Glutathione-responsive biodegradable poly(urea-urethane)s containing L-cystine-based chain extender

Abstract

A series of glutathione-responsive biodegradable poly(urea-urethane)s were synthesized from poly(ethylene glycol) as the soft segment and 1,6-hexamelthylene diisocyanate incorporating cystine-based chain extender as the hard segment. Structure and thermal properties of the poly(urea-urethane)s were characterized with attenuated total reflectance Fourier transform infrared, ¹H NMR, gel permeation chromatography, differential scanning calorimeter and thermogravimetric analyses. In vitro degradation test was carried out under physiological conditions in the presence of glutathione and the degradability of poly(urea-urethane)s were evaluated by the decrease in their molecular weight (M _w), on which the degradation rate constants were calculated and kinetic equations were established. PU[Cys] had the highest degradation rate and it remained only 30% of the original M _w in eight days. All the poly(urea-urethane)s were testified with noncytotoxicity and good biocompatibility.

Keywords:

• biodegradable
• polyurethane
• cystine
• glutathione
• degradation kinetics

Acknowledgments

This project is supported by the National Science Fund of China (20974061) and the Shanghai Leading Academic Discipline Project (No. B202).