壳聚糖包覆ZIF-90的药物释放及抗菌性能研究

Study on drug release and antibacterial properties of Chitosan Coated ZIF-90

以沸石咪唑骨架(zeolite imidazole framework,ZIF)为载体,高效合成了新型生物相容性抗菌药物缓释系统Levo@ZIF-90@CS。将抗菌药物左氧氟沙星(levofloxacin,Levo)负载到ZIF-90分子筛中,载药量为481 mg/g。在药物释放过程中,壳聚糖(chitosan,CS)作为一种pH敏感的生物材料,通过席夫碱反应共价修饰在ZIF-90表面,提高了复合材料的pH响应性。在pH=5.5的酸性条件下(细菌通过代谢导致局部酸性微环境)快速释放Levo,92%的Levo在40 h内被释放,而在正常环境下40 h的释放量为46%。抗菌试验结果表明,Levo@ZIF-90@CS对大肠杆菌、金黄色葡萄球菌均有较好的抑制作用。Levo@ZIF-90@CS具有较高的载药量和较好的抗菌性能,可作为一种良好的抗菌药物释放系统。

Using zeolite imidazole framework(ZIF)as a carrier,a new biocompatible antibacterial drug sustained-release system Levo@ZIF-90@CS was efficiently synthesized.The antibacterial drug levofloxacin(Levo)was loaded into ZIF-90 molecular sieve,and the drug loading was about 481 mg/g.During the drug release process,chitosan(CS),as a pH-sensitive biological material,is covalently modified on the surface of ZIF-90 through aldoamine condensation to improve the pH responsiveness of the composite Levo@ZIF-90@CS.By releasing a large amount of Levo under acidic conditions pH=5.5(bacterial metabolism leads to a local acidic microenvironment),about 92%of Levo was released within 40 h,while the amount released under normal conditions,about 46%of Levo was released within 40 h.The results of antibacterial experiments show that Levo@ZIF-90@CS has inhibitory effects on E.coli and Staphylococcus aureus.According to the corresponding experimental results,Levo@ZIF-90@CS has high Levo drug loading,great antibacterial performance,and can be used as a good antibacterial drug release system.