Polymer- coated magnetic nanoparticles formulation enhanced blood-stage Malaria DNA vaccine delivery with the best PEI/Fe ratio

Abstract

Superparamagnetic nanoparticles SPIONs with specific sizes and surface characteristics can promote potent immune responses against different parasitic infection by enhancing antigen uptake of proper immune-stimulatory cell types. Magnetite (Fe 3 O 4) nanoparticles have shown many potential bio-applications due to their biocompatibility and special characteristics. The use of Polyethylenimine (PEI) polymer-coated superparamagnetic nanoparticles (SPIONs) to deliver malaria genes via magnetofection shows promise in improving the efficiency of gene delivery in vitro application. Here, superparamagnetic nanoparticles with high magnetization value were stabilized with trisodium citrate and successfully coated with Polyethylenimine polymer (PEI) by chemically attaching branched PEI to the surface of iron oxide nanoparticles using two different concentrations of SPIONs in suspension and two different R % mass ratios (w: w) PEI:SPIONs. Plasmid DNA encoding Plasmodium yoelii merozoite surface protein VR1020-PyMSP119 and plasmid DNA encoding a green fluorescent protein (GFP) were added to the PEImagnetic complexes with different N/P ratios. During particles characteristic experiments, a remarkably small particle hydrodynamic size and highly positive surface charge were shown when iron oxides suspension was 0.1 mg/ml. The magnetic vectors containing R%= 10% mass ratio PEI: SPIONs accompanied by applying permanent magnetic field yielded the highest gene transfection efficiency than others. This phenomenon was attributed to the more effective balanced distribution of the PEI molecules across the surface of the magnetic nanoparticles and to the low range of complex amounts due to the dose effect aiding to colloidal stable beads in the cell culture media.