Prof. Nobuki Kudo

Title: Sonoporation using microbubbles: A technique for gene transduction and drug delivery


Graduate School of Information Science and Technology, Hokkaido University

Nobuki KUDO


Sonoporation is a technique to induce a transient increase in cell membrane permeability by exposure of biological cells to ultrasound. The technique is used to deliver genes and drugs that normally have no membrane permeability into cells, and early studies showed that ultrasound exposure in the presence of micron-sized bubbles greatly improves effects of sonoporation, suggesting that mechanical effects of oscillating cavitation bubbles on cells are responsible for inducing the effects. Continuous efforts have been made to elucidate the mechanisms; however, they have still not been fully elucidated. A high-speed microscopic observation system was developed to elucidate the mechanisms of sonoporation. Dynamics of microbubbles under the condition of exposure to ultrasound 1 MHz in center frequency was captured at a maximum framing rate of 16 million frames per second (Mfps). A newly developed high-speed video camera with high image quality was also used to visualize interaction between bubbles and transparent living cells at a framing rate of 10 Mfps. These results of observation confirmed the presence of several mechanisms by which oscillating microbubbles create cell membrane rupture, indicating the importance of direct observation to understand sonoporation phenomena.


Nobuki Kudo was born in Hokkaido, Japan, in 1957. He received a B.S. degree in electronics engineering from Hokkaido University, Sapporo, Japan in 1982 and M.S. and Ph.D. degrees in bioengineering from Hokkaido University in 1984 and 1987, respectively.

    From 1987 to 1995, he belonged to Toshiba Cooperation and was engaged in the development of an extra-corporeal shockwave lithotripter. In 1995, he acquired the position of Research Associate in Faculty of Engineering, Hokkaido University and became Associate Professor of the Graduate School of Information Science and Technology, Hokkaido University in 2009. His research interest is application of ultrasound and optical techniques for medical engineering. He is a board member of the Japan Society on Ultrasound in Medicine. He has roles as associate editor of IEEE trans. on UFFC and area editor of Journal of Medical Ultrasonics.


Joomla templates by a4joomla