载BSA壳聚糖纳米纤维体外缓释的研究

Study on the Sustained Release of BSA from Chitosan-OREC/BSA Films Coated Mats in Vitro

目的探讨体外不同因素对载BSA壳聚糖纳米纤维缓释的影响。方法利用层层自组装技术,制备壳聚糖及壳聚糖-有机累托石纳米纤维,以BSA为模型蛋白,探讨pH值、自组装层数及加入有机累托石对复合材料药物缓释的影响。结果最初1 h只有少量的BSA释放,8 h达到最高峰。在相同的自组装层数以及测试时间点,PBS溶液中BSA的缓释量要多于盐酸溶液中的释放量。pH1.2和pH7.4条件下,自组装5,5.5层与10,10.5层相比较,蛋白的释放量差异无统计学意义(t=0.651~1.324,P>0.05)。加入OREC后,BSA释放量明显增加(t=2.264~2.305,P<0.05)。结论 BSA的释放受到环境的pH值、自组装层数、释放时间,以及是否加入OREC等因素的综合影响。

Objective To investigate the sustained release of BSA from chitosan-OREC/BSA films coated mats in vitro. Meth- ods The negatively charged cellulose acetate （CA） fibrous mats were modified with muhilayers of the positively charged chitosan or chitosan-OREC intercalated composites and the negatively charged bovine serum albumin （BSA） via electrostatic layer-by-layer （LBL） self-assembly technique. The adsorption and rinsing steps were repeated until the desired number of deposition bilayers was obtained. The in vitro BSA encapsulation and release experiments demonstrated that OREC could af- fect the degree of protein loading capacity and release ficiency of the LBL films coating. Results In the pH-gradient release assay,only a small amount of BSA was released from the mats in 1 h. As the time increased, the release rate of BSA of all the samples gradually went up to the maximum data within 8 h. For the samples with identical number of bilayers and record time,obvious increasing of the release amount could be seen in pH 7.4,in comparison with pH 1.2. Besides,doubling bilayers film-coated mats generally. Meanwhile,it was slightly distinguishable between 5 and 5.5 as well as 10 and 10.5 bilayers （t=0. 651- 1. 324, P〉0.05）. Interestingly, it could be seen that protein release of the chitosan-OREC/BSA films coated mats remarkably increased compared with that of chitosan/BSA films coated mats（t= 2. 264- 2. 305, P〈0.05）. Conclusion The release of protein in the initial time could be controlled by adjusting the number of deposition bilayers, the outmost layer and the composition of coating bilayers.