13 July 2017 Can photoacoustic imaging quantify surface-localized J-aggregating nanoparticles?
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We investigate the feasibility of photoacoustic (PA) imaging to quantify the concentration of surface-localized nanoparticles, using tissue-mimicking phantoms and imaging with a commercial PA instrument at 815 nm and a linear-array transducer at a center frequency of 40 MHz. The nanoparticles were J-aggregating porphysomes (JNP) comprising self-assembling, all-organic porphyrin-lipid micelles with a molar absorption coefficient of 8.7×108  cm−1 M−1 at this wavelength. The PA signal intensity versus JNP areal concentration followed a sigmoidal curve with a reproducible linear range of ∼17  fmol/mm2 to 11  pmol/mm2, i.e., ∼3 orders of magnitude with ±34% error. For physiologically-relevant conditions (i.e., optical scattering-dominated tissues: transport albedo <0.8) and JNP concentrations above ∼330  fmol/mm2, the PA signal depends only on the nanoparticle concentration. Otherwise, independent measurement of the optical absorption and scattering properties of the underlying tissue is required for accurate quantification. The implications for surface PA imaging, such as in the use of targeted nanoparticles applied topically to tissue as in endoscopic diagnosis, are considered.
© 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)
Liang Lim, Robert Mastragostino, Kenneth Ng, Gang Zheng, Brian C. Wilson, "Can photoacoustic imaging quantify surface-localized J-aggregating nanoparticles?," Journal of Biomedical Optics 22(7), 076008 (13 July 2017). https://doi.org/10.1117/1.JBO.22.7.076008 . Submission: Received: 16 January 2017; Accepted: 21 June 2017
Received: 16 January 2017; Accepted: 21 June 2017; Published: 13 July 2017

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