载万古霉素PLGA-PEG-PLGA温度敏感水凝胶的体外抗菌性能

利用聚乙二醇（PEG 1500）引发乙交酯和D，L-丙交酯开环共聚合制备聚丙交酯乙交酯（PLGA）三嵌段共聚物（PLGA-PEG-PLGA）温敏水凝胶材料，并通过核磁共振氢谱（¹H NMR）确定产物的结构及组成.应用倒置小瓶法测量得到不同浓度下PLGA-PEG-PLGA水凝胶的溶胶-凝胶相变温度为27~32℃.此外，体外降解实验及细胞毒性实验结果表明，质量分数为25%的水凝胶有满意的降解速度及良好的生物相容性.同时，利用紫外-可见光谱分析了载万古霉素水凝胶的体外药物释放行为，结果表明，万古霉素可以持续释放12 d.抗菌实验结果表明，载万古霉素水凝胶具有良好的抗菌效果.表明PLGA-PEG-PLGA三嵌段温敏水凝胶是一种较理想的万古霉素缓释载体，具有良好的临床应用前景.

%In vitro% Antibacterial Activity of PLGA-PEG-PLGA Thermosensitive Hydrogels Loaded with Vancomycin

The poly(D,L-lactide-co-glycolide)-poly(ethylene glycol)-poly(D,L-lactide-co-glycolide)(PLGA-PEG-PLGA) triblock copolymer was synthesized via ring opening copolymerization of D,L-lactide(D,L-LA) and glycolide(GA) by PEG(Mn=1500) as a macromolecular initiator.The chemical structure and composition of the copolymer were determined by 1H NMR spectra.The sol-gel phase transitions of the PLGA-PEG-PLGA solutions in PBS(pH=7.4) were studied by the vial tilting method.The phase-transition temperatures of polymer with different concentrations were from 27 ℃ to 32 ℃, which confirmed by rheology analysis.In addition, the degradation and biocompatibility of the 25%(mass fraction) hydrogels were investigated in vitro.And the results show a satisfied degradation behavior and good cyto-compatibility.Meanwhile, UV-Vis spectroscopy was used to measure the release properties of vancomycin loaded thermosensitive hydrogel.The release of vancomycin lasted to 12 d.The result of antibacterial experiment in vitro indicated that the vancomycin loaded thermosensitive hydrogels possessed excellent antibacterial properties.Therefore, the PLGA thermosensitive hydrogels hold potential as promising platforms for delivery of vancomycin for preventing infections in clinical treatment.