Biomedical Engineering Reference
In-Depth Information
100
(a)
150
100
50
0
(c)
(b)
Fe
3
O
4
80
TEOS
60
40
-50
-100
-150
(a)
(b)
(c)
(d)
Fe
3
O
4
@nSiO
2
(a)
(b)
(c)
20
TEOS + CTAB
0
0 0 0 0 0
Time (hour)
50
60
70
80
CTAB
Applied Field (Oe)
7000
6000
5000
4000
3000
2000
1000
0
(d)
Fe
3
O
4
@nSiO
2
@CTAB/mSiO
2
Extraction
of CTAB
PL functionalization
with YVO
4
: Eu
3+
Fe
3
O
4
@nSiO
2
@mSiO
2
YVO
4
: Eu
3+
0
20
40
60
80
100
Fe
3
O
4
@nSiO
2
@mSiO
2
Release of IBU (%)
FIGURE 3.11
(a) The formation process of the multifunctional Fe
3
O
4
@nSiO
2
@mSiO
2
@YVO
4
:Eu
3+
compos-
ite microspheres. (b) Magnetic hysteresis loops of pure (a) Fe
3
O
4
, (b) Fe
3
O
4
@nSiO
2
@mSiO
2
, (c)
Fe
3
O
4
@nSiO
2
@mSiO
2
@ YVO
4
:Eu
3+
, (d) IBU-Fe
3
O
4
@nSiO
2
@mSiO
2
@ YVO
4
:Eu
3+
. (c) Cumulative
IBU releases from the (a) IBU-Fe
3
O
4
@nSiO
2
@mSiO
2
@ YVO
4
:Eu
3+
, (b) IBU-Fe
3
O
4
@nSiO
2
@mSiO
2
,
and (c) IBU-Fe
3
O
4
@nSiO
2
@mSiO
2
@YVO4:Eu
3+
-NH
2
systems versus release time. (d) PL emis-
sion intensity of Eu
3+
in IBU-Fe
3
O
4
@nSiO
2
@mSiO
2
@YVO
4
:Eu
3+
as a function of cumulative
released IBU. (Reprinted from Yang P., Quan Z., Hou Z., et al.,
Biomaterials
30: 4786-4795, 2009,
with permission from Elsevier Ltd.)
Fe
3
O
4
nanospheres as core, ordered mesoporous silica as shell, and further
deposition of phosphors (down-conversion YVO
4
:Eu
3+
or up-conversion
NaY F
4
:Yb,Er/Tm phosphor nanocrystals) on the core-shell nanoparticles
(FigureĀ 3.11). These core-shell magnetic-luminescent mesoporous silica
nanoparticles exhibit high magnetization, sustained drug release, and excel-
lent luminescent properties. Furthermore, the emission intensity of the mul-
tifunctional carrier also increases with the released amount of model drug,
thus allowing the release process to be monitored and tracked by the change
of photoluminescence intensity. In addition, magnetic-luminescent mesopo-
rous silica nanoparticles were prepared by the combination of magnetism
and dye/QDs in mesoporous silica nanoparticles for drug delivery. Liong
et al. (2008) and Lee et al. (2010) successfully prepared Fe
3
O
4
/Dye/mSiO
2
core-shell nanoparticles. Here, dye is doped in a mesoporous silica matrix,
and Fe
3
O
4
nanoparticles are designed as the core in the center or satellites
on the surface. Also, Kim et al. (2006) synthesized magnetic-luminescent
delivery vehicle using uniform mesoporous silica nanoparticles simultane-
ously embedded with monodisperse Fe
3
O
4
and CdSe/ZnS QDs. Chen, Chen,
Zhang et al. (2011) reported the Fe
3
O
4
/QDs/mSiO
2
core-shell nanoparticles
for drug delivery with CdTe QDs self-assembled onto the surface of Fe
3
O
4
@
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