Cationic Polymers for the Delivery of Therapeutic Nucleotides - Nanotechnology for the Delivery of Therapeutic Nucleic Acids - page 45

150 nm, implicating its potential for intracellular delivery. It showed
lower cytotoxicity, much higher transfection efficiencies in three
cell lines compared with PEI.

90

A few hyperbranched poly(amino
ester) synthesized showed transfection efficiency comparable to PEI
(25 kDa) for in vitro DNA delivery.

blended poly(amino ester) with PLGA for DNA
vaccination, and microparticles prepared were used for significant
lessening of tumor size in mice with the release of pDNA for several
years.

Wu et al.

synthesized PAE using a new amine monomer,
2-(pyridyldithio)-ethylamine (PDA). These cationic, degradable
polymers containing pyridyldithio functionalities were reacted
with mercaptoethylamine (MEA) and the thiol peptide RGDC. These
two polymer derivatives displayed strong DNA binding; complexes
displayed low cellular toxicity and ability to mediate transfection at
levels comparable to PEI in human hepatocellular carcinoma cells.
These results suggested PDA based poly(amino ester)s as a modular
platform for polymer-mediated gene delivery in the therapeutic
delivery of DNA.

91, 92

Zugates et al.

93

2.3.5.3 Poly(amido amine)s
Poly(amino amine)s (PAA) polymers are water-soluble,
biodegradable, and biocompatible with lower cytotoxicity profiles.
They can be easily synthesized by Michael-type polyaddition
of primary or bis-secondary amines to bis(acrylamide)s. These
PAA have the advantage to degrade into oligomeric products in
aqueous media within days or weeks, depending on their structure.
PAA are degradable in aqueous solution by means of hydrolytic
cleavage of the amidic bonds in their main chain. These polymers
have high potential in biomedical applications and are found to be
particularly suitable for use as intracytoplasmic and endosomolytic
vectors for the delivery of anticancer drugs, proteins, and nucleic
acids.

94, 95
Series of novel bioreducible PAA containing multiple disulfide
linkages (SS-PAA) were synthesized and evaluated as non-viral gene
vectors by Lin The SS-PAA polymers are relatively stable in

medium mimicking physiological conditions but are rapidly degraded
in the medium mimicking the intracellular reductive environment.
The results indicate bioreducible PAA have excellent properties for
the development of highly potent and non-toxic polymeric gene
carriers.

et al.

96

Similarly, series of reducible hyperbranched PAA with