^(32)P-磷酸铬-紫杉醇-聚L乳酸缓释粒子实体瘤间质植入microSPECT-CT韧致辐射显像的实验研究

Experimental study on microSPECT-CT bremsstrahlung imaging in solid tumor mesenchymal implantation of ^(32)P-chromic phosphate-paclitaxel-poly-L-lactic acid sustained-release seeds

目的以^(32)P-磷酸铬-紫杉醇微球-聚L乳酸(^(32)P-CP-PSP-PLLA)缓释粒子实体瘤间质靶向植入后,行小动物单光子发射计算机断层成像-透射断层成像(microSPECT-CT)韧致辐射显像,探讨其32 P体内生物学分布及其降解缓释特性。方法构建前列腺癌皮下移植瘤动物模型,microSPECT-CT融合显像介导完成实体瘤间质植入^(32)P-CP-PSP-PLLA缓释粒子,显像和生物学分布实验验证放射性^(32)P在荷瘤鼠体内分布,电镜下观察粒子超微结构变化。结果 microSPECT-CT韧致辐射显像可有效指导缓释粒子实体瘤内植入操作,显像清晰,缓释的部分^(32)P主要在实体瘤内滞留,在肝脾等重要脏器分布少,并为生物学分布结果证实,缓释粒子瘤内植入后电镜下可见粒子表面及内部微孔和隧道形成并进行性增加、融合和贯通。结论 microSPECT-CT韧致辐射显像可有效监测^(32)P-CP-PSP-PLLA缓释粒子及缓释的^(32)P体内生物学分布,为缓释粒子前列腺癌靶向植入治疗奠定基础。

Objective To investigate the value of single photon emission computed tomography （CT） imaging and transmis‐sion CT imaging （microSPECT‐CT ） bremsstrahlung imaging for the solid tumor mesenchymal implantaion of ^32P‐chromic phos‐phate‐paclitaxel‐poly‐L‐lactic acid （^32P‐CP‐PSP‐PLLA） sustained release seeds and to investigate the ^32P in vivo biodistribution and degradation sustained release churacteristics .Methods The animal model of prostate cancer subcutaneously transplanted tumor was established .^32P‐CP‐PSP‐PLLA sustained‐release seeds were intratumorally implanted by the mediation of microSPECT‐CT brems‐strahlung imaging and the ^32P distribution in bearing tumor mouse was verified by the imaging and biological distrubtion tests .The ultrastructural changes of ^32P seeds were observed by the scanning electron microscope .Results The MicroSPECT/CT brems‐strahlung imaging could effectively guide the intratumoral implantation operation of the ^32P sustained‐release seeds with clear visu‐alization .Partial sustained‐release ^32P was remained in the tumor tissues with little distribution in important organs of spleen and liver ,which was proved by the biodistribution results .The particle surface and inside micropores and tunnels formation ,their pro‐gressive increase ,fusion and connection were found by the electronic microscope after the ^32P sustained‐release seeds intratumoral implantation .Conclusion The MicroSPECT/CT bremsstrahlung imaging can effectively monitor the ^32P sustained‐release seeds and their in vivo biodistribution and lays a foundation for the sustained‐release seeds prostatic targeted implantation.