左氧氟沙星壳聚糖微球对兔海水浸泡创伤的早期治疗作用

Treatment of soft tissue wound with seawater immersion by administration of levofloxacin-chitosan microsphere at early stage

目的 了解早期应用左氧氟沙星壳聚糖微球对兔海水浸泡创伤的治疗作用。方法 建立兔软组织海水浸泡伤模型。比较对照组（n=8）、原料药组（n=8）和局部应用左氧氟沙星壳聚糖微球组（n=8）在海水浸泡前和浸泡结束后6、12、24、48、72h创伤局部菌落计数、血浆内毒素、局部组织和血浆TNF-a水平，以及后两组浸泡后72h局部组织和血浆中左氧氟沙星浓度的变化。结果 海水浸泡后6h起微球组和原料药组菌落计数明显低于对照组（P〈0．01）。浸泡后48h起微球组菌落计数较原料药组更低（P〈0．01）。微球组于海水浸泡后6～72h、原料药组于浸泡后6～48h血浆内毒素水平低于对照组（P〈０．01）。微球组在海水浸泡后6～72h、原料药组在浸泡后6～24h局部组织TNF－a浓度低于对照组（P〈0．01或P〈0．05）；微球组在海水浸泡后12～72h、原料药组在海水浸泡后12～48h血浆TNF－a浓度低于对照组（P〈０．01）。微球组局部组织药物浓度升高较原料药组缓慢，并能在72h内维持较高的抗菌药浓度。微球组血浆药物浓度变化也较原料药组平缓。结论 该药物微球如局部应用于海水浸泡伤口，可缓慢释出抗菌药物，发挥抑制局部感染、减少局部组织继发损伤的作用。

Objective To evaluate the effect of levofloxacin-chitosan microsphere administrated in early stage seawater immersed wound of soft tissue. Methods A rabbit model of seawater immersed wound of soft tissue was reproduced. Among the control group （n=8） and the group locally treated with levofloxacin powder （n=8） or levofloxacin-chitosan microsphere （n=8）, the bacteria number in the wound, the serum endotoxin level, the content of tumor necrosis factor-alpha（TNF-a） in the wound and the serum were assayed before and 6, 12, 24, 48, 72h after seawater immersion. In the latter 2 groups, levofloxaxin concentration in plasma and wound was compared 6, 12, 24, 48, 72h after seawater immersion. Resdts The bacteria number of the wound in the microsphere group and levofloxacin powder group was lower than that in the control group since 6h after seawater immersion（P〈0. 01）, and the number bacteria in the microsphere group was lower than that of the levofloxacin powder group since 48h after immersion （P〈0. 01）. In microsphere group and levofloxacin group, the plasma endotoxin level was lower than that in the control group （P〈0. 01） between 6-72h and 6-48h after immersion, respectively, the TNF-a content of the wound tissue was lower than that in the control group between 6-72h and 6-24h after immersion （P〈0. 01 or P〈0. 05）, respectively, and the plasma TNF-a content was lower than that in the control group between 12-72h and 12-48h after immersion （P〈0. 01）, respectively. The drug concentration in microsphere group, which maintained at a high level in 72h, increased more slowly than that in levofloxacin powder group after immersion, and the drug concentration changed less dramatically in microsphere group than in levofloxacin powder group. Conclusion Local application of levofloxacin-chitosan microsphere results in a slow release of the drug, 2 reduces the inflammatory reaction in the seawater immersed wound, and allays the secondary injury to local tissue.