Olive oil-derived degradable polyurethanes for bone tissue regeneration

Abstract

Engineering biomaterials for tissue regeneration with an appropriate degradation rate that is faster than the widely-used slow degrading polyesters and rapidly degrading surface-eroding polymers is challenging. Polyurethanes exhibit the desired combination of physico-mechanical properties along with good biocompatibility and thus find widespread use in the clinic. Clinically, polyurethanes are used in catheters, tubing, patches, coating of pacemaker leads, and left ventricular assisted devices. In this study, two different polyurethanes were synthesized from olive oil, optionally incorporating polyethylene glycol (PEG). The presence of degradable ester groups in the monomers derived from oil imparts degradability to the synthesized polyurethanes. The hydrophilicity and thus degradability of polyurethanes were improved by incorporating PEG into the polymer network. The synthesized polymers were analyzed through physical, mechanical, and thermal characterization. The reduction in storage modulus from 38.7 to 3.7 MPa was observed after incorporating PEG. In 63 days, neat oil-based polyurethane degraded 3.3%, whereas PEG-containing polyurethane showed 10.8% mass loss. The synthesized polymers can be fabricated into a variety of two-dimensional substrates and three-dimensional scaffolds by compression molding and particulate leaching techniques. The prepared polyurethanes showed good cytocompatibility in vitro and efficiently supported the osteogenic differentiation of pre-osteoblasts. The incorporation of PEG adversely affected osteogenic differentiation. Thus, these olive oil-based polyurethanes are shown to be promising biomaterials for developing scaffolds with tunable degradation and mechanical properties for tissue regeneration.