Fig. 5
From: Quantitative characterization of 3D bioprinted structural elements under cell generated forces
Determining cell generated stress from instability thresholds and axial contraction. a We tune the average cell-generated stress within microbeams by varying cell volume fraction, ϕ, at constant collagen concentration (2 mg/mL) and microgel shear modulus (0.46 Pa). Beams with ϕ < 0.03 do not buckle; data from sparse beams are marked undetermined as buckling is not observed but difficult to rule-out. Low aspect ratio beams (L/D < 10) remain straight. (separate measurements displayed: n = 36 buckled, n = 11 stable, and n = 8 undetermined data points.) b We estimate the average stress generated by single cells, σcell, in beams that buckle, break-up, and contract. Most data points follow a scaling law relating σcell to E that nearly extrapolates to 2D and 3D traction force microscopy data. Error bars correspond to ±standard deviation of repeated measurements. (separate measurements displayed: n = 5 GL261 buckling, n = 3 GL261 breakup, n = 4 GL261 contraction, n = 1 3t3 buckling, n = 2 3t3 contraction; literature data: n = 11 2D, and n = 3 3D.)
