Elastin-Based Biopolymers: Chemical Synthesis and Structural Characterization of Linear and Cross-Linked Poly(OrnGlyGlyOrnGly)

Poly(OrnGlyGlyOrnGly) was synthesized by classical procedures in solution. The monomeric sequence -OrnGlyGlyOrnGly- was chosen as a modification of -ValGlyGlyValGly-, typical of elastin, to impart primary amine functionality, susceptible to cross-linking with appropriate bifunctional reagents. Herein we focus on the cross-linking of poly(OrnGlyGlyOrnGly) with glutaraldehyde. The polymers, both linear and cross-linked, were characterized and investigated for their molecular and supramolecular properties. Circular dichroism studies performed on linear poly(OrnGlyGlyOrnGly) revealed a variety of conformations similar to elastin. At a supramolecular level, different kinds of aggregates were found such as the elastin-like twisted-rope pattern of filaments and fibrils, together with other specific morphologies, similar to those recently identified in some elastin-mimetic polypeptides.