The preparation of sulfur hexafluoride lipid-coated microbubbles

Objective To prepare phospholipid-based sulfur hexafluoride gas-filled microbubbles, which were designed for targeting microbubbles. Methods The microbubbles composed of DSPC and mPEG2000-PE were produced by film-sonication method,and were compared with SonoVue. In the physical chemistry characteristics studies, the morphology, particle diameter, concentration, pH value and osmotic pressure were investigated. In the echogenicity studies, contrast harmonic imaging technique was used to investigate the enhancement of vitro water sac and normal rabbit kidney parenchyma. Results The lipid microbubbles were well-distributed, round with air holes. The average diameter of self-made microbubbles and SonoVue were 2.25 μm and 2.50μm respectively. The average diameter of self-made microbubbles and SonoVue distributed from 0.4 μm to 10 μm and 0.2 μm to 10 μm,and 90% were under 6 μm and 8 μm respectively,the concentration were 5 x 108～10 x 108/ml and 1 x I08～5 x 108/ml respectively with a stability of 6 hours. In vitro water sac, the gray scale of self-made lipid microbubbles and SonoVue were 121.67±6.76 and 122.33 ± 4.53 respectively( P>0.05). In normal rabbit kidney parenchyma, the peak video intensity of normal rabbit kidney parenchyma of self-made lipid microbubbles and SonoVue were 72.00 ± 7.21 and 74. 65± 10.93 respectively(P>0.05). Conclusions The lipid microbubbles have satisfactory physical chemistry characteristics and echogenicity. Key words: Ultrasonography; Microbubbles