Supplementary Fig. 1.

Scanning electron microscopy of the scaffolds after chondrogenic and osteogenic differentiation. Note extracellular matrix (ECM) formation on all scaffolds; arrows point to the edge of the ECM. A) Unmodified scaffolds. B) NH₂ modified scaffolds. C) COOH modified scaffolds in chondrogenic differentiation conditions. D) Unmodified scaffolds. E) NH₂ modified scaffolds. F) COOH modified scaffolds in osteogenic differentiation conditions. Scale bar in A: 200 μm; all images are at the same magnification.