Influence of carboxylic acid functionalization on the cytotoxic effects induced by single wall carbon nanotubes on human endothelial cells (HUVEC)

► SWCNT are toxic for endothelial cells as it is demonstrated by the results obtained with different toxicity biomarkers. ► Functionalization with carboxylic acid has an influence on the toxicity, and COOH-SWCNT are more toxic than SWCNT. ► It is important to know the non-toxic concentrations of CNT, and from 12.5 μg/ml COOH-SWCNT show toxic effects.