Ultrasound-mediated microbubble destruction enhances beta-galactosidase gene transfection and expression in HKCs

To investigate the efficiency and safety of ultrasound-mediated microbubble destruction in enhancing beta-galactosidase gene (beta-gal gene) transfer into human proximal tubular cells(HKCs).

beta-gal gene was transfected to HKCs as a mark gene with ultrasound-mediated microbubble destruction. Cultured HKCs were grouped to receive the following 7 treatments respectively: ultrasound alone; microbubble alone; naked plasmid; ultrasound and plasmid; microbubble and plasmid; ultrasound, microbubble, and plasmid; and VigoFect and plasmid. In Group 6, HKCs were exposed to ultrasound under different sound intensities and time. X-gal staining, trypan blue staining, and Hochest staining were used to detect the transfection efficiency, cell survival rate, and cell apoptosis rate, respectively.

Beta-galactosidase expression could be observed in the ultrasound-mediated microbubble destruction groups. Along with the increasing of sound intensity and exposure time, the cell survival rate of HKCs decreased, and the cell apoptosis rate increased gradually. The transduction efficiency and survival rate in middle intensity (0.3 W/cm(2)*60 s) of ultrasound exposure were higher than those of other groups, similar to those of Group 7.

Under optimum sound intensity and exposure time, ultrasound-mediated microbubble destruction can increase gene transfer into HKCs. This non-invasive gene transfer method may be a useful tool for clinical gene therapy.