Modification of human monocytes and macrophages by magnetic nanoparticles in vitro for cell-based delivery

The aim of the study was to develop a method for the modification of human monocytes/macrophages by iron oxide magnetic nanoparticles in vitro. Materials and methods. Iron oxide magnetic nanoparticles were obtained by a co-precipitation method and coated with a thin SiO2 layer and polyethylene glycol 3000. Murine macrophage-like cell line RAW 264.7, primary human monocytes and macrophages were incubated with magnetic nanoparticles for 1-24 hours. The efficiency of cellular uptake of nanoparticles was measured using a ferrozine-based method and microcopy with Perls' Prussian blue staining. The cell viability was tested by fluorescent flow cytometry using SYTOX Green. Results. Incubation of RAW264.7 cell, human monocytes and macrophages with magnetic nanoparticles at a concentration > 5 mu g/mL on a rotator for 1 hour at 37 degrees C provides the loading of nanoparticles into > 99% of cells. The magnetic nanoparticles have no adverse effect on the cell viability. The RAW264.7 cells modified with nanoparticles showed no change in migration activity. The efficiency of the nanoparticle uptake by macrophages was >50 pkg (Fe)/cell. Conclusion. According to the proposed method, macrophages loaded with magnetic nanoparticles have proved viable, they retain the ability to migrate, and therefore can be used as cell-based delivery systems for tumor diagnostic and therapy.