Antibody binding: The anti-His antibody was covalently linked to
FVIOs via EDC/NHS reaction. DHCA-FVIOs (1 mg) were reacted with EDC (10
mM) and NHS (10 mM) for 15 min in MES buffer (0.1 M, pH 6.0). Then, the
solution was adjusted to pH 7.4, and 5 μL of mouse monoclonal anti-His
antibody was added and shaken for 2 hours. The final products were
washed with PBS to remove unbound antibodies and dispersed in PBS before
in vitro and in vivo testing.
Characterization: The crystal structure of magnetic nanoheaters
was characterized by X-ray diffraction (XRD) patterns using a powder
diffractometer (Bruker, D8 Advance, Germany). The morphology of
nanoheaters was observed by scanning electron microscopy (SEM, Hitachi
SU8010, Japan). The anti-His antibody-coated nanoheaters were stained
with phosphotungstic acid and characterized by transmission electron
microscopy (TEM, HT-7700, Japan). The hydrodynamic diameters of
nanoheaters were examined by dynamic light scattering (DLS, Malvern,
England). The Fe concentration of nanoheater suspensions was detected
using inductively coupled plasma mass spectrometry (ICP-MS, Agilent
7900, America). The magnetization curves were determined using a
vibrating sample magnetometer (VSM, BKT-4600, China).