An Experiment Study On Transgene Expression In Intervertebral Disc Cells In Vivo Mediated By Microbubble-Enhanced Ultrasound Gene Therapy

Background Intervertebral disc degeneration is a formidable problem. Although various gene therapy have been reported as having promising therapeutic potential to regenerate disc.But more attentions and study have to pay on it to find a really safety and high effiency gene transfer.Objective To evaluate the effect of ultrasound contrast agent on expression of plasmid in intervertebral disc of Sprague-Dawley rats.Design, Time AND Setting A randomized control was performed in Medical And Molecular lab,Chongqing Medical University between March 2008 and December 2008.Methods Forty adult Sprague-Dawley rats were studied. The rats were randomly divided into 4 groups. Two different reporter plasmid DNA encoding green fluorescent protein (GFP) and firefly luciferase were used. Plasmid DNA was mixed with ultrasonography contrast agent (microbubbles) and injected into coccygeal intervertebral discs of Sprague-Dawley rats. The ultrasound was irradiated on the surface of injected discs.Main Outcome Measures Rats were killed 7 days after gene transduction.Harvested nucleus pulposus tissues were used to evaluate gene expression by scan the luciferase,PCR and microscope scan.Results Significant luciferase activity was observed in group 4;less in the other groups and none in the control. PCR has got the same result.Conclusion Ultrasound with microbubble contrast agent induced efficient gene transfer to interverbetebral disc of rats after local injection of plasmid.