Macrophage physiological function after superparamagnetic iron oxide labeling.

Our goal was to analyze the changes in morphology and physiological function (phagocytosis, migratory capabilities, humoral and cellular response, and nitric oxide secretion) of murine macrophages after labeling with a clinically used superparamagnetic iron oxide (SPIO), ferucarbotran. In SPIO-treated macrophages, nanoparticles were taken up in the cytoplasm and accumulated in a membrane-bound organelle. Macrophage proliferation and viability were not modified after SPIO labeling. Phagocytic function decreased after labeling with only 10 microg Fe/mL SPIO, whereas other functions including migration and production of tumor necrosis factor-alpha and nitric oxide increased at the highest SPIO concentration (100 microg Fe/mL).