Collagen/elastin hydrogels cross-linked by squaric acid

• Published in: Materials Science & Engineering C Vol. 60; pp. 100 - 108
• Main Authors: Skopinska-Wisniewska, J., Kuderko, J., Bajek, A., Maj, M., Sionkowska, A., Ziegler-Borowska, M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2016
• Subjects: Biocompatible Materials - chemistry; Cellular; Collagen; Collagen - chemistry; Collagens; Cross-linking; Cross-Linking Reagents - chemistry; Crosslinking; Cyclobutanes - chemistry; Degradation; Elastin; Elastin - chemistry; Hydrogel; Hydrogels; Hydrogels - chemistry; Materials science; Squaric acid; Three dimensional; Hydrogel; Squaric acid; Cross-linking; Collagen; Elastin
• ISSN: 0928-4931; 1873-0191
• DOI: 10.1016/j.msec.2015.11.015

Hydrogels based on collagen and elastin are very valuable materials for medicine and tissue engineering. They are biocompatible; however their mechanical properties and resistance for enzymatic degradation need to be improved by cross-linking. Up to this point many reagents have been tested but more secure reactants are still sought. Squaric acid (SqAc), 3,4-dihydroxy 3-cyclobutene 1,2-dione, is a strong, cyclic acid, which reacts easily with amine groups. The properties of hydrogels based on collagen/elastin mixtures (95/5, 90/10) containing 5%, 10% and 20% of SqAc and neutralized via dialysis against deionized water were tested. Cross-linked, 3-D, transparent hydrogels were created. The cross-linked materials are stiffer and more resistant to enzymatic degradation than those that are unmodified. The pore size, swelling ability and surface polarity are reduced due to 5% and 10% of SqAc addition. At the same time, the cellular response is not significantly affected by the cross-linking. Therefore, squaric acid would be regarded as a safe, effective cross-linking agent. •Collagen/elastin gels obtained by dialysis against water and cross-linked by squaric acid•The hydrogels cross-linked by SqAc are stiffer of and more resistant to enzymatic degradation.•The use of SqAc does not affect the cellular response on the collagen/elastin gels.•The SqAc is a safe cross-linking agent for protein materials.