Fabrication of Insoluble Elastin by Enzyme-Free Cross-Linking.

Elastin is an essential extracellular matrix protein that enables tissues and organs such as arteries, lungs, and skin, which undergo continuous deformation, to stretch and recoil. Here, we describe an approach to fabricate artificial elastin with close-to-native molecular and mechanical characteristics. We polymerized recombinantly produced tropoelastin through coacervation and allysine-mediated cross-linking induced by pyrroloquinoline quinone (PQQ). We developed a technique that allows the recovery and repeated use of PQQ for protein cross-linking by covalent attachment to magnetic Sepharose beads. The produced material closely resembles natural elastin in its molecular, biochemical and mechanical properties, enabled by the occurrence of the cross-linking amino acids desmosine, isodesmosine and merodesmosine. It possesses elevated resistance against tryptic proteolysis and its Young's modulus ranging between 1-2 MPa is similar to that of natural elastin. The approach described herein enables the engineering of mechanically resilient, elastin-like materials for biomedical applications. This article is protected by copyright. All rights reserved.