Gold nanorods (GNRs) offer a tunable optical absorption in the near infra-red wavelength region due to their plasmon resonance, which results in strong photoacoustic (PA) signal and make them suitable as contrast agent by means of PA imaging. The aim of this study was to examine the performance of synthesized polyethilene glicol (PEG)-GNRs as contrast agent for in vivo PA imaging and to evaluate their accumulation and distribution real time. Two-three month old FVB female mice were enrolled for the study, a bolus of 200μL of synthesized PEG-GNRs (53 nm length and 11 nm axial diameter, plasmon resonance at 840 nm, 1 mM Au concentration) solution was injected intravenously and detected with PA imaging. The accumulation of GNRs in the spleen was studied by means of the amplitude dynamic variation of the PA signal during time. GNRs contrast was clearly distinguished from endogenous background thanks to the nanoparticle spectroscopic specificity. Our results suggest that PA imaging could allow an efficient and noninvasive tool for in vivo detection of GNRs content and for the assessment of the kinetic parameters in target organs. The coregistration of μ-ultrasound and PA imaging is crucial for the real time evaluation of the GNRs distribution in different organs.

Date Published: 11 March 2015
PDF: 7 pages
Proc. SPIE 9323, Photons Plus Ultrasound: Imaging and Sensing 2015, 93234C (11 March 2015); doi: 10.1117/12.2077947

Published in SPIE Proceedings Vol. 9323:
Photons Plus Ultrasound: Imaging and Sensing 2015
Alexander A. Oraevsky; Lihong V. Wang, Editor(s)