Biomedical Engineering Reference
In-Depth Information
with simultaneous combinatorial anticancer effects of curcumin and 5-fluoroura-
cil (Anitha et al. 2014).
A group headed by Deng et al. employed hyaluronic acid conjugated chitosan
nanoparticles (HA-CS NPs) for delivering miR-34a (a tumor suppressive molecule in
breast cancer) and doxorubicin to breast cancer cells with special emphasis on over-
coming metastatic relapse. The study also showed the synergistic anticancer effects
attained by codelivery of miR-34a and doxorubicin by HA-CS NPs (Deng et al. 2014).
In order to attain stimulated release of drug in a cancer specific milieu, a pH sen-
sitive and temperature responsive poly(
N
-isopropylacrylamide)-chitosan nanohy-
drogels were synthesized by Jaiswal et al. Fe
3
O
4
magnetic nanoparticles were also
incorporated in nanohydrogel for hyperthermia for temperature stimulation of the
composite system by AC magnetic field (AMF). The anticancer potentials of the
therapeutic system was validated against human breast (MCF-7) and cervical carci-
noma (HeLa) cells under in vitro conditions, which was 35-45 % in HeLa cells and
20-70 % in MCF-7 cells depending upon the AMF applied (Jaiswal et al. 2014).
A chitosan derivative,
N
-Carboxyethyl chitosan ester (CS-EA) was synthesized
by another group to attain aptamer (MUC1 DNA) mediated targeted delivery of
SN38 to colon cancer. The anticancer potentials of the system was investigated
against MUC1 positive cell line and the corresponding cellular uptake and tar-
geting was confirmed by confocal microscopy (Yoon et al. 2014). Poly(ethylene
glycol) grafted chitosan copolymer was conjugated with tumor targeting siRNA/
folic acid to form a theranostic nanoformulation. The theranostic system attained
better compatibility with erythrocytes and effectively inhibited proliferation by
gene knockout in BALB/c mice bearing OVK18 tumor xenograft by in vivo imag-
ing. The preliminary in vitro studies were well complimented with flow cytometry
RT-qPCR and western blot analysis for transfection and gene silencing activity
(Li et al. 2014). Glycol chitosan has also been modified with different extents of
hydrophobic
N
-acetyl histidine (NAcHis-GC) which is tagged with I
131
. Similarly
I
131
tagged doxorubicin was also encapsulated within NAcHis-GC for continu-
ous monitoring using a gamma camera. The same system was evaluated under in
vivo conditions with near-infrared fluorescence Cy5.5-labeled NAcHis-GC. The
therapeutic outcomes of NAcHis-GC nanoparticles loaded with doxorubicin was
compared with other alternative carriers reported thus far and was verified against
xenograft mice models (Lee et al. 2010).
It is clear from afore mentioned examples that polymers have revolutionized the
field of cancer therapy and diagnostics. The targeted delivery of two or more syner-
gistic drugs to cancer cells with simultaneous real-time imaging system would be
sought after as the future theranostic system for efficient management of cancer.
2 Dendrimers: Introduction
Dendrimers represent a class of chemically synthesized globular molecules
with very well-defined structures. From the view of polymer chemistry, den-
drimers are nearly defect-free, monodisperse (meaning consistent size and
