International Journal on Magnetic Particle Imaging IJMPI
Vol. 2 No. 2 (2016): Int J Mag Part Imag
Processing of SPIO in macrophages and tumor tissue for MPI lymph node imaging in breast cancer
Main Article Content
Copyright (c) 2016 Dominique Finas, Janine Stegmann-Frehse, Benjamin Sauer, Gereon Hüttmann, Achim Rody, Thorsten Buzug, Kerstin Lüdtke-Buzug
This work is licensed under a Creative Commons Attribution 4.0 International License.
Abstract
The most common cancer in women worldwide is breast cancer. To avoid tissue damaging while axillary surgery in BC we aim to develop a new sentinel lymph node biopsy methode using superparamagnetic iron oxide nanoparticles (SPIOs) and magnetic particle imaging. It is well known from i.v. SPIO application in magnetic resonance imaging that macrophages (MP) are key role player in processing of SPIOs causing a drop of signal intensity. Nevertheless, knowledge lacks concerning enrichment processes of SPIOs after injection in breast tissue, the adjacent lymphatic tissues and associated cells, especially in BC and metastatic lymph nodes. Previously we evaluated the distribution of SPIOs in an in vivo healthy and tumor mouse model. Based on these studies we investigate the processing of the SPIOs in MP.
To evaluate SPIO processing we established a tumor bearing mouse model as we previously published. Tumor tissue was than analyzed by conventionally hematocylin histology combined with Berlin blue staining and autofluorescence multiphoton microscopy. Additionally, the MP cell line J774A.1 was incubated either by Resovist in culture medium, or culture medium only as control. This process was observed in vivo by multiphoton microscopy. Detection of SPIOs was realized by excitation at 1200 nm.
Resovist showed no toxic effects on macrophages after incubation. MP showed activity in phagocytosis of Resovist after incubation in multiphoton microscopy. SPIOs were detectable within tumor tissue by conventional hematoxylin microscopy as well as particle processing by 3-photon microscopy. The cell associated SPIO processing signal was detected by in vivo imaging.
After injection of Resovist into tumor tissue the SPIOS can be detected well distributed within the tissue by conventional histology and by a 3-photon device in a bio-medical context. System wide scanning is known (MRI, MPI), but now we are also able to identify the link to subcellular processing and localization of SPIOs. Further processing of SPIOs in MP is under development.