Study On In Vivo Tumor Imaging Based On TaOx Nanopa Rticles Encapsulated Fluorescent Protein

In vivo fluorescence imaging has been widely used in many research fields because of its easy operation,rapid imaging,and no radioactive hazards.In particular,a variety of fluorescence-based probes can perform sensitive and specific imaging through tissues,which has greatly promoted clinical related research.However,the delivery and signal penetration problems of traditional fluorescent probes put new demands on its performance.In this paper,we use hollow tantalum oxide(TaO_x)nanoparticles to encapsulate fluorescent activated protein(FAP)for in vivo imaging of tumor cells.We found that the TaO_x shell can protect the fluorescein/FAP complex from photobleaching and significantly improve its photostability.In addition,the nanoshells also provide a natural protective layer for the contained proteins to protect them from the effects of ordinary biodegradation.We believe that this strategy of blocking and delivering fluorescent biomolecules will be an attractive alternative to bioimaging.This paper mainly includes the following two aspects of work:1.Preparation,characterization and performance study of TaO_x@FAPdL5**nanoparticlesIn this paper,a one-step synthesis method was used to prepare hollow TaO_x nanoparticles,and then modified with polyethylene glycol(PEG)to obtain good physiological stability.The synthesis steps of TaO_x@FAPdL5**nanoparticles and TaO_x nanoparticles are basically the same,just replace the deionized water with the fluorescence excitation protein FAPdL5**.After obtaining TaO_x@FAPdL5**nanoparticles,the electron microscope and particle size of the nanoparticles were characterized by a transmission electron microscope(TEM)and a particle size analyzer.In order to further optimize its fluorescence imaging effect and improve the stability of fluorescence imaging,the hollow TaO_x nanostructure is used to wrap MG/FAPdL5**in it to protect it.This article has successively explored the photostability and resistance to enzymatic degradation of TaO_x@MG/FAPdL5**.The results show that TaO_x@MG/FAPdL5**has better light stability and resistance to enzymatic degradation than MG/FAPdL5**.2.In cell and in vivo imaging research based on TaO_x@FAP dL5**The phagocytosis and intracellular distribution of MCF-7 cells on TaO_x@MG/FAPdL5**,TaO_x+FAPdL5**and FAPdL5**were investigated in the multidimensional live cell imaging system.The results showed that the nanoparticles can enter MCF-7 cells and mainly distributed in cell lysosomes.On this basis,TaO_x@FAPdL5**nanoparticles and FAPdL5**were injected into nude mice by tail vein injection,24 hours later,MG was injected intratumorally in situ to observe its feasibility for in vivo fluorescence imaging research Then,the mice were dissected to further verify the accuracy of the in vivo imaging experiment and to investigate whether the TaO_x@FAPdL5**nanoparticles caused tissue inflammation in the mice.The results of in vivo fluorescence imaging showed that the tumor produced a strong fluorescent signal.The organ imaging showed that most of the nanoparticles were enriched in the tumor,and the content of nanoparticles in liver and kidney was very small.The H&E staining results also confirmed that the nanoparticles were The tissue does not cause inflammation.