Evidence for a direct interaction between poly-dispersed single-wall carbon nanotubes and murine erythrocytes resulting in in vitro and in vivo cytotoxicity

S. Sachar, R.K. Saxena
Jawaharlal Nehru University, IN

Keywords: SWCNTs, erythrocytes, toxicity


Single wall Carbon Nanotubes (SWCNTs) are highly hydrophobic in nature and agglomerate strongly. Treatment of SWCNTs with sulphuric and nitric acid (acid functionalization) results in the introduction of carboxy and sulfonate groups on SWCNTs and deagglomerate them. In the present study, effect of AF-SWCNTs on murine erythroid system was examined. Incubation of erythrocytes with AF-SWCNTs but not with SWCNTs resulted in phosphatidylserine externalization and progressive lysis of erythrocytes. Uptake of AF-SWCNTs by reticulocytes and erythrocytes in vitro was shown by using fluorescent probe tagged AF-SWCNT by flow cytometry and con-focal microscopy. Intravenous administration of AF-SWCNTs resulted in a significant yet transient anemia as seen by a sharp decline in blood erythrocyte count accompanied with a significant drop in blood haemoglobin level. By using the technique of a two-step in vivo biotinylation of erythrocytes that enables simultaneous enumeration of young (age <10 days) and old (age>40 days) erythrocytes in mouse blood, in vivo toxic effect of AF-SWCNTs was found to be more pronounced on older than the younger subpopulation of erythrocytes. Taken together our study indicates that AF-SWCNTs are internalized by erythrocytes and appear to have a direct cytotoxic effect in vitro and induce transient anemia in mice in vivo.