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

• Published in: Nature communications Vol. 8; no. 1; p. 15782
• Main Authors: Chen, Yun-Sheng, Yoon, Soon Joon, Frey, Wolfgang, Dockery, Mary, Emelianov, Stanislav
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 08.06.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 59; 631/67/2321; 639/301/357/354; 639/925/357/354; 692/308/2778; 692/699/67/2321; Acrylic Resins - chemical synthesis; Animals; Biomedical engineering; Computer engineering; Contrast agents; Contrast Media - chemistry; Contrast Media - pharmacokinetics; Humanities and Social Sciences; Hydrogels; Image Enhancement - methods; Male; Metal Nanoparticles - chemistry; Mice, Nude; Molecular Imaging - methods; multidisciplinary; Nanoparticles; Nanostructures - chemistry; Phantoms, Imaging; Phase transitions; Photoacoustic Techniques - instrumentation; Photoacoustic Techniques - methods; Science; Science (multidisciplinary); Atlanta Georgia; Georgia; United States > US; Texas
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms15782

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 . Photoacoustic imaging becomes an enabling technology that is designed for clinic diagnosis of disease. Here, Chen et al . report an imaging contrast agent—plasmonic nanoparticles caged in hydrogel subject to reversible volume change depending on temperature, which exhibits tunable photoacoustic signal.