机构地区: 华南理工大学材料科学与工程学院材料科学研究所
出 处: 《化学进展》 2011年第11期2353-2359,共7页
摘 要: 聚N-异丙基丙烯酰胺(PNIPAm)在水中是具有温度响应性的智能高分子材料,可用于细胞培养和自动脱附。本文从材料的制备方法出发,介绍了电子束照射接枝、等离子体处理接枝、表面活性自由基聚合、水凝胶等方法制备的材料对细胞培养及脱附的影响;阐述了细胞的脱附机理;讨论了加快细胞脱附的方法,包括共聚改性PNIPAm、PNIPAm接枝多孔膜、聚乙二醇(PEG)共聚PNIPAm接枝多孔膜、聚偏氟乙烯(PVDF)膜辅助细胞转移。从PNIPAm温敏性材料表面智能分离得到的细胞片因结构完整并保留了细胞外基质成分,在组织修复中得到了应用。 Poly(N-isopropylacrylamide)(PNIPAm) exhibits temperature-response due to the hydrophilic-hydrophobic transition in aqueous solutions and hydrogels at the lower critical solution temperature(LCST).This characteristic has been used for cell proliferation at the hydrophobic PNIPAm surface and spontaneous detachment of the cell sheet upon the hydrophilic transition at LCST.In this review,several methods were introduced to prepare temperature-responsive substrates for the cell culture,proliferation and detachment,including electron beam irradiation grafting,plasma treatment grafting,living radical polymerization on surface,and hydrogels.The two-step mechanism of spontaneous cell detachment from the PNIPAm modified substrates was briefly discussed considering the hydrophilic-hydrophobic transition and the cells' shape change induced by the cell metabolism.The limitation of this mechanism to other sorts of cells was pointed out.Some approaches to accelerate the spontaneous detachment of cells from PNIPAm modified substrates for rapid cell harvest were described,such as copolymerization of PNIPAm to increase hydrophilicity below the LCST,PNIPAm grafted porous membrane for fast water diffusion,poly(ethylene glycol)-co-PNIPAm grafted porous membrane for increasing hydrophilicity,and poly(vinylidene difluoride) membrane assistant cell transfer.Cell sheets harvested from the temperature-responsive PNIPAm substrates by lowering the temperature without enzymatic treatment retained their intact structure with the cell-cell junctions and deposited extracellular matrices(ECM),which promised applications in tissue repair.