Short‐Term Application of Magnetic Core‐Shell Nanoparticles—Effect on Immune Cells

The effect of magnetic nanoparticles on the survival of leukocytes in general and especially the lymphocytes as important parts of the immune system during incubation and separation was analyzed. Primary leukocytes were inoculated with magnetic core/carboxymethyl‐dextran (CMD) nanoparticles for 4 to 30 minutes. Labelled cells were separated by MACS, counted and analyzed by FACS. T‐Lymphocytes were identified by CD3 and B‐Lymphocytes by CD19. After magnetic separation granulocytes represented the majority of cells in both, the positive and negative fraction. Most of the lymphocytes were detected in the negative fraction. The number of T‐Lymphocytes in the positive fraction increased 2.5‐fold from 4 to 16 minutes, whereas the amount of B‐Lymphocytes remains constant. T cells could be expanded after short‐term incubation with nanoparticles indicating full biological activity. Our enrichment procedure of tumor cells from peripheral blood preserves the integrity and biological activity of leukocytes in the neg...