温敏水凝胶Dex-PCL-HEMA/PNIPAAm的生物学性能

Biological character of Dex-PCL-HEMA/PNIPAAm as a kind of heat sensitivity hydrogel

目的:对温度敏感水凝胶葡聚糖接枝聚己内酯-甲基丙烯酸羟乙酯共聚N-异丙基丙烯酰胺(Dex-PCL-HEMA/PNIPAAm)合成及体外降解进行研究,了解水凝胶的体外生物学性能。方法:利用自由基聚合法合成Dex-PCL-HEMA/PNIPAAm,并对其作LC-ST的测定、内部形貌观察、体外降解、体外控制释放胎牛血清蛋白(BSA)。结果:水凝胶的较低临界溶解温度(LCST)为33.2～34.2°C;内部形貌观察到水凝胶的孔径随着Dex-PCL-HEMA的含量的增大而缩小;体外酶降解显示DN水凝胶在前3天降解比较快,在第4～16天间,DN1、DN2、DN3、DN4四种水凝胶的降解率依次增大,16天后基本上不再降解;DNDex-PCL-HEMA/PNIPAAm凝胶体外释放BSA曲线显示前5小时内释放最快,此后逐渐减慢。结论:Dex-PCL-HEMA/PNIPAAm水凝胶保持了其良好的温度敏感性,体外实验显示生物相容性良好,因此可以作为动物实验的材料。

Objective：To study the process of syntyesis and degradation in vitro of Dex-PCL-HEMA/PNIPAAm as a kind of heat sensitivity hydrogel,and to research its biological character.Methods：To synthesize Dex-PCL-HEMA/PNIPAAm through free radical polymerization,to detect lower critical solution temperature（LCST）,to observe internal structure through scanning electron microscope（SEM）;to make degradation test in vitro and to controllc release bovine serum albumin in vitro.Results：LCST of Dex-PCL-HEMA/PNIPAAm was 33.2～34.2 °C;the pore diameter of Dex-PCL-HEMA/PNIPAAm decreased when the contents of Dex-PCL-HEMA increased;DN hydrogel degraded quickly in the first three days,sequences of degradation rate were DN1〈DN2〈DN3〈DN4 in 4～16 d,its weight kept stable state and stopped degradation after 16 d;BSA curve showed Dex-PCL-HEMA/PNIPAAm release quickly in the first 5 h and then stepped down gradually.Conclusion：Dex-PCL-HEMA/PNIPAAm possesses satisfactory temperature sensitivity and biocompatibility in vitro,so Dex-PCL-HEMA/PNIPAAm is a good material in animal studies.