title: Collagen/elastin hydrogels cross-linked by squaric acid.
abstract: 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.
authors.affiliation: Faculty of Chemistry, Nicolaus Copernicus University, Gagarina 7, 87-100 Torun, Poland. Electronic address: joanna@chem.umk.pl.
authors.forename: J
authors.initials: J
authors.lastname: Skopinska-Wisniewska
authors.affiliation: Faculty of Chemistry, Nicolaus Copernicus University, Gagarina 7, 87-100 Torun, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Kuderko
authors.affiliation: Collegium Medicum Nicolaus Copernicus University, Karlowicza 24, 85-092 Bydgoszcz, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Bajek
authors.affiliation: Collegium Medicum Nicolaus Copernicus University, Karlowicza 24, 85-092 Bydgoszcz, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Maj
authors.affiliation: Faculty of Chemistry, Nicolaus Copernicus University, Gagarina 7, 87-100 Torun, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Sionkowska
authors.affiliation: Faculty of Chemistry, Nicolaus Copernicus University, Gagarina 7, 87-100 Torun, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Ziegler-Borowska
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D003094:Collagen / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D003503:Cyclobutanes / Q000737:chemistry*; D004549:Elastin / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D003503:Cyclobutanes; D020100:Hydrogels; D003094:Collagen; D004549:Elastin; C030042:squaric acid
keywords: Collagen; Cross-linking; Elastin; Hydrogel; Squaric acid