3.3.2. Cell Adhesion

Figure 6 shows the average cell distributions of three donors after three and seven days. Because of the differences on the cells quality and viability between donors, the total number of healthy cells varied and it was better to calculate, for each gradient, the distribution in terms of percentages.

The comparison between Figures 4b and 6 demonstrates that, for the SMATed samples, the adhesion was preferentially done in the gradients where the roughness was important (75 and 100% of Nb). For the same roughness (P and S + P samples), the cells seemed to be randomly distributed. After seven days, the distribution trended to be the same for all samples but the nanostructured microstructure decreased the time needed to reach the distribution equilibrium. This indicated that the microstructure modification (dislocations cells, finer grains, etc.) induced by severe plastic deformation only played a role just after adhesion, at the early stage of proliferation.

**Figure 6.** Cells distribution on TiNb after three and seven days.
