Figure 5.

Comparsion of the progressive stem cell differentiation (PSCD) model with experimental results for electrically stimulated (blue box) and non-stimulated (red box) cell culture samples after 7, 14, 21 and 28 days. (A) The total number of cells in a scaffold over time. The solid curve is the fit of the analytical solution of PSCD model, given by Equation (7), to the experimental data. (B) The total ALP activity of cells in a scaffold cultivated in the stimulation chamber. The solid curve is the fit of the analytical solution of the PSCD model, given by Equation (9), to the experimental data. Error-bars show the standard deviation in the experimental data. (C) The result of the fit of the PSCD model to the experimental data for the total number of cells suggests that the divison rate k_d of the stem cells in the hMSC population is inversely proportional to the stem cell number density ρ. (D) The result of the fit of the PSCD model to the experimental data for the total ALP activity suggests that the degradation rate of the ALP activity of a cell is inversely proportional to the strength of the applied EF. d_o indicates the rate of osteogenic differentiation.