Nanoinmunoliposomes targeted to cancer cells with anti EGF-antibodies

IEZZI ME; WERBAJH S; LLOYD R; RODRIGUEZ G; CANZIANI G; POLICASTRO L; PODHAJCER O

Congreso; 51 Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2015

Mar del Plata

The aim of this study was to develop a nanoimmunovehicle to deliver a genetic medicine to EGFR (epidermal growth factor receptor) overexpressing cancer cells. The final goal is to deliver a chimeric ROS-responsive DNA element (ROS-RE) driving the expression of therapeutic genes. We compared several methods for the efficient encapsulation of the DNA in stealth liposomes. Subsequently, both a humanized anti-EGFR Fab´fragment as well as a camelid VHH nanobody fragment was conjugated to the nanovehicle. As a proof of concept we encapsulated a plasmid where luciferase expression was driven by the ROSRE. The internalization of the nanovehicle was followed by confocal microscopy. Initial studies showed poor gene expression indicating that the DNA was unable to reach the nucleus. In subsequent studies the cationic polymer PEI was used to improve immunoliposomes exit from the lysosomes. Complexes of PEI/DNA performed at different nitrogen to phosphate ratio (N/P=3, 5 y 10) were encapsulated in liposomes and luciferase activity was evaluated in cell cultures. Luciferase expression of liposomes containing complexes at N/P 10 was 1300 times higher than liposomes with complexes at N/P 3 ratio. In addition, liposomes containing PEI/DNA complexes did not shown toxicity over treated cells (95-98% cell survival). In future studies, we will evaluate the therapeutic efficacy in in vivo models.