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.