Abstract 12752: Ultrasound-Responsive Liposome Enhanced Gene Delivery for Heart Disease

Introduction: Genome editor-CRISPR/Cas9 holds much promise for treatment of heart disease. A critical step is the development of gene transfer platform that can deliver genes into heart muscle efficiently. We have developed ultrasound (US)-responsive echogenic liposomes (ELIP) for controlled payload release, and enhanced payload penetration upon ultrasound application. Hypothesis: We hypothesize that ELIP in combination with ultrasound application can enhance gene delivery in cardiomyocytes. Methods: FITC (green fluorescence) labeled NF-kB oligonucleotides were used as a prototype for gene delivery. ELIP containing NF-kB-FITC (ELIP-NF-kB-FITC) were prepared by a conventional procedure of hydrating the lipid film, sonication, freezing and drying. Rats were divided into control, ELIP-NF-kB-FITC without US, and ELIP-NF-kB-FITC with US. ELIP-NF-kB-FITC were administered into the left ventricle by injection with the aorta clamped. Ultrasound (1 MHz at 0.5 W/cm2, 100% duty cycle) was applied to the heart for 5 min. Thereafter, heart was excise, fixed and imaged by fluorescent microscopy. The fluorescent intensity of the left ventricular wall was quantified by NIH ImageJ software. Results: ELIP-NF-kB-FITC delivered without ultrasound application showed limited green fluorescence in the heart. Ultrasound (US) in combination with ELIP enhanced NF-kB-FITC penetration into the ventricular walls (Fig. 1A). Quantitatively, ultrasound provided 2-fold increase (2.0 ± 0.27, P < 0.01 vs control) in the mean green fluorescence (Fig. 1 B). Conclusions: Ultrasound application in combination with ELIP enhanced gene delivery into the ventricular walls. This platform offers a promising delivery system of CRISPR components for the correction of cardiomyopathies caused by gene mutation/change.