Cationic polysaccharides for gene delivery

Cationic polysaccharides were synthesized by conjugation of various oligoamines including monoquaternary ammonium oligoamines and spermine to oxidized dextran by reductive amination and tested for gene transfection. Monoquaternary ammonium polycations were expected to strongly complex DNA due to increased surface cationic charge of the carrier which may result in a higher transfection yield. However, the transfection yields were much lower compared to the parent vector, dextran–spermine conjugate, which was highly effective both in vitro and in vivo. Modification of dextran–spermine conjugate with increasing amounts of the oleic acid and MPEG resulted in high gene transfection in vivo.