Plasmid GFP Transfer Into Skeletal Muscle In Mice Via Ultrasound And Microbubble In Vitro And In Vivo

Part I Gene transfer with microbubble ultrasound and plasmidDNA into skeletal muscle: a comparison between commerciallyavailable microbubble agents[Abstract] Objectives: To determine the effect of ultrasound microbubble to gene transfer in skeletal muscle, we therefore performed a systematic comparison between commercially available microbubble agents, with and without ultrasound for their effect on gene transfer in mouse skeletal muscle. Methods: All comparisons were performed between microbubbles (Levovist, Sonovue and Optison) with and without ultrasound using plasmid GFP (Green Fluorescent Protein). In vitro studies on H2K myoblast cells, we studied the trend of transfection efficiency and cell viability under different conditions. In vivo studies, we assessed transfection efficiencies by counting GFP positive fibres on mice skeletal muscle. Tissue damage was assessed on serial sections. Results: Ultrasound alone showed better trend of transfection efficiency than microbubbles in vitro and addition of microbubbles had the effect to reduce cell viability. In vivo, both Sonovue and Optison with ultrasound had significant effect on transgene expression compared with plasmid + ultrasound. Optison only also showed significant effect compared with plasmid only. Levosist with or without ultrasound had no effect on gene transfer, instead it increased tissue damage. Conclusion: The PFCgas-filled microbubbles hold great promise in gene delivery in skeletal muscle with undetectable tissue damage. Both the components of microbubble shell and cavitation threshold of microbubbles may play a role for the efficiency of gene delivery.