Biomedical Engineering Reference
In-Depth Information
Fig. 23 (a) Post-Gd axial MRI of the rat brain illustrating the regions of interest (ROIs) for the
tumor (
red
) and contralateral (
yellow
) brain. (b) Post-monocrystalline iron oxide nanoparticle
(MION) axial MRI of the rat illustrating the ROIs for the gray (
gray
) and white (
white
) matter.
(c-f) Binarized images of tissue sections of microfilled vessels at 20
magnification of tumor (c),
contralateral brain (d), gray matter (e), and white matter (f) ROIs. The color of each frame (
red
,
yellow
,
gray
or
white
) corresponds to the color of the ROI from which the tissue sections were
sampled for histology. (Adapted from [
81
])
change in the MRI signal. Cells expressing specific molecular markers of disease,
infection, or injury are detected in this way. Previously, monocrystalline iron oxide
nanoparticles (MION) had been synthesized for MRI applications. One such appli-
cation is illustrated in Fig.
23
. Josephson et al. [
81
] have shown the effects of iron
oxides on proton relaxivity. The post-MION axial MRI of the rat, illustrating the
regions of interest (ROIs) for the gray and white matter, have been demonstrated.
Antibody-Conjugated MNPs
Antibody targeting of drug substances can improve the therapeutic efficacy of the
drug, as well as improve the distribution and concentration of the drug at
the targeted site of drug action. McCarron et al. studied two novel approaches for
the creation of immunonanoparticles with improved therapeutic effect against
colorectal tumor cells [
82
]. They used poly(lactide) polymers and CD95/APO-1
antibody to target nanoparticles. Pan et al. used dendrimer-MNPs for efficient
delivery of gene-targeted systems for cancer treatment [
83
]. Detection of colon
cancer is also possible by using Fe
3
O
4
-rch24 antibody conjugates. FePt-Au
nanoparticles conjugated with HmenB1 antibodies, can be used to identify neuro-
blastoma cells (CHP-134) with a polysialic acid overexpression. These, along with
their capability of being manipulated under an external magnetic field, provide
controllable means for magnetically tagging of all biomolecules, leading to highly
