Novel biodegradable terpolymer poly (1,3‐trimethylene carbonate‐b‐(l‐lactide‐r‐glycolide)) grafted with poly(N‐isopropylacrylamide) (PTLG‐PNIPAAm) is prepared by plasma‐induced polymerization. The experimental results show that PNIPAAm segments of samples have a dramatic effect on surface layer structure and cell behavior of PTLG‐PNIPAAm. The thickness of PNIPAAm layer on PTLG surface increases rapidly from 50 nm to 1 µm with the molecular weight of samples increasing. Cell toxicity analysis indicates that PTLG‐PNIPAAm possesses good cytocompatibility to human adipose‐derived stem cells (hADSCs). For cell adhesion and detachment process on modified surface, the “hook and loop” process is proposed to understand the cell adhesion on modified surface with coiled conformation PNIPAAm segments at 37 °C, and then the cell sheet detached from surface spontaneously due to the conformation of PNIPAAm segments extends below its lower critical solution temperature. The research demonstrates that with increasing thickness of the PNIPAAm layer on PTLG surface, the hADSCs with well cell viability presents rapider thermal‐responsive detachment behavior. Therefore, the surface modification of biodegradable PTLG with stimuli‐sensitive functional PNIPAAm is an efficacious route for further application in stem cell culture and tissue engineering stent.

中文翻译：

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PNIPAAm对PTLG三元共聚物的表面改性及其细胞粘附/脱离行为

新型可降解三元共聚物聚（1,3-三亚甲基碳酸酯b - （升-lactide- ř -glycolide）），与聚接枝（Ñ异丙基丙烯酰胺（PTLG-PNIPAAm）是通过等离子诱导聚合制备的。实验结果表明，样品的PNIPAAm片段对PTLG-PNIPAAm的表面层结构和细胞行为具有显着影响。随着样品分子量的增加，PTLG表面上PNIPAAm层的厚度从50 nm迅速增加到1 µm。细胞毒性分析表明，PTLG-PNIPAAm与人类脂肪干细胞（hADSCs）具有良好的细胞相容性。对于修饰表面上的细胞粘附和脱离过程，提出“钩环”过程以了解在37°C下具有卷曲构象PNIPAAm片段的修饰表面上的细胞粘附，然后由于构象而自发地从表面剥离细胞片PNIPAAm链段的延伸延伸至其较低的临界溶解温度以下。研究表明，随着PTLG表面PNIPAAm层厚度的增加，具有良好细胞生存力的hADSCs表现出更快的热响应性分离行为。因此，用刺激敏感的功能性PNIPAAm对可生物降解的PTLG进行表面修饰是在干细胞培养和组织工程支架中进一步应用的有效途径。