壳聚糖/纳米多层结构羟基磷灰石/明胶复合膜的性能

Properties of the composite membrane of chitosan/ nanometer multilayer hydroxyapatite/gelatin

背景：壳聚糖和明胶具有良好生物相容性和生物可降解特性。壳聚糖/羟基磷灰石和明胶/羟基磷灰石复合材料作为骨组织支架的应用研究也越来越多得到人们的关注。目的：制备一种生物相容性好的壳聚糖/纳米多层结构羟基磷灰石/明胶复合膜,探讨其是否可作为潜在的骨修复和再生的组织支架材料。设计：对比观察。单位：江汉大学化学与环境工程学院。材料：实验于2007-02/08在江汉大学化学与环境工程学院精细化工实验室完成。壳聚糖（浙江玉环海洋生物化学有限公司,重均相对分子质量为1.344×105,脱乙酰度为93%）,明胶（上海医药公司）。方法：壳聚糖/氯化钙溶液在玻璃板上通过流延法形成壳聚糖/氯化钙复合膜。壳聚糖/氯化钙复合膜分别浸泡在磷酸二氢钾溶液,0.1mol/L氢氧化钠溶液和质量分数为0.03的明胶溶液中,所得的复合膜洗涤并干燥得到壳聚糖/羟基磷灰石/明胶复合膜。重复上述过程,得到具有多层纳米羟基磷灰石的壳聚糖/羟基磷灰石/明胶复合膜。扫描电镜观察复合膜的断裂面及膜内羟基磷灰石的形貌。用GMT6503型微机控制电子万能试验机测定壳聚糖膜和复合膜的拉伸强度和断裂伸长率。用WCT-2C微机差热天平测定复合膜的热稳定性。主要观察指标：扫描电镜下复合膜的断裂面及膜内羟基磷灰石的形貌。测定复合膜的力学性能及热稳定性。结果：①扫描电镜下复合膜内羟基磷灰石晶体为厚400nm的多层结构。②随着沉积次数逐渐增加,复合膜的拉伸强度和断裂伸长率分别为3.83~10.25MPa,3.97%~10.14%。③复合膜的热分解温度为310℃,高于壳聚糖/明胶复合膜的热分解温度（305℃）。结论：通过在壳聚糖/氯化钙溶液、磷酸二氢钾溶液、氢氧化钠溶液和明胶溶液中交替沉积方法制备的壳聚糖/羟基磷灰石/明胶复合膜具有良好的生物相容性和较大的界面积,可作为一种潜在的组织支架材料。

BACKGROUND： Chitosan and gelatin have good biocompatibility and biodegradable properties. More and more attentions have been given to the application of the composite membrane of chitosan/hydroxyapatite （HA） and gelatin/HA as the tissue scaffolds. OBJECTIVE： To prepare a biocompatible composite membrane of chitosan/HA/gelatin having nanometer multilayer HA, and to investigate whether such a membrane might be a candidate of the tissue scaffolds for the bond repair and regeneration. DESIGN： Controlled observation. SETTING： College of Chemistry and Environmental Engineering, Jianghan University MATERIALS： The experiments were performed at the Laboratory of Fine Chemistry, College of Chemistry and Environmental Engineering, Jianghan University from February to August 2007. Chitosan （Yuhuan Ocean Biochemistry Co.,Ltd, Zhengjiang, China, Mw 13.44 × 10^4, 93% degree of deacetylation）, and gelation（provided by Shanghai Chemical Reagent Co., Shanghai, China） were used in the present study. METHODS： The mixture chitosan/CaCl2 solution was casted on a glass plate to give the membrane of chitosan/CaCl2. Then, the membrane was soaked in KH2PO4 solution, 0. 1 mol/L NaOH solution, and 3 wt% gelatin aqueous solution, respectively. The resulted membrane was washed and dried to obtain the chtiosan/ HA /gelatin composite membrane. The morphological observation of the composite membrane and HA crystal were carded on a scanning electron microscope. The mechanical properties of the composite membrane were measured using the universal testing machine. The tensile strength （ σ b） and the elongation at break （ ε ） were calculated. The thermal stability of composite membrane was determined using a WCT-2C thermobalance. MAIN OUTCOME MEASURES： The morphologies, the mechanical properties, and the thermal stability of the composite membrane and HA crystal were observed. RESULTS： The multilayer HA crystal with 400 nm thickness in the composite membrane was observed. The tensile strength （σb） and the elongation at break （ ε ） of the composite membrane were 3.83-10.25 MPa and 3.97%-10.14%, respectively. The decomposition temperature of HA-treated membrane was 310 ℃, which was higher than that of chitosan/gelatin membrane （305 ℃）. CONCLUSION： The composite chitosan/ HA/gelatin membrane was prepared by using chitosan/CaCl2, KH2PO4 and gelatin solutions. Such a biocompatible composite membrane with multilayer HA might be a promising tissue scaffold.