DNA Intracellular Delivery into 3T3 Cell Line Using Fluorescence Magnetic Ferumoxide Nanoparticles

Gene delivery is a widespread strategy in current experimental medicine. In this work, we report a method for low-toxic intracellular DNA vector delivery and post transfection localisation of this vector in mouse embryonic fibroblast cell lines. The surface of modified ferumoxide nanoparticles conjugated with Rhoda-mine B isothiocyanate (FeNV-Rh) was modified with linear polyethyleneimine and medium molecular weight chitosan to increase Accelerated Sensor of Action Potentials DNA vector adhesion. The size of the FeNV-Rh/DNA transfection complex was studied using dynamic light scattering (DLS) and scanning electron microscopy (SEM) techniques. The transfection complex internalisation of plasmid expression and FeNV-Rh, and stability of rhodamine fluorescence in intracellular space were observed at time periods 6, 12, 24 and 48 h post transfection. Results showed high transfection complex intracellular biocompatibility—cell viability after Rh-MNP labelling was higher than 97% 24 h after transfection, and higher than 95% after the next 24 h. Selective FeNV-Rh localisation in the lysosomes was quantified. More than 82% of nanoparticles were localised in the lysosomes 12 h post transfection and 94% of lysosomes had a significant and long-term deposit of nanoparticles. DNA vector expression was visible in >65% of the cells and precise protein localisation on the cell membrane was confirmed using confocal microscopy.