Biomedical Engineering Reference
In-Depth Information
(a)
(b)
100 nm
100 nm
(c)
(d)
50 nm
50 nm
Figure 10.9
Transmission electron microscopy images of
PLGA(MNP/DOXO) nanoparticles embedded with (a) 7 nm,
and (b), (c) 15 nm Fe
3
O
4
nanoparticles, and (d) PLGA(QD/
DOXO) nanoparticles embedded with 3 nm CdSe/ZnS
nanocrystals. Reprinted with permission from Ref. [107];
© 2008, Wiley-VCH Verlag GmbH & Co. KGaA.
confi rmed the effectiveness of the folate-functionalized PLGA nanospheres (con-
taining QDs) in targeting the KB cells. Cytotoxicity studies showed that the PLGA
nanospheres with MNPs but without DOX exhibited almost no toxicity in KB cells,
whereas the folate-functionalized PLGA nanospheres encapsulating MNPs and
DOX were more cytotoxic than free DOX (0.4
M
). In addition, the simultaneous
use of folate active targeting and magnetic fi eld on PLGA nanospheres encapsulat-
ing MNPs and DOX led to a synergistic increase in the cell growth inhibitory effect
on the KB cells.
μ
10.4.3.8
PEI and Transferrin - Mediated Gene Delivery
The use of polymer-coated MNPs for gene delivery has also been reported [109].
Cationic lipid-coated MNPs associated with transferrin were evaluated as gene
transfer vectors in the presence of a static magnetic fi eld. MNPs were prepared by
the coprecipitation method and surface-coated with cationic lipids, composed of
dimethyldioctadecylammonium bromide/soy phosphatidylcholine (DDAB/soy
PC) at 60 : 40 (mol/mol). Based on DLS measurements, the size of the cationic
lipid-coated MNPs was found to be approximately 78.3 nm, while TEM images
