Design and synthesis of photoacoustic probe for in situ imaging of hydrogen polysulfides in organs in vivo

Abstract

Hydrogen polysulfide (H2Sn), the oxidation product of H2S, plays a critical role in driving the signal regulation of ion channels and tumor suppressors, and the homeostatic imbalance of H2Sn is closely related to various diseases. However, the fluorescence imaging probe for the currently developed H2Sn cannot realize in situ real-time monitoring of H2Sn in living organs in vivo because of limited imaging depth. This study reports on the first rational design, synthesis, and evaluation of an H2Sn-activated photoacoustic (PA) probe (AP-Sn), which enables in situ visual tracking of changes in H2Sn levels in living organs in mice via H2Sn-activated PA imaging. After an AP-Sn solution was administered to the mouse via tail-vein injection, AP-Sn probe responses to H2Sn in the liver area allowed quick imaging of H2Sn in the near-infrared window. Changes in H2Sn levels in the liver attributed to lipopolysaccharides (LPS)-induced overexpression of CSE mRNA were used to monitor the pathological progression of drug-induced acute liver injury (ALI) in inflammatory mice. ALI can be dynamically evaluated in vivo at very high resolutions owing to enhanced depths and low scattering of tissues in the PA image.