Abstract
Background
Polyethylenimine (PEI) is toxic although it is one of the most successful and widely used gene delivery polymers with the aid of the proton sponge effect. Therefore, development of new novel gene delivery carriers having high efficiency with less toxicity is necessary.
Methods
In this study, a degradable poly(ester amine) carrier based on poly(ethylene glycol) diacrylate (PEGDA) and low molecular weight linear PEI was prepared. Furthermore, we compared the gene expression of the polymer/DNA complexes using two delivery methods: intravenous administration as an invasive method and aerosol as a non‐invasive method.
Results
The synthesized polymer had a relatively small molecular weight (MW = 7980) with 25 h half‐life in vitro. The polymer/DNA complexes were formed at an N/P ratio of 9. The particle sizes and zeta‐potentials of the complexes were dependent on N/P ratio. Compared to PEI 25K, the newly synthesized polymer exhibited high transfection efficiency with low toxicity. Poly(ester amine)‐mediated gene expression in the lung and liver was higher than that of the conventional PEI carrier. Interestingly, non‐invasive aerosol delivery induced higher gene expression in all organs compared to intravenous method in an in vivo mice study. Such an expressed gene via a single aerosol administration in the lung and liver remained unchanged for 7 days.
Conclusions
Our study demonstrates that poly(ester amine) may be applied as an useful gene carrier. Copyright © 2007 John Wiley & Sons, Ltd.