两种消毒方式对壳聚糖水凝胶温敏性能及模型蛋白体外缓释性能的影响

目的探索两种消毒方式对壳聚糖水凝胶温敏性能及缓释性能的影响，为壳聚糖水凝胶临床应用前消毒方式的选择提供依据。 方法在制备壳聚糖温敏水凝胶前，采用两种方式进行消毒处理。（1）传统组：高压蒸汽消毒壳聚糖-醋酸溶液；（2）改良组：高压蒸汽消毒壳聚糖粉末。检测两组凝胶的成胶时间、旋转粘度；扫描电镜观察表面及截面形貌；傅立叶红外光谱检测特征性吸收峰；采用牛血清白蛋白（BSA）作为模型蛋白，观测体外缓释性能；SDS-PAGE检测缓释后的蛋白完整性。结果采用两独立样本的t检验进行统计。 结果37℃时，传统组成胶时间明显长于改良组（t= 61.677，P= 0.000）；改良组的旋转粘度在37℃时达15 000 mPa.s，传统组37℃时粘度为1560 mPa.s，40℃时上升至11 500 mPa.s；两组凝胶表面致密完整，截面均呈三维立体网状多孔结构，传统组孔隙大于改良组；两实验组与未消毒壳聚糖的吸收光谱基本一致；两组均有良好的缓释性能，改良组缓释性能更佳（t= 61.415，P= 0.000），且释放出的模型蛋白分子结构完整。 结论采用改良消毒方式的壳聚糖水凝胶成胶时间更短，温敏性能更佳，缓释性能良好，且与传统组一样能保持缓释蛋白结构完整性。

Effects of two sterilization methods on the thermo-gelation behavior and in vitro protein release characteristics of chitosan hydrogel

ObjectiveTo compare the effects of two different sterilization methods on the thermo-gelation behavior and protein release characteristics of chitosan hydrogel in vitro. MethodsChitosan thermo-sensitive hydrogel was routinely fabricated and sterilized by two methods: (1) conventional group: steam sterilization on chitosan solution; (2) modified group: steam sterilization on chitosan powder. Gelation time was recorded and the viscosity was measured using a viscometer. The topography and the cross section of the chitosan hydrogel were observed by a scanning electron microscopy (SEM) . Fourier transform infrared (FTIR) spectra were obtained with a Fourier Transform IR Spectrophotometer. In vitro protein release characteristics were observed using bovine serum albumin (BSA) as a model protein. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used to determine the structural integrity of model protein. ResultsAt 37℃, the gelation time of modified group was significantly longer than that of conventional group (t=61.677, P= 0.000) . The viscosity of modified group was 15000 mPa.s at 37℃, while the viscosity of conventional group was 1560 mPa.s at 37℃ and increased to 11 500 mPa.s at 40℃. SEM observation showed three-dimensional mesh porous structures in both groups. Mean pore size of conventional group was larger than those of modified group. Both groups presented great controlled-release of the model protein, modified group was better than conventional group (t= 61.415, P= 0.000) . There is no significant difference on the FTIR spectra of the two sterilized groups. The result of SDS-PAGE indicated that the protein released from both groups remained structural integrity. ConclusionsAutoclaving chitosan powder had shorter gelation time, better thermo-gelation behavior and could prolong the release of model protein in vitro than autoclaving chitosan/β-GP solution.