Characterization of magnetic nanoparticles for magnetic particle spectroscopy-based sensitive cell quantification

In the era of precision medicine, cell-based therapy is one of the most promising techniques to fight against cancer cells or for the regeneration of diseased tissues/organs. In cell-based therapy, sensitive and quantitative detection of cells is of great importance and interest to understand the behavior of the cells in vivo. Existing techniques, including magnetic resonance imaging, X-ray computed tomography and optical imaging, suffer from some limitation on sensitive cell quantification. In this paper, we report on the approach of sensitive and quantitative detection of magnetic nanoparticle (MNP)-labelled cells with magnetic particle spectroscopy (MPS). The influence of the MNP dynamics on the MPS signal of the MNPs is investigated and analyzed. Finally, the MPS signal of the MNPs is measured to quantify cell amount with a limit-of-detection of 200 and with a linearity of better than 98%. The work presented in this paper has great potential for providing a novel tool for in vivo cell detection and tracking during cell-based therapy.