Cationic Polymers for the Delivery of Therapeutic Nucleotides - Nanotechnology for the Delivery of Therapeutic Nucleic Acids - page 37

activities and compared dendritic PLL (KG6) with linear PLL. KG6
formed a neutral DNA complex, and its DNA compaction level was
weaker than that of PLL. The amount of DNA binding and uptake
into cells mediated by PLL was fourfold higher than that with KG6.
However, KG6-mediated gene expression was 100 fold higher than
by PLL. Amount of induced cytokine production after intravenous
injection of DNA complexes with KG6 and PLL was low and was
found similar to when DNA was injected alone.

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designed replica particles based on PLL polymers
cross-linked via a homobifunctional linker to support co-adsorption
of pDNA and a peptide hormone for concurrent transfection and
induction of a cellular function. PLL replica particles were prepared
by infiltrating polymer into mesoporous silica particles, cross-linking
the adsorbed chains by using a homobifunctional cross-linker and
finally removing the template particles. Melanin stimulation and gene
expression were simultaneously evaluated and PLL replica particles
were found as a promising vector for gene therapy and hormone
stimulation.

Zhang et al.

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Similarly, a terplex gene delivery system consisting of
pDNA, low density lipoprotein (LDL), and hydropholized PLL was
designed and characterized by Kim. pDNA when formulated with
hydropholized PLL and LDL forms a stable and hydrophobicity/
charge-balanced terplex system for efficient cellular uptake. Terplex
DNA complex showed significantly longer retention in the vascular
space than naked DNA. This system was used in the augmentation of
myocardial transfection at an infraction site with VEGF gene.

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2.3.3 Cationic Polysaccharides

Cationic polysaccharides are attractive candidates for gene delivery.
They are non-toxic, biodegradable, and biocompatible materials. The
use of biodegradable polysaccharide carriers is especially suitable
for transfection and biological applications because they are water
soluble, can be readily transported to cells

, and thus act as
an effective vehicles for transporting agents complexed with them.

in vivo

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Major cationic polysaccharides used in therapeutic purposes are
natural (chitosan and cyclodextrin) or semisynthetic in origin.
Semisynthetic cationic polysaccharides have been synthesized by
conjugation of various oligoamines to oxidized polysaccharides
by reductive amination and were tested for antiprion activity.