Formulation and characterization of DNA-polyethylenimine-dextran sulfate nanoparticles.

Polyethylenimine (PEI) is a promising non-viral gene delivery polymer that produces high transfection efficiency both in vitro and in vivo. The use of PEI, however, is hindered by its toxicity, reflecting its polycationic nature. In an attempt to decrease this charge-dependent cytotoxicity, a polyanionic polymer, dextran sulfate (DS), has been incorporated into self-assembling PEI-DNA complexes with zinc as stabilizing agent.

Insulin containing polyethylenimine-dextran sulfate nanoparticles.

An aqueous nanoparticle delivery system has been developed which employs the oppositely charged polymers polyethylenimine (PEI) and dextran sulfate (DS) with zinc as a stabilizer. It is found that the pH of PEI solutions, the weight ratio of the two polymers, and zinc sulfate concentrations all play significant roles in controlling particle size. Spherical particles of 250 nm mean diameter were produced under optimal conditions which have a zeta potential of approximately +30 mV.