New degradable cationic polyesters for nonviral gene delivery

A new family of biodegradable cationic polyesters consisting of aspartic acid and aliphatic diols of various lengths has been synthesized. Since the polymers formed are strictly alternating, the cationic charge density can be controlled by simply changing the size of the spacer aliphatic monomer. One such polymer, poly(aspartic anhydride-co-ethylene glycol) (PAE), was found to be capable of self-assembly (∼100 nm) into polymeric micelles and complexation with DNA. Kinetic studies reveal PAE initially complexes DNA into sub-100 nm complexes and subsequently releases it after 3-6 days at room temperature. With the ability to degrade and unpack its genetic material, this new family of biodegradable cationic polymers shows promise as versatile gene carriers for in vitro and in vivo applications.