Aliphatic polyester elastomers derived from erythritol and α,ω-diacids

Soft polyester elastomers have emerged as a promising family of biodegradable materials for drug delivery and tissue engineering. Specifically referring to soft tissue engineering, potential biomaterials should be elastic and flexible, so as to mimic the mechanical properties of natural tissue. Herein, we report the design of several elastomers based on the polycondensation of erythritol, a sugar substitute that is approved for human consumption by the Food and Drug Administration, and one of eight dicarboxylic acids: glutaric, adipic, pimelic, suberic, azelaic, sebacic, dodecanedioic, and tetradecanedioic acids. By varying the length of the diacid and the curing conditions, several elastomers were designed with a range of physical and mechanical properties. Poly(erythritol glutarate), poly(erythritol adipate), poly(erythritol pimelate), poly(erythritol suberate), poly(erythritol azelate), poly(erythritol sebacate) poly(erythritol dodecanedioate), and poly(erythritol tetradecanedioate) achieved Young's modulus, ultimate tensile stress, and rupture strain values of 0.08–80.37 MPa, 0.14–16.65 MPa, and 22–466%, respectively. Additionally, as tissue engineering may require the use of complex 3-dimensional designs, embossed films and porous films were designed in order to demonstrate the ease of processing. Hydrolytic degradation rates ranging from 100% in 3 weeks to 6.4% in 6 weeks were obtained in phosphate-buffered saline solutions at 37 °C. Finally, in vitro cytotoxicity was studied with Swiss albino 3T3 fibroblasts and human mesenchymal stem cells. Based on these results, we believe that the poly(erythritol dicarboxylate) series are excellent candidates for potential soft biomaterials.