Biodegradation of single-walled carbon nanotubes by eosinophil peroxidase

Fernando T. Andón, Alexandr A. Kapralov, Naveena Yanamala, Weihong Feng, Arjang Baygan, Benedict J. Chambers, Kjell Hultenby, Fei Ye, Muhammet S. Toprak, Birgit D. Brandner, Andrea Fornara, Judith Klein-Seetharaman, Gregg P. Kotchey, Alexander Star, Anna A. Shvedova, Bengt Fadeel, Valerian E. Kagan

Research output: Contribution to journalArticlepeer-review

104 Scopus citations


Eosinophil peroxidase (EPO) is one of the major oxidant-producing enzymes during inflammatory states in the human lung. The degradation of single-walled carbon nanotubes (SWCNTs) upon incubation with human EPO and H₂O₂ is reported. Biodegradation of SWCNTs is higher in the presence of NaBr, but neither EPO alone nor H₂O₂ alone caused the degradation of nanotubes. Molecular modeling reveals two binding sites for SWCNTs on EPO, one located at the proximal side (same side as the catalytic site) and the other on the distal side of EPO. The oxidized groups on SWCNTs in both cases are stabilized by electrostatic interactions with positively charged residues. Biodegradation of SWCNTs can also be executed in an ex vivo culture system using primary murine eosinophils stimulated to undergo degranulation. Biodegradation is proven by a range of methods including transmission electron microscopy, UV-visible-NIR spectroscopy, Raman spectroscopy, and confocal Raman imaging. Thus, human EPO (in vitro) and ex vivo activated eosinophils mediate biodegradation of SWCNTs: an observation that is relevant to pulmonary responses to these materials.

Original languageEnglish (US)
Pages (from-to)2720-2729
Number of pages10
JournalSmall (Weinheim an der Bergstrasse, Germany)
Issue number16
StatePublished - Aug 26 2013
Externally publishedYes


  • biodegradable materials
  • carbon nanotubes
  • eosinophil peroxidase
  • molecular modeling

ASJC Scopus subject areas

  • General Chemistry
  • Biotechnology
  • General Materials Science
  • Biomaterials


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