The manipulation of natural killer cells to target tumor sites using magnetic nanoparticles.

The present work demonstrates that Cy5.5 conjugated Fe(3)O(4)/SiO(2) core/shell nanoparticles could allow us to control movement of human natural killer cells (NK-92MI) by an external magnetic field. Required concentration of the nanoparticles for the cell manipulation is as low as ~20 μg Fe/mL. However, the relative ratio of the nanoparticles loaded NK-92MI cells infiltrated into the target tumor site is enhanced by 17-fold by applying magnetic field and their killing activity is still maintained as same as the NK-92MI cells without the nanoparticles. This approach allows us to open alternative clinical treatment with reduced toxicity of the nanoparticles and enhanced infiltration of immunology to the target site.