RESUMEN
Objective:To prepare liquid-gas phase modified nanoparticles (TMZ/PFP/PLGA NPs) of perfluoropentane (PFP) and temozolomide (TMZ) encapsulated by polylactic-glycolic acid copolymer (PLGA), combined with low intensity focused ultrasound (LIFU) irradiation, and to investigate its ultrasound imaging ability and intervention effect on human glioma cells in vitro.Methods:TMZ/PFP/PLGA NPs were prepared by compound emulsion method. The basic physical and chemical properties and drug loading ability of TMZ/PFP/PLGA NPs were detected. CCK-8 assay was used to detect the cytotoxicity of nanoparticles in vitro and the effect of synergistic intervention with LIFU on the survival rate of glioma cells. The expression levels of apoptosis related proteins Bcl-2, Bax and caspase-3 were detected by Western blot.Results:Under transmission electron microscope, TMZ/PFP/PLGA NPs showed a circular core-shell structure with regular morphology, particle size was (137.9±63.31)nm, encapsulation efficiency of TMZ was (83.01±5.57)%, drug loading was (3.19±0.22)%. The survival rate of U251 cells was still above 70% after 24 hours of co-incubation with nanoparticles. Under the synergistic effect of LIFU irradiation, the apoptosis of U251 cells was accelerated and the survival rate of U251 cells was significantly decreased. The results of Western blot showed that the synergic intervention could significantly down-regulate the expression of apoptosis related protein Bcl-2, and significantly up-regulate the expression of Bax protein and caspase-3 protein (all P<0.05). Conclusions:TMZ/PFP/PLGA NPs have good basic physical and chemical properties. TMZ/PFP/PLGA NPs have low cytotoxicity in vitro while efficiently loading chemotherapeutic drug timozolomide. Synergistic intervention under LIFU irradiation can significantly accelerate the apoptosis of U251 glioma cells, which has a good application prospect.