1. National Centre for the Replacement, Refinement & Reduction of Animals in Research, 20 Park Crescent, London, W1B 1AL, UK.
2. University College London, UCL Tissue Repair & Engineering Centre (TREC), Institute of Orthopaedics, Royal National Orthopaedic Hospital, Stanmore, HA7 4LP, UK.
3. Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.