Structure and properties of biocompatible poly(glycerol adipate) elastomers modified with ethylene glycol

Polyesters poly(glycerol adipate)s or PGAs were prepared through a catalyst-free polycondensation reaction involving different proportions of adipic acid and glycerol. Additionally, another set of PGAs was formulated by adding ethylene glycol to the reaction mixture, creating three PGA-co-ethylene glycols of different ethylene glycol-to-glycerol ratios. All prepolymers were chemically crosslinked into elastomeric films according to specific experimental conditions. A full characterization of elastomers revealed an ease of tunability according to monomer ratios and curing conditions. Mechanical properties presented a variety of Young's modulus values ranging from 0.07 to 8.33 MPa. Within this range, a number of Young's modulus values of soft tissues can be included. Moreover, a cytotoxicity analysis performed on embryonic mouse fibroblasts (NIH/3T3) showed an absence of cytotoxicity and good adherence over all PGA and PGA-co-ethylene glycol elastomers. In addition, fibroblasts underwent a differentiation process into neuron-like cells, thus exhibiting excellent potential for soft tissue engineering.