Nanomaterials: Versatile Drug Carriers for Nanomedicine
267
The activation of anti-apoptotic pathways is another problem faced in MDR.
Cells have developed anti-apoptotic pathways such as genetic and epigenetic modifications of cancer cells to avoid death. The alterations include overexpression of
B-cell lymphoma 2 (Bcl-2), which is an anti-apoptosis regulator protein, and also
mutation in p53 (tumor suppressor) gene [40]. The nano-carriers can also be used for
the co-delivery of the cytotoxic drug along with the gene targeting apoptosis regulator
protein such as transcription factor NF-κB, hypoxia-inducible factor-alpha (HIF-1α)
[23] and Bcl-2 [41]. Such a synergistic effect can increase the therapeutic effect by
intracellular drug accumulation. For example, the synthesis of nanoparticles attained
by calcium carbonate (CaCO 3 ) co-precipitation method was used for co-delivery of
DOX and p53 gene [42]. These nanoparticles have achieved higher cell inhibition
and promoted tumor cell apoptosis with more efficiency.
7 Multifunctional Nano-Carriers
Multifunctional nano-carriers are used for the synergistic effects which are capable
of delivering therapeutic drugs along with the image contrast enhancement agent at
targeted body sites. Kim et al. synthesized chitosan-based nanoparticles, containing
anti-cancer drug paclitaxel and near-infrared fluorescent (Cy5.5) [43]. C-NPs are
stable in serum, deformability, and readily uptaken by cancer cells. A new era in
cancer therapy is considered where early-stage cancer diagnostics, drug delivery
and non-invasive real-time monitoring of therapeutic efficacy can be carried out
simultaneously. Yang et al. have succeeded in nano-structure for multifunctional
systems uniting chemotherapeutic drug DOX and magnetic nanocrystals with therapeutic antibodies [44]. These nanosystems have the ability of treatment, imaging,
and targeting.
Nanomaterials with multifunctional abilities have been used for in vivo imaging,
silencing of the tumor, and siRNA delivery. Magnetic nanoparticles are synthesized
labeled with a near-infrared dye that is covalently linked to siRNA molecules that
translocate to cytosol with high gene transduction efficiency [45]. Guo et al. synthesized a multifunctional nano-carrier using a graft-degradable cationic co-polymer
named poly (ε -caprolactone)-graft-poly (2- (N, N-dimethylamino) ethyl methacrylate) (PCL-g-PDMAEMA) [46]. These nano-carriers were found to load DNA and
entrap hydrophobic paclitaxel simultaneously. It was found that the nano-carriers
are pH-sensitive, i.e., the drug is liberated faster in an acidic environment. While,
as compared with Lipofectamine
TM 2000, PCL-g-PDMAEMA NPs exhibited high
gene transfection efficiency. It was also found that the nano-carriers escapes the
endosome and thus release the cargo in cytoplasm effectively. This has helped to
achieve the synergistic effect of drug and gene therapy in vivo.
The application of nanomaterials as pharmaceutical nano-carriers, such as
micelles, liposomes, and bio-MSN, have shown a heterogeneity of useful properties,
such as longer blood circulations, increased intracellular penetration, and specific
targeting. The continuous advancements in biomarkers and targeting ligands have
267
The activation of anti-apoptotic pathways is another problem faced in MDR.
Cells have developed anti-apoptotic pathways such as genetic and epigenetic modifications of cancer cells to avoid death. The alterations include overexpression of
B-cell lymphoma 2 (Bcl-2), which is an anti-apoptosis regulator protein, and also
mutation in p53 (tumor suppressor) gene [40]. The nano-carriers can also be used for
the co-delivery of the cytotoxic drug along with the gene targeting apoptosis regulator
protein such as transcription factor NF-κB, hypoxia-inducible factor-alpha (HIF-1α)
[23] and Bcl-2 [41]. Such a synergistic effect can increase the therapeutic effect by
intracellular drug accumulation. For example, the synthesis of nanoparticles attained
by calcium carbonate (CaCO 3 ) co-precipitation method was used for co-delivery of
DOX and p53 gene [42]. These nanoparticles have achieved higher cell inhibition
and promoted tumor cell apoptosis with more efficiency.
7 Multifunctional Nano-Carriers
Multifunctional nano-carriers are used for the synergistic effects which are capable
of delivering therapeutic drugs along with the image contrast enhancement agent at
targeted body sites. Kim et al. synthesized chitosan-based nanoparticles, containing
anti-cancer drug paclitaxel and near-infrared fluorescent (Cy5.5) [43]. C-NPs are
stable in serum, deformability, and readily uptaken by cancer cells. A new era in
cancer therapy is considered where early-stage cancer diagnostics, drug delivery
and non-invasive real-time monitoring of therapeutic efficacy can be carried out
simultaneously. Yang et al. have succeeded in nano-structure for multifunctional
systems uniting chemotherapeutic drug DOX and magnetic nanocrystals with therapeutic antibodies [44]. These nanosystems have the ability of treatment, imaging,
and targeting.
Nanomaterials with multifunctional abilities have been used for in vivo imaging,
silencing of the tumor, and siRNA delivery. Magnetic nanoparticles are synthesized
labeled with a near-infrared dye that is covalently linked to siRNA molecules that
translocate to cytosol with high gene transduction efficiency [45]. Guo et al. synthesized a multifunctional nano-carrier using a graft-degradable cationic co-polymer
named poly (ε -caprolactone)-graft-poly (2- (N, N-dimethylamino) ethyl methacrylate) (PCL-g-PDMAEMA) [46]. These nano-carriers were found to load DNA and
entrap hydrophobic paclitaxel simultaneously. It was found that the nano-carriers
are pH-sensitive, i.e., the drug is liberated faster in an acidic environment. While,
as compared with Lipofectamine
TM 2000, PCL-g-PDMAEMA NPs exhibited high
gene transfection efficiency. It was also found that the nano-carriers escapes the
endosome and thus release the cargo in cytoplasm effectively. This has helped to
achieve the synergistic effect of drug and gene therapy in vivo.
The application of nanomaterials as pharmaceutical nano-carriers, such as
micelles, liposomes, and bio-MSN, have shown a heterogeneity of useful properties,
such as longer blood circulations, increased intracellular penetration, and specific
targeting. The continuous advancements in biomarkers and targeting ligands have