title: Fates of Fe3O4 and Fe3O4@SiO2 nanoparticles in human mesenchymal stem cells assessed by synchrotron radiation-based techniques.
abstract: Superparamagnetic iron oxide nanoparticles (SPIOs) have been widely used as the magnetic resonance imaging (MRI) contrast agent in biomedical studies and clinical applications, with special interest recently in in vivo stem cell tracking. However, a full understanding of the fate of SPIOs in cells has not been achieved yet, which is particularly important for stem cells since any change of the microenvironment may disturb their propagation and differentiation behaviors. Herein, synchrotron radiation-based X-ray fluorescence (XRF) in combination with X-ray absorption spectroscopy (XAS) were used to in situ reveal the fate of Fe3O4 and Fe3O4@SiO2 NPs in human mesenchymal stem cells (hMSCs), in which the dynamic changes of their distribution and chemical speciation were precisely determined. The XAS analysis evidences that Fe3O4 NPs cultured with hMSCs are quite stable and almost keep their initial chemical form up to 14 days, which is contradictory to the previous report that Fe3O4 NPs were unstable in cell labeling assessed by using a simplified lysosomal model system. Coating with a SiO2 shell, Fe3O4@SiO2 NPs present higher stability in hMSCs without detectable changes of their chemical form. In addition, XRF analysis demonstrates that Fe3O4@SiO2 NPs can label hMSCs in a high efficiency manner and are solely distributed in cytoplasm during cell proliferation, making it an ideal probe for in vivo stem cell tracking. These findings with the help of synchrotron radiation-based XAS and XRF improve our understanding of the fate of SPIOs administered to hMSCs and will help the future design of SPIOs for safe and efficient stem cells tracking.
authors.affiliation: Institute of Functional Nano & Soft Materials (FUNSOM) & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, China; Key Laboratory for Nano-Bio Interface Research, Suzhou Key Laboratory for Nanotheranostics, Division of Nanobiomedicine and i-Lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Tian
authors.affiliation: Key Laboratory for Nano-Bio Interface Research, Suzhou Key Laboratory for Nanotheranostics, Division of Nanobiomedicine and i-Lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China.
authors.forename: Guangcun
authors.initials: G
authors.lastname: Chen
authors.affiliation: Division of Nanobionics, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China.
authors.forename: Peiwei
authors.initials: P
authors.lastname: Yi
authors.affiliation: Department of Materials and Energy Sciences & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China.
authors.forename: Jichao
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Materials and Energy Sciences & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China.
authors.forename: Aiguo
authors.initials: A
authors.lastname: Li
authors.affiliation: Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Lirong
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Division of Nanobionics, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China.
authors.forename: Zongwu
authors.initials: Z
authors.lastname: Deng
authors.affiliation: The First Affiliated Hospital of Soochow University, Orthopedic Institute, Soochow University, Suzhou 215006, China. Electronic address: qshisz@126.com.
authors.forename: Qin
authors.initials: Q
authors.lastname: Shi
authors.affiliation: Institute of Functional Nano & Soft Materials (FUNSOM) & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, China. Electronic address: rpeng@suda.edu.cn.
authors.forename: Rui
authors.initials: R
authors.lastname: Peng
authors.affiliation: Key Laboratory for Nano-Bio Interface Research, Suzhou Key Laboratory for Nanotheranostics, Division of Nanobiomedicine and i-Lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China. Electronic address: qbwang2008@sinano.ac.cn.
authors.forename: Qiangbin
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000818:Animals; D058948:Cell Tracking; D003911:Dextrans / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D008247:Lysosomes / Q000378:metabolism; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D008819:Mice, Nude; D008954:Models, Biological; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D011827:Radiation; D012822:Silicon Dioxide / Q000737:chemistry*; D017356:Synchrotrons; D056928:X-Ray Absorption Spectroscopy
chemical_list: D003911:Dextrans; D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; C000499:ferric oxide; D012822:Silicon Dioxide; C065507:ferumoxides
keywords: Chemical speciation; Distribution; Fe(3)O(4) nanoparticles; Fe(3)O(4)@SiO(2) nanoparticles; Human mesenchymal stem cells; Synchrotron radiation