聚乙二醇制备的透明质酸衍生物的生物降解性

目的对聚乙二醇(PEG)交联制备的透明质酸(HA)衍生物薄膜的含水量及其体内和体外生物降解特性进行初步研究。方法25℃利用5 d时间制备200μm厚的HA衍生物薄膜,将其干燥后制备成10 mm×10 mm规格的试样,浸泡24 h后计算其含水量。将上述得到的HA衍生物薄膜浸入磷酸盐缓冲液(PBS)和植入到白鼠背部皮下组织,测试其体外和体内降解特性。结果当PEG浓度大于2.5%,pH 8.0时,经交联制备的HA衍生物水凝胶含水量可低于60%(w/w);当pH 8.0,PEG浓度为3.8%时HA衍生物薄膜在37℃浸泡在PBS中至少10 d无任何重量改变;将其植入白鼠皮下组织1周后,约有75%的交联薄膜仍存留在白鼠皮下组织中。结论可以利用PEG交联制备含水量较低、生物降解性小的HA衍生物凝胶材料。

Biological degradation characteristics of hyaluronic acid derivative modified by polyethylene glycol

Purpose Water content and in vitro and in vivo biological degradation characteristics of Hyaluronic acid(HA) derivative cross-linked by polyethylene glycol films were studied in this paper.MethodsThe cross-linked HA film with 200 μm thickness was got at 25℃ for 5 d.After being dried,cross-linked films of 10 mm×10 mm were weighed and immersed in phosphate buffered saline(PBS,pH 7.4) at 37℃ for 24h,and their water content was calculated.Meanwhile,cross-linked HA derivative films were immersed in phosphate buffered saline(PBS,pH 7.4) at 37℃ and the film of HA derivative modified with pH 8.0 was implanted subcutaneously in the back of white rats to test its vitro or in vivo degradation characteristics.ResultsBased on all the above testing and analysis,it was concluded that when concentration of PEG is about more than that 2.5%,water content of HA hydrogel cross-linked by polyethylene glycol at pH 8.0 is as low as 60%(w/w);and the HA derivative film cross-linked at pH 8.0 with 3.8% PEG exhibits practically no weight change for at least 10 days in PBS(pH 7.4) at 37℃.After 1 week of implanatation of the above HA derivative,approximately 75% of the cross-linked film still remained in the subcutaneous tissue of rats.ConclusionHA derivative gel crosslinked by polyethylene glycol,which has low water content and high anti-degradation performance was be obtained.