Controllable Stabilization of Poly(N-isopropylacrylamide)-Based Microgel Films through Biomimetic Mineralization of Calcium Carbonate

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• 作者：Yongqing Xia ; Yanfeng Gu ; Xuan Zhou ; Hai Xu ; Xiubo Zhao ; Mohammed Yaseen ; Jian Ren Lu
• 刊名：Biomacromolecules
• 出版年：2012
• 出版时间：August 13, 2012
• 年：2012
• 卷：13
• 期：8
• 页码：2299-2308
• 全文大小：668K
• 年卷期：v.13,no.8(August 13, 2012)
• ISSN：1526-4602

文摘

Two types of thermoresponsive microgels, poly(N-isopropylacrylamide) (PNIPAM) microgels and poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAMAC) microgels were synthesized and used as templates for the mineralization of amorphous calcium carbonate (ACC) by diffusion of CO₂ vapor under ambient conditions. Thermosensitive PNIPAM/CaCO₃ hybrid macroscopic hydrogels and micrometer-sized PNIPAMAC/CaCO₃ hybrid microgels were controllably obtained and different mineralization mechanistic processes were proposed. The impact of the loaded CaCO₃ on the size, morphology, stability, and thermosensitivity of the microgels was also analyzed. PNIPAM/CaCO₃ hybrid macrogels had a slight decrease in thermoresponsive phase transition temperature, while PNIPAMAC/CaCO₃ hybrid microgels showed a clear increase in phase transition temperature. The difference reflected different amount and location of ACC in the gel network, causing different interactions with polymer chains. The PNIPAMAC/CaCO₃ microgels formed stable monolayer films on bare silica wafers and glass coverslips upon drying. The microgel films could facilitate the attachment and growth of 3T3 fibroblast cells and their subsequent detachment upon temperature drop from 37 掳C to the ambient condition around 20 掳C, thus, offering a convenient procedure for cell harvesting.