Figure 3. Scaling of cell volume, traction force, and strain energy with the number of interacting microposts in mechanically homogeneous arrays.
(A) Cumulative frequency distribution of the number of posts (npost) contacted by MSCs cultured for 24h in 4 kPa or 20 kPa arrays. The npost Mean ± SD: 4 kPa = 3.78 ± 1.97; 20 kPa = 3.02 ± 1.48. (B) Scaling of cell volume with npost. (C) Scaling of traction force (i) per cell, (ii) per post with npost. (D) Scaling of strain energy (i) per cell, (ii) per post with npost. For (B)-(D), All data points were fitted to a power law equation, Y = A0 + A.npostα. Values for each graph in terms of (A0, A, α): (B) 4 kPa = (4000, 752.6, 1.7), 20 kPa = (4000, 510.4, 1.7); (C, i) 4 kPa = (0, 2.2, 2.2), 20 kPa = (0, 13.1, 1.8); (C, ii) 4 kPa = (0, 2.0, 1.3), 20 kPa = (0, 23.8, 0.6); (D, i) 4 kPa = (0, 4.5, 2.0), 20 kPa = (0, 3.7, 2.2); (D, ii) 4 kPa = (0, 3.5, 1.3), 20 kPa = (0, 6.8, 0.7). All error bars represent 95% confidence intervals. n ≥ 94 cells pooled from 2 donors for each E array, grouped based on npost.