壳聚糖-细菌纤维素复合膜的制备及其生物相容性的研究

Preparation and biocompatibility of a chitosan-bacterial cellulose composite membrane

目的通过制备壳聚糖(CS)-细菌纤维素(BC)复合膜,并测试该复合膜在干态和湿态下的拉伸强度及其生物相容性,探究CS-BC复合膜作为引导骨再生膜的可行性。方法将CS和BC按不同的质量比混合,超声破碎使两者分散均匀,通过自蒸发分别制备出纯CS膜和CS∶BC分别为10∶1、10∶3、10∶5、10∶7和10∶9的复合膜,将制备的各组膜通过氢氧化钠乙醇溶液浸泡除酸处理后备用。采用力学万能实验机来测试各组膜分别在干态和湿态下的拉伸强度(n=6)。通过扫描电镜和透射电镜观察拉伸强度最大组复合膜的微观结构,而其成分构成则通过傅立叶变换红外光谱仪和X-射线衍射进行表征。将大鼠骨髓干细胞分别与空白对照组(不加膜)、纯CS膜组和拉伸强度最大的复合膜组(n=5)共培养1、4、7 d后通过CCK-8法检测各组细胞存活率。结果在CS基质中加入BC后,扫描电镜观察示复合膜的横截面呈现出有序的层状结构,傅立叶变换红外光谱分析及X-射线衍射分析显示复合膜中存在BC。CS-BC复合膜的拉伸强度随BC比例增加呈现出先增加后降低的趋势,在CS和BC的质量分数比为10∶7时该复合膜在干、湿态的拉伸强度均达到最大,分别为(204.7±63.0)、(44.4±6.4)MPa。与大鼠骨髓干细胞共培养1、4、7 d后,纯CS膜组、CS-BC复合膜组(n=5)大鼠骨髓干细胞的数量与空白组对比差异均无统计学意义。结论CS∶BC为10∶7时,复合膜在干态和湿态的拉伸强度最大,且具有良好的细胞相容性。

Objective To explore the feasibility of CS-BC composite membrane as guided bone regeneration(GBR)membrane by preparing chitosan(CS)-bacterial cellulose(BC)composite membrane,and testing the mechanical strength of the composite membrane both in dry and wet states as well as evaluating its cytocompatibility.Methods The CS solution and BC solution were mixed in different weight ratios and were dispersed evenly by ultrasonic.Pure CS membrane and composite membranes with different weight ratios of CS and BC(10∶1,10∶3,10∶5,10∶7 and 10∶9)were prepared by self-evaporation process.Thereafter,the fabricated membranes were immersed into sodium hydroxide ethanol solution to remove the acid.The tensile strength of the as-fabricated membranes under dry condition and under hydration were measured via mechanical universal testing machine(n=6).The microstructures of the composite membrane with the highest tensile strength were observed by scanning electron microscopy(SEM)and transmission electron microscopy(TEM).To characterize the chemical composition of the composite membrane,Fourier transform infrared(FTIR)spectrometer and X-ray diffraction(XRD)were used.CCK-8 assay was carried out to evaluate the survival rate of cells in the control group(without any membrane),the pure CS membrane group and the composite membrane group with maximum tensile strength(n=5)after cocultured with rat bone marrow stem cells(RBMSCs)for 1,4 and 7 d.Results The cross-section of the composite membrane displayed ordered layer structure after introducing BC into CS matrix.The results of FTIR and XRD indicated the existence of BC in the composite membrane.The tensile strength of the CS-BC composite membrane increased first and then decreased with the increase of BC ratio.The tensile strength of the composite membrane reached the highest in dry and wet states when the weight ratio of CS and BC is 10∶7,which were almost(204.7±63.0)MPa and(44.4±6.4)MPa respectively.After cocultured with RBMSCs for 1,4 and 7 d,there was no significant difference in the number of cells among the pure CS group,the CS-BC composite membrane group and the blank control group.Conclusion When the weight ratio of CS and BC is 10∶7,the tensile strength of the composite membrane are the best both in dry and wet state and the cell compatibility is excellent.