SPECT／MRI 双模态显像剂SPION-DMSA-99 Tcm的制备及其性质研究

摘要

为制备纳米材料 SPION‐DMSA 及其标记物 SPION‐DMSA‐99 Tcm ，探讨该标记物作为 SPECT ／MRI 双模态显像剂的可能性，本工作先采用高温热解法合成了 SPION ，然后用 DMSA 包覆获得 SPION‐DMSA 并进行各种表征。用99 Tcm 标记 SPION‐DMSA 得到 SPION‐DMSA‐99 Tcm ，并对该标记物进行荷U87MG 人脑神经胶质瘤裸鼠的生物分布和显像研究。实验结果表明，SPION‐DMSA 具有超顺磁性，99 Tcm 标记率大于98％。 SPION‐DMSA‐99 Tcm 在血液中清除较快，在肝脏中的摄取较高。 SPION‐DMSA‐99 Tcm 与 DMSA‐99 Tcm （Ⅴ）在小鼠体内的生物分布差异较大。 SPION‐DMSA‐99 Tcm 在肿瘤中并没有明显的摄取。 SPION‐DMSA 和 SPION‐DMSA‐99 Tcm 的 MRI 和 SPECT 显像结果表明，SPION‐DMSA 和 SPION‐DMSA‐99 Tcm 的肿瘤被动靶向作用有限。因此，对于荷 U87MG 人脑神经胶质瘤裸鼠， SPION‐DMSA‐99 Tcm 还不是一种理想的 SPECT ／MRI 双模态显像剂。%Nanoparticle SPION‐DMSA and its radiolabeled SPION‐DMSA‐99 Tcm were prepared in order to investigate the possibility of SPION‐DMSA‐99 Tcm as a SPECT /MRI dual‐modal imaging agent .SPION was synthesized by a hydrothermal process ,and then coated with DMSA to afford SPION‐DMSA .SPION‐DMSA was characterized by means of various methods .SPION‐DMSA‐99 Tcm was obtained by labeling with 99 Tcm . The data of biodistribution and the SPECT and MRI images were acquired after injecting SPION‐DMSA‐99 Tcm into the nude mice bearing U87MG human glioma in various inter‐vals .The results show that SPION‐DMSA exhibits super‐magnetic properties . The labeling yield of SPION‐DMSA with 99 Tcm was more than 98% .SPION‐DMSA‐99 Tcm is cleared from the blood quickly and has higher uptake in the liver . There was a big difference of biodistributions between SPION‐DMSA‐99 Tcm and DMSA‐99 Tcm ( Ⅴ ) in the nude mice .The uptake of SPION‐DMSA‐99 Tcm in tumor is not obvious .The results of imaging made by MRI and SPECT using SPION‐DMSA and SPION‐DMSA‐99 Tcm respectively show that the tumor passive targeting of SPION‐DMSA and SPION‐DMSA‐99 Tcm is limited . Therefore , SPION‐DMSA‐99 Tcm is not an ideal SPECT /MRI dual‐modal imaging agent for the nude mice bearing U87MG human glioma .