In the past, the preclinical and clinical utility of transfecting cytokine-induced killer (CIK) cells with viral vectors has been demonstrated. Improvements in nanotechnology, materials science, and nucleic acid chemistry have led to the development of non-viral gene delivery systems that can overcome the limitations of viral vectors. Preclinical targets for these non-viral vectors may include CIK cells and dendritic cells (DCs). To determine whether the introduction of a foreign protein into immune cells via mRNA could result in a higher transfection efficiency compared to conventional methods, we investigated the non-viral transfection of CIK cells and DCs using ternary nanoformulations.

In addition, we investigated the effect of transfection on the relative viability of immune cells. We observed that the highest transfection efficiency of 2.55% was achieved with 1.5 µg/ml EGFP mRNA for CIK cells and 5.05% with 2.5 µg/ml for DCs. An increase in the relative viability of the mRNA-treated group was observed compared to the untreated group. In conclusion, transfection of CIK cells and DCs with mRNA in a non-viral approach using ternary nanoformulations did not provide any additional benefit compared to conventional methods.