Biomedical Engineering Reference
In-Depth Information
Figure 6.4
(a) T
2
- weighted fast spin - echo
images (TR/TE of 4200 ms/102 ms) at 0 and
3.5 h post injection of 14.7 mg Fe kg
−
1
of Cy5.5
TCL-SPION at the level of tumor (320 mm
3
)
on the fl ank above the upper left thigh of a
nude mouse. The allograft tumor region is
shown by the dashed circle with the red
arrow; (b) Optical fl uorescence images
(exposure time 1 s with a Cy5.5 fi lter channel)
of the same mouse at 0 and 3.5 h post
injection. The position of the allograft tumor
is marked by the red arrows. The color scale
indicates relative fl uorescence intensity.
(Reprinted with permission from Ref. [117].
chelated G2 PAMAM dendrimer was reduced and then attached to a maleimide-
functionalized biotin. The new MRI agent had a well-defi ned dendron structure
and a unique biotin functionality. The immobilization of up to four copies of
biotinylated dendrimer to fl uorescently labeled avidin yielded a supramolecular
avidin- biotin - dendrimer - Gd(III) complex. The avidin - biotin - dendrimer target-
ing system effi ciently targeted ovarian cancer in mice, and delivered suffi cient
amounts of chelated Gd(III) and rhodamine green fl uorophores. This dual-
imaging probe produced visible changes in the tumors by both MRI and optical
imaging, respectively [118] .
