Study On Assembling Inorganic/Organic Nano-platforms For Multi-functional Imaging And Theranostics

Cancer threatens people's life safety and has always been a medical problem.Early diagnosis and timely treatment are of great significance for fighting cancer.Single imaging detection often leads to a false-positive result,multi-mode imaging can provide more comprehensive and accurate information,and it is more conducive to cancer screening.On the other hand,cancer cells are characterized by unlimited proliferation,transformation and metastasis,which are seriously destructive to the normal tissues of the body.Therefore,diagnosis reagent integrated development of diagnosis and treatment of medicine has a potential significance in tumor control and timely treatment,the pathological and structural of the tumor can be well analyzed via a treatment agent,which are also used for the effective inhibition of cancer,especially for real-time monitoring of the treatment process,providing valuable information to guide and optimize the treatment effect.Herein,BaGdF5 nanoparticles were prepared by the solvothermal method,and metal-polyphenol network(MPN)-coated BaGdF5 nanocomposites were prepared by self-assembly of rare earth europium metal ions and tannic acid.The prepared BaGdF5@MPN nanocomposite contains Ba,Gd,and Eu with a large atomic number metal and good X-ray absorption,which can be used as a contrast agent for enhancing CT;Gd compounds have the function of changing the surrounding proton magnetic field,and can be used for the magnetic resonance imaging(MRI);in the addition,the BaGdF5@MPN nanocomposite contains rare earth metal europium element and tannic acid molecule,which exhibits dual fluorescence properties,using as fluorescence probe in bological imaging.The in vitro cytotoxicity assay based on MTT assay showed that the BaGdF5@MPN nanocomposites have lower cytotoxicity and significantly lower cytotoxicity than the pure BaGdF5 nanoparticles.Fluorescence spectra showed that BaGdF5@MPN nanocomposites can exhibit characteristic emission peaks of green and red at 520 nm and 590 nm.From the two-photon laser confocal microscopy(CLSM)results,BaGdF5@MPN nanocomposites can be well taken up by HepG2 tumor cells.In vitro CT studies have shown that this nanocomposite has a good CT enhancement effect,and the enhancement effect was in dependence of the concentration of the composite material.Both in vitro and in vivo MRI studies demonstrated that BaGdF5@MPN nanocomposite exhibited excellement T1 enhanced MR imaging property with the longitudinal relaxation rate was 2.457 mM-1 s-1.These results indicate that the BaGdF5@MPN nanocomposite has potential as a trimodal CT/MRI/optical probe.In addition,we construct a novel nanoplatform,composed of low cost bovine serum albumin(BSA),sulfonamides(SAs)and iron porphyrin nanoscale metal organic frameworks(NMOFs),which possesses the capabilities of active targeting to tumor cells,and magnetic resonance imaging(MRI)can be visualized to guide synergetic photodynamic/photothermal therapy.These constructed BSA/SAs-NMOFs nanoplatform can be more accumulated in tumor site,achieving that this system can be the "visualization" of tumors with synergetic photodynamic/photothermal therapy.The as-prepared BSA/SAs-NMOFs nanocomposites were successfully synthesized by being charactered with FT-IR,XPS,TEM,etc.The BSA/SAs-NMOFs nanocomposites can be well dispersed in aqueous solution,phosphate buffer solution(PBS)and cell culture solution.DLS test showed that the nanocomposites were well stabilized and in vitro cytotoxicity result showed that the BSA/SAs-NMOFs nanocomposites were low cytotoxicity.Cellular uptake and western blot results demonstrated that BSA/SAs-NMOFs nanocomposites can be actively targeted to tumor site by inhibiting tumor cell CA IX enzyme.In vitro and in vivo MRI studies have shown that the composite material has T1,T2 signal enhancement potency,longitudinal relaxation rate r1 = 2.7 mM-1 s-1,transverse relaxation value r2=19.68 mM-1 s-1,and its MRI weighting effect can be guided the timely treatment of tumors with composites.These BSA/SAs-NMOFs nanocomposites have excellent light absorption in bio-optical windows(600-1000 nm)and simultaneous triggered photodynamic/photothermal effects to generate large amounts of single-state oxygen and heat to kill tumor cells.The results of photodynamic and photothermal therapy demonstrated that this combination therapy had better tumor suppression than single photothermal or photodynamic therapy.The results of all studies indicate that the prepared BSA/SAs-NMOFs nanocomposites as a nanoplatform for diagnosis and treatment have great application prospects in the biomedical field.