title: Inflammatory and hyperalgesic effects of oxidized multi-walled carbon nanotubes in rats.
abstract: We evaluated local inflammatory activity of oxidized multiwalled carbon nanotubes in rat experimental models of acute inflammation (paw edema and hyperalgesia) by analyzing their toxicity in non-mesoendothelial tissues. Subcutaneous injection of the nanotubes induced paw edema, that was maximal in the first 2 h after administration at 0.1 mg/kg (43.25 +/- 3.8 AUC) and 1 mg/kg (30.1 +/- 1.8 AUC) compared to saline (18.32 +/- 02.05 AUC). The histopathological analysis showed acute inflammation characterized by vasodilatation, edema formation, neutrophil infiltrate and tissue damage. The nanotubes also elicited hyperalgesic response, seen by the increase of animal paw withdrawal that was maximal in the first 3 hours. The data obtained at the 3rd h was: 75 +/- 9.3% (0.01 mg/kg), 58 +/- 8.3% (0.1 mg/kg) and 53 +/- 6.69% (1 mg/kg) in relation with saline (28 +/- 3.5%). In conclusion, the oxidized multiwalled carbon nanotubes elicit inflammatory and hyperalgesic effects associated to severe tissue damage in rats.
authors.affiliation: Institute of Biomedical Sciences, State University of Ceara, Av Paranjana, 1700, 60740-000 Fortaleza, CE-Brazil.
authors.forename: Nilson Vieira
authors.initials: NV
authors.lastname: Pinto
authors.forename: Nadia Ferreira
authors.initials: NF
authors.lastname: de Andrade
authors.forename: Diego Stéfani Teodoro
authors.initials: DS
authors.lastname: Martinez
authors.forename: Oswaldo Luiz
authors.initials: OL
authors.lastname: Alves
authors.forename: Antonio Gomes
authors.initials: AG
authors.lastname: Souza Filho
authors.forename: Mário Rogério Lima
authors.initials: MR
authors.lastname: Mota
authors.forename: Kyria Santiago
authors.initials: KS
authors.lastname: Nascimento
authors.forename: Benildo Sousa
authors.initials: BS
authors.lastname: Cavada
authors.forename: Ana Maria Sampaio
authors.initials: AM
authors.lastname: Assreuy
mesh_terms: D000818:Animals; D019540:Area Under Curve; D004487:Edema / Q000473:pathology; D006930:Hyperalgesia / Q000188:drug therapy / Q000378:metabolism*; D007249:Inflammation / Q000188:drug therapy*; D008297:Male; D036103:Nanotechnology / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009504:Neutrophils / Q000378:metabolism; D010100:Oxygen / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D037742:Nanotubes, Carbon; D010100:Oxygen