RESUMO
OBJECTIVE: To study ultrasonic naked gene delivery and its effect control, and to investigate the new methods, which are easy-to-use, reliable and non-cytotoxic for application in gene therapy so as to build an optimal parameter set. METHOD: Suspensions of different kinds of cells were exposed to calibrated ultrasound field (35.1 kHz) with different parameters for gene delivery. Morphology, membrane permeability, naked gene expression efficiency, threshold of cell damage and cell viability were examined by laser scanning confocal microscopy, fluorescent microscopy, flow cytometry and spectrophotometer. RESULT: The plasmid of green fluorescent protein (GFP) was delivered into S180 cells under optimal parameters without cell damage. The transfection rate was about 35.83% +/- 2.53% (n=6) in viable cells. The GFP expression intensity in ultrasound exposure group had a higher fluorescent peak than AVV-GFP group and control group (P<0.001). CONCLUSION: Ultrasound can effectively deliver naked gene into cells using optimal parameters without cell damage. The gene uptake depends on energy accumulation at 90% of cell viability, and the tendency of apoptosis is found in S180 tumor cells.
