| Can HARN deposit in the distal lung? | Does the HARN dissolve very slowly in lung lining and/or lysosomal fluid? | Is HARN length > 5 µm? | Is the HARN rigid and maintain a fibrous, needle-like morphology? | Does the HARN cause frustrated phagocytosis? |
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Tier 1 | Estimated Dae based on mean diameter and assumed density of not appropriate for heterogenous HARN | No data from in vitro dissolution studies. MWCNT predicted to be durability based on graphene structure | Size distribution profiles not available. Mean length reported | Diameter of primary particle reported plus supporting SEM images where available | Frustrated phagocytosis not specifically addressed |
Tier 2 | Measured MMAD not reported | No data from intracellular dissolution studies | Size distribution of aerosolized MWCNT not reported | Size distribution of aerosolized MWCNT not reported | No data from 3D granuloma model |
Tier 3 | Deposition after inhalation exposure not reported | Qualitative evidence of biopersistence in lung was available | Â | Qualitative evidence of fibre rigidity for NM-401 and NRCWE006 in BAL macrophages and lung and liver tissue was available | Qualitative evidence of frustrated phagocytosis of NM-401 and NRCWE006 in BAL macrophages was available |