*2.7. Cell Cultures and Treatments*

Human Keratynocytes cell lines (HaCat) were grown in Dulbecco's Modified Eagle Medium DMEM, supplemented with 10% (*v*/*v*) heat-inactivated FBS, penicillin 100 U/mL and streptomycin 100 µg/mL (Sigma Aldrich, MI, USA). The cells were grown on tissue culture plates (BD Bioscience-Falcon, San Jose, CA, USA), in a humidified atmosphere (95% air and 5% CO2, *v*/*v*) at 37 ◦C.

UF\_Ret20Pow whey powder was dissolved in ultrapure (bi-distilled) water at a concentration of about 20 g/L (*w*/*v*) and sterilized by microfiltration on 0.22 µm filter devices. The sample was diluted with PBS to a final titer of 2 and 4 g/L before being added to the medium. Opportunely diluted PBS was used as control in the medium. During the wound healing assay, the concentration of FBS in the medium was reduced to 1% *v*/*v* to slow down the migration phenomena that could then be better evaluated.
