Synthesis of morpholine-2,5-dione derivative copolymer and its degradation in vitro

Abstract

In this experiment we prepared the copolymer of L-lactide (L-LA) and (3s)-[(benzyloxycarbonyl) methyl] morpholine-2,5-dione (BMD) using tin(II)-octanoate initiated ring-opening copolymerization. The maximum relative number-average molecular weight (M _n) of copolymer was over 8.0?10⁴. The degradation study proceeded in vitro and poly(L-lactide-co-glycollide) used as the control sample. Changes in mass and molecular weight were studied during the immersion in buffer solutions [phosphate-buffered saline solution (PBS), pH = 7.4] at 37?C. The hydrolytic degradation of both the morpholine-2,5-dione derivative copolymer and the control sample were completed in 3 months. A palladium on charcoal catalyst [Pd/C (5%)] was used as the catalyzer for hydrogenolysis. 1H-NMR (nuclear magnetic resonance) analysis and gel permeation chromatography (GPC) were used to investigate the degree of the hydrogenolysis of the copolymer with different M _n. The contact angle showed that the biodegradable copolymer had good hydrophilicity. These findings suggested that this copolymer would have a high potential application for pharmaceutical products.