title: Cross-linking of dermal sheep collagen using a water-soluble carbodiimide.
abstract: A cross-linking method for collagen-based biomaterials was developed using the water-soluble carbodiimide 1-ethyl-3-(3-dimethyl aminopropyl)carbodiimide hydrochloride (EDC). Cross-linking using EDC involves the activation of carboxylic acid groups to give O-acylisourea groups, which form cross-links after reaction with free amine groups. Treatment of dermal sheep collagen (DSC) with EDC (E-DSC) resulted in materials with an increased shrinkage temperature (Ts) and a decreased free amine group content, showing that cross-linking occurred. Addition of N-hydroxysuccinimide to the EDC-containing cross-linking solution (E/N-DSC) increased the rate of cross-linking. Cross-linking increased the Ts of non-cross-linked DSC samples from 56 to 73 degrees C for E-DSC and to 86 degrees C for E/N-DSC samples, respectively. For both cross-linking methods a linear relation between the decrease in free amine group content and the increase in Ts was observed. The tensile strength and the high strain modulus of E/N-DSC samples decreased upon cross-linking from 18 to 15 MPa and from 26 to 16 MPa, respectively. The elongation at break of E/N-DSC increased upon cross-linking from 142 to 180%.
authors.affiliation: Department of Chemical Technology, University of Twente, Enschede, The Netherlands.
authors.forename: L H
authors.initials: LH
authors.lastname: Olde Damink
authors.forename: P J
authors.initials: PJ
authors.lastname: Dijkstra
authors.forename: M J
authors.initials: MJ
authors.lastname: van Luyn
authors.forename: P B
authors.initials: PB
authors.lastname: van Wachem
authors.forename: P
authors.initials: P
authors.lastname: Nieuwenhuis
authors.forename: J
authors.initials: J
authors.lastname: Feijen
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry / Q000378:metabolism; D000588:Amines / Q000737:chemistry; D000818:Animals; D001672:Biocompatible Materials; D003094:Collagen / Q000737:chemistry* / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000737:chemistry*; D005022:Ethyldimethylaminopropyl Carbodiimide / Q000737:chemistry* / Q000378:metabolism; D012756:Sheep; D012867:Skin / Q000378:metabolism*; D012995:Solubility; D013388:Succinimides / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D000588:Amines; D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D013388:Succinimides; D014867:Water; C006903:carbopol 940; D003094:Collagen; C001426:N-hydroxysuccinimide; D005022:Ethyldimethylaminopropyl Carbodiimide