Chondrocytic differentiation of mesenchymal stem cells sequentially exposed to transforming growth factor-beta1 in monolayer and insulin-like growth factor-I in a three-dimensional matrix. - Worster,A.A.; Brower-Toland,B.D.; Fortier,L.A.; Bent,S.J.; Williams,J.; Nixon,A.J. (J Orthop Res, 2001)