Photo-regulative transfection using a cationic polyazobenzene dendrimer

A new cationic L-lysine-modified polyazobenzene dendrimer (Lys-G 2) was exa mined as a synthetic vector for a mammalian cell. UV irradiation after the incorporation of Lys-G 2-complex with plasmid DNA into a cytoplasm caused a 50% increase in the transfection efficiency as compared with the case with out UV irradiation; namely, the trans-to-cis photo-isomerization bad proton ated amines serried and decreased the cationic density on the surface of th e complex to suppress the cationic repulsion. The decreased charge density was also confirmed by zeta potential measurements. This work demonstrates t hat the transfection efficiency is controllable by UV irradiation using a c ationic dendrimer which possesses a photochromic polyazobenzene structure.