title: Design of an elasticized collagen scaffold: A method to induce elasticity in a rigid protein.
abstract: Type I collagen is widely applied as a biomaterial for tissue regeneration. In the extracellular matrix, collagen provides strength but not elasticity under large deformations, a characteristic crucial for dynamic organs and generally imparted by elastic fibers. In this study, a methodology is described to induce elastic-like characteristics in a scaffold consisting of solely type I collagen. Tubular scaffolds are prepared from collagen fibrils by a casting, molding, freezing and lyophilization process. The lyophilized constructs are compressed, corrugated and subsequently chemically crosslinked with carbodiimide in the corrugated position. This procedure induces elastic-like properties in the scaffolds that could be repeatedly stretched five times their original length for at least 1000 cycles. The induced elasticity is entropy driven and can be explained by the introduction of hydrophobic patches that are disrupted upon stretching thus increasing the hydrophobic-hydrophilic interface. The scaffolds are cytocompatible as demonstrated by fibroblast cell culture. In conclusion, a new straightforward technique is described to endow unique elastic characteristics to scaffolds prepared from type I collagen alone. Scaffolds may be useful for engineering of dynamic tissues such as blood vessels, ligaments, and lung.
  
  
  
  In this research report, a methodology is presented to introduce elasticity to biomaterials consisting of only type I collagen fibrils. The method comprises physical compression and corrugation in combination with chemical crosslinking. By introducing elasticity to collagen biomaterials, their application in regenerative medicine may be expanded to dynamic organs such as blood vessels, ligaments and lung. The combination of strength and elasticity in one single natural biomaterial may also "simplify" the design of new scaffolds.
authors.affiliation: Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein 26-28, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Luuk.Versteegden@radboudumc.nl.
authors.forename: Luuk R
authors.initials: LR
authors.lastname: Versteegden
authors.affiliation: Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein 26-28, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Henk@Hoogenkamp.eu.
authors.forename: Henk R
authors.initials: HR
authors.lastname: Hoogenkamp
authors.affiliation: Department of Surgery, Radboud University Medical Center, Geert Grooteplein 26-28, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Roger.Lomme@radboudumc.nl.
authors.forename: Roger M
authors.initials: RM
authors.lastname: Lomme
authors.affiliation: Department of Surgery, Radboud University Medical Center, Geert Grooteplein 26-28, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Harry.vanGoor@radboudumc.nl.
authors.forename: Harry
authors.initials: H
authors.lastname: van Goor
authors.affiliation: Department of Urology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein 26-28, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Dorien.Tiemessen@radboudumc.nl.
authors.forename: Dorien M
authors.initials: DM
authors.lastname: Tiemessen
authors.affiliation: Department of Urology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein 26-28, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Paul.Geutjes@radboudumc.nl.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Geutjes
authors.affiliation: Department of Urology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein 26-28, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Egbert.Oosterwijk@radboudumc.nl.
authors.forename: Egbert
authors.initials: E
authors.lastname: Oosterwijk
authors.affiliation: Department of Urology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein 26-28, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Wout.Feitz@radboudumc.nl.
authors.forename: Wout F
authors.initials: WF
authors.lastname: Feitz
authors.affiliation: Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein 26-28, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Theo.Hafmans@radboudumc.nl.
authors.forename: Theo G
authors.initials: TG
authors.lastname: Hafmans
authors.affiliation: Department of Orthopedics, Radboud University Medical Center, Geert Grooteplein 26-28, PO Box 9101, 6500 HB Nijmegen, The Netherlands; Department of Biomechanical Engineering, University of Twente, Drienerlolaan 5, PO Box 217, 7500 AE Enschede, The Netherlands. Electronic address: Nico.Verdonschot@radboudumc.nl.
authors.forename: Nico
authors.initials: N
authors.lastname: Verdonschot
authors.affiliation: Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein 26-28, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Willeke.Daamen@radboudumc.nl.
authors.forename: Willeke F
authors.initials: WF
authors.lastname: Daamen
authors.affiliation: Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein 26-28, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Toin.vanKuppevelt@radboudumc.nl.
authors.forename: Toin H
authors.initials: TH
authors.lastname: van Kuppevelt
mesh_terms: D000818:Animals; D002417:Cattle; D016923:Cell Death; D003094:Collagen / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D004548:Elasticity; D008422:Materials Testing; D051379:Mice; D041681:NIH 3T3 Cells; D016062:Porosity; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D003432:Cross-Linking Reagents; D003094:Collagen
keywords: Biomaterial; Collagen; Compression; Crosslinking; Elasticity; Regenerative medicine