PEI-PEG-Chitosan-Copolymer-Coated Iron Oxide Nanoparticles for Safe Gene Delivery: Synthesis, Complexation, and Transfection

Gene therapy offers the potential of mediating disease through modification of specific cellular functions of target cells. However, effective transport of nucleic acids to target cells with minimal side effects remains a challenge despite the use of unique viral and non‐viral delivery approaches. Here, a non‐viral nanoparticle gene carrier that demonstrates effective gene delivery and transfection both in vitro and in vivo is presented. The nanoparticle system (NP–CP–PEI) is made of a superparamagnetic iron oxide nanoparticle (NP), which enables magnetic resonance imaging, coated with a novel copolymer (CP–PEI) comprised of short chain polyethylenimine (PEI) and poly(ethylene glycol) (PEG) grafted to the natural polysaccharide, chitosan (CP), which allows efficient loading and protection of the nucleic acids. The function of each component material in this nanoparticle system is illustrated by comparative studies of three nanoparticle systems of different surface chemistries, through material property characterization, DNA loading and transfection analyses, and toxicity assessment. Significantly, NP–CP–PEI demonstrates an innocuous toxic profile and a high level of expression of the delivered plasmid DNA in a C6 xenograft mouse model, making it a potential candidate for safe in vivo delivery of DNA for gene therapy. A gene transfection nanovector made from an iron oxide nanoparticle coated with a copolymer consisting of poly(ethylene glycol), chitosan, and poly(ethylenimine) demonstrates stable binding and effective transfection of DNA in C6 glioma cells both in vitro and in vivo. Significantly, this gene delivery vehicle demonstrates an innocuous toxic profile.