Biophysical, biochemical and biological properties of nanotextured collagen fibres

Abstract

Event Abstract Back to Event Biophysical, biochemical and biological properties of nanotextured collagen fibres Anna Sorushanova1, 2, Anne M. Mullen3, Abhay Pandit2 and Dimitrios I. Zeugolis1, 2 1 NUI Galway, REMODEL, Ireland 2 NUI Galway, CURAM, Ireland 3 Food Research Centre, Teagasc, Ireland Introduction: Through self-assembly, macromolecules with chemical complementarity form supramolecular structures,, which are held together by weak bonds. Thus, exogenous cross-links are required to produce stable constructs. Specifically in collagen-based scaffolds, chemical, physical and/or biological cross-linking methods are under investigation to control the biophysical, biochemical and biological properties of the produced devices[1]-[3]. However, biological and physical methods are not suitable for load-bearing tissues, due to the weak-induced stability, whilst chemical stabilisation methodologies are associated with foreign body response. Although the potential of multi-functional poly(ethylene glycol) systems as stabilisation and functionalisation agents for collagen hydrogels / sponges has been shown[4],[5], it is still unclear whether such agents can induce proportional stability to traditional cross-linking methods, without associated cytotoxicity. Herein, we hypothesise that 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate (PEG) can produce cytocompatible collagen fibres for tendon repair and regeneration, with biophysical, biochemical and biological properties, superior to customarily used chemical approaches. Experimental Methods: Collagen fibres were fabricated and cross-linked with PEG of different concentrations; 0.5mM, 1mM, 2.5mM, 5mM and 10mM. Structural characteristics were assessed with Scanning Electron Microscopy (SEM). Thermal stability was assessed with Differential Scanning Calorimetry (DSC). The extent of cross-linking was assessed with ninhydrin and collagenase assays. Mechanical properties were assessed with tensile testing. In vitro cytocompatibility, protein expression and gene analysis was assessed with human skin fibroblasts, human tenocytes and human bone marrow mesenchymal stem cells (BMSCs) after 3, 7, 14, 21 and 28 days in culture. Morphological analysis was assessed using ImageJ. Non-cross-linked and glutaraldehyde (GTA) cross-linked fibres acted as control. Conclusion: PEG-based fibres were characterised by crevices and ridges running parallel to the longitudinal axis of the fibres. This surface topography induced bidirectional cell attachment, elongation and growth. PEG-based fibres had similar mechanical properties to GTA cross-linked fibres. Further, PEG-based fibres did not induce any cell cytotoxicity, whilst GTA fibres were found to be cytotoxic at the effective concentration. PEG fibres maintained tenocyte phenotype and differentiated BMSCs towards tenogenic lineage. Overall, our data clearly indicate the potential of these fibres for tendon repair and regeneration. ReValueProtein Research Project (Exploration of Irish meat processing streams for Recovery of high Value Protein based ingredients for food and non-food uses, Grant Award No. 11/F/043) is supported by the Department of Agriculture, Food and the Marine (DAFM) under the National Development Plan 2007–2013 funded by the Irish Government.