氧氟沙星人工骨缓释特性的实验研究

Experimental study on sustained release property of ofloxacinhydroxylapatitewax

目的：了解用蜂蜡包裹的氧氟沙星人工骨（ＯＦＬＸＰＨＡｗａｘ）植入山羊体内前后不同时间的理化特性及释药量。方法：用扫描电镜观察ＰＨＡｗａｘ的超微结构；用ＩＲ和ＸＲＤ测定ＰＨＡｗａｘ植入前后的结构变化及相组成；用ＵＶ在不同时间分别测定体外及植入体内ＯＦＬＸＰＨＡｗａｘ中氧氟沙星的浓度；用光学显微镜观察ＯＦＬＸＰＨＡｗａｘ植入体内的组织学变化。结果：蜡类高分子材料能形成疏水性微脂粒，阻塞和占据ＰＨＡ的深部孔道；ＯＦＬＸＰＨＡｗａｘ植入体内后结构与物相和ＰＨＡ相符；ＯＦＬＸＰＨＡ体外释药１７ｄ，包裹２００ｍｇ·ｍｌ－１和熔融蜂蜡ＯＦＬＸＰＨＡｗａｘ体外释药分别为８１和９０ｄ。ＯＦＬＸＰＨＡ植入体内，持续释药４个月，而用２００ｍｇ·ｍｌ－１蜂蜡包裹的ＯＦＬＸＰＨＡｗａｘ可持续释药８个月；ＯＦＬＸＰＨＡｗａｘ植入体内与骨直接结合紧密。结论：ＯＦＬＸＰＨＡｗａｘ即有利于骨修补。

OBJECTIVE: To study the physiochemical property and the dissolution characteristic of ofloxacin in a ofloxacin hydroxylapatite ceramic composite (OFLXPHA) encapsulated with wax, in vitro and implanted in goat's body. METHODS: The microstructures of OFLXPHAwax comopsite were observed by scanning electron microscope, the changes of OFLXPHAwax composite in vitro and implanted in the femurs of the goats were studied by IR and Xray diffraction XRD analysis, the drug releasing in vitro and in vivo was measured by UV method, the host tissue responses were observed under microscope. RESULTS: Wax framed granules and covered most pores of porous hydroxyapatite ceramic. IR analysis indicated the drug releasing and bone formation in OFLXPHAwax composite in vivo, and no phase composition change was detected by XRD analysis. In vitro, OFLX existed 17 days in the composite without wax, 81 days in the composites with wax 200 mg·ml-1, 90 days in the composites with melting wax; in vivo, OFLX existed 4 months in the composites without wax, 8 months in the composites with wax 200 mg·ml-1 wax. Histological observation showed that the bone binded with the composites and some pores of PHA were covered by new bone tissue at 8 months after implantation. CONCLUSION: The above results demonstrated that OFLXPHAwax composite appears to be beneficial for bone repair and sustained drug releasing property.