The Construction Of Fluorescent Probe And Its Application In Biomedicine

With the rapid development of medicine and molecular biology,fluorescence labeling technology has become one of the important labeling technologies in biomedical research.However,the traditional fluorescent probe still has some disadvantages,such as poor light stability,low brightness,easy to bleach,high toxicity,and the influence of self-fluorescence of biological tissues.It posed great difficulties for the further development of high-sensitivity imaging techniques and high-throughout assays.In addition,single model imaging model can not meet the needs of clinical medicine.In the face of these problems,how to develop and design new multifunctional fluorescent materials has become an urgent problem to be solved.Therefore,the new fluorescent probe used for the integration of disease imaging and treatment has a broad prospect in the biomedical field,and is worth studying.The development of fluorescence labeling techniques has provided effective research tools to investigate many fundamental processes in the biomedical.In this paper,several luminescent materials such as sodium lanthanum fluoride(Na Ln F₄:Ln³⁺),metal-organic frameworks(MOF-Ln³⁺)and polymer quantum dots?Pdot?were introduced,which were used for cell labeling,drug delivery and subcellular labeling,respectively.The specific research results are as follows:?1?NaGdF₄:Ln³⁺@MOF-Gd nanocomposite has excellent chemical and photochemical stability.After combining it with MOF-Gd:Eu³⁺,we prepared Na Gd F₄:Ln³⁺@MOF-Gd nanocomposite.The up-down luminescence properties of Na Gd F₄:Ln³⁺@MOF-Gd were studied in detail.A dual-mode light-emitting Na Gd F₄:Ln³⁺@MOF-Gd fluorescent probe was constructed to successfully label cancer cells by encapsulating amphiphilic polymer polyvinyl pyrrolidone?PVP?.?2?Based on the previous chapter,we found that Na YF₄ is a very effective luminescence matrix material.MOF-Y:Eu³⁺as a new rare earth metal organic framework has outstanding potential in biological imaging and drug delivery.We prepared Na YF₄:Ln³⁺@MOF-Y nanocomposite by hydrothermal method,using the synergistic effect of Na YF₄:Tm³⁺/Yb³⁺and MOF-Y:Eu³⁺for bioimaging and drug delivery.The experimental results showed that Na YF₄:Ln³⁺@MOF-Y loaded with the anticancer drug adriamycin hydrochloride?DOX?could successfully release the drug in the simulated cancer cell environment,and the cumulative drug release amount was up to 85.8%.The results of MTT method proved that dual-mode luminescence Na YF₄:Ln³⁺@MOF-Y multifunctional nanocomposite had good biocompatibility.Na YF₄:Ln³⁺@MOF-Ycould be used for the diagnosis and treatment of cancer cells.?3?We have successfully labeled cancer cells,but the labeling of subcellular structures requires a small size.Therefore,we introduced Pdot,and Pdot is a very important fluorescent labeling material.The functionalized Pdot was prepared by co-precipitation,and the Pdot-PSMA-Ig G bioconjugate was generated by EDC catalysis.The morphology,size and luminescence properties of Pdot-PSMA-Ig G were investigated.Different color fluorescent Pdot-PSMA-Ig G was used to label microtubules,mitochondria and nuclear membrane.The results showed that the fluorescent probe Pdot-PSMA-Ig G could effectively and specifically label the subcellular structure.