机械指数对超声响应型聚合物纳米液滴造影成像的影响  

Effects of mechanical index on contrast-enhanced imaging of ultrasound-responsive polymeric nanodroplets

作　　者：李亚琼 刘瑞青 刘露文 张椰 吴玥瑾 段少博 常志扬 张连仲 Li Yaqiong;Liu Ruiqing;Liu Luwen;Zhang Ye;Wu Yuejin;Duan Shaobo;Chang Zhiyang;Zhang Lianzhong(Department of Pharmacy,Henan Provincial People′s Hospital,People′s Hospital of Zhengzhou University,Zhengzhou 450003,China;Henan Engineering Technology Research Center of Ultrasonic Molecular Imaging and Nanotechnology,Zhengzhou 450003,China;Department of Interventional Therapy,Henan Provincial People′s Hospital,People′s Hospital of Zhengzhou University,Zhengzhou 450003,China;Department of Ultrasound,Henan Provincial People′s Hospital,People′s Hospital of Zhengzhou University,Zhengzhou 450003,China)

机构地区：[1]河南省人民医院郑州大学人民医院药学部,450003 [2]河南省超声分子影像与纳米技术工程研究中心,郑州450003 [3]河南省人民医院郑州大学人民医院综合介入科,450003 [4]河南省人民医院郑州大学人民医院超声科,450003

出　　处：《中华超声影像学杂志》2020年第9期807-811,共5页Chinese Journal of Ultrasonography

基　　金：国家重点研发计划数字诊疗装备研发重点专项(2018YFC0114606)。

摘　　要：目的制备以嵌段聚合物聚乙二醇-聚己内酯(PEG-PCL)为外壳、全氟戊烷(PFP)为核心的超声响应型纳米液滴,探讨机械指数(MI)对纳米液滴超声造影成像特性的影响。方法应用透析法制备PEG-PCL胶束,然后将胶束与PFP混合后超声乳化制备纳米液滴。测定纳米液滴的粒径和zeta电位,透射电镜下观察其形态,考察其在25℃和37℃下储存后的稳定性。应用超声诊断仪观察不同MI下纳米液滴的体外造影成像特性。结果纳米液滴的粒径为(356.6±5.6)nm,zeta电位为-(7.30±0.14)mV,透射电镜下纳米液滴接近球形,有清晰的核壳结构。于25℃或37℃放置一段时间后,纳米液滴平均粒径变大,且分散度增加。体外造影成像结果显示37℃下纳米液滴在MI≥0.4时可产生回声增强,且MI越大,回声越强。结论纳米液滴的造影成像特性与所采用的MI紧密相关,较高的MI可以使更多的纳米液滴发生相转变,产生较强的回声。此研究可以为纳米液滴在超声诊断及靶向治疗中的应用提供依据。Objective To prepare ultrasound-responsive nanodroplets with block polymer PEG-PCL as shell and perfluoropentane(PFP)as core,and study the effects of mechanical index(MI)on contrast-enhanced imaging properties of nanodroplet.Methods PEG-PCL micelles were first prepared by dialysis,and then the micelles were mixed with PFP for emulsification to obtain nanodroplets.The particle size and zeta potential of nanodroplets were measured,and the morphology of nanodroplets were observed using transmission electron microscope(TEM).The stability of nanodroplets after storage at 25℃and 37℃was investigated.The phase transition and contrast-enhanced imaging of nanodroplets in vitro under a series of mechanical index(MI)were studied using an ultrasound diagnostic instrument.Results The particle size of the nanodroplets was(356.6±5.6)nm,and the zeta potential was-(7.30±0.14)mV.The nanodroplets were close to spherical under TEM and had a clear core-shell structure.The particle size and dispersion of the nanodroplets increased after storage at 37℃and 25℃.For imaging in vitro,no acoustic signal were observed at 25℃when the MI varied from 0.08 to 1.0.At 37℃,acoustic signals were observed when MI≥0.4,and the intensity was stronger for higher MIs.Conclusions The contrast-enhanced imaging of nanodroplets are closely related to the MI,and a higher MI could induce the phase transition of more nanodroplets and produce stronger contrast enhancement.This study could provide basis for the application of polymeric nanodroplets in ultrasound diagnosis and targeted therapy.

关 键 词：纳米液滴 机械指数 相转变 造影成像 

分 类 号：R445.1[医药卫生—影像医学与核医学]