Cationic Polymers for the Delivery of Therapeutic Nucleotides - Nanotechnology for the Delivery of Therapeutic Nucleic Acids - page 50

transfer efficiency. Study also showed that there was a clear trend
of increasing size of the complexes as the amount of pDNA was
increased.

111

It was also observed, during

administration, polyplexe
aggregates are formed, and they are entrapped in pulmonary
endothelium. In some cases, amendment of the polyplexes with
antibody in order to decrease the zeta potential increases the

in vitro

in vitro

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transfection efficiencies in the lung endothelial cells. Similarly,

a target receptor is being set in liver delivery technique to deliver
the liver-specific polymeric carriers known as asialoglycoprotein
receptors,whichisexclusively expressedon hepatocytesand mediates
cellular uptake through the specific recognition and endocytosis of
ligands. Perales

reported supervision of targeted polyplexes via
tail vein injection into mice resulted in increased uptake of polyplexes
into the liver and higher liver-specific expression.

et al.

113

2.5.5 Brain Delivery

Brain delivery can be achieved via the systemic delivery or by
localized injection to the brain parenchyma, although some limita-
tions are there in case of systematic delivery. Posadas describe

efficient delivery of genetic material (both DNA and small interfering
RNA) to neuronal tissue using non-viral vectors, including the use of
cationic lipids, PEI derivatives, dendrimers, carbon nanotubes, and
the combination of carbon-made nanoparticles with dendrimers.

et al.

114

Barret during their study of PLL-based polyplexes concluded

that neuronal transfection efficiencies can be enhanced using PLL
polymer.

et al.

115

2.6 Conclusion

Non-viral vectors have shown immense potential for successful
gene therapy and delivery of therapeutics nucleotides. Without a
doubt, polycations represent the effective carriers for polymer/
nucleotide complexes. It represents extremely promising research
area where remarkable efforts have been made to apply various
different cationic polymers as vectors in gene delivery. Cationic
polymers are more advantageous as compared to viral vectors
because of their low immune response against the cells and