Fig. 5
Cell proliferation and alkaline phosphatase (ALP) activity in three-dimensional (3D) cell culture. Cells (25 × 103) were pipetted into 3D collagen sponge scaffolds and cultured up to 28 days. a Cells were harvested by dissolving the collagen scaffolds with collagenase B and counted thereafter at days 1, 7, 14, 21 and 28. b To measure ALP activity in 3D cultures, the collagen scaffolds were dissolved and cells were harvested. ALP activity was measured spectrophotometrically at 405 nm at days 4, 7, 14 and 21. CTRL control, DIFF differentiation, FCS fetal calf serum, ns not significant, PLP platelet lysate and plasma