Design And Preparation Of Optical Probes And Their Applications For Detecting And Imaging Biological Tissue Microenvironment

Some biosubstances?such as reactive oxygen species and enzymes?of biological tissue microenvironment play important roles in various physiological processes.In addition,the acidity of the micro-environment in living organisms also plays an important role in some physiological processes.Therefore,it is of great significance to develop methods for real-time detection and imaging of these important biological substances and acidic microenvironments.Due to its advantages of less invasiveness and high sensitivity,optical imaging?fluorescence imaging?method has an important application prospect.Considering the above,in this study,we designed and prepared three kinds of probe systems,and investigated their fluorescence/photoacoustic detection and imaging of some biological substances?active oxygen species and enzymes,etc.?and acidic microenvironment in cell and animal models.The main contents include:?1?A ratiometric fluorescent nanoprobe Nano-MTPE for Cl O^-detection and imaging was prepared.First the tetraphenylethylen derivative was designed and synthesized as the probe compound,and the structure of the probe compound was characterized by ¹H NMR and mass spectrometry.Then the nanoprobe was fabricated by assembling the probe compound with amphiphilic surfactant,and the spectral properties of the nanoprobe were measured by absorption and fluorescence spectra.In the presence of Cl O^-,the carbon-carbon double bond in the probe compound is cleaved,resulting in the change of push-pull electron capacity,which leads to the change of spectral properties,and subsequently the ratiometric fluorescence detection and imaging of Cl O^-is achieved.The detection limit is 0.47?M.MTT assay was used to verify the low cytotoxicity of the nanoprobe.In addition,the nanoprobe was used to detect and image endogenous Cl O^-in living cells and zebrafish models.?2?A LAP-activated photoacoustic/fluorescent dual-mode imaging probe DLP was designed and synthesized.The near-infrared chromophore NIR-OH was prepared by the coupling reaction of benzoindole and chromene derivative,and the enzyme-responsive group was introduced onto NIR-OH to form the probe DLP.The related compounds were characterized by ¹H NMR and mass spectrometry,and the spectral properties of the probe were studied.In the presence of LAP,the probe underwent a specific enzymatic reaction,thereby releasing the chromophore NIR-OH with near-infrared absorption and emission,thus producing photoacoustic and fluorescence signals.The dual-mode detection and imaging of endogenous LAP in living cells by DLP were investigated.The detection limit is 0.047 U/L.In addition,the dual-mode detection and imaging of LAP level were also used to detect and locate drug-induced liver injury in mouse model.?3?An iron ion-polyphenol-mediated multifunctional nanoparticle TFLZ based on phthalocyanine was prepared for acidic microenvironment imaging.A zinc phthalocyanine compound Zn Pc-OCH₃ containing methoxy group was synthesized and its structure was characterized by ¹H NMR and mass spectrometry.The nanoparticles were prepared by simple nano-precipitation method,and the particle size and distribution were measured by dynamic light scattering method and transmission electron microscopy.Under acidic conditions,the drug and photosensitizer in the nanosystem could be released quickly,and the fluorescence and photosensitive properties of the photosensitizer were recovered at the same time.Fluorescence was generated by the photosensitizer released from the nanoparticles in the acidic microenvironment of tumor cells,thus the fluorescence imaging of the acidic microenvironment was realized in cell and mouse model.Meantime,the nanoparticle has high tumor inhibition effect.