Studies on Adriamycin Magnetic Gelatin Microspheres

The preparation and properties of adriamycin magnetic gelatin microspheres(Adr- MG-ms)were reported.The synthesis of magnetic iron oxide ultrafine particle and embolization effects of magnetic gelatin microspheres(MG-ms)in dog were studied.Adr- MG-ms consist of 2%(w/w)of adriamycin(Adr)as the core,and 68% of gelatin and 30% of magnetite as the shell with a mean particle size of 22 μm. In vitro experiment,the release rate of drug demonstrated that the microspheres have sustained-release properties.The average diameter of magnetic iron oxide was approximately l0 nm. Transcatheter embolization with MG-ms and ￣(99m)Tc-labelled MG-ms was performed under external magenet control in dog liver,respectively.Gamma photography and angiogram revealed that MG-ms level was almost equal both in left and right hepatic arteries without magnet,while with magnet(1200 Gs),MG-ms level in left hepatic artery(target site)was about 2.25 fold higher than in right hepatic artery,and few MG-ms in thyroid gland,brain and heart was observed.Results showed that the MG-ms is a promising embolic agent for treatment of hepatic cancer under external magnet control.

磁性微球载体靶向分布的实验研究

在体外５００ｍＴ磁场的导引下，从大鼠肝动脉注入平均５０μｍ的磁性微球载体（ＭＭＣ），剂量１０ｍｇ／ｋｇ。磁球中含顺铂３０％（Ｗ／Ｗ），阿霉素１０％，磁材２０％，纤维素多糖４０％。术后２、２、７２、１６８小时采用无火焰原子吸收光谱法分别测量靶区（左肝）及非靶区（右肝）的铂含量。经ｔ检验加磁场组左、右肝铂含量差异有非常显著性．证明磁性微球载体具有良好的靶向栓塞作用。

阿霉素白蛋白微球体内缓释作用及对正常大白鼠栓塞作用的研究

本实验对阿霉素白蛋白微球的缓释特性及在正常大白鼠肝内的栓塞作用进行了初步探讨，结果表明：以５０ｍｇ／ｋｇ剂量注入大白鼠肝动脉内，可见肝细小动脉充满栓塞颗粒，肝细胞索呈局灶状坏死；将阿霉素白蛋白微球与阿霉素水溶液实验对照发现前者释药速度明显缓慢，第７小时外周血液浓度达高峰３５．９５ｕｇ／ｍｌ，第２４０小时仍维持在８．０３ｕｇ／ｍｌ，阿霉素水溶液组大白鼠外周血药物浓度仅是“一过性”升高，第０．２５小时达８９．４２ｕｇ／ｍｌ，之后迅速下降，第３０小时接近零，瘤体内直接注入药物，阿霉素白蛋白微球组瘤体局部药物存留量明显高于常规剂型，第４０、１２０小时时前者分别是３２．５２ｕｇ／ｇ和５．８８ｕｇ／ｇ，后者分别是１２．００ｕｇ／ｇ和０。

磁性顺铂微球肝动脉栓塞的实验研究

从大鼠肝动脉注入平均粒径100μm的磁性顺铂微球，剂量4mg／kg。微球中含药量50％，载磁材量10％。体外用5200Gs磁场导向。术后2h、24h、72h、168h采用无火焰原子吸收光谱法分别测量靶区（左肝）及非靶区（右肝）的铂含量。结果各组经t检验均有显著差异。尤其是术后168h靶区含量高于非靶区接近一倍。证明磁性顺铂微球有良好的靶向分布作用。