Structure-property-function relationships in triple-helical collagen hydrogels
- PDF / 212,197 Bytes
- 6 Pages / 432 x 648 pts Page_size
- 82 Downloads / 208 Views
Structure-property-function relationships in triple-helical collagen hydrogels Giuseppe Tronci,1,2 Amanda Doyle,1,2 Stephen J. Russell,2 and David J. Wood1 1 Biomaterials and Tissue Engineering Research Group, Leeds Dental Institute, University of Leeds, Leeds LS2 9LU, United Kingdom 2 Nonwoven Research Group, Centre for Technical Textiles, University of Leeds, Leeds LS2 9JT, United Kingdom ABSTRACT In order to establish defined biomimetic systems, type I collagen was functionalised with 1,3-Phenylenediacetic acid (Ph) as aromatic, bifunctional segment. Following investigation on molecular organization and macroscopic properties, material functionalities, i.e. degradability and bioactivity, were addressed, aiming at elucidating the potential of this collagen system as mineralization template. Functionalised collagen hydrogels demonstrated a preserved triple helix conformation. Decreased swelling ratio and increased thermo-mechanical properties were observed in comparison to state-of-the-art carbodiimide (EDC)-crosslinked collagen controls. Ph-crosslinked samples displayed no optical damage and only a slight mass decrease (~ 4 wt.-%) following 1-week incubation in simulated body fluid (SBF), while nearly 50 wt.-% degradation was observed in EDC-crosslinked collagen. SEM/EDS revealed amorphous mineral deposition, whereby increased calcium phosphate ratio was suggested in hydrogels with increased Ph content. This investigation provides valuable insights for the synthesis of triple helical collagen materials with enhanced macroscopic properties and controlled degradation. In light of these features, this system will be applied for the design of tissue-like scaffolds for mineralized tissue formation. INTRODUCTION Collagen is the main protein of the human body, ruling structure, function and shape of biological tissues. Also in light of its unique molecular organization, collagen has been widely applied for the design of vascular grafts [1], fibrous materials for stem cell differentiation [2], biomimetic scaffolds for regenerative medicine [3], and tissue-like matrices for hard tissue repair [4]. However, collagen properties are challenging to control in physiological conditions, mainly because its hierarchical organization and chemical composition in vivo can only be partially reproduced in vitro. Functionalisation and crosslinking of collagen molecules, e.g. via carbodiimide [5,6], glutaraldehyde [7,8] or hexamethylene diisocyanate [9], have proved to enhance macroscopic properties in aqueous environment, although much is still left to do to establish biomimetic systems with defined structure-property-function relationships. Here, the design of type I collagen hydrogels was investigated via covalent lysine functionalisation with 1,3-Phenylenediacetic acid (Ph). It was hypothesized that incorporation of a stiff, aromatic segment among collagen molecules could offer a novel synthetic route to the formation of mechanically-relevant materials. Ph was selected as bifunctional segment, in order to promote crosslinking of dist
Data Loading...
