1. Tissue Engineering Centre, Imperial College School of Medicine, London SW10 9NH, UK., and Department of Histochemistry, Imperial College School of Medicine, London W12 0NN, UK.
2. Tissue Engineering Centre, Imperial College School of Medicine, London SW10 9NH, UK., and Department of Histochemistry, Imperial College School of Medicine, London W12 0NN, UK
3. Tissue Engineering Centre, Imperial College School of Medicine, London SW10 9NH, UK.
4. Mammalian Neurogenesis Group, MRC Clinical Sciences Centre, London W12, UK.
5. Department of Periodontology, Royal London and St. Bartholomew's School of Medicine, London EC1 2AD. UK.
6. Department of Orthopaedic and Trauma Surgery, Imperial College School of Medicine, London W6 8RF, UK.