Purpose. The aim of this study was to develop a non-toxic polymeric gene ca
rrier For this purpose, biodegradable cationic polymer, poly[alpha-(4-amino
butyl)-L-glycolic acid] (PAGA) was synthesized. PAGA was designed to have e
ster linkage because polyesters usually show biodegradability.
Methods. Degradation of PAGA in an aqueous solution was followed by matrix-
assisted laser desorption/ionization time-of-flight mass spectrometry (MALD
I-TOF MS). PAGA/DNA complexes were characterized by gel electrophoresis, at
omic force microscopy (AFM), dynamic light scattering (DLS). The transfecti
on was measured by using the: beta-galactosidase reporter gene.
Results. PAGA was degraded in aqueous solution very quickly and the final d
egradation product was a monomer (L-oxylysine). Formation of self-assemblin
g biodegradable complexes between PAGA and DNA at a charge ratio 1:1 (+/-)
was confirmed by gel band shift assay and AFM. In these studies, controlled
release of DNA from the complexes could be seen. The complexes showed abou
t 2-fold higher transfection efficiency than DNA complexes of poly-L-lysine
(PLL), a structural analogue of PAGA, which is the most commonly used poly
-cation for gene delivery. The polymer did not show cytotoxicity, possibly
because of its degradability and the biocompatibility of the monomer.
Conclusions. The use of the biodegradable poly-cation, PAGA, as a DNA conde
nsing agent will be useful in safe gene delivery.