4. Bioelastomers in Tissue Engineering

The rapid progress in cell and developmental biology has clearly revealed that substrate elasticity and mechanical stimulation significantly affect cell function and tissue development. Further, many engineered soft-tissue constructs such as vascular grafts, cardiac patches, and cartilage are implanted in a mechanically dynamic environment, thus successful implants must sustain and recover from various deformations without mechanical irritations to surrounding tissues. Ideal scaffolds for these tissue engineering applications would be made of biodegradable elastomers with properties that resemble those of the extracellular matrix, providing a biomimetic mechanical environment and mechanical stimulation to cells and tissues. However, traditional biodegradable scaffold materials such as polylactide, polyglycolide, and poly(lactide-co-glycolide) are stiff and are subjected to plastic deformation and failure under cyclic strain. Consequently, for the past decade, many novel bioelastomers have been developed and extensively investigated for applications in tissue engineering. Both thermoplastic elastomers such as polyurethane, poly(ε-caprolactone) copolyester, poly(ether ester) and thermoset elastomers such as crosslinked polyesters have been developed and evaluated to engineer various tissues such as heart muscle and valves, blood vessels, skin, and cartilage. This chapter will cover representative bioelastomers and their applications in tissue engineering to highlight recent advances in this area.