Table 2.

Effects of temperature on the copper accumulation and the viability of NP-exposed C6 glioma cells

	Cellular LDH activity (% of initial)		Specific cellular copper content (nmol/mg protein)
	37 °C	4 °C	37 °C	4 °C
Control	97 ± 1	90 ± 4	0.03 ± 0.01	0.08 ± 0.1
CuO-NPs	7 ± 4	86 ± 7##	532 ± 65	102 ± 23##
CuO-Fe-NPs	18 ± 9	90 ± 4##	457 ± 46	88 ± 6##

C6 cells were incubated without (control) or with 1 mM CuO-NPs or CuO-Fe-NPs in IB-BSA for 30 min at 37 °C or 4 °C before the cellular LDH activity and specific cellular copper contents were determined. The data shown represent means ± SD of values obtained in three independent experiments. Hashes indicate the significance of differences of data from cells that had been treated at 37 °C or at 4 °C (^##p < 0.01; paired t test)