目的 考察植入动物的种类和不同部位对植入剂组织相容性和生物可解降性的影响。方法 将纳曲酮植入剂植入到小鼠、大鼠、白兔和狗等不同动物以及白兔的不同部位，通过组织切片观察实验动物的组织相容性，采用凝胶色谱法测定植入剂中聚乳酸的相对分子质量，并比较聚乳酸的重量来考察其生物可降解性。结果 纳曲酮植入剂在4种动物体内组织相容性良好，组织反应的程度略有差异。控释基质聚乳酸在体内外条件下均能降解，但体内降解比体外快，大动物的体内降解比小动物略快。结论 纳曲酮植入剂在不同动物具有良好的组织相容性和体内可降解性，植入动物的种类和植入部位对植入剂上述特性的影响不大。

OBJECTIVE To investigate the effects of the different animal species and implant locations on the biocompatibility and biodegradability of naltrexone implants (NTX-IMPs). METHODS NTX-IMPs were implanted subcutaneously in mice,rats,rabbits and dogs respectively,and also implanted intramuscularly in rabbits.Photomicrographs of histology sections of implant sites were provided to illustrate the biocompatibility of implants.The biodegradability of implants was characterized by measuring the molecular weight decrease and the mass loss of poly-lactic acid(PLA) in NTX-IMPs.Gel permeation chromatography was used to determine the molecular weight of PLA. RESULTS When NTX-IMPs were implanted subcutaneously in mice,rats,rabbits and dogs,respectively,or implanted intramuscularly in rabbits,good tissue compatibility was observed with an initial acute inflammatory response as shown by microscopy examination.The tissue reaction process of NTX-IMPs was observed as that of the normal biocompatible materials.The degree of the host response after subcutaneous implantation was slightly severe in small species,but was almost same in different implant locations in rabbits.NTX-IMPs could be degraded both in vivo and in vitro.The faster degradation rate was observed in vivo than that in vitro.NTX-IMPs were biodegraded a little faster in large species. CONCLUSION NTX-IMPs had good biocompatibility and biodegradability,which were affected only slightly by the differences in animal species and implant locations.