[1] Tigenix Ltd, Cambridge CB4 0WZ, England
[2] Univ Cambridge, Dept Mat Sci & Met, Cambridge CB2 3QZ, England
[3] Univ Cambridge, Addenbrookes Hosp, Orthopaed Res Unit, Cambridge CB2 2QQ, England
[4] Natl Univ Ireland Galway, Network Excellence Funct Biomat NFB, Galway, Ireland