OBJECTIVETo compare the toxic effects of three different particles on vascular endothelial cells, and to investigate the influences of particle composition and sizes on the cardiovascular toxic effects.

METHODSNano-SiO2 particles, nano-TiO2 particles, and standard quartz particles were selected as the test substances, and the nano-TiO2 particles and standard quartz particles were used as composition controls and size controls, respectively. The human umbilical vein endothelial cells were exposed to different doses (5.0, 10.0, 20.0, 40.0 µg/ml) of the three particles as well as particle-free DMEM medium (0 µg/ml dust) for 24 h. Then, the culture supernatants were collected, and the activities of lactic dehydrogenase (LDH) and total superoxide dismutase (SOD) as well as the releases of NO, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were measured.

RESULTSCompared with those of 0 µg/ml dose group, the LDH activities of all nano-SiO2 groups, 10.0, 20.0, and 40.0 µg/ml nano-TiO2 groups, and 10.0, 20.0, and 40.0 µg/ml standard quartz groups were significantly increased (P < 0.01); the SOD activities of 5.0, 10.0, and 20.0 µg/ml nano-SiO2 groups, 40.0 µg/ml nano-TiO2 group, and 20.0 and 40.0 µg/ml standard quartz groups were significantly increased (P < 0.05), but that of the 40.0 µg/ml nano-SiO2 group was significantly decreased (P < 0.01); the TNF-α releases of 10.0, 20.0, and 40.0 µg/ml nano-SiO2 groups, all nano-TiO2 groups, and 40.0 µg/ml standard quartz group were significantly increased (P < 0.01); the IL-6 releases of 10.0, 20.0, and 40.0 µg/ml nano-SiO2 groups, 20.0 and 40.0 µg/ml nano-TiO2 groups, and 40 µg/ml standard quartz group were significantly increased (P < 0.01). When the dust doses were 5.0, 10.0, 20.0, and 40.0 µg/ml, the LDH activities of nano-SiO2 groups were significantly higher than those of standard quartz groups (P < 0.05); when the dust doses were 10.0, 20.0, and 40.0 µg/ml, the LDH activities of nano-TiO2 groups were significantly lower than those of standard quartz groups (P < 0.05). When the dust doses were 5.0, 10.0, 20.0, and 40.0 µg/ml, the SOD activities of nano-SiO2 groups were significantly higher than those of standard quartz groups (P < 0.01); when the dust dose was 20 µg/ml, the SOD activity of nano-TiO2 group was significantly higher than that of standard quartz group (P < 0.01). When the dust doses were 5.0, 10.0, 20.0, and 40.0 µg/ml, the TNF-α releases of nano-SiO2 groups were significantly higher than those of standard quartz groups (P < 0.01); when the dust doses were 5.0 and 10.0 µg/ml, the TNF-α releases of nano-TiO2 groups were significantly higher than those of standard quartz groups (P < 0.01). When the dust doses were 5.0, 10.0, 20.0, and 40.0 µg/ml, the IL-6 releases of nano-SiO2 groups were significantly higher than those of standard quartz groups (P < 0.05); when the dust doses were 20 and 40 µg/ml, the IL-6 releases of nano-TiO2 groups were significantly higher than those of standard quartz groups (P < 0.05).

CONCLUSIONAll the three particles are able to exert certain toxic effects on vascular endothelial cells. Nano-SiO2 particles have the most toxic effects, and nano-TiO2 particles and standard quartz particles show uncertain effects. The toxicity of particles is linked to their composition and sizes.