Fig. 2

Exposure of cells at the ALI to aerosols of NMs. Cells at the ALI in inserts were exposed simultaneously to aerosols of NMs or to air in two different VitroCell® exposure chambers. NM aerosols were generated at a 5 L/min flow rate by nebulization of suspensions using a nebulizer. Aerosols were dried using a dryer to reduce relative humidity to 90 %. The aerosols were sucked using a vacuum pump to allow the NM deposition on the cells. At the cell level, the flow rate was reduced to 5 mL/min/well using flow controllers to prevent cell damage. Aerosols were characterized in real time using a SMPS and a COP, to assess the size distribution and by gravimetric measurements, to assess the mass concentration. The deposition of NMs on the cells was assessed by performing QCM and ICP-MS measurements and TEM analysis, to assess the mass, shape, size and distribution of the NMs on the cells