Development and Characterization of Ultrasound Activated Lipopolyplexes for Enhanced Transfection by Low Frequency Ultrasound in In Vitro Tumor Model.

This work focuses on the development of ultrasound contrast vesicles for ultrasound-mediated enhanced transfection of nucleic acids in the cancer cells and projects its application as a tool for diagnostic imaging. The ultrasound contrast vesicles are stable, anionic, nanoscaled vesicles with ultrasound contrast equivalent to the commercially available SonoVue. These anionic lipid vesicles establish electrostatic interaction with cationic polyplexes based on linear polyethylenimine (22kDa) forming lipopolyplexes with ultrasound contrast. The lipopolyplexes are characterized regarding shape, size, and zeta potential. When exposed to low frequency ultrasound, these carriers show elevated transfection efficiency and reduced cytotoxicity. The effect of post-transfection ultrasound on cellular uptake of lipopolyplexes is also evaluated. An analogous transfection is also observed in the tumor mimicking multicellular 3D spheroid culture of ovarian cancer cells. The emergence of tumor imaging and enhanced gene delivery by medical ultrasound, a noninvasive imaging modality, is considered paving the way for efficient theranostic gene therapy.