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

Abstract

A dozen commercial NIR-II dyes are screened for simple formulation and one is applied for in vivo optical imaging in mice.

Activatable Carbocyanine Dimers for Photoacoustic and Fluorescent Detection of Protease Activity

“…Our work uses cyanine dyes because of their utility in chemical detection. − These dyes offer high absorption coefficients, tunable fluorescence quantum yields, and long excitation and emission wavelengths. In biological settings, they have exhibited excellent biocompatibility and low toxicityindocyanine green, a cyanine derivative, has been in clinical use for over 60 years .…”

Development of Second Near-Infrared Photoacoustic Imaging Agents

“…OMDs based on conjugated systems are characterized by the merits of good biocompatibility, low cytotoxicity, structural tunability, and desirable degradability and have been extensively applied for PAI. The absorption wavelength of these dyes was expanded from visible to NIR region by several tactics, including extending the π-conjugated system and enhancing ICT, which provides the possibility of OMDs for deep-tissue and high-contrast NIR-II PAI [52][53][54]. Reproduced, with permission, from [41].…”

“…It is worth noting that the absorption wavelength of cyanine dyes can be adjusted to the NIR-II region through the aggregation strategy. For example, a dye BIBDAH in free form exhibited an absorption peak at 900 nm (Figure 4D) [53], while by simply dissolving in biocompatible surfactants Kolliphor HS 15 (HS 15), BIBDAH showed a representative strong absorption peak at 1030 nm, which was attributed to its J-aggregated form in HS 15. Owing to its favorable NIR-II photochemical properties, BIBDAH in HS 15 has been successfully utilized for PA imaging in nude mice bearing subcutaneous tumors.…”

Photoacoustic in vivo 3D imaging of tumor using a highly tumor-targeting probe under high-threshold conditions

“…In addition to endogenous and semi-endogenous chromophores, there is a wide range of exogenous or artificial contrast agents that are absorption-tunable in the near-infrared (NIR) region (700–900 nm) and modifiable, particularly with biocompatible polymers 13 – 18 , so that their biofunctions, such as their circulation in blood, selectivity, and efficiency, can be improved. Recent attention has also been paid to contrast agents in the so-called second NIR (1000–1700 nm) window (NIR-II) region 19 , 20 and their formulation 21 to allow higher spatial resolution, deeper penetration, and lower interference by tissue substrates with minimal autofluorescence. Under these circumstances, PA imaging of tumors in animals has been intensely studied in recent years using various types of NIR and NIR-II 21 contrast agents (dyes 22 – 24 , quantum dots 25 , nanoparticles 26 – 28 , semi-conducting polymers 29 , and so on 30 , 31 ) in a variety of formulations and with diverse targeting strategies 32 .…”

“…Recent attention has also been paid to contrast agents in the so-called second NIR (1000–1700 nm) window (NIR-II) region 19 , 20 and their formulation 21 to allow higher spatial resolution, deeper penetration, and lower interference by tissue substrates with minimal autofluorescence. Under these circumstances, PA imaging of tumors in animals has been intensely studied in recent years using various types of NIR and NIR-II 21 contrast agents (dyes 22 – 24 , quantum dots 25 , nanoparticles 26 – 28 , semi-conducting polymers 29 , and so on 30 , 31 ) in a variety of formulations and with diverse targeting strategies 32 . Hopefully, the tumors, even when they are small and buried deep in the body, can be three-dimensionally drawn by these probes.…”