转铁蛋白修饰聚乳酸纳米微粒表面的^(99m)TC标记及体内分布

^(99m)Tc Radiolabeling of PLA nanoparticles Surface-modified by Transferrin and their Biodistribution

以转铁蛋白溶液为外水相,聚乳酸丙酮溶液为油相,纳米沉淀法制备了表面结合转铁蛋白的聚乳酸纳米微粒,以二氯亚锡为还原剂,直接法和CDPTA螯合法对纳米微粒进行99mTc放射性标记,以C6胶质瘤细胞实验考察了标记对纳米微粒表面转铁蛋白活性的影响,结果表明直接法标记率较高,大于80.1%,对转铁蛋白活性有影响。CDPTA螯合法标记法较低(72.3%),对转铁蛋白活性影响较小。以脑部荷胶质瘤大鼠为动物模型,鼠尾静脉注射放射性标记纳米微粒,SPECT示踪和γ计数器检测显示:以转铁蛋白表面修饰的聚乳酸纳米微粒经静脉注射后主要分布于肝、脾,与正常鼠相比,荷胶质瘤大鼠对纳米微粒的摄取率有所提高。

PLA nanoparticles coated with transferrin were prepared by nano-precipitation using transfen＇in liquor as external aqueous phase. The nanoparticles were radiolabeled by two methods, i.e., directly labelling by ^99mTc and DTI＇AA chelate indirectly labeling, using SnCl2 as reducing agent. The activity of transferrin on the surface of PLA nanoparticles radiolabeled was studied by C6 glioma cell experiment in vitro, and the results showed that The activity of transferrin was damaged when directly deoxidized with SnC12, whereas DTPAA indirectly labeling has little eftect on the transferrin activity. The biodistribution of radiolabeled nanoparticles was investigated by SPECT and γ counter technologies. The distributions of surface-containing transferrin PLA nanoparticles were concentrated mainly at liver and spleen after intravenous injection. When seeding the brain with C6 glioma cell, the brain ingestion of surfacecontaining transferrin PLA nanoparticles was slightly increased.