Synthesis, characterization, and in vitro biodegradation of poly(ethylene glycol) modified poly[N-5-(2-hydroxyethyl-L-glutamine]

The synthesis and in vitro biodegradation of poly(ethylene glycol) modified poly[N-(2-hydroxyethyl)-L-glutamine] are described. Poly(ethylene glycol) (PEG) with terminal amino endgroup was coupled onto 4-nitrophenyl chloroformate activated poly[N-(2-hydroxyethyl)-L-glutamine] (PHEG). The influence of the degree of substitution and the molecular weight of PEG side groups on the degradability of the PHEG backbone exposed to isolated rat liver lysosomal enzymes was determined. These data indicate that substitution of PHEG with PEG side-chains only slightly alters the degradability of the carrier. The PEG-grafted polymers showed potential tensioactive properties. DSC analysis demonstrated phase separation of the PEG side-groups in solid state.