Safe-by-design strategies for lowering the genotoxicity and pulmonary inflammation of multiwalled carbon nanotubes: Reduction of length and the introduction of COOH groups

Potentially, the toxicity of multiwalled carbon nanotubes (MWCNTs) can be reduced in a safe-by-design strategy. We investigated if genotoxicity and pulmonary inflammation MWCNTs from same batch were lowered by a) reducing length b) introducing COOH-groups into structure. Mice administered: 1) long pristine MWCNT (CNT-long) (3.9 μm); 2) short CNT (CNT-short) (1 3) modified with high ratio (CNT-COOH-high); 4) low (CNT-COOH-low). dosed intratracheal instillation at 18 or 54 μg/mouse (∼0.9 2.7 mg/kg bw). Neutrophils numbers highest after CNT-long exposure, both shortening addition (day 1 28). Likewise, induced genotoxicity, which was absent CNT-short introduction COOH groups. In conclusion, lowered, but not eliminated, fibres COOH-groups.