Efficiency of granulocyte colony-stimulating factor immobilized on magnetic microparticles on proliferation of NFS-60 cells

Magnetic particles are promising carriers for targeted drug delivery. Granulocyte colony-stimulating factor (G-CSF) is a cytokine which stimulates neutrophil proliferation process. In this study, G-CSF molecules were successfully covalently immobilized on magnetic silica gel beads (MagBs) surface. Comparison of free and on MagBs immobilised G-CSF (MagBs-G) on proliferation efficiency and viability of mouse myeloid cell line NFS-60 was performed using XTT assay. Cytotoxic or stimulation effects of used MagBs on NFS-60 cell proliferation were not observed. However, the positive effect on proliferation of cells was noticed increasing the concentration of MagB-G in the test wells from 0.5 mu g/ml to 50 mu g/ml. Proliferation of cells in the presence of 50 mu g/ml MagBs-G (2.7 mu g/ml G-CSF) resulted in maximal proliferation response, which was reached using free G-CSF. Comparing the concentration of G-CSF that gives half-maximal response of free (3.6 pM) and on MagBs immobilized (11.4 nM) G-CSF can be concluded that immobilized G-CSF possessed the same efficiency as free G-CSF molecules, however the higher amount of immobilized G-CSF is required.