Dynamic contrast-enhanced photoacoustic imaging using photothermal stimuli-responsive composite nanomodulators

• Type of Material: Article
• Authors: Yun-Sheng Chen, Stanford University; Soon Joon Yoon, University of Texas at Austin; Wolfgang Frey, University of Texas at Austin; Mary Dockery, University of Texas at Austin; Stanislav Emelianov, Emory University
• Language: English
• Date: 2017-06-08
• Publisher: Nature Publishing Group
• Publication Version: Final Published Version
• Copyright Statement: © The Author(s) 2017
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1038/ncomms15782
• Title of Journal or Parent Work: Nature Communications
• ISSN: 2041-1723
• Volume: 8
• Start Page: 15782
• End Page: 15782
• Grant/Funding Information: We would also like to thank partial support from the National Institutes of Health under grants CA 149740, EB 008101 and CA158598, and funding from the Breast Cancer Research Foundation.
• Keywords: PROTEIN; GOLD NANORODS; HYDROGELS; Science & Technology - Other Topics; N-ISOPROPYLACRYLAMIDE; Science & Technology; THERAPY; DRUG-DELIVERY; NANOPARTICLES; Multidisciplinary Sciences; LIVING MICE
• Research Categories: Health Sciences, Radiology; Physics, Radiation

Abstract

Molecular photoacoustic imaging has shown great potential in medical applications; its sensitivity is normally in pico-to-micro-molar range, dependent on exogenous imaging agents. However, tissue can produce strong background signals, which mask the signals from the imaging agents, resulting in orders of magnitude sensitivity reduction. As such, an elaborate spectral scan is often required to spectrally un-mix the unwanted background signals. Here we show a new single-wavelength photoacoustic dynamic contrast-enhanced imaging technique by employing a stimuli-responsive contrast agent. Our technique can eliminate intrinsic background noises without significant hardware or computational resources. We show that this new contrast agent can generate up to 30 times stronger photoacoustic signals than the concentration-matched inorganic nanoparticle counterparts. By dynamically modulating signals from the contrast agents with an external near-infrared optical stimulus, we can further suppress the background signals leading to an additional increase of more than five-fold in imaging contrast in vivo.