Novel Cationic Triblock Copolymer of Poly[2‐(dimethylamino)ethyl methacrylate]‐ block ‐poly(β‐amino ester)‐ block ‐poly[2‐(dimethylamino)ethyl methacrylate]: A Promising Non‐Viral Gene Delivery System

This manuscript reports the synthesis of a new cationic block copolymer based on poly[2‐(dimethylamino)ethyl methacrylate] and poly(β‐amino ester) from different polymerization strategies. For the first time, it is proposed a triblock copolymer based only on cationic segments, aiming a high biocompatibility, enhanced buffering capacity and stimuli‐responsive character in a single structure. The new block copolymer successfully condensed the plasmid DNA into nanosized polyplexes. The polyplexes were tested in two different cell lines revealing ∼4‐fold and ∼6‐fold (in HeLa cells), and ∼11‐fold (in COS‐7 cells) higher transgene expression than branched PEI and TurboFect™, respectively. These results show that this new block copolymer is a promising candidate to be used as a polymeric non‐viral vector.