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Degradable copolymers were synthesized by ring opening polymerization of lactide in the presence of poly(ethylene glycol) (PEG), using CaH2 as a biocompatible initiator. The resulting PLA/PEO/PLA triblock copolymers were dissolved in a biocompatible solvent, namely tetraglycol. Physically crosslinked hydrogels were then prepared by introducing small amounts of water into the thus obtained solutions. Hydrolytic degradation of the highly swollen hydrogels was realized in 0.13 M pH=7.4 phosphate buffer, while the enzymatic degradation was carried out in 0.05 M pH=8.6 Tris buffer containing a PLA-degrading enzyme, proteinase K. In both cases, degradation was initially very fast with dramatic weight loss. The LA/EO ratio of the remaining material increased rapidly, in agreement with the release of PEO-rich segments. In a second phase, the degradation rate slowed down. The presence of proteinase K strongly accelerated the degradation rate of the hydrogels, indicating that the enzyme was able to penetrate inside and attack the PLA domains which constituted nanometric nodes in the gel network.

The click reaction between azides and alkynes is been increasingly employed in the preparation of polymers. In this article, we describe the synthesis and click polyaddition reaction of a new A‐B‐type amide monomer—prepared from d‐glucose as renewable resource—containing the alkyne and azide functions. Both Cu(I)‐catalyzed and metal‐free click polymerization methods were used to prepare glucose‐derived poly(amide triazole)s. The resulting polymers had weight‐average molecular weights in the 45,000–129,000 range and were characterized by GPC, IR, and NMR spectroscopies. Thermal and X‐ray diffraction studies revealed them to be amorphous. Their qualitative solubilities in various solvents and their water sorption have been studied. The poly(amide triazole)s having the alcohol functions protected as methyl ether were water‐soluble. The presence of the amide functions along the polymer chain made these polytriazoles degradable in the presence of sodium deuteroxide. The degradation was monitored by NMR analysis, and the degradation product was characterized by HRMS. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 629–638

This paper describes the hydrolytic degradation of three stereoregular poly(ester amides) which were obtained by polycondensation reaction of 1-amino-1-deoxy-2,3,4-tri-O-methyl-5-O-[(pentachlorophenoxy)succinyl]-L-arabinitol, 1-amino-1-deoxy-2,3,4-tri-O-methyl-5-O-[(pentachlorophenoxy)glutaryl]-L-arabinitol, and 1-amino-1-deoxy-2,3,4-tri-O-methyl-5-O-[(pentachlorophenoxy)succinyl]-D-xylitol hydrochlorides. The degradation study was carried out at 37 °C in bidistilled water and/or in buffered salt solution at pH 7.4, and was monitored by mass loss, GPC, SEM, and FAB-MS, IR, and NMR spectroscopies. The hydrolytic degradation of these poly(ester amides) occurs by hydrolysis of the ester linkages and is characterized by rapid rates of hydrolysis. The differences in degradation rates are ascribed to differences in crystallinity and hydrophilicity of the polymers. Our results show that the poly(ester amides) derived from succinic anhydride degrade to a final monomeric product in which a succinimide ring has been formed.