Long term growth of calvarial-derived cells on scaffold proteins. After four weeks under routine culture conditions and in the absence of exogeneous osteogenic factors mineralized matrix was visualized with Alizarin red staining. There was little evidence of mineralised matrix on (a) Tol alone, whilst abundant deposition was observed on (b) Tol-BMP-ST and a small amount on (c) Tol-OP-ST surfaces. Size bar = 400 μm. (d) Image analysis shows significant evidence of mineralised matrix deposition only on Tol-BMP surfaces. Data representative of three independent experiments; results are mean ± SEM; ** P < 0.01. Significance was determined by ANOVA with Tukey post test.