Delivery of plasmid DNA encoding Oct 4 with polyethylenimine-modified superparamagnetic iron oxide nanoparticles in HEK-293T cells

In order to improve the gene-delivering efficiency of polyethylenimine-modified superparamagnetic iron oxide nanoparticle (PEI-SPION) and elucidate the related mechanisms, the binding ratio and protection actions of PEI-SPION to plasmid DNA (pDNA), the physical characteristics of PEI-SPION/pDNA complex, and effects of exogenous factors (including magnetic field, inhibitors, and activator) on gene transfection in human embryonic kidney 293T cells (HEK-293T cells) were explored here. The results showed that the diameter of PEI-SPION was about 45 nm. When PEI-SPION and pDNA encoding Oct 4 (pDNA-Oct 4) were mixed at the mass ratio of 1: 1, the hydrodynamic diameter (299.10 ± 5.01 nm) of conjugate complex was significantly smaller than that of complex at the mass ratio of 1: 2 (469.23 ± 28.86 nm; P 0.05), and similar results were found for treatments of nystatin. Compared with control group, 2-deoxy-D-glucose (2-DG) and amiloride could significantly decrease the transfection efficiency (P