Study On The Method Of Gold Nanoparticles Radiolablled By⁵⁹Fe Doping

Gold nanoparticles?GNPs?and their complexes have been widely concerned.They have special properties of optics,photoelectromanetism and photochemistry.They can be applied to medicine,biology and spectroscopy.Taking into account their potential application in medical diagnosis and drug delivery,it is necessary to carefully study the in vivo metabolism of GNPs or their complexes.Many previous studies,both ours and others,have demonstrated that GNPs or their complexes mainly target the endoplasmic reticulum system organs,such as liver and spleen,and could be retained there for long periods of time.In addition,nanomaterials,once enter the organisms,will interact with biomacromolecules in body fluids,and thus further influence their metabolism in vivo.The study of "nano-bio" interactions as well as the consequences has become a hot area in the field of nanotoxicology.In order to better understand the metabolism of GNPs or their complexes,especially how the "nano-bio" interaction affect their in vivo fate,we need to develop more sensitive and more reliable quantitative method.Radiotracer is a widely used method for metabolic quantification.By using 198Au labelling,quantitative data of the bio-distribution of GNPs could be obtained with a very high sensitivity.However,198Au has a very short radioactive half-life?2.7 days?,therefore could not be used to track the fate of GNPs in a long-term exposure.Herein,we choose ⁵⁹Fe,which has a relative longer half-time,to track GNPs or their complexes via radiolabelling.First,we tried to radiolabel the iron oxides coated with Au shell?IONPs@Au?.IONPs@Au can be used as drug carrier,DNA molecular probe and so on.However,the as-synthesized IONPs@Au have very poor homogeneity in their nanoproperties,with the presence of both core-shell and non-core-shell structures.The heterogeneity might result in misleading information about the metabolic behaviors of IONPs@Au.Therefore,we also tried to develop an iron doping strategy to radiolabel GNPs.Gold nanorods?GNRs?are NPs with an anisotropic crystal structure.Their morphology and aspect ratio are easy to control,and the range of Localized Surface Plasmon Resonance?LSPR?is wide.This excellent optical property makes GNRs subject to extensive attention.They have shown promise for application in the medical field,especially in cancer treatment and gene therapy.Therefore,it is important to explore the in vivo distribution and fate of GNRs.Generally,this paper mainly deals with the following two points:1.Fe₃O₄ particles with diameter about 50nm were synthesized by solvothermal method.Au seeds with 1?2nm were prepared by THPC as reducing agent.Then the Au seeds were adsorbed on Fe₃O₄,and different reducing agents were used to facilitate the seed growth.Finally,Fe₃O₄@Au were collected by magnetic separation.2.GNRs were radiolabelled by ⁵⁹Fe doping.Different doping conditions were tested to modify the radioactivity in the synthesized GNRs.In this paper,we choosed 3-MPA to combine Au and ⁵⁹Fe.As a result,GNRs were doped with radioactive ⁵⁹Fe³⁺,with no obvious change in their morphology.The long-term metabolism of ⁵⁹Fe³⁺-doped GNRs in vivo will be investigated in the further study.