Scale-up synthesis of a polymer designed for protein therapy

•Successful optimization and scale-up of a cationic polyester, PEAD.•PEAD/heparin coacervate is used for protein delivery to extend the half lives.•New synthesis route improves the production safety and yield, and reduces the cost.•The successful scale-up makes it easier to commercialize this polycation.•This work may also inform scale-up efforts of similar polymers.