Branched poly (trimethylphosphonium ethylacrylate-co-PEGA) by RAFT: alternative to cationic polyammoniums for nucleic acid complexation

Cationic and highly branched poly (trimethylphosphonium ethylacrylate- co-poly (ethylene glycol) acrylate) (p (TMPEA- co-PEGA)), and its ammonium equivalent, have been synthesised from post-polymerisation modification of a poly (bromo ethylacrylate- co-poly (ethylene glycol) acrylate) (p (BEA- co-PEGA)) precursor polymer produced using reversible addition fragmentation chain transfer (RAFT) polymerisation. The cationic polymers were evaluated for their ability to complex nucleic acids, their i n vitro cytotoxicity and their GFP pDNA transfection efficiency. The results show RAFT copolymerisation of BEA and PEGA is a simple route to polyphosphoniums showing reduced cytotoxicities and higher transfection efficiencies than their polyammonium alternatives.