RESUMO
Objective To investigate the effect of lipid encapsulated 1,1,2-trichlorotrifluoroethane phase change nanodroplets for high intensity focused ultrasound (HIFU) ablation.Methods The lipid encapsulated 1,1,2-trichlorotrifluoroethane phase change nanodroplets was prepared with membrane hydration method,and its physicochemical properties were examined.The synergistic effect of HIFU ablation was verified with experiments in vitro and in vivo experiments.For in vitro experiment,the isolated bovine liver tissues were irradiated with HIFU (250 W,10 s,continuous wave).For in vivo experiment,the livers of New Zealand rabbits were irradiated with HIFU (200 W,5 s,continuous wave).The volume of coagulative necrosis,energy efficiency factors (EEF) and the volume of the hyperechoic area after HIFU radiation were measured.And the statistical analysis was performed.Results Phase change nanoparticles were spherical in solution and uniform in size.For in vitro experiment,the coagulative necrosis volume,EEF and hyperechoic area of bovine liver tissue injected with nanodroplets were significantly higher than those of untreated bovine liver tissue (t=28.80,19.55,14.30;P=0.01,0.02,0.02) after HIFU.For in vivo experiment,the coagulative necrosis volume,EEF and hyperechoic area of rabbit liver tissue injected with nanodroplets were significantly higher than those of untreated rabbit liver tissue (t=9.41,13.52,15.67;P=0.02,0.01,0.01) after HIFU.Conclusion The lipid encapsulated 1,1,2-trichlorotrifluoroethane phase change nanodroplets can significantly improve the efficiency of HIFU ablation significantly.