3.9.2. Proliferation Assay

Samples (n = 4) were cut into disks of 2 cm diameter, sterilized with UV-C irradiation (λ = 254 nm, 2.5 min on each side, 80 W) and placed in non-treated 24-well plates. Scaffolds were kept in a fixed position with the use of O-rings. L929 cells were seeded on top of the scaffolds at 8.10<sup>4</sup> cells per well and were placed at 37 ◦C and 5% CO2.. The number of cells was assessed after 1, 2, 3, 4 and 7 days of contact with the scaffolds using a PrestoBue assay that evaluates the transformation of weakly fluorescent blue resazurin into highly fluorescent red resorufin through the mitochondrial activity of the cell. Briefly, this reagen<sup>t</sup> was placed at a volume ratio of 1:10 in each well and incubated in the dark for 40 min at 37 ◦C. Fluorescence intensity was then read in a CLARIOstar® microplate reader (wavelength: excitation 558 nm, emission 590 nm). After each measurement, the supernatant was replaced with fresh medium to continue the cell culture until day 7.
