Development And Recognition Performance Of Oxygenated Small Molecule Fluorescent Probes

Objective:To explore new fluorescent probes with the identification of nitric oxide?NO?and hypochlorite?ClO^-?oxygen molecules,and to investigate their recognition performance in vitro and in vivo.Methods:Using the MTT assay and commercial lysosomal targeting agent DND-99 on human breast cancer cells?MDA-MB-231?to test the toxicity and lysosomal targeting properties of NO fluorescent probe L₁?5-aminofluorescein morpholine?,which developed by previous studies of the research group.Using A?_25-35 to establish SD rat model with Brain inflammation;and employing lipopolysaccharide?LPS?to induce two mice inflammatory models?mouse liver inflammation model and subcutaneous inflammation model in mice?,renal inflammation model induced by ischemia-reperfusion.As the experimental group,L₁ was examined for detecting NO performance on the frozen slices,sliced from above established models by Olympus IX73 system,while using Saline as a control.The near-infrared identification ClO^-fluorescent probe L₂ was prepared by substitution reaction of the cyanine dye IR780 with methyl mercaptan,in which the cyanine dye IR780 was used as the nucleus of the fluorophore.Its structure was confirmed by ¹H NMR,¹³C NMR,high resolution mass spectrometrys and infrared spectra analysis.The Olympus IX73 system was used to investigate the recognition performance of L₂ for ClO^-in HepG2 cells and frozen sections of nephritis model tissues.L₂ was examined for the detection in vivo of ClO^-performance in zebrafish and established B16F10 tumor model C57 mice.Results:1.L₁ has low toxicity to human breast cancer cells and can achieve cell lysosomal targeting;L₁ has a good fluorescence detection performance for NO in the established SD rat model of Brain inflammation,the two mouse models with inflammation induced by LPS and renal inflammation model induced by ischemia-reperfusion in mice.2.Modern analytical techniques of ¹H NMR,¹³C NMR,HR-MS and FT-IR confirmed that L₂ was the expected target molecule.In vitro selective experiments showed that L₂ can selectively recognize ClO^-by fluorescence quenching.And L₂ can recognize ClO^-in HepG2 cells,nephritis model,zebrafish and tumor model.Conclusion:1.L₁,which was constructed in the early stage of the research group,can detect fluorescence of NO produced in Brain inflammation.2.The newly designed fluorescent probe L₂ has specific selectivity for ClO^-,and real-time fluorescence quenching in vivo and in vitro for detection of ClO^-imaging.The study of this paper provides experimental support for the detection of NO and ClO^-of oxygenated small molecules in animal model diseases,showing the good application prospects of the two probes in vivo.