Mesenchymal Stem Cell Heterogeneity and Ageing In Vitro: A Model Approach - Computational Modeling in Tissue Engineering - page 187

Fig. 5 Simulation results on noise driven MSC differentiation. a Noise-profiles with monoto-
nously increasing f(E): 0 \ f(E) = f 0 \ 1 were applied. b The calculated differentiation profiles
of the MSCs demonstrate accumulation of the cells in differentiated states a [ a d . The amount of
differentiated cells increases with f 0 . c Equilibration of the profiles occurs on the scale of a few
days. Shown are snapshots of a fast equilibrating system with 1/s = 0 after switching f(E) from 0
to 1 (time steps Dt = 3 h). Eventually all cells accumulate in the fully differentiated state (bin:
0.95 \ a \ 1.00). Except for the first profile at 3h (+) its fraction exceeds 0.2. d The normalised
entropy of the a-distributions strongly decreases if f(E) gets close to one. For 1/s = 11 h (dark
grey) the systems equilibrate as shown in b. For 1/s = 0(light grey) the tendency to differentiate
is more pronounced and more homogeneous populations are formed
depend or even require such interactions [ 93 ]. A well known control mechanism of
proliferation based on cell-cell interaction is contact inhibition of growth.
According to this mechanism cells that form close contacts stop proliferation.
Preventing this phenomenon by applying sophisticated culture conditions can
significantly enlarge cell culture harvest [ 57 ].
In order to consider such regulation individual cell-based models of cell
populations have been established [ 26 , 32 , 33 ]. In these models each individual
cell is described by a physical object that can deform, adhere to other cells or a