Nanoparticle-Mediated Delivery System for Gene Therapy

Gene editing with the CRISPR/Cas9 system is one of the options that sets a new trend in the development of gene therapy. The most commonly used delivery of DNA into the cells are via viruses. Nevertheless, they are often unable to take CRISPR/Cas9 system, which can be bigger than several kb. Nanoparticles (NPs), as non-viral transporters, seem to be a good alternative delivery system. For this work magnetic Fe3O4 NPs (MNPs) were selected, because of their excellent properties such as multifunctionality, biocompatibility, easy degradation and simple synthesis. The aim of this work was to synthesise MNPs and a complex of MNPs coated with PEI/CRISPR-Cas9 plasmid and to characterize them by physicochemical methods. The created complex MNPs/PEI/CRISPR-Cas9 was defined by exact parameters that are suitable for possible cell uptake. The hypothesis of stabilization of the MNPs/CRISPR-Cas9 plasmid complex by polyethylenimine (PEI), which can also protect plasmid DNA against restriction endonucleases, was verified. Next a stable modified cell line HEK293-TLR3, designed to evaluate the efficacy of double strand break (DSB) repair by nonhomologous end joining (NHEJ) or homologous recombination (HR) was, transfected with the synthesised MNPs/PEI/CRISPR-Cas9 complex. The results indicate a 25% transfection..