Innovative Construction And Application Of Fluorescent Molecular Probes Targeting Apoptosis

Aim: Apoptosis is the orderly death of cells that occurs autonomously and participates in various physiological and pathological processes in organisms.Abnormal apoptosis behaviors will lead to virous types of diseases,including tumor and HIV.Therefore,the development of techniques to monitor apoptosis signaling will contribute to the early diagnosis and treatment of human diseases.In recent years,fluorescent probes have become one of the research hotspots in many disciplines due to their excellent photophysical properties,high sensitivity,high spatiotemporal resolution,and non-invasiveness.Therefore,it is of great significance to construct novel fluorescent probes to detect apoptosis.Methods: Novel probes were evaluated in various aspects by means of organic synthesis and characterization,detection in vitro,cytotoxicity investigation and confocal fluorescence imaging.Results and conclusion:(1)The fluorescent probe AEM-DEVD with aggregation-induced emission(AIE)effect was constructed with caspase-3 as the target.The probe was precipitated in apoptotic cells after being transformed by endogenous enzymatic reactions,and in situ imaging of apoptosis has been successfully achieved.(2)Innovatively designed and synthesized a near-infrared(NIR)ESIPT fluorescent probe ABTT-DEVD with AIE effect.Through the change of water solubility after the response,the probe promoted the activation of the triple mechanism of AIE,ESIPT and ICT,exhibited significant fluorescence enhancement,and successfully achieved quantitative detection and in situ imaging of cell apoptosis.(3)Based on the morphological changes of apoptosis,a fluorescent probe HDIP with NIR emission was synthesized.The probe targeted intracellular mitochondria through electrostatic interaction to realize fluorescence imaging of early apoptotic cells.As apoptosis progresses,the probe transferred to the nucleus and bound to degraded DNA,showing fluorescent signals in late apoptotic cells.The phenomenon of fluorescence translocation is expected to visualize the different stages and the whole process of apoptosis.The above work provides a new tool for quantitative detection and imaging of apoptosis.This dissertation contains 63 Figures,6 Tables and 152 references.