Redox Reducible and Hydrolytically Degradable PEG-PLA Elastomers as Biomaterial for Temporary Drug-Eluting Medical Devices

Abstract

With the aim to develop biomaterials for temporary medical devices, a series of novel reducible and/or degradable elastomers has been prepared from PLA-b-PEG-b-PLA copolymers photo-crosslinked with diallyl sulfide or pentaerythritol tetrakis(3-mercaptopropionate). Thermal and mechanical properties, including elastic limit and Young modulus, are assessed. Degradation is then evaluated under standard hydrolytic conditions. Reducibility of a selected elastomer is then illustrated using 2-mercaptoethanol or glutathione as reducing agents. The redox-sensitivity of the selected elastomer and the possibility to modulate the degradability are shown. Considering drug-eluting elastomeric devices applications, anti-inflammatory drug ibuprofen loading is illustrated with the two simplest elastomer formulations. A rapid or slow linear release is observed as a function of the low or high molecular weight of the triblock pre-polymers. Finally, the cytocompatibility of the degradable elastomers is assessed with regard to their potential to favor or inhibit L929 murine fibroblasts proliferation as a function of the hydrophilicity/hydrophobicity of the triblock copolymers.

Keywords: degradation; drug release; elastomers; medical device; polyesters; redox.