Ultrasound-targeted cationic microbubble-mediated gene transfection and inhibition of retinal neovascularization

To investigate whether ultrasound-targeted cationic microbubbles (CMBs) destruction could deliver endostatin-green fluorescent protein (GFP) plasmids efficiently to the human retinal endothelial cells (HRECs) and inhibit retinal neovascularization in mice.

CMBs were prepared and the presentation of GFP reporter was confirmed by flow cytometry and laser confocal microscopy. Experiments assessing HRECs migration and vascular formation were performed to evaluate gene therapy's efficiency in vitro. A mouse model of oxygen-induced retinopathy was employed and the expression of Bcl-xl, Bcl-2, vascular endothelial growth factor (VEGF) and endostatin in the retina of mice were determined by Western blotting and quantitative polymerase chain reaction (qPCR). The expression of endostatin-GFP in the retina was examined by laser confocal microscopy at 5, 14, and 28d after treatment.

The gene expression of endostatin was the highest in the group of the CMBs. Besides, the inhibition and antiangiogenesis effect of the migration and development of HRECs were improved following treatment with CMBs compared with the other groups in vitro. In vivo, retinal neovascularization was significantly inhibited and the fluorescence intensity of endostatin-GFP in the mouse retina was importantly higher in the group of CMBs than that in other groups.

The research illustrates ultrasound-targeted CMBs destruction possessed distinct effect on the inhibition of the vascular formation and the development of retinal neovascularization both in vitro and in vivo.