Toxicity determinants of multi-walled carbon nanotubes: The relationship between functionalization and agglomeration

• DOI: 10.1016/j.toxrep.2016.01.011
• Publication Date: 2016-01-19T15:36:06Z
• Authors: Manfredi Allegri; Dimitrios K. Peri...; Massimiliano G. B...; Martina Chiu; Alessandra Pagliaro; Malamatenia A. Ko...; Aikaterini-Flora ...; Enrico Bergamaschi; Ovidio Bussolati; Constantinos A. C...
• Keywords: Surface Modification; Agglomerate; Viability assay

The elucidation of toxicity determinants multi-walled carbon nanotubes (MWCNT) is still incomplete. Functionalization with carboxyl groups is, however, commonly used to mitigate MWCNT toxicity, although the rationale for mitigating effect has not been fully clarified yet. In this work, two optimized chemical vapor deposition methods were employed obtain comparable length but different diameter, which subsequently functionalized. For diameter larger than 40 nm, no detrimental effects on cell viability macrophages observed, while mild cytotoxicity was recorded diameters between 15 and a functionalization. To investigate factors responsible mitigation, we thinnest preparation models, evaluating several endpoints, such as viability, production nitric oxide (NO), expression pro-inflammatory markers, Trans-Epithelial Electrical Resistance (TEER), clonogenic activity. Substantial mitigation changes caused by pristine observed only carboxyl- also amino-functionalized MWCNT, suggesting that negative or positive surface charge main factor effect. Instead, either functionalized exhibited stronger tendency agglomerate strictly dependent presence proteins. Moreover, found adsorbed amount serum proteins counterparts, distinctive pattern each type MWCNT. We propose, therefore, formation agglomerates, upon protein coronae, contributes biological in protein-rich media.