Biomedical Engineering Reference
In-Depth Information
Winter and coworkers [
93
] presented results of a combinatory approach of MR
molecular imaging and drug targeting of atherosclerosis with this contrast agent. To
that end, they used the
a
v
b
3-specific nanoparticles to target the aortic vessel wall
after balloon injury. For therapeutic purposes they included fumagillin in the lipid
monolayer of the nanoparticles and observed an anti-angiogenic effect with MRI
that was confirmed histologically.
Approximately 15% of cancer patients are diagnosed in stage I or II with
conventional diagnostic tools; MR contrast effects may help to improve the rate
of cancer diagnosis in its earliest stages. One successful example is the molecular
imaging of breast cancer using Fe
3
O
4
magnetism-engineered iron oxide (MEIO)
nanoparticle probes. Breast cancer cells typically overexpress HER2/neu. When
nanoparticles with relaxivity coefficient of 218 mm
1
s
1
are conjugated with the
HER2/neu-specific antibody Herceptin, the SK-BR-3 breast cancer cell lines can be
detected (Fig.
28a
)[
95
]. Furthermore, Fe
3
O
4
-Herceptin probes make the ultrasen-
sitive in vitro detection of cancer cells possible since these probes interact with all
HER2/neu-positive cancer cells, including Bx-PC-3 cells which have only a mini-
mal level of HER2/neu (Fig.
28b
)[
96
].
A composite scaffold drug delivery system (CS-DDS) for osteoarticular tuber-
culosis therapy has been prepared by loading bi-component drugs into a
Fig. 28 (a) In vitro MR detection of HER2/neu-positive breast cancer (SK-BR-3) by Fe
3
O
4
(MEIO)-Herceptin nanoparticle probes. (b) MR contrast enhancement effects of various cancer
cells with different HER2/neu expression levels, (c-e) Highly-sensitive in vivo cancer detection by
utilization of MnFe
2
O (MnMEIO)-Herceptin nanoparticle probes. (c) Intravenous tail-vein injec-
tion of the MEIO-Herceptin probes into a mouse with a small (ca. 50 mg) HER2/neu-positive
cancer in its proximal femur region. For comparison, MEIO-Herceptin probes and CLIO-
Herceptin probes were also tested. (d) Color-mapped MR images of the mouse at different times
following injection. (e) Time-dependent relaxivity (
R
2) changes at the tumor site after injection of
the probes (Adapted from [
94
])
