Figure 1. Mechanical stress accumulates around growing tumor spheroids.

(A) A growing spheroid (green) and its surrounding micro-beads (red). Scale bar = 100 µm. (B) Quantification of relative micro-bead density (ρ _bead) in 10-µm thick shells of agarose gel around the growing spheroid shown in A as a function of the distance of the shell from spheroid center (dist). (C) Correlation between spheroid diameter (D_sphd) and the strain in the first 10-µm thick shell of agarose gel (ε _gel,1) around spheroids. R is the linear regression coefficient; slope of the regression line is significantly greater than zero (p<0.0001).