万古霉素-脂质体对兔股骨头置换感染模型预防作用的实验研究

The Use of Vancomycin Lipidosome in Postoperative Infection after Artificial Femoral Head Replacement: an Experiment Study in Rabbits

目的:制备万古霉素脂质体抗生素缓释系统,研究该缓释系统在治疗兔人工股骨头置换术后感染中的作用,为临床的进一步应用提供理论基础和实验依据。方法 :建立兔人工股骨头置换术后感染模型,将配置好的万古霉素-脂质体药物释放系统、万骨霉素于术中即分别放入关节腔及髓腔内,同时设对照组。大体观察左侧髋关节及观察右髋关节的活动度。实验动物于人工股骨头置换术后即刻、第4、8周,分别行髋关节X线摄片检查。实验动物建立感染模型6周后,分别取关节腔内肉芽组织或假膜组织,观察细菌生长情况,计数细菌菌落。并用4%的甲醛溶液固定组织,石蜡包埋(骨组织先用EDTA脱钙处理),HE染色,光镜观察组织炎细胞浸润状况。实验动物建立感染模型术前和术后第1、3、6周后,测定血清C-反应蛋白和血沉的变化。结果:成功建立了兔人工股骨头置换术后感染模型,各组兔人工股骨头置换术后股骨头均在位,经万古霉素-脂质体药物释放系统治疗后,万古霉素-脂质体组翻修术后8周X线结果提示关节间隙清晰,无明显骨缺损即透亮线形成,而万古霉素-骨水泥组置换术前后对比片,无明显变化。对照组感染未控制者术后6周X线结果显示,关节间隙模糊,假体及股骨结合部出现轻度骨吸收。细菌培养结果显示,空白对照组中实验动物细菌感染率为100%,而加入万古霉素后,万古霉素-PMMA组的实验动物细菌感染率为33.3%,显著降低;万古霉素-脂质体组实验动物细菌感染率为16.7%,与万古霉素-PMMA组相比,感染率显著降低(P<0.05);联合应用万古霉素-PMMA和万古霉素-脂质体,与其它组相比较,感染率显著降低(P<0.05),提示这种模式具有良好的抑菌效果。病理组织切片,发现实验动物建立感染模型6周后,空白对照组中实验动物感染人工股骨头周围股骨组织明显充血及炎性细胞浸润,万古霉素-PMMA组、万古霉素-脂质体组和万古霉素-脂质体组+万古霉素-PMMA的实验动物,炎性细胞浸润明显减少,提示术后关节周围细菌感染得到了有效的抑制。与术前相比较,各组CRP均显著升高(P<0.01),而经过万古霉素-PMMA组、万古霉素-脂质体组和万古霉素-脂质体组+万古霉素-PMMA治疗的实验动物,CRP均显著低于空白对照组中实验动物(P<0.05)。结论:本实验中首先建立兔人工股骨头置换术后感染模型,并观察了万古霉素-脂质体药物释放系统对兔人工股骨头置换术后感染的效应,通过X线检查、细菌培养、病理组织切片观察以及血清C-反应蛋白和血沉变化的测定,结果表明,通过上述方法制备的万古霉素脂质体对于人工股骨头置换术后感染具有良好的预防和治疗作用,为临床的进一步应用提供了初步的实验基础和理论依据。

Objective： To prepare the vancomycin lipidosome as an antibiotic delivery system and to describe its characteristic. To observe infection controls when vancomycin lipidosome was employed to manage hemiprosthetic hip joints infection in rabbits. Methods： To establish the postoperative infection model of rabbit after artificial femoral head replacement. Through the method of X-ray analysis, to observe the change of articulatio coxae. By bacterium culturing, to analysis the growth of bacterium in articulatio coxae. They were placed on culture media of agar which had been inoculated 1.5×10^8CFU of MRSE, and the inhibitory zones were measured after incubated at 37 for 24 hours. HE staining can help us observe the inflammation in articulatio coxae after artificial femoral head replacement. We also detected the change of C-reactive protein and erythrocyte sedimentation rate. Results： After artificial femoral head replacement, there are no significant difference for the concentration of vancomycin in rat plasma. X-ray demonstrated the hemiprothetic hip joints space clouding in the adjacent bone tissues. The cultures of MRSE showed an positive result up to 8.3% in vancomycin lipidosome- vancomycin impregnated PMMA group, and that were 16.7% and 33.3% respectively in vancomycin lipidosome group and vancomycin impregnated PMMA group. From the results of HE staining, there are significant inflammatory cell infiltrations in the control group, and it was reduced in the other groups in the adjacent bone tissues. It was suggested that there were much less inflammatory cells infiltration in the adjacent bone tissue if the infection was controlled. After 1 × 10^8 CFU of MRSE was injected into the joints right after the hip arthroplasty, the cultures of MRSE were positive in all animals and the levers of CRP and ESR were elevated quickly（P〈0.01）. And comparing with the control group, the levers of CRP and ESR decreased in the other groups. Conclusion： We established the vancomycin lipidosome delivery system successfully which have well stability, high envelop rate and characteristic of drug released slowly in vitro, and in vivo. It also have the significant bacteriostasis effect in vitro and in vivo. This study objectively demonstrated that the outcome of hip joints infection improves significantly when vancornycin lipidosome is employed.