Abstract
Photoacoustic (PA) imaging allows visualization of the physiology and pathology of tissues with good spatial resolution and relatively deep tissue penetration. The method converts near-infrared (NIR) laser excitation into thermal expansion, generating pressure transients that are detected with an acoustic transducer. Here, we find that the response of the PA contrast agent indocyanine green (ICG) can be enhanced 17-fold when it is sealed within a rigid nanoparticle. ICG encapsulated in particles composed of porous silicon (pSiNP), porous silica, or calcium silicate all show greater PA contrast relative to equivalent quantities of free ICG, with the pSiNPs showing the strongest enhancement. A liposomal formulation of ICG performs similar to free ICG, suggesting that a rigid host nanostructure is necessary to enhance ICG performance. The improved response of the nanoparticle formulations is attributed to the low thermal conductivity of the porous inorganic hosts and their ability to protect the ICG payload from photolytic and/or thermal degradation. The translational potential of ICG-loaded pSiNPs as photoacoustic probes is demonstrated via imaging of a whole mouse brain.
| Original language | English |
|---|---|
| Article number | 1800512 |
| Journal | Advanced Materials |
| Volume | 30 |
| Issue number | 27 |
| DOIs | |
| State | Published - Jul 5 2018 |
Bibliographical note
Publisher Copyright:© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Funding
J.K. and D.K. contributed equally to this work. This work was supported by the Defense Advanced Research Projects Agency (DARPA) under Cooperative Agreement HR0011-13-2-0017, by the National Science Foundation under Grant No. CBET-1603177, and by the National Institutes of Health, through Grant No. R01 AI132413-01. J.K. acknowledges financial support from the UCSD Frontiers of Innovation Scholars Program (FISP) fellowship. D.K. acknowledges the Basic Science Research Program of the Korea National Research Foundation (NRF) funded by the Ministry of Education (Grant No. 2017R1C1B5075766). Y.H. and J.-H.P. acknowledge the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (Grant No. NRF-2017R1E1A1A01074847). J.V.J. acknowledges NIH funding from DP2 HL137187 and R00 HL117048 and infrastructure from S10 OD021821. All animal work was conducted with permission from the institutional animal care and use committee at UCSD under protocol #S15050.
| Funders | Funder number |
|---|---|
| National Science Foundation Arctic Social Science Program | CBET-1603177 |
| National Science Foundation Arctic Social Science Program | |
| National Institutes of Health (NIH) | DP2 HL137187, 15050, S10 OD021821, R01 AI132413-01 |
| National Institutes of Health (NIH) | |
| National Heart, Lung, and Blood Institute (NHLBI) | R00HL117048 |
| National Heart, Lung, and Blood Institute (NHLBI) | |
| Defense Advanced Research Projects Agency | HR0011-13-2-0017 |
| Defense Advanced Research Projects Agency | |
| University of California San Diego Health | |
| Ministry of Education China | 2017R1C1B5075766 |
| Ministry of Education China | |
| Ministry of Science, ICT and Future Planning | NRF-2017R1E1A1A01074847 |
| Ministry of Science, ICT and Future Planning | |
| National Research Foundation of Korea |
Keywords
- brain imaging
- contrast agents
- in vivo imaging
- indocyanine green
- ultrasound
ASJC Scopus subject areas
- General Materials Science
- Mechanics of Materials
- Mechanical Engineering