Facile formulation of a long-wavelength cyanine for optical imaging in the second near-infrared window
Hailey I. Kilian, Homan Kang, Nikhila Nyayapathi, Takeshi Fukuda, Eeswar Adluru, Huijuan Zhang, Breandan Quinn, Jun Xia, Hak Soo Choi, Jonathan F. Lovell
Abstract
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.