中文摘要：

以壳聚糖（CS）为原料,在1-乙基-3-（3-二甲胺丙基）碳-二亚胺盐酸盐（EDC.HCL）和N-羟基琥珀酰亚胺（NHS）的活化作用下,合成了半乳糖基化壳聚糖（GC）单体,并与N-异丙基丙烯酰胺（NIPAAm）反应,制备了温敏性半乳糖基化壳聚糖N-异丙基丙烯酰胺共聚水凝胶（Gal-CS-g-PNIPAAm）.通过红外光谱（FTIR）、光电子能谱（XPS）和扫描电子显微镜（SEM）等测试方法对其成分和结构进行了表征,并对其溶胀率和表面亲疏水性进行了研究.在Gal-CS-g-PNIPAAm凝胶表面培养人正常肝细胞系（HL-7702）,研究其生长、脱附及转载（再增殖）行为.结果表明Gal-CS-g-PNIPAAm水凝胶具有良好的温度响应性和生物相容性,与PNIPAAm水凝胶相比,Gal-CS-g-PNIPAAm凝胶表面更有利于HL-7702细胞增殖.将温度降低至临界温度（LCST,32.5℃）以下,细胞可以从凝胶表面自发脱附,与酶消化脱附相比,细胞损伤更少.Gal-CS-g-PNIPAAm凝胶表面脱附的细胞比PNIPAAm凝胶表面脱附的细胞活性更高,表明PNIPAAm水凝胶引入GC单体后,凝胶的生物相容性得到改善,且脱附后细胞的增殖活力明显增加.

英文摘要：

The galactosylated chitosan （GC） was synthesized by the reaction of the amino group of chitosan and carboxyl group of laetobionic acid under the activation of lethyl3-（3dimethyllaminopropyl）carbodiimide hydrochloride （EDC） and N-hydroxysulfosuccinimide sodium salt （NHS）. Subsequently, thermo-sensitive galactosylated chitosan-grafi-poly（N-isopropylacrylamide） （GaI-CS-g-PNIPAm） hydrogels were prepared via free radical polymerization method. The chemical composition and structure of the novel copolymer obtained were characterized by Fourier transform infrared spectroscopy （FTIR）, X-ray photoelectron spectroscopy （XPS） and scanning electron microscopy （SEM）, respectively. Thermo-sensitive feature of the hydrogel was studied by measuring its swelling ratio and contact angle. The results showed that Gal-CS-g-PNIPAm hydrogels exhibited good temperature response. HL-7702 cell behaviors such as proliferation, detachment and cell transfer were carefully investigated via cell culture on the surface of Gal-CS-g-PNIPAAm hydrogels in vitro. The results indicated that Gal-CS-g-PNIPAAm hydrogel exhibited a good biocompatibility. HL-7702 cells cultured on this hydrogel surface proliferated better than on the PNIPAAm hydrogel. Besides, HL-7702 cells could spontaneously detach from the surface of the Gal-CS-g-PNIPAAm hydrogel by lowering the temperature below the LCST （32.5℃ ） ,and the detached cells showed less damage than those detached by enzymes from TCPS. Meanwhile,cells detached from Gal-CS-g-PNIPAAm hydrogel showed higher viability than those from the PNIPAAm hydrogel, suggesting that introduction of GC monomer to PNIPAAm hydrogel evidently improved the activity of the detached cells.