Effects of Double-Walled and Multi-Walled Carbon Nanotubes on Primary Immune Cells In Vitro

The effects of DWCNTs and MWCNTs on primary immune cells in vitro were studied at cell level. The results indicated that DWCNTs (1, 10, 25, and 50μg/mL) promoted the proliferation of the spleen cells. MWCNTs had no significant effect on the proliferation of the spleen cells at concentrations of 1, 10, and 10μg/mL, but promoted the proliferation at concentration of 25μg/mL. DWCNTs (1, 10 25, and 50μg/mL) promoted the proliferation of T lymphoid cells stimulated by ConA, MWCNTs (1 and 10μg/mL) also promoted the proliferation of T lymphoid cells stimulated by ConA, but had no significant effect on the proliferation of T lymphoid cells stimulated by ConA at concentrations of 25 and 50μg/mL. DWCNTs and MWCNTs promoted the proliferation of B lymphoid cells stimulated by LPS at concentrations of 10, 25, and 50μg/mL, but had no significant effect on the proliferation of B lymphoid cells stimulated by LPS at concentration of of 1μg/mL. DWCNTs significantly promoted NK cell activity at concentrations of 1 and 10μg/mL, but turned to inhibit NK cell activity at concentrations of 25 and 50μg/mL. MWCNTs significantly promoted NK cell activity at concentration of 1μg/mL, then had no effect NK cell activity at concentration of 10μg/mL, but turned to inhibit NK cell activity at concentrations of 25 and 50μg/mL. The results suggest that the effects of CNTs on primary immune cells in vitro depend on their species and size, moreover, they are pivotal factors for switching the biological effects of CNTs from toxicity to activity, from damage to protection, or from down-regulation to up-regulation.