Abstract
Many studies have examined carbon nanomaterials (CNMs) as biomaterials for medical application. However, CNMs introduced into the living body may accumulate in lymph nodes to exert unknown cellular effects. This study evaluated the cellular response of human lymphatic endothelial cells (HLECs) derived from lymph nodes to CNMs.
Four CNMs (untreated carbon nanohorns [CNHs], oxidized CNHs [oxCNHs]), carbon black [CB], and multi-walled carbon nanotubes [MWCNTs]) were assessed for cellular responses in HLECs in terms of cytotoxicity, intracellular uptake, and inflammatory reactions.
In cytotoxicity tests, cell viability was significantly reduced in the MWCNT group at concentrations of 50 and 100 μg/mL after 48 h exposure as compared with the dispersant-only control group. Regarding cellular uptake, transmission electron microscopy and fluorescence microscopy revealed that all CNMs were localized in lysosomes for degradation. Quantitative evaluation of cellular uptake showed the highest levels for the MWCNT group (MWCNT>CB>oxCNH>CNH). In inflammatory response assessments, exposure to MWCNTs at a concentration of 100 μg/mL significantly increased the expression of IL-6, CCL5, CXCL8, and TNF versus the control group.
The above results suggested that whereas all CNMs were taken up by HLECs, none except MWCNTs showed short-term effects on the lymphatic system. Further evaluation of the impact of CNMs accumulated in cells is needed.
