^(99)Tc^m-MIBI脂质体纳米粒制备及生物分布实验研究

A study on the preparation of ^(99)Tc^m-MIBI nanoliposomes and its biodistribution in mice

目的探索^(99)Tc^m-MIBI脂质体纳米粒的制备方法,考察其在体外条件下的物理、生物学表征和稳定性,并研究其在小鼠体内的生物学分布特征。方法采用乙醇滴注-超声分散工艺制备^(99)Tc^m-MIBI脂质体纳米粒。测定其粒径及包封率指标。在体外37℃条件下,观察^(99)Tc^m-MIBI脂质体纳米粒在正常人血清和生理盐水中(NS)不同时间点的放化纯及其稳定性,研究其在小鼠体内15、60、120 min的分布特征。结果乙醇滴注-超声分散方法制备的^(99)Tc^m-MIBI脂质体纳米粒在电镜下观察呈球形、均匀,平均粒径(168.2±18.6)nm。体外稳定性实验表明,在正常人血清和NS中将^(99)Tc^m-MIBI脂质体纳米粒孵育15、30、60、120 min,其放化纯分别达96%、93%、90%、89%和92%、89%、86%、85%。体内生物分布实验表明,与^(99)Tc^m-MIBI比较,静脉注射^(99)Tc^m-MIBI脂质体纳米粒后,在观察时间内发现脾脏摄取显著,肾脏的放射性摄取率较低。结论^(99)Tc^m-MIBI脂质体纳米粒的制备方法简单,具有较为理想的物理、生物学表征,在血清中的稳定性较好。与^(99)Tc^m-MIBI比较肾脏摄取率低,在动物体内的循环时间延长。

Objective To explore the method of preparing 99Tcm-MIBI liposome nanoparticles, investigate its＇ physical, biological characterization and stability in vitro, and study its biological distribution characteristics in mice. Methods The 99Tcm-MIBI liposome nanoparticles were prepared by the ethanol infusion-ultrasonic dispersion process. The particle size and encapsulation efficiency were measured. The radioactivity purity and stability of 99Tcm-MIBI liposome nanoparti- cles in normal human serum and normal saline（NS） at different time points were observed under the condition of 37 ~C in vitro. The distribution characteristics of 15, 60, and 120 min in mice were studied. Results The 99Tcm-MIBI liposome nanoparticles prepared by ethanol infusion-ultrasonic dispersion method were spherical and homogeneous under the elec- tron microscope, with an average diameter of （168.2 ± 18.6）nm. In vitro stability test showed that 99Tcm-MIBI liposome nanoparticles incubated 15, 30, 60, 120 min in normal serum and NS respectively, and their radiochemical purity was 96%, 93%, 90%, 89% and 92%, 89%, 86% and 85%, respectively. In vivo biodistribution experiment showed that compared with 99mTc-MIBI, after intravenous injection of 99Tcm-MIBI liposome nanoparticles, the spleen uptake was sig- nificantly observed and the radioactivity uptake rate of kidney was low during the observation time. Conclusion The preparation method of 99Tcm-MIBI liposome nanoparticles is simple and has ideal physical, biological characterization, and the stability in serum is good. Compared with 99Tcm-MIBI the kidney uptake rate was low, and the circulation time in vivo of the mice was prolonged.