Design And Biological Applications Of NAD(P)H-responsive Multifunctional Near-infrared Fluorescence Probe

The oxidation-reduction pair of nicotinamide adenine dinucleotide(phosphate)(NAD(P)H/NAD(P)),as the electronic carrier of the biological enzyme catalytic process,participates in the regulation of various cell functions.The disorder of NAD(P)H level often indicates or leads to the occurrence of various diseases,especially the development of cancers,during that tumor cells usually express five times higher NAD(P)H levels than normal cells.Therefore,the detection and imaging of NAD(P)H in vivo and in vitro are very important for the physiological and pathological research.The designable organic fluorescent dye can detect and image NAD(P)H in different dimensions simply and efficiently.Nevertheless,the current NAD(P)H fluorescence probe still has these problems: 1.The single-channel emission probe is uncertain with the test conditions,thereby the suspicious value cannot be excluded;2.The interference of pH and other measuring environments cannot be corrected;3.The emission wavelength is mostly below 650 nm with a shallow tissue imaging depth.To solve these problems,this dissertation focuses on the synthesis of multi-functional NAD(P)H-activated nearinfrared fluorescence probes with dual-channel,dual-response,and dual-mode by reasonable molecular design,and their application of NAD(P)H imaging in vivo and in vitro.The detailed works are as follows:(1)A visible-near infrared dual-channel fluorescence probe was designed and synthesized for the detecting and imaging of NAD(P)H in vivo and in vitro.The visible and near-infrared dual-channel emission can be activated by NAD(P)H and eliminate the interference of sulfur compounds through the abnormal ratio of the dual-channel intensity.This probe can realize the mutual verification of the detection and imaging of intracellular and extracellular NAD(P)H through dual-channel emission,and the fluorescence imaging of living tissues through near-infrared channel emission with good biocompatibility,showing the possibility of monitoring NAD(P)H levels in biological systems.(2)A pH/NAD(P)H dual-responsive fluorescence probe was designed and synthesized for the pH-corrected detection and imaging of intracellular and extracellular NAD(P)H.The pH/NAD(P)H dual-responsive probe turned on fluorescence that activated by NAD(P)H to detect NAD(P)H,meanwhile,the pH environment was determined by the ratio of dual-channel fluorescence.This probe realized imaging and tracking of NAD(P)H levels and its pH environment in the process of cell glycolysis and mitochondrial autophagy,demonstrating the feasibility of the probe for simultaneous monitoring of intracellular and extracellular NAD(P)H and pH.(3)A near-infrared fluorescence/photoacoustic dual-mode probe was designed and synthesized for NAD(P)H imaging in tumor tissue.The near-infrared fluorescence and photoacoustic signal were activated by NAD(P)H,that combined the advantages of high spatial resolution of near-infrared fluorescence in cell imaging and dual-mode imaging in tissue imaging.The probe realized to image NAD(P)H level in intracellular energy metabolism and drug therapy by fluorescence,and diagnosis of tumor-bearing mice in vivo by near-infrared fluorescence/photoacoustic dual-mode imaging.It demonstrated the feasibility of NAD(P)H detection and tracking in various physiological and pathological research processes.