Study on the parameter optimization for therapeutic ultrasound mediated microbubble destruction enhancs gene transfection in rat muscle in vivo

To search for the most suitable gene transfection conditions for rat muscle in vivo by therapertic ultrasound-mediated microbubble destruction (UMMD). A mixture of microbubbles and enhanced green flurescence protein (EGFP) plasmids was injected into rat tibialis anterior muscle and the muscels treated with ultrasound irradiation by different output intensity, duty cycle and irradiation time of therapeutic ultrasound. The transfection efficiency was demonstrated by the EGFP expression results under fluorescent staining and immunohistochemical staining. And the most favorable ultrasound conditions as well as local intra-muscle and intravenous injection methods were selected based on the best transfection efficiency and the least muscle damage under HE staining. The rats were divided into four groups: 1) ultrasound + microbubbles + plasmid; 2) microbubble + plasmid; 3) ultrasound + plasmid; 4) plasmid only. The favorable ultrasound conditions and injection method were selected out on the basis of above steps. EG