Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.



Facile formulation of a long-wavelength cyanine for optical imaging in the second near-infrared window

Author affiliations

Abstract

The second near-infrared window (NIR-II) beyond 1000 nm has attracted attention for optical contrast imaging in small animals. We sought to assess whether commercially available NIR-II dyes could be easily formulated for this purpose. 13 hydrophobic NIR-II dyes were purchased and screened by formulating them in simple solubilizing agents with established use in humans: propylene glycol, Cremaphor EL, Kolliphor HS15 (HS15), Tween 80, and cyclodextrin. Based on the absorption at 1064 nm (matching the Nd:YAG laser output commonly used in photoacoustic imaging), three of the dyes were further assessed at varying dye and surfactant concentrations. Of these, benzo indole butyl diphenylaminocyclopentene heptamethine (BIBDAH) tetrafluoroborate in HS15 generally showed the most favorable NIR-II character. 1 mg mL−1 BIBDAH in 25% HS15 exhibited a single absorption peak at 1030 nm with a calculated intensity greater than 100, which was relatively stable for weeks in storage. Following intravenous administration to mice, determination of BIBDAH pharmacokinetics was possible by absorption measurements of sampled plasma, revealing a circulating half-life of about one hour. Most of the dye was taken up by the liver. BIBDAH was used in vitro and in vivo as a photoacoustic contrast imaging agent and its accumulation could be detected in subcutaneous tumors in mice. BIBDAH was used for fluorescence imaging of blood vessels in mice, including in the brain (through intact skull), and dye clearance from blood to the liver was visualized. Taken together, this study confirms that accessible, strongly-absorbing dye can readily be formulated for injection by simply dissolving them in biocompatible surfactants and used for high-contrast preclinical optical imaging in the second NIR window.

Graphical abstract: Facile formulation of a long-wavelength cyanine for optical imaging in the second near-infrared window

Back to tab navigation

Supplementary files

Article information


Submitted
10 Apr 2020
Accepted
03 Jun 2020
First published
04 Jun 2020

Biomater. Sci., 2020, Advance Article
Article type
Paper

Facile formulation of a long-wavelength cyanine for optical imaging in the second near-infrared window

H. I. Kilian, H. Kang, N. Nyayapathi, T. Fukuda, E. Adluru, H. Zhang, B. Quinn, J. Xia, H. S. Choi and J. F. Lovell, Biomater. Sci., 2020, Advance Article , DOI: 10.1039/D0BM00572J

Social activity

Search articles by author

Spotlight

Advertisements