99Tcm-MIBI脂质体的制备及特征分析

目的 研究99Tcm-甲氧基异丁基异腈（MIBI）脂质体的制备方法，并对其特征进行分析。方法 采用乙醇注入-超声法制备99Tcm-MIBI脂质体，测定脂质体粒径大小和包封率，对超声时间、大豆卵磷脂与胆固醇的质量比等条件进行优化，观察99Tcm-MIBI脂质体的稳定性。结果 当制备的99Tcm-MIBI质量浓度为0.01 mg/mL时，平均粒径大小为（171.4±25.2）nm，包封率的平均值为（8.5±1.3）%。大豆卵磷脂与胆固醇的质量比为4:1和超声时间为5 min为最佳条件。电镜图显示，制备第1天后粒径较小，形态较为规则、均匀，呈完整球形或椭圆形；30 d后粒径大小及形态未见明显改变。结论 采用乙醇注入-超声法制备的99Tcm-MIBI脂质体粒径较小、包封率高，且较稳定。

Preparation and characteristic analysis of 99Tcm-MIBI liposomes

Objective To study the preparation and analyze the characteristics of 99Tcm-methoxy isobutyl isonitrile (MIBI) liposomes.Methods 99Tcm-MIBI liposomes were prepared through the ethanol injection-ultrasonication method. Liposome size and encapsulation efficiency were determined, and ultrasonication duration and soybean lecithin-to-cholesterol mass ratio were optimized to observe their effects on the stability of 99Tcm-MIBI liposomes.Results When the mass concentration of 99Tcm-MIBI was 0.01 mg/mL, the average particle size was (171.4±25.2) nm, and the average encapsulation efficiency was (8.5±1.3)%. The optimal preparation conditions consisted of the mass ratio of soy lecithin to cholesterol of 4:1, the 99Tcm-MIBI mass concentration of 0.01 mg/mL, and ultrasonication duration of 5 min. Electron micrograph images revealed that after the first day, particles reduced in size and appeared regular and uniform in shape. The particles appeared completely spherical or elliptical. Particle sizes and shapes negligibly changed after 30 d.Conclusion 99Tcm-MIBI liposomes with small particle size, high encapsulation efficiency, and stable entrapment efficiency can be obtained through the ethanol-ultrasonication technique.