In vitro toxicity evaluation of engineered cadmium-coated silica nanoparticles on human pulmonary cells

Cytotoxicity of cadmium-containing silica nanoparticles cd-sio 2nps (0.05-100 μg/ml) versus sio2nps and cdcl 2 was evaluated by an in vitro test battery in a549 by assessing (i) mitochondrial function,(ii) membrane integrity/cell morphology,(iii) cell growth/proliferation,(iv) apoptotic pathway,(v) oxidative stress,after short- (24-48 h) and long-term (10 days) exposure. both cd-sio2nps and cdcl2 produced dose-dependent cytotoxic effects: (i) mtt-assay: similar cytotoxicity pattern was observed at both 24 and 48 h,with a more cd-sio2nps pronounced effect than cdcl2. cd-sio 2nps induced mortality (about 50%) at 1 g/ml,cdcl2 at 25 g/ml; (ii) calcein-am/pi staining: decrease in cell viability,noticeable at 25 g/ml,enhanced markedly at 50 and 100 g/ml,after 24 h. cd-sio2nps induced higher mortality than cdcl2 (25% versus 4%,resp.,at 25 g/ml) with further exacerbation after 48h; (iii) clonogenic assay: exposure for longer period (10 days) compromised the a549 proliferative capacity at very low dose (0.05 g/ml); (iv) a progressive activation of caspase-3 immunolabelling was detected already at 1 g/ml; (v) gsh intracellular level was modified by all compounds. in summary,in vitro data demonstrated that both cd-sio 2nps and cdcl2 affected all investigated endpoints,more markedly after cd-sio2nps,while sio2nps influenced gsh only. © 2013 uliana de simone et al.