ABSTRACT
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.
ABSTRACT
Objective To study the effects and its probable mechanism of ultrasound-irradiation docetaxel-loaded microbubbles on apoptosis in human liver cancer cells MHCC97-H.Methods The MHCC97-H cells were randomly divided into 4 groups:control group,docetaxel-loaded microbubb[es group(DM),Ultrasound group (US),ultrasound irradiating docetaxel-loaded microbubbles group (DM + US).The livability,the morphological change of cells,cell apoptosis rate and the expression of proliferating cell nuclear antigen and MAPK pathway members of each group were respectively detected.Results After 24h,MTT test showed that the livability of MHCC97-H cells of DM group,US group and DM + US group were (76.0±3.0)％,(73.0± 5.0)％ and (52.0 ± 6.0)％ respectively,which was significantly declined comparing with control group (P ＜ 0.05).The morphological of tumor cells in control group remain normal size and grow eugenic,while the cells of DM group,US group and DM + US group decreased,their shapes were irregular,the intercellular space increased,and cells apoptosis occured in the medium.The cells in DM + US group were changed significantly.FCM showed the apoptosis rate of DM + US group was (26.81 ± 2.82) ％,which was declined clearly compared with (2.90 ± 0.99) ％ of the control group (P ＜0.05).Western-blot showed that the expression of proliferating cell nuclear antigen and p-ERK1/2 protein in DM + US group were down-regulated,and meanwhile p-p38 protein in human liver cancer cells MHCC97-H was up-regulated.Conclusions The method of ultrasound irradiating docetaxel-loaded microbubbles can significantly induce human liver cancer cells MHCC97-H apoptosis by regulating the expression of related protein.