains from an extended and highly hydrated to a collapsed coil-like state. At 37 degrees C, cultivated fibroblasts adhere and spread normally on this surface and detach by reducing the temperature below the lower critical solution temperature (LCST). Layers can repeatedly be used without loss of their functionality. In order to quantify the capability of the copolymer layer to induce cell detachment, defined shear forces are applied to the cells. For this purpose, the laminar flow in a microfluidic device is used. Our approach provides a strategy for the optimization of layer properties that is based on establishing a correlation between a functional parameter and molecular details of the layers.
细胞黏附的控制在细胞生物技术的许多过程中至关重要。合成了一种热响应性聚（N-异丙基丙烯酰胺）-聚（乙二醇）-硫醇（PNIPAAm-PEG-硫醇）共聚物，用于形成自组装单分子层（SAM），从而实现对细胞在金基底上黏附的控制。水在这些层上的接触角在45℃时为65度，在25℃时为54度。这种行为与聚合物链从伸展且高度水合状态转变为塌陷的盘绕状状态一致。在37℃时，培养的成纤维细胞在该表面正常黏附并铺展，通过将温度降低到低临界溶液温度（LCST）以下而脱离。这些层可以反复使用而不丧失其功能。为了量化共聚物层诱导细胞脱离的能力，对细胞施加确定的剪切力。为此，使用微流控装置中的层流。我们的方法提供了一种优化层性质的策略，该策略基于建立功能参数与层的分子细节之间的相关性。
