超声辐照十二氟戊烷相变纳米微泡治疗冠状动脉微循环血栓栓塞的体外实验研究

Treatment of coronary micro-circulation thrombus by dodecafluoropentane acoustic vaporizable nano-droplet with ultrasound irradiation ： an in vitro experimental study

目的应用十二氟戊烷（dodecafluoropentane，C5F12,DDFP）超声能量敏感型相变纳米微泡联合超声辐照作用，提高冠状动脉微循环栓塞的靶向溶栓效率，探讨DDFP相变纳米微泡在心肌梗死急诊治疗中的应用价值。方法实验分为三组：A组为PBS缓冲液空白对照组；B组为SonoVue微泡组；C组为DDFP相变纳米微泡组，通过旋转蒸发仪及声振仪制备，由Malvern表面电位检测仪及荧光显微镜观察相变微泡制备情况。制备动脉全血血栓并构建人工血管血栓栓塞模型用于检测C组在超声辐照下产生空化效应的稳定性及其溶栓效率，并与A组和B组进行比较。称量各组溶栓前后血栓重量并观察比较各组溶栓后血栓病理切片。结果DDFP相变纳米微泡大小为（424．7±30．2）nm，75％相变微泡在300-750mm范围内。荧光显微镜显示在液体相时结构稳定，大小均一，分散性好，在超声辐照下由小变大逐渐发生相变，形成〉3μm的微泡。在溶栓后C组血栓重量损失[（199．0±35．8）mg，（32．1±4．4）％]〉A组[（30．2±17．8）mg，（5．0±2．4）％]和B组[（72．6±20．7）mg，（12．7±2．8）％]（均P〈（1．01）。结论DDFP声能量敏感型相变纳米微泡在超声辐照作用下可以产生持续稳定的空化效应，能够有效清除人工血管血栓栓塞，达到心肌梗死急诊治疗疏通冠状动脉微循环的作用。

Objective To explore the clinical value of a new tactic with novel dodeeafluoropentane （C5F12, DDFP ） acoustic vaporizable nano droplets for the therapy of coronary micro-circulation thrombolysis. Methods Group A was poly butylene succinate buffer solution as blank control;group B was SonoVue microbubbles;group C was DDFP acoustic vaporizable nano-droplets, which were produced with emulsion process by ultrasonic oscillation instrument and rotary evaporator. The size of the nano-droplet was tested by Malvern laser particle size detector and observed with fluorescence microscope. The stability and efficiency of cavitation effect of group C for thrombolysis were tested in an in-vitro artificial vascular system with arterial thrombus model, comparing with group A and B. Weights and pathological sections of the inserted thrombus before and after the thrombolysis in these groups were compared for the thrombolytic efficiency. Results The average size of DDFP nano-droplets were （424.7 ± 30.2）nm. More than 75% of the nano droplets were ranged from 300 - 750 nm. The fluorescence microscope showed the DDFP nano- droplets were uniformed round shaped and stable structured with favorable dispersity;the nano-droplets had gradually turned into over 3 μm microbubbles under ultrasound irradiation. The thrombus weight loss after thrombolysis in group C E（199.0±35.8）mg, （32.1 ± 4.4）%]was significantly larger than those in group A [（30.2± 17,8） rag, （5.0 ± 2.4）%] and B [ （72.6 ± 20.7） mg, （12.7 ±2.8）%] （all P〈0.01）.Conclusions DDFP vaporizable nano-droplets with ultrasound irradiation is effective for thrombus elimination in coronary micro-circulation through lasting and stable cavitation effect.