ABSTRACT
Objective To discusse the influence of permeating perfluoropentane drops-encapsulated mesoporous silica nanocapsules (MSNC-PFP) on HIFU surface ablation in vitro bovine liver.Methods Fifity bovine liver tissues were divided into 5 groups:Control group,0.25 mg/ml group,0.50 mg/ml group,1.00 mg/ml group,2.00 mg/ml group according to the concentration of MSNC-PFP.The synergistic agent was injected along the ablation line path under the guiding of ultrasound.The surface ablation model was structured by 6 coagulation necrosis side by using HIFU linear scanning,inner region without melting,and the ultrasonographic changes were observed in the melt area.The coagulation necrosis range was assessed by TTC staining,and necrosis degree was observed by HE staining.The coagulation necrosis volume was measured,the coverage index (CI),external volume index (EI),energy efficiency factor (EEF) were used to evaluate the ablation effect in each group.Results The MSNC-PFP more than 1.00 mg/ml was shown as strong echo in ultrasonic image,fade after 3-5 min.The grey value was changed in HIFU ablation area related to the concentration of MSNC-PFP.The total ablation volume of 0.50 mg/ml group,1.00 mg/ml group,2.00 mg/ml group were more than control group,the EEF was lower than that of the control group (all P＜0.01).The CI and EI of 1.00 mg/ml group and 2.00 mg/ml group were higher than those of the other group (all P＜0.01).The coagulation necrosis became complete when the concentration of MSNC-PFP above 0.50 mg/ml.Conclusion MSNC-PFP can increase the volume of coagulation necrosis,decrease the EEF and increase the efficiency of HIFU surface ablation of bovine liver in vitro.