Biomedical Engineering Reference
In-Depth Information
(a)
(b)
100
80
60
40
20
0
0
10
20
30
Time (h)
40
50
Figure 6.6
Autoradiography of whole body of
mice euthanized at 24 h after an intravenous
injection of 40 mCi (50
μ
g) of di - scFv/
4 mg of
111
In - DOTA - di - scFv - NP.
Radioimmunonanoparticles were mostly
accumulated in the kidney and liver. The
tumor localization was
∼
5% (black arrow).
(b) Pharmacokinetic study of
radioimmunonanoparticles (RINP) in mice
with HBT3477 human breast cancer
xenografts. Clearances of the blood (
) and
body (
) of RINP was compared to the blood
(
) and body (
×
) of bioprobes at various time
points of 2, 4, 24, and 48 h. The bioprobe data
were plotted from previously published data
in Ref. [5]. Reprinted with permission from
Ref. [130].
apparent change was observed in the color- coded MR images (Figure 6.7 d - f). The
percentage change in R2 at the tumor tissue was
34% at 2 h for
MnMEIO-Herceptin, and in the case of CLIO-Herceptin was almost zero or
−
25% at 1 h, and
−
5%,
respectively, at the tumor site (Figure 6.7g). The color-coded MR images (Figure
6.7h) of tumor tissue explanted from a mouse treated with the MnMEIO-
Herceptin conjugate showed darkened MR images, with R2 signal enhancement
(
<
Δ
R2/R2
control
=
−
31%; Figure 6.7g, h), whereas very little MR contrast (
Δ
R2/R2
control
<
5%) was seen at the tumor site of a mouse treated with CLIO-Herceptin conju-
gate (Figure 6.7g, h). These
in vivo
results indicated that the high MR sensitivity
of MnMEIO-Herceptin conjugates enables the MR detection of tumors as small
as 50 mg [136] .
Biodistribution studies of MnMEIO-Herceptin conjugates labeled with radioac-
tive
111
In using gamma-counter analyses showed that the uptake of injected par-
ticles by various organs (expressed as % of the dose per g tissue) was 3.4% in
tumor tissue, 12.8% in the liver, 8.7% in the spleen, and 1.0% in muscle. These
results provided further support for the use of MNPs, when linked with appropri-
ate cancer-targeting molecules, for the diagnosis of various cancers by ultrasensi-
tive MRI and radioimmunodetection systems. Ultimately, high- performance
