The effect of titanium dioxide nanoparticles on pulmonary surfactant function and ultrastructure

Respiratory Research

Table 1 Surface activity evaluated with the pulsating bubble surfactometer.

	Polystyrene NSP	Polystyrene MSP	Quartz MSP
Direct effects - γ _ads [mN/m]
0 μg/ml	29.2 ± 1.5	28.9 ± 2.7	25.9 ± 1.5
50 μg/ml	28.3 ± 1.4	28.3 ± 2.2	25.0 ± 1.6
100 μg/ml	30.8 ± 2.2	28.6 ± 2.3	25.0 ± 2.0
200 μg/ml	32.4 ± 2.1	30.1 ± 3.0	26.3 ± 2.9
500 μg/ml	34.1 ± 2.2**	28.3 ± 2.3	25.2 ± 1.5
Direct effects - γ _min [mN/m]
0 μg/ml	4.0 ± 0.9	2.4 ± 1.2	4.9 ± 0.5
50 μg/ml	5.1 ± 0.9	2.2 ± 0.9	4.1 ± 0.9
100 μg/ml	4.0 ± 1.0	2.8 ± 1.8	4.6 ± 0.8
200 μg/ml	4.7 ± 1.1	3.1 ± 1.3	4.1 ± 0.9
500 μg/ml	6.8 ± 1.2**	3.0 ± 1.5	5.0 ± 0.8
Surface area cycling - γ _ads [mN/m]
Control	27.1 ± 1.5	27.4 ± 2.7	28.1 ± 0.8
0 μg/ml	45.7 ± 1.0	46.4 ± 1.3	43.7 ± 0.8
50 μg/ml	42.4 ± 2.2	43.7 ± 2.2	47.1 ± 0.9
100 μg/ml	47.1 ± 1.3	43.1 ± 0.8	45.8 ± 2.8
200 μg/ml	44.6 ± 2.1	45.3 ± 2.3	45.4 ± 3.1
500 μg/ml	51.4 ± 0.9*	42.7 ± 1.7	48.4 ± 1.5
Surface area cycling - γ _min [mN/m]
Control	1.1 ± 0.2	1.1 ± 0.2	1.2 ± 0.4
0 μg/ml	1.2 ± 0.2	1.1 ± 0.2	1.7 ± 0.4
50 μg/ml	2.1 ± 0.4	1.1 ± 0.4	0.9 ± 0.3
100 μg/ml	1.5 ± 0.5	1.2 ± 0.2	2.1 ± 0.9
200 μg/ml	6.3 ± 2.8	1.8 ± 0.5	2.8 ± 0.7
500 μg/ml	17.5 ± 1.4***	1.9 ± 0.5	1.0 ± 0.3

Direct effects were measured immediately after addition of particles, effects after surface area cycling were measured following 8 hour rotation at 0.43 Hz with or without particles. Adsorption surface tension (γ_ads) was obtained from the value of a static bubble. Surface tension at minimal bubble size (γ_min) was recorded during pulsation. Values are given as means ± SEM of at least 4 experiments. * indicates p values < 0.05; ** indicates p values < 0.01; *** indicates p values < 0.001; all compared with the control without particles (0 μg/ml). In case of surface area cycling, the 0 μg/ml control was rotated for 8 hours at 0.43 Hz. NSP - nanosized particles; MSP - microsized particles.

ISSN: 1465-993X