In vivo magnetic enrichment and multiplex photoacoustic detection of circulating tumour cells

Nat Nanotechnol. 2009 Dec;4(12):855-60. doi: 10.1038/nnano.2009.333. Epub 2009 Nov 15.


The spread of cancer cells between organs, a process known as metastasis, is the cause of most cancer deaths. Detecting circulating tumour cells -- a common marker for the development of metastasis -- is difficult because ex vivo methods are not sensitive enough owing to limited blood sample volume and in vivo diagnosis is time-consuming as large volumes of blood must be analysed. Here, we show a way to magnetically capture circulating tumour cells in the bloodstream of mice followed by rapid photoacoustic detection. Magnetic nanoparticles, which were functionalized to target a receptor commonly found in breast cancer cells, bound and captured circulating tumour cells under a magnet. To improve detection sensitivity and specificity, gold-plated carbon nanotubes conjugated with folic acid were used as a second contrast agent for photoacoustic imaging. By integrating in vivo multiplex targeting, magnetic enrichment, signal amplification and multicolour recognition, our approach allows circulating tumour cells to be concentrated from a large volume of blood in the vessels of tumour-bearing mice, and this could have potential for the early diagnosis of cancer and the prevention of metastasis in humans.

Publication types

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

MeSH terms

  • Acoustics*
  • Animals
  • Cell Line, Tumor
  • Early Detection of Cancer / methods*
  • Humans
  • Light*
  • Magnetics / methods*
  • Mice
  • Molecular Mimicry
  • Nanoparticles
  • Neoplasm Metastasis / diagnosis*
  • Neoplasm Metastasis / pathology
  • Neoplasms / pathology
  • Neoplastic Cells, Circulating / pathology*
  • Rheology