OBJECTIVETo observe the effect of nano-alumina on nerve cell viability through different detection kits of cell viability, using micro-alumina and nano-carbon as controls.

METHODSPrimary culturing nerve cells of mouse in vitro, which were exposed to 7 doses of 0 µmol/L, 62.5 µmol/L, 125.0 µmol/L, 250.0 µmol/L, 500.0 µmol/L, 1.0 mmol/L, 2.0 mmol/L concentrations of nano-alumina (nano-Al), micro alumina (micro-Al) and nano-carbon (nano-C), detecting cell viability (A(570) values) with CCK-8, MTT and LDH methods.

RESULTS(1) The results of CCK-8 kit showed that, in doses of 250.0 µmol/L - 2.0 mmol/L, the cell viability values of nano-alumina (the values of A(570) were 0.878 ± 0.009, 0.823 ± 0.016, 0.647 ± 0.008, 0.594 ± 0.013, respectively) were significantly lower than that of micro-Al (the values of A(570) were 0.960 ± 0.008, 0.951 ± 0.036, 0.833 ± 0.008, 0.708 ± 0.012, respectively) and nano-C (the values of A(570) were 0.977 ± 0.003, 0.973 ± 0.002, 0.924 ± 0.006, 0.891 ± 0.023, respectively). While, comparing nano-Al with the same dose of micro-Al, there was significant difference (the t values were -0.082, -0.128, -0.186, -0.114, respectively, P < 0.01), and so as to the comparison of nano-Al with the same dose of nano-C (the t values were -0.099, -0.150, -0.277, -0.297, respectively, P < 0.01). (2) MTT results showed that in the doses of 500.0 µmol/L and 1.0 mmol/L, the cell viability of nano-Al (the values of A(570) were 0.648 ± 0.095 and 0.575 ± 0.061) were lower than that of micro-Al (the values of A(570) were 0.830 ± 0.044 and 0.816 ± 0.014) and nano-C (the values of A(570) were 0.889 ± 0.009 and 0.765 ± 0.049), and the differences were significant (nano-Al compared with the same dose of micro-Al, the t values were -0.183 and -0.242, P < 0.01; nano-Al compared with the same dose of nano-C, the t values were -0.241 and -0.190, P < 0.01). (3) LDH results showed that in the dose from 125.0 µmol/L to 2.0 mmol/L, the LDH release of nano-Al group (the values of A(570) were 1.862 ± 0.102, 1.905 ± 0.066, 1.930 ± 0.037, 1.946 ± 0.033, 1.967 ± 0.068, respectively) were higher than that of nano-C (the values of A(570) were 1.484 ± 0.110, 1.559 ± 0.039, 1.663 ± 0.014, 1.732 ± 0.076, 1.765 ± 0.073, respectively), and the differences were significant (the t values were -0.377, 0.346, 0.266, 0.213, 0.202, respectively, P < 0.01). In the dose from 125.0 µmol/L to 1.0 mmol/L, the LDH release of nano-Al group were higher than that of micro-Al (the values of A(570) were 1.578 ± 0.011, 1.639 ± 0.025, 1.727 ± 0.024, 1.808 ± 0.020, respectively), and the differences were significant (the t values were 0.284, 0.266, 0.202, 0.172, respectively, P < 0.01).

CONCLUSIONThe toxicity of nano-Al is greater than nano-C and micro-Al on the viability of nerve cells; LDH is more suitable for detecting changes of cell viability after the effect of nano-materials than CCK-8 and MTT.