Abstract
We have developed a theranostic system that enables both drug delivery and imaging of drug distribution
for efficient and side effects-free pharmacological therapy. In this system, nanosecond light pulses are
used both for photoacoustic (PA) imaging and drug delivery. With low-energy light pulses, thermoelastic
waves (PA waves) are induced in tissue for imaging blood vessels as well as drug distribution, while
strong pressure waves called photomechanical waves (PMWs) are generated by irradiating a lightabsorbing
material with high-energy light pulses to increase the permeability of blood vessels for
targeted transvascular drug delivery. Conditions for drug delivery can be adjusted on the basis of
information on blood vessel structures and drug distribution with the system. In this article, we describe
the principle, design and characteristics of the system. The system was applied to drug delivery to
tumors in mice. The results are also reported.
