金属有机纳米粒的制备及其在高强度聚焦超声治疗小鼠肝癌中的增效作用

Preparation of doxorubicin-loaded metallic organic nanoparticles and their effect for enhancing efficacy of high-intensity focused ultrasound therapy in tumor-bearing mice

目的制备一种金属有机纳米粒,并探究其在高强度聚焦超声(HIFU)治疗肿瘤中的增效作用。方法制备二氧化锰(MnO_(2))纳米粒,利用物理吸附法将葡萄糖氧化酶(GOD)、MnO_(2)、三价铁离子(Fe^(3+))与抗癌药物阿霉素(DOX)自组装形成GODMnO_(2)-Fe^(3+)-DOX纳米粒(GMFD NPs)并进行表征。建立HepG2肝癌细胞荷瘤裸鼠模型,随机分为生理盐水+HIFU和GMFD NPs+HIFU组。HIFU治疗声功率为90W,治疗总时间为3 s。观察HIFU辐照前后肿瘤灰度值变化。HIFU辐照结束24 h后观察肿瘤组织凝固性坏死情况,收集肿瘤组织,苏木精-伊红染色法(HE染色)观察各组织的形态结构变化。结果成功制备GMFD NPs,其粒径为131.23±0.84 nm,表面电位为+21.87±1.72 mV。其中DOX的载药率为40.18%,在酸性环境中,DOX在4 h内释放的药物超过77.2%。体内动物实验结果表明HIFU辐照后,GMFD NPs组灰度增强(25.5±4.50)明显高于生理盐水组(18.7±3.85),差异具有统计学意义(P=0.04)、凝固性坏死体积GMFD NPs组(105.80±1.21 mm^(3))明显大于生理盐水组(38.02±0.34 mm^(3))、能效因子(EEF)GMFD NPs组(1.79)明显低于生理盐水组(4.97),差异具有统计学意义(P<0.001)。结论制备的GMFD NPs可增强HIFU对瘤鼠肿瘤组织的消融效果并释放抗癌药物DOX以治疗残留的肿瘤组织。

Objective To prepare metallic organic nanoparticles that produce synergistic effect in high-intensity focused ultrasound(HIFU)therapy of tumors.Methods Glucose oxidase(GOD),MnO_(2),ferric iron(Fe^(3+))and doxorubicin(DOX)were self-assembled by physical adsorption with previously prepared manganese dioxide(MnO_(2))nanoparticles to obtain GODMnO_(2)-Fe^(3+)-DOX nanoparticles(GMFD NPs).HepG2 tumor-bearing nude mouse models were given intravenous injections of normal saline or GMFD NPs followed 4 h later by HIFU at the acoustic power of 90 W with a total treatment time of 3 s.The changes of tumor gray value before and after HIFU irradiation were observed and 24 h after HIFU irradiation,coagulation necrosis in the tumor tissues was examined;the histological changes of the tumor tissues were observed with HE staining.Results We successfully prepared GMFD NPs,which had an average particle size of 131.23±0.84 nm with a surface potential of 21.87±1.72 mV.GMFD NPs,with a drug loading rate of 40.18%,was capable of releasing more than 77.2%of the loaded DOX within 4 h in acidic environment.In the tumor-bearing mouse models,HIFU irradiation following GMFD NP injection,as compared with saline injection,resulted in significantly enhanced gray value of the tumor(25.5±4.5 vs 18.7±3.9,P=0.04)and greater volume of coagulation necrosis(105.80±1.21 mm^(3) vs 38.02±0.34 mm^(3)).The energy efficiency factor(EEF)was significantly lower in GMFD NPs group than in saline group(1.79 vs 4.97,P<0.001).Conclusion GMFD NPs prepared in this study can enhance tumor ablation efficacy of HIFU and release DOX for further treatment of the residual tumor tissue in mice.