polyglutamates are well known to be highly biocompatible , biodegradable and multifunctional polymers , which have been already used as building blocks in polymer drug conjugates and polymeric micelles . those systems have been applied to various medical applications ranging from therapy to molecular imaging . furthermore a polyglutamic acid paclitaxel conjugate has already entered clinical studies . in this context , a synthetic pathway to a plethora functional polyglutamates with well - defined structure , adjustable molecular weight and low dispersity applying the ring opening polymerization of n - carboxyanhydrides has been developed . additionally , the acid moieties of the polyglutamates can be activated with 4 -- 4 - methylmorpholinium and various functionalities can be easily introduced by “ post - polymerization modification ” yielding a set orthogonal reactive attachment sides . the reactive moieties , such as azides , maleimides , thiols , alkynes offer the opportunity of specific conjugation of the drugs , targeting moieties or markers . besides introducing reactive groups the functionalization strategy was also used for pegylation of pga reducing charge induced interactions and therefore pharmacological properties , such as blood circulation time may be adjusted . in summary , a tool kit of various polyglutamates has been developed enabling the synthesis of a variety of polymer drug conjugates or polymer based imaging agents . the functional polymeric precursors developed will allow us to functionalize and therefore adjust the polymer properties to a desired application .