Phosphatidylserine targets single-walled carbon nanotubes to professional phagocytes in vitro and in vivo

PLoS One. 2009;4(2):e4398. doi: 10.1371/journal.pone.0004398. Epub 2009 Feb 9.

Abstract

Broad applications of single-walled carbon nanotubes (SWCNT) dictate the necessity to better understand their health effects. Poor recognition of non-functionalized SWCNT by phagocytes is prohibitive towards controlling their biological action. We report that SWCNT coating with a phospholipid "eat-me" signal, phosphatidylserine (PS), makes them recognizable in vitro by different phagocytic cells - murine RAW264.7 macrophages, primary monocyte-derived human macrophages, dendritic cells, and rat brain microglia. Macrophage uptake of PS-coated nanotubes was suppressed by the PS-binding protein, Annexin V, and endocytosis inhibitors, and changed the pattern of pro- and anti-inflammatory cytokine secretion. Loading of PS-coated SWCNT with pro-apoptotic cargo (cytochrome c) allowed for the targeted killing of RAW264.7 macrophages. In vivo aspiration of PS-coated SWCNT stimulated their uptake by lung alveolar macrophages in mice. Thus, PS-coating can be utilized for targeted delivery of SWCNT with specified cargoes into professional phagocytes, hence for therapeutic regulation of specific populations of immune-competent cells.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Female
  • Flow Cytometry
  • HeLa Cells
  • Humans
  • In Vitro Techniques
  • Macrophages / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Microscopy, Electron, Scanning
  • Microscopy, Electron, Transmission
  • Nanotubes, Carbon / chemistry*
  • Nanotubes, Carbon / toxicity
  • Phagocytes / metabolism*
  • Phosphatidylserines / chemistry*
  • Phosphatidylserines / metabolism
  • Rats

Substances

  • Nanotubes, Carbon
  • Phosphatidylserines