Study On The Application Of Prussian Blue Analogs In The Decorporation Of Cesium

Objective:The radioactive cesium(¹³⁷Cs,¹³⁴Cs)contained in nuclear waste water is one of the important radioactive elements that cause long-term environmental pollution.Once radioactive cesium is released into the environment,due to its high water solubility and migration,it will enter the human body through water,atmosphere,soil,food chain and other paths.Radionuclide cesium will induce a large amount of Reactive oxygen Species（ROS）after entering organisms,leading to serious radiation damage and even cancer.Prussian Blue is the only excretion-promoting drug approved by the U.S.Food and Drug Administration（FDA）for use in human radionuclide contamination,but the low diffusion coefficient of cesium ions in Prussian blue crystals limits the therapeutic effectiveness of this drug in clinical use.In addition,the removal of excess ROS can further mitigate the damage caused by radioactive internal contamination.However,there are very few studies on the repair of oxidative stress damage caused by radioactive cesium poisoning,so it is a great significance to develop new synergistic therapeutic drugs of high efficiency emission promotion+radiation protection’for the efficacy of radioactive cesium internal contamination.It was found that by replacing Fe in Prussian blue with different transition metals,different Prussian blue analogs（PBAs）were formed.PBAs have been widely used in the treatment of radioactive cesium-contaminated seawater due to their similar chemical structure.However,The application of PBAs in cesium emission promotion has not been reported.In addition,PBAs have multiple antioxidant enzyme activities,which can remove ROS induced by radioactive cesium radiation and alleviate radiation damage.Based on this,the composition of Prussian blue was optimized to promote efficient emission of cesium ions and reduce radiation damage induced by contamination of radioactive cesium by utilizing its scavenging ability for ROS.Methods:Firstly,a series of PB and PBAs nanoparticles with similar size and morphology were prepared by hydrothermal method.Transmission electron microscopy and X-ray diffraction spectroscopy were used to confirm the consistency of material morphology and size.Secondly,the adsorption activity and biosafety of PB and PBAs nanoparticles for cesium ion were evaluated at the test tube level and cell level respectively,and the interaction mechanism between PBA and cesium ion was explored by X-ray photoelectron spectroscopy（XPS）and electron paramagnetic resonance（ESR）.Finally,PBA nanoparticles with good adsorption effect and high biosafety were selected,and their anti-radiation damage and cesium ion emission promotion effects were evaluated at the cell and animal levels,and the rules were summarized to establish the structure-activity relationship.Results:The cesium ion adsorption experiments show that the cesium adsorption performance of PB and PBAs is dependent on chemical element composition and defect density,and the cesium adsorption efficiency of PBAs is obviously higher than that of PB.Among the five kinds of PB and PBAs nanoparticles prepared,Mn₂[Fe（CN）₆]₃（Mn Fe）and Cu₂[Fe（CN）₆]₃（CuFe）showed better cesium adsorption activity.Because CuFe has better biocompatibility and stability,CuFe is chosen as the next research object.It is found that more defect sites in CuFe is the key factor affecting cesium adsorption capacity.The results of animal experiments show that CuFe has higher cesium emission promoting effect than PB.In addition,CuFe also has strong ROS scavenging ability and anti-radiation damage ability.Conclusion:The results of this work show that the cesium adsorption performance of Prussian blue can be significantly improved by metal replacement and defect density regulation.In vitro and animal levels,it was successfully proved that CuFe nanoparticles with more defect sites showed higher cesium adsorption and excretion promoting properties.In addition,CuFe has high biosafety and multiple antioxidant enzyme activities,which can effectively alleviate radiation damage caused by radionuclide cesium.Cufe provides a new design idea for the research and development of radionuclide cesium emission promoting drugs,and is expected to become a new generation of radionuclide cesium emission promoting drugs.