低强度聚焦超声联合载过氧化氢相变纳米粒靶向助溶模拟冠状动脉循环的人工血管血栓栓塞

H2O2/PFP-loaded acoustic phase-change lipid nanoparticles enhancing thrombolysis in artificial vessel for simulation of coronary circulation: an in-vitro study by low intensity focused ultrasound irradiation

目的制备可释氧的载过氧化氢(H2O2)相变纳米粒,联合低强度聚焦超声(LIFU)靶向溶解人工血管内血栓,探讨其在急性心肌梗死(AMI)冠状动脉溶栓治疗中的价值。方法采用薄膜水化和双乳化法制备包载H2O2和液态氟碳(PFP)的脂质相变型纳米粒。取家兔颈总动脉血50ml制备成质量约400~800mg的血栓块。本实验分为4组:PBS对照组(A组)、SonoVue微泡组(B组)、PFP相变纳米粒组(C组)和载H2O2相变纳米粒组(D组)。每组血栓样本均置入体外溶栓模拟循环装置的人工血管中联合LIFU辐照。称量各组溶栓前后血栓重量并观察比较各组溶栓后HE染色切片;溶氧仪检测溶栓后循环液中纳米粒释氧量。结果载H2O2相变纳米粒粒径大小为(456.7±31.2)nm;荧光显微镜示纳米粒液体相时结构稳定,大小均一。溶栓后四组血栓重量损失及损失率分别为A组(52.2±11.5)mg、(9.7±3.5)%,B组(110.0±21.9)mg、(19.4±2.4)%,C组(239.6±46.3)mg、(39.7±6.3)%,D组(309.8±44.8)mg、(54.2±6.6)%,C组和D组溶栓前后的重量损失及损失率明显大于A、B两组,差异有统计学意义(均P<0.01);C组、D组间差异无统计学意义(P>0.05)。溶氧仪检测纳米粒释氧量随着H2O2浓度的增加而逐渐增高。结论载H2O2相变纳米粒可高效溶解人工血管血栓栓塞,并通过释氧改善组织缺氧,为AMI患者冠状动脉血栓栓塞提供潜在的治疗新方式。

Objective To prepare a novel H2O2-loaded and phase-change nanoparticles,combined with low intensity focused ultrasound(LIFU)to dissolve intravascular thrombosis for the evaluation of its value in the treatment of coronary artery thrombolysis in the patients with acute myocardial infarction(AMI).Methods H2O2-loaded and phase-change nanoparticles were prepared by membrane hydration method.50 ml arterial blood was collected from rabbit carotid artery and made into 400-800 mg thrombus blocks.They were divided into four groups randomly:poly butylene succinate buffer(PBS)solution as blank control(group A),SonoVue microbubbles group(group B),PFP phase-change nanoparticles group(group C),H2O2-loaded and phase-change nanoparticles group(group D).Each group of thrombus samples were placed into the artificial blood vessels of the extracorporeal thrombolysis simulation cycle device and combined with LIFU irradiation.The weights and pathological presentations were compared before and after thrombolysis.The volume of O2 in the vascular system was inspected using Dissolved Oxygen Detector(DOD)after LIFU exposure.Results The average size of H2O2-loaded nano-droplets was(456.7±31.2)nm.Fluorescence microscopy showed that the structure of nanoparticles was stable and uniform in size.The weight loss and rates of thrombus in the four groups after thrombolysis were:group A(52.2±11.5)mg,(9.7±3.5)%;group B(110.0±21.9)mg,(19.4±2.4)%;group C(239.6±46.3)mg,(39.7±6.3)%and group D(309.8±44.8)mg,(54.2±6.6)%,respectively.The weight loss and rates of thrombus in group C and D were higher than those in group A and B(all P<0.01),but there was no significant difference between group C and D(P>0.05).The DOD showed that along with the increase of H2O2 concentration,O2 release was rising.Conclusions H2O2/PFP nanoparticles with LIFU performs efficient thrombolysis and provides O2 to improve hypoxia,which provides a potential novel treatment method for AMI patients with coronary embolism.