Fig. 3.

Simulation of the static culture with diffusion barrier

(A) Scheme of the barrier structure with HSPG. (B) Scheme of the simulation. The cells are placed at the bottom (y = 0), which is covered with the culture medium (y > 0). Each square is 20 μm by 20 μm. Striped area is barrier-like structure where the diffusion is slow. Diffusion constants of Noggin, BMP4, and Noggin-BMP4 are 1/400 in the diffusion barrier.

(CD) Scatter plot of [N (barrier thickness < y < y_max)] and total exposed BMP4 at t = 72 h when the barrier-like structure was applied from y = 0 to 0 (no barrier), 40, 80, 160, and 320 μm and not applied. The diffusion in the barrier was set to 1/400 in B and 1/1000 in C. Vertical dotted line indicates the threshold of cell differentiation. Horizontal dotted line indicates [N (barrier thickness < y < y_max)]. The concentration was 10 ng/mL and the medium volume was 200 μL.