In vitro degradation study of polymers prepared from sebacoyl chloride with (di)ethylene glycol monomers and polymer

Abstract

In this study, some ethylene glycol based polymers, namely poly(ethylene sebacate), poly(diethylene sebacate), and poly(ethylene glycol)-sebacate copolymers having three different molecular weights were prepared by condensation polymerization with sebacoyl chloride in very good yields ranging from 81-88%. All polymers designed to be ended with hydroxyl groups. The prepared polymers were characterized by infrared spectroscopy and molecular weight determination using end-groups analysis method and both methods were confirmed the right structures of the prepared polymers. Biodegradation studies of all the prepared polymers were carried out by pressing the polymer sample in the form of compact disc weighing 0.2 g and about 1 cm in diameter. In vitro biodegradability studies was done using %weight loss of constant body temperature (37°C) in human plasma pH=7.4, and determination of intrinsic viscosity of the solution of the degradable polymers. The results revealed that the poly(diethylene sebacate) polymer needed more than four months to reach only 21% loss while poly(ethylene sebacate) reached nearly 25% in the same period of time. The same behavior was observed in the intrinsic viscosity study. Under the same conditions, degradation of the polymers produced from condensation polymerization of poly(ethylene glycol) having different molecular weight, i.e. (400, 10000, 20000) g/mole with sebacoyl chloride was also studied by determining of their degradable solution intrinsic viscosities. The results obtained imply that the number of polymeric repeated units has a great influence on the degradation of the polymer, the more repeated unit the less degradation. This is considered as a good sign for these polymers to be used as a drug carrier in controlled drug delivery systems as they increase residence time in the body.