Synthetic Route and Characterization of Main Chain Ester-Containing Hydrolytically Degradable Poly(N,N-dimethylaminoethyl methacrylate)-Based Polycations

The possibility of introducing hydrolytically cleavable ester linkages onto the poly(N,N-dimethylaminoethyl methacrylate) for the formation of less toxic and degradable polycations is shown in this work. For achieving this aim, the copolymerization behavior of 5,6-benzo-2-methylene-1,3-dioxepane (BMDO), with N,N-dimethylaminoethyl methacrylate (DMAEMA) is studied by free radical ring-opening polymerization. Structural characterization is performed using 1D and 2D NMR techniques. Under optimized reaction conditions, quantitative ring-opening of BMDO took place during the copolymerizations leading to the formation of poly(DMAEMA-co-ester)s. Blocky random copolymers were further quaternized by alkyl bromide to generate degradable cation containing polymers. Cytotoxicity results were highly encouraging and showed less cytotoxicity as compared to polyethyleneimine, which was used as a positive control. The formation and characterization of highly stable copolymer/DNA polyplexes is also shown here.