Crosslinked α-elastin biomaterials: towards a processable elastin mimetic scaffold

Elastin is a critical biochemical and biomechanical component of vascular tissue. However, elastin is also highly insoluble and therefore difficult to process into new biomaterials. We present a simple approach for synthesizing elastin-based materials from two commercially available and water-soluble components: α-elastin and a diepoxy crosslinker. Reaction pH was shown to modulate the degree of crosslinking, as demonstrated by materials characterized with a range of swelling ratios (∼10-25), enzymatic degradation rates (∼8-50% per h in 0.1 u/ml elastase), and elastic moduli (∼4-120 kPa). Crosslinking with a combination alkaline and neutral pH process results in materials with the highest degree of crosslinks, as indicated by a swelling ratio of 10, slow degradation rate, and high elastic moduli (∼120 kPa). Furthermore, the crosslinked α-elastin materials support vascular smooth muscle cell (VSMC) adhesion and a decreased proliferation rate compared to polystyrene controls. The functional outcomes of the crosslinking reaction, including the dependence of structure-function properties on reaction pH, are discussed. Our approach towards 'processable' elastin-based materials is versatile and could be integrated into existing tissue engineering methodologies to enhance biomaterial performance by providing a natural elastomeric and biofunctional component.