Photoacoustic Response of Magnetic Nanoparticles to Pulsed Laser Irradiation

We investigate the capability of a photoacoustic technique to detect magnetic nanoparticles taken up by macrophage cells in the atherosclerotic vulnerable plaque from the murine animal model. The photoacoustic technique with monocrystalline iron oxide nanoparticles(MION) showed enhanced acoustic signal amplitude. Since the propagation of acoustic waves can deliver minimally altered information about biological tissue structure, the results of this study indicate that as a non-invasive imaging modality, photoacoustic imaging combined with the administration of MION in tissue may potentially be applied to detect the early stages of atherosclerotic plaque with an advantage of exceptional sensitivity and selectivity. We note that this result was the first experimental report to demonstrate the feasibility of the photoacoustic modality combined with MION as a screening test to detect the early stage of atherosclerotic vulnerable plaque.