BC polymer with and without hydroxyapatite promotes ALP activity. Following culture onto BC polymers ALP activity was measured by alkaline phosphatase substrate p-NPP. Different levels of ALP activity were observed in the range of 5 to 9 mM with the hydroxyapatite rich BC polymers; compared with the BC polymer without hydroxyapatite. Data were presented as the mean + S.D. (n = 4).