2012 Volume No 23 – pages 28-40
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Title: Engineering stable topography in dense bio-mimetic 3D collagen scaffolds |
Author: T Alekseeva, E Hadjipanayi, EA Abou Neel, RA Brown |
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Address: University College London, Tissue Repair and Engineering Centre, Institute of Orthopaedics, Stanmore Campus, London, HA7 4LP, UK |
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E-mail: rehkrab at ucl.ac.uk |
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Key Words: Plastic compressed collagen, stable surface topology, micro-moulding, phosphate-based glass fibres |
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Publication date: January 29th 2012 |
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Abstract: Topographic features are well known to influence cell behaviour and can provide a powerful tool for engineering complex, functional tissues. This study aimed to investigate the mechanisms of formation of a stable micro-topography on plastic compressed (PC) collagen gels. The uni-directional fluid flow that accompanies PC of collagen gels creates a fluid leaving surface (FLS) and a non-fluid leaving surface (non-FLS). Here we tested the hypothesis that the resulting anisotropy in collagen density and stiffness between FLS and non-FLS would influence the fidelity and stability of micro-grooves patterned on these surfaces. A pattern template of parallel-aligned glass fibres was introduced to the FLS or non-FLS either at the start of the compression or halfway through, when a dense FLS had already formed. Results showed that both early and late patterning of the FLS generated grooves that had depth (25 ±7 µm and 19 ±8 µm, respectively) and width (55 ±11 µm and 50 ±12 µm, respectively) which matched the glass fibre diameter (50 µm). In contrast, early and late patterning of the non-FLS gave much wider (151 ±50 µm and 89 ±14 µm, respectively) and shallower (10 ±2.7 µm and 13 ±3.5 µm, respectively) grooves than expected. The depth to width ratio of the grooves generated on the FLS remained unaltered under static culture conditions over 2 weeks, indicating that grooves were stable under long term active cell-mediated matrix remodelling. These results indicate that the FLS, characterised by a higher matrix collagen density and stiffness than the non-FLS, provides the most favourable mechanical surface for precise engineering of a stable micro-topography in 3D collagen hydrogel scaffolds. |
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Article download: Pages
28-40 (PDF file) |
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