metal-magnetism-2018-keynote

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I n t e r n a t i o n a l C o n f e r e n c e o n
Metal, Mining and
Magnetic Materials
Journal of Material Sciences
ISSN: 2321-6212
N o v e m b e r 0 1 - 0 2 , 2 0 1 8
P a r i s , F r a n c e
Metal and Magnetism 2018
Page 17
To get homogeneous nanoparticles (NPs), the protein (apoferritin) cavity has
been utilized as a reaction chamber. A protein shell served as a template to
restrain particle growth and as a coating to prevent coagulation between NPs.
Apoferritin is an iron storage protein found in many biological species, known to
mineralize several metal ions in vitro. It is a hollow, spherical protein composed
of 24 subunits (L-chain and H-chain), with outer and inner diameters of 13 nm
and 7.4 nm, respectively. Here, we report synthesis of magnetite crystal (Fe3O4)
nanoparticle in the apoferritin cavity. Magnetite containing apoferritin is known as
magnetoferritin, and its magnetic properties and applications were reported many
times. However, crystallinity of these nanoparticles was not exactly controlled.
Native horse spleen ferritin (contains about 15% of H-chain) or recombinant
human H-ferritin was used for these experiments. H-chain has Fe (II) oxidation
site and thus oxidation occurs very quickly at each oxidation site in the cavity.
In this reason, synthesized nanoparticles were amorphous or polycrystalline.
We have used recombinant L-chain apoferritin which lacked Fe (II) oxidation site
and oxidation proceeds slowly. Utilizing slow oxidation process and magnetic-
column chromatography purification process, we succeeded to obtain magnetite
NPs with nearly single crystal domain which expected to have high T2 relaxivity in
MRI and high efficiency for hyperthermia therapy. We extended the N-terminus of
the apoferritin subunits, which exposed to the external surface of the molecule,
with peptide chain having specific binding ability to the cancer cell. Combining
high quality magnetite nanoparticles and cancer cell specific apoferritin, this
magnetoferritin would show high potential for cancer treatment
Biography
Hideyuki Yoshimura has completed his PhD in 1982 from Na-
goya University and Postdoctoral studies in Institute of Physical
and Chemical Research (RIKEN). He moved to Biometrology
Lab in JEOL Ltd., as a Research staff in 1984. He was also join-
ing JRDC, ERATO NAGAYAMA Protein Array Project from 1990
to 1995, as a Manager of Array Characterization Group. After
1995, he moved to Meiji University, Department of Physics, as
an Associate Professor. He was promoted to Professor in 2000
at the same department. His current interests are development
of an X-ray microscope for biology and synthesis of nanoparti-
cles utilizing protein function.
Synthesis of single crystal magnetite
nanoparticles encapsulated in apoferritin
Hideyuki Yoshimura
Meiji University, Kawasaki, Japan
Hideyuki Yoshimura, J Mat. Sci. 2018, Volume:6
DOI: 10.4172/2321-6212-C7-031