Transitory membrane permeability increase of human umbilical vascular endothelial cells by microbubble contrast agents combined with ultrasound exposure

Abstract

Objective To investigate the efficiency of microbubble contrast agents combined with ultrasound exposure on membrane permeability of human umbilical vascular endothelial cells(HUVECs) in vitro. Methods HUVECs were exposed to continuous wave Doppler ultrasound (Frequency, 1.9 MHz;TIS, 0.8 ;Gain ,80% ; I SATA 80.0 mW/cm2) for 1 min, then microbubble contrast agent (2% SonoVue) was added. 0 min, 1 min, 5 min, 30 min and 2 h later, HUVEC suspension was infused with fluorescein isothiocyanate-dextran (FD500) respectively. The uptake of FD500 in HUVEC was observed under fluorescence microscopy. Fluorescent rate of cell was measured with flow cytometry. The survival rate of HUVEC was calculated with trypan blue staining. Results Positive fluoreascence-stain was observed in cytoplasm. The percentages of fluorescence-stained cells were (61.63±18.35)% , (57.26±13.53)%, (14.66±6.07)%, (4.12±0.96)%,(5.93±1.45)% in 0 min, 1 min, 5 min,30 min and 2 h respectively. The percentages of positive fluorescence-stained cells were significantly higher in 0 min, 1 min groups than those of other groups ( P<0.01 ). Conclusions Microbubble contrast agents with diagnostic ultrasound can increase the membrane permeability of HUVEC transitorily. The effect of cavitation can induce cell membrane hole. Key words: Cavitation; Microbubble contrast agent; Human umbilical vascular endothelial cells; Membrane permeability