The biorecognition‐based control of attachment/detachment of MCF‐7 cancer cells from polymer‐coated surfaces is demonstrated. A glass surface is coated with a thermoresponsive statistical copolymer of poly(N‐isopropylacrylamide‐co‐acrylamide) [p(NIPAm‐co‐Am)], which is end‐capped with the Gly‐Arg‐Gly‐Asp‐Ser (GRGDS) peptide, and the hydrophilic polymer poly(ethylene glycol) (PEG). Below the lower critical solution temperature (LCST) of p(NIPAm‐co‐Am) (38 °C), the copolymers are in the extended conformation, allowing for accessibility of the GRGDS peptides to membrane‐associated integrins thus enabling cell attachment. Above the LCST, the p(NIPAm‐co‐Am) polymers collapse into globular conformations, resulting in the shielding of the GRGDS peptides into the PEG brush with consequent inaccessibility to cell‐surface integrins, causing cell detachment. The surface coating is carried out by a multi‐step procedure that included: glass surface amination with 3‐aminopropyltriethoxysilane; reaction of mPEG_5kDa‐N‐hydroxysuccinimide (NHS) and p(NIPam‐co‐Am)_15.1kDa‐bis‐NHS with the surface aminopropyl groups and conjugation of GRGDS to the carboxylic acid termini of p(NIPam‐co‐Am)_15.1kDa‐COOH. A range of spectrophotometric, surface, and microscopy assays confirmed the identity of the polymer‐coated substrates. Competition studies prove that MCF‐7 cancer cells are attached via peptide recognition at the coated surfaces according to the mPEG_5kDa/p(NIPam‐co‐Am)_15.1kDa‐GRGDS molar ratio. These data suggest the system can be exploited to modulate cell integrin/GRGDS binding for controlled cell capture and release.

中文翻译：

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用于基于生物识别的细胞粘附和受控分离的热敏“智能”表面

证明了基于生物识别的 MCF-7 癌细胞从聚合物涂层表面的附着/脱离控制。玻璃表面涂有聚(N-异丙基丙烯酰胺-共-丙烯酰胺) [p(NIPAm-co-Am)] 的热响应统计共聚物，其末端为 Gly-Arg-Gly-Asp-Ser (GRGDS) ) 肽和亲水聚合物聚 (乙二醇) (PEG)。在低于 p(NIPAm-co-Am) (38 °C) 的临界溶解温度 (LCST) 下，共聚物处于扩展构象，允许 GRGDS 肽与膜相关整合素相接触，从而实现细胞附着。在 LCST 之上，p(NIPAm-co-Am) 聚合物塌陷成球状构象，导致 GRGDS 肽被屏蔽到 PEG 刷中，从而无法进入细胞表面整合素，导致细胞脱离。表面涂层通过多步程序进行，包括：用 3-氨基丙基三乙氧基硅烷进行玻璃表面胺化；mPEG的反应_5kDa -N-羟基琥珀酰亚胺 (NHS) 和 p(NIPam-co-Am) _{15.1kDa -bis} -NHS 具有表面氨基丙基和 GRGDS 与 p(NIPam-co-Am) _15.1kDa -COOH的羧酸末端的共轭. 一系列分光光度法、表面和显微镜检测证实了聚合物涂层基材的身份。竞争研究证明，根据 mPEG _5kDa /p(NIPam-co-Am) _15.1kDa -GRGDS 摩尔比，MCF-7 癌细胞通过肽识别附着在涂层表面。这些数据表明该系统可用于调节细胞整合素/GRGDS 结合以控制细胞捕获和释放。