Fig. 7
From: Contrast agents for photoacoustic imaging: a review of stem cell tracking
a Schematic illustration of SPIO@Au nanoparticle containing SPIO core, silica, and gold coating. b Dynamic light scattering analysis and c transmission electron microscopic image of SPIO@Au indicating the size of the nanoparticle. Scale bar is 100 nm. d Ultraviolet-visible light absorption spectrum and e optoacoustic (OA) profile of SPIO@Au. f In vivo OA imaging of mouse brain at 72 h after intra-carotid artery injection of SPIO@Au-labelled MSCs or MSCs alone. Yellow arrows on B-mode ultrasound images of the brain indicate the bolt placement where the U87 cells were implanted into the brain. The OA images were taken at 810 nm, and the signal intensity was calculated within the green regions of interest. Average OA values were obtained by averaging all PA intensity values above the signal-noise threshold within the regions of interest. Reproduced with permission from [67].Copyright \(\copyright\) 2018, IOP Publishing. All rights reserved