In vitro exposure
STERILE
PM samples were resuspended in DMSO (20 µL/mg PM) 30 min before exposure, sterile distilled water was added to make the stock concentration (5 mg/mL). Samples were then sonicated for 30 min at room temperature to obtain a homogenous mixture. Cell lines were exposed to WSP at four different concentrations: 38, 75, 150 or 300 µg/mL for 6 h at 37 °C, 5% CO