Figure 5.

Relationship between the effective cell modulus, E_cell, and the predicted cell strain in compressed 1% and 3% agarose enables analysis of temporal changes in cell mechanics. (a) The influence of E_cell on the cell strain estimated using the linear elastic model. The hyperelastic Ogden model produced accurate estimates of cell strain in 1% agarose (14%) when optimized to experimental data for cells cultured for 24 h in alginate. However, the Ogden model overestimated the cell strain in 3% agarose (31%), suggesting that the modulus in 3% agarose may be substantially larger than that predicted in the softer alginate. The linear elastic models best match the experimental cell strain values in 1% and 3% agarose at moduli of 5.3 kPa and 20 kPa, respectively. (b) The relationship between modulus and cell strain may be used to derive the temporal changes in cell mechanics for chondrocytes in 1% and 3% agarose after 1 h and 24 h in culture. Values represent mean cell moduli ±SD based on the mean experimental cell strain values at 20% gross compression.