A controlled and versatile NCA polymerization method for the synthesis of polypeptides

A versatile and simple methodology for the preparation of well-defined polyglutamate nanocarriers is described. For the first time ammonium salts with non-nucleophilic tetrafluoroborate anions are used as initiators for the ring opening polymerization of α-N-carboxyanhydrides (NCAs) allowing a multigram scale polyglutamate synthesis with defined molecular weight (up to 800 units), low polydispersity (<1.2), controlled chain end functionality and adequate stereoselectivity and absence of any trace of toxic impurity to allow biomedical applications.