Physikalisch-Technische Bundesanstalt, Berlin, Germany.
Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Medizinische Klinik für Kardiologie und Angiologie, Campus Mitte, Berlin, Germany.
Sci Rep. 2020 Feb 5;10(1):1922. doi: 10.1038/s41598-020-58853-3.
Magnetic particle imaging (MPI) is a non-invasive, non-ionizing imaging technique for the visualization and quantification of magnetic nanoparticles (MNPs). The technique is especially suitable for cell imaging as it offers zero background contribution from the surrounding tissue, high sensitivity, and good spatial and temporal resolutions. Previous studies have demonstrated that the dynamic magnetic behaviour of MNPs changes during cellular binding and internalization. In this study, we demonstrate how this information is encoded in the MPI imaging signal. Through MPI imaging we are able to discriminate between free and cell-bound MNPs in reconstructed images. This technique was used to image and quantify the changes that occur in-vitro when free MNPs come into contact with cells and undergo cellular-uptake over time. The quantitative MPI results were verified by colorimetric measurements of the iron content. The results showed a mean relative difference between the MPI results and the reference method of 23.8% for the quantification of cell-bound MNPs. With this technique, the uptake of MNPs in cells can be imaged and quantified directly from the first MNP cell contact, providing information on the dynamics of cellular uptake.
磁粒子成像（MPI）是一种用于可视化和量化磁性纳米粒子（MNPs）的非侵入性、非电离成像技术。该技术特别适用于细胞成像，因为它提供了来自周围组织的零背景贡献、高灵敏度以及良好的空间和时间分辨率。先前的研究表明，MNPs 的动态磁行为在细胞结合和内化过程中发生变化。在本研究中，我们展示了如何在 MPI 成像信号中对这些信息进行编码。通过 MPI 成像，我们能够在重建图像中区分游离和细胞结合的 MNPs。这项技术用于成像和量化体外实验中游离 MNPs 与细胞接触并随时间发生细胞摄取时的变化。通过比色法测量铁含量对定量 MPI 结果进行了验证。结果表明，MPI 结果与参考方法定量细胞结合 MNPs 的平均相对差异为 23.8%。通过这项技术，可以直接从第一个 MNP 与细胞接触开始对细胞内的 MNPs 摄取进行成像和定量，提供有关细胞摄取动力学的信息。
