Xanthene‐Based Nitric Oxide‐Responsive Nanosensor for Photoacoustic Imaging in the SWIR Window

Abstract

Shortwave infrared (SWIR) dyes are characterized by their ability to absorb light from 900 to 1400 nm, which is ideal for deep tissue imaging owing to minimized light scattering and interference from endogenous pigments. An approach to access such molecules is to tune the photophysical properties of known nearinfrared dyes. Herein, we report the development of a series of easily accessible (three steps) SWIR xanthene dyes based on a dibenzazepine donor conjugated to thiophene (SCR-1), thienothiophene (SCR-2), or bithiophene (SCR-3). We leverage the fact that SCR-1 undergoes a bathochromic shift when aggregated for in vivo studies by developing a ratiometric nanoparticle for NO (rNP-NO), which we employed to successfully visualize pathological levels of nitric oxide in a drug-induced liver injury model via deep tissue SWIR photoacoustic (PA) imaging. Our work demonstrates how easily this dye series can be utilized as a component in nanosensor designs for imaging studies.

Oxidative stress biomarker triggered multiplexed tool for auxiliary diagnosis of atherosclerosis

“…Despite the technological advances of our multiplexed tool, there are still some drawbacks that demand further study. First, the signal variation of PA nanoprobe in vivo is relatively small, which may decrease sensitivity in live imaging (50)(51)(52)(53). This limitation can be addressed by developing more specific and sensitive probes for different biological targets.…”