Study of mechanism of sonoporation using lipid bilayer and surface-modified microbubble

Abstract

Microbubble enhanced sonoporation is one of gene therapies and expected to be safe, less invasive, and controllability of treatment area, but its induction rate is very low and its mechanism remains to be explained. The objective is to analyze the mechanism and obtain an optimal design. Because microbubble density distribution was unstable during sonication and ultrasound intensity on the cell surface was affected by distribution change through attenuation change during propagation, microbubble distribution should be controlled and localized only near the membrane to realize high reproducibility. An artificial lipid bilayer modified by biotin-avidin to bind microbubbles was used for this purpose. We have three steps: build lipid bilayer, binding with microbubbles, and introduction of sonication and observation system. We built the lipid bilayer with a diameter of 1 mm using Black Lipid Membrane method. With a capacitance measurement with impedance analyzer (NF, ZM2375), the lipid bilayer thickness was confirmed and its duration is more than an hour. Then, we introduced the sonication and observation system to the lipid bilayer, and we are observing a behavior of the lipid bilayer under irradiation of ultrasound. Afterward we will observe that of a lipid bilayer modified of microbubbles.