2.1 Chemicals.
HAuCl4, and KCl used for Zeta potential measurements were purchased from Sigma-Aldrich (Milan, Italy). The Snail Slime was received from the Società Agricola Dap, di Francesco Paolo Perrotta & C. S.a.s - via Diego Rapolla, - 85029 Venosa (Potenza, Basilicata, Italy). NCTC2544 human keratynocytes and RAW 264.7 macrophages were obtained from American Type Culture Collection (ATCC, Rockville, MD) and maintained at 37°C in DMEM media (Eurclone) in a humidified 5% CO2 incubator maintained at 37°C (Thermo Scientific, Waltham, MA). For RAW 264.7 cells, the complete media contained L-glutamine, 100 U penicillin or streptomycin/ml, and 10% inactivated fetal calf serum (FBS, Euroclone). In the LPS stimulated macrophage experiments, RAW 264.7 cells were pre-treated overnight with 1μg LPS/mL. The day after, the LPS was removed and the cells replaced with fresh media in presence of AuNPs-SS.