Chemistry Reference
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construct consisting of a lysine wedge with Gd-DTPA complexes
was conjugated to biotinylated anxA5, coupled to streptavidin-
coated QDs-based nanoparticles. The molecular structures of the
biotinylated Gd-DTPA (a) and biotinylated Gd-wedge (b) structures
with biotin (red) and Gd-DTPA (blue) are presented by Fig. 5.2. The
particles exhibit intense fluorescence and a large magnetic resonance
relaxivity (
−1
−1
per nanoparticle due to the
newly designed construct which increased the Gd-DTPA loading.
The nanoparticles were suitable for both anatomical and subcellular
imaging of structures in the vessel wall.
r
) of 3000−4500 mM
s
1
Figure 5.1
(a) Schematic representation for the preparation of Gd
3+
-DOTA
functionalized CdSeTe/CdS QDs with glutathione (GSH)
coating; (b
T1-weighted
magnetic resonance axial image for a mouse. A phantom
containing 10 mM of Gd
3+
-DOTA-QDs is embedded into the
mouse abdomen. The arrow heads on the red broken lines
represent the location of the phantom being visualized by
fluorescence imaging and MRI. The white bar in the magnetic
resonance image corresponds to 1 cm in length [54].
) a NIR-fluorescence image and (b
) a
T
1
2
1
Yang
et al
. grafted Gd (III) ions on ZnS-passivated CdS: Mn QDs [57].
N
-(Trimethoxysilylpropyl)ethyldiamine, triacetic acid trisodium salt
(TSPETE) was attached to the QDs. A yield of 107 Gd
3+
ions per QD
was reported. However, TSPETE has only five coordination sites for
gadolinium compared with the eight coordination sites for DOTA and
nine for DTPA. Thus it would be expected to be less stable
in vivo
. The
−1
−1
magnetic resonance relaxivities of the QDs were
r
= 20.5 mM
s
1
