Expression of thymidine kinase mediated by a novel non-viral delivery system under the control of vascular endothelial growth factor receptor 2 promoter selectively kills human umbilical vein endothelial cells

Figure 1 Schematic diagram of gene transfection. Transducer with contact gel (CG) was placed on the cell suspension covered with a 6-&mgr;m poly-ester film (PEF) under 1.9 MHz continuous ultrasound with a 80.0 mW/cm² output intensity. The 24-well plate was kept in a water bath at 37°C, and a sponge mat was placed in the water bath.