Figure 4
Biocompatibility of the cell extraction method. (a) Scheme of the experimental design. First, we embedded two different cell types independently in collagen hydrogels (HCT-116 and U-251 MG cells). After 24 hours, cells were extracted from the hydrogels by enzymatic degradation with an 8 mg/ml solution of collagenase in PBS. Recovered cells were washed with PBS and re-embedded in collagen hydrogels. Cell viability was assessed after 72 hours using confocal imaging, the cell nuclei were stained (Hoechst 33342, blue) and a dead cell indicator was added to distinguish dead cells (propidium iodide, red). Results from extracted reseeded cells were compared with non-treated cells (control). Images of the control cells can be observed in (b) for HCT-116 cells and (c) for U-251 MG cells. Images of the recovered and re-embedded cells can be observed in (d) for HCT-116 cells and (e) for U-251 MG cells. (f) Quantification of cell viability for control and extracted and re-embedded cells, for both mentioned cell types used in this study (P-value > 0.67 for HCT-116 cells and p-value > 0.99 for U-251-MG cells as determined via two-way ANOVA and post-hoc Bonferroni test).
