Fig. 4

Efficiency and specificity of cardiac uptake of RORα plasmid/CMBs in vivo. (A) Schematic diagram of UTMD-mediated RORα delivery to the heart. (B) Representative ultrasound contrast images of CMBs in the heart were obtained before and after plasmid/CMBs injection, as well as after ultrasound-targeted microbubble blast. The second harmonic mode (transmitting at 1.6 MHz and receiving at 3.2 MHz) with an electrocardiograph (ECG)-mediated trigger was used to induce CMBs burst. Following CMBs injection, microbubbles with high-echo intensity filled the left ventricle (L), right ventricle (R), and the ventricular wall tissue (arrows). After complete CMBs blasting, only a small amount of microbubbles remained in the heart cavity and showed a low echo shadow. (C) Fluorescence images of successful GFP plasmid transfection dependent on UTMD technique, DAPI for nucleus; green for GFP (scale bar of 50 μm). (D) Relative mRNA levels of RORα expression in the heart and other organs (n = 4). (E) Western blots and quantification of RORα expression in multiple organs (n = 4). (F) Immunohistochemical images of RORα expression in cardia tissue after UTMD treatment (scale bar of 50 μm). (G) RT-qPCR demonstrated that UTMD mediated the overexpression of cardiac RORα in rats with severe sepsis (n = 3)