Zwitterionic modification of ultrasmall iron oxide nanoparticles for reduced protein corona formation

Karina Pombo-García, Carmen L. Rühl, Raymond Lam, Jose A Barreto, Ching-Seng Ang, Peter J Scammells, Peter Comba, Leone Spiccia, Bim Graham, Tanmaya Joshi, Holger Stephan

Research output: Contribution to journalArticleResearchpeer-review

13 Citations (Scopus)


Polyacrylic-acid-coated ultra-small super-paramagnetic iron oxide nanoparticles were surface-modified with low-molecular-weight sulfobetaines or 3-(diethylamino)propylamine in order to generate nanoparticles with zwitterionic character (ZW-NPs). The ZW-NPs proved highly resistant to serum protein corona formation invitro, as revealed by atomic force microscopy, SDS-PAGE and proteomics analysis, and exhibited low cytotoxicity towards A431 and HEK293 cells. The presence of unreacted carboxylic acid groups enabled additional functionalization with fluorescent (Cy5) and radioactive [64Cu-dmptacn; dmptacn=1,4-bis(2-pyridinylmethyl)-1,4,7-triazacyclononane] moieties. Overall, the ZW-NPs represent promising platforms for the development of new multimodal diagnostic/therapeutic agents possessing "stealth" properties.

Original languageEnglish
Pages (from-to)638–646
Number of pages9
Issue number4
Publication statusPublished - 2017


  • Iron oxide nanoparticles
  • Multimodal imaging
  • Protein corona
  • Proteomics
  • Zwitterions

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