Development of a Microvascular Phantom for Studies on Microbubble Dynamics and Bubble-Cell Interaction Inside a Capillary

Phantoms for studies on sonoporation and BBB opening were developed to understand the bubble dynamics and bubble-cell interaction inside capillary vessels. A capillary tube phantom that has a lumen diameter similar to that of capillary vessels was developed using a gel to mimic an in vivo situation, and dynamics of bubbles inside the lumen was observed using a high-speed camera. The results showed that inflation of the lumen was induced by bubble expansion, indicating that bubble dynamics cause a significant increase in tensile force applied to the lumen surface. A vascular phantom with cultured cells on its lumen surface was also developed and used for high-speed observation of bubble-cell interaction inside a lumen and confocal microscopic observation of resulting cell damage. Cell membrane damage was observed near the oscillating bubbles, suggesting the importance to observe bubble-cell interaction using a vascular phantom for elucidation of the mechanisms of sonoporation and BBB opening.