title: Multi-scale mechanical characterization of highly swollen photo-activated collagen hydrogels.
abstract: Biological hydrogels have been increasingly sought after as wound dressings or scaffolds for regenerative medicine, owing to their inherent biofunctionality in biological environments. Especially in moist wound healing, the ideal material should absorb large amounts of wound exudate while remaining mechanically competent in situ. Despite their large hydration, however, current biological hydrogels still leave much to be desired in terms of mechanical properties in physiological conditions. To address this challenge, a multi-scale approach is presented for the synthetic design of cyto-compatible collagen hydrogels with tunable mechanical properties (from the nano- up to the macro-scale), uniquely high swelling ratios and retained (more than 70%) triple helical features. Type I collagen was covalently functionalized with three different monomers, i.e. 4-vinylbenzyl chloride, glycidyl methacrylate and methacrylic anhydride, respectively. Backbone rigidity, hydrogen-bonding capability and degree of functionalization (F: 16 ± 12-91 ± 7 mol%) of introduced moieties governed the structure-property relationships in resulting collagen networks, so that the swelling ratio (SR: 707 ± 51-1996 ± 182 wt%), bulk compressive modulus (Ec: 30 ± 7-168 ± 40 kPa) and atomic force microscopy elastic modulus (EAFM: 16 ± 2-387 ± 66 kPa) were readily adjusted. Because of their remarkably high swelling and mechanical properties, these tunable collagen hydrogels may be further exploited for the design of advanced dressings for chronic wound care.
authors.affiliation: Nonwovens Research Group, School of Design, University of Leeds, Leeds LS2 9JT, UK Biomaterials and Tissue Engineering Research Group, School of Dentistry, University of Leeds, Leeds LS2 9LU, UK g.tronci@leeds.ac.uk.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Tronci
authors.affiliation: Advanced Materials Engineering RKT Centre, School of Engineering, University of Bradford, Bradford BD7 1DP, UK.
authors.forename: Colin A
authors.initials: CA
authors.lastname: Grant
authors.affiliation: Molecular and Nanoscale Physics, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK Biomineralisation Research Group, School of Dentistry, University of Leeds, Leeds LS2 9LU, UK.
authors.forename: Neil H
authors.initials: NH
authors.lastname: Thomson
authors.affiliation: Nonwovens Research Group, School of Design, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Russell
authors.affiliation: Biomaterials and Tissue Engineering Research Group, School of Dentistry, University of Leeds, Leeds LS2 9LU, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Wood
mesh_terms: D000812:Anhydrides / Q000737:chemistry*; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D002460:Cell Line; D003094:Collagen / Q000737:chemistry*; D019245:Compressive Strength; D055119:Elastic Modulus; D004548:Elasticity; D004852:Epoxy Compounds / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry*; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D051379:Mice; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D055668:Photochemical Processes; D011137:Polystyrenes; D011145:Polyvinyls / Q000737:chemistry; D011312:Pressure; D000644:Quaternary Ammonium Compounds; D051381:Rats; D013314:Stress, Mechanical; D013329:Structure-Activity Relationship; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D000812:Anhydrides; D001672:Biocompatible Materials; D004852:Epoxy Compounds; D020100:Hydrogels; D008689:Methacrylates; D011137:Polystyrenes; D011145:Polyvinyls; D000644:Quaternary Ammonium Compounds; C114826:poly(vinylbenzyltrimethylammonium chloride); D003094:Collagen; C080604:polyvinylbenzyl chloride; C007870:glycidyl methacrylate
keywords: atomic force microscopy; collagen; covalent network; functionalization; hydrogel; swelling