Design of a pDNA nanocarrier with ascorbic acid modified chitosan coated on superparamagnetic iron oxide nanoparticles for gene delivery

Among various approaches of gene delivery, there is a growing interest in oral administration of plasmid DNA (pDNA) as one of the safest and most straightforward vaccination methods. Inclusion of chitosan is expected to prevent pDNA degradation in gastric environments and contribute to releasing it in target intestinal fluids. In this paper, ascorbic acid-modified chitosan is used as a biomolecular coating on superparamagnetic iron oxide nanoparticles (SPION) to serve as a pDNA nanocarrier. The nanoparticles are studied by FE-SEM, DLS, zeta potential, FT-IR spectroscopy, XRD, and VSM. The pDNA release in a simulated intestinal environment is measured by agarose gel electrophoresis. The cytotoxicity of the nanoparticles is evaluated by MTT assay using epithelial Vero and EPC cells. Results show that the nanocarriers are formed spherically with a mean hydrodynamic diameter of 100 nm and zeta potential of + 25 mV. The nanocarrier gastric stability is confirmed by treating with DNase I test. The results show that the pDNA release is promising and amounts to 45% after 48 h. MTT assay results show that the SPION@CsVC nanocarriers are biocompatible to Vero and EPC cell lines. It is found that chitosan can effectively shield the pDNA in the extremely acidic gastric environment, yet allows it to be released when passing through the target alkaline intestinal tissue. In other words, chitosan is presented as an effective biopolymer for application in non-viral vectors for gene delivery through a facile oral route. [Display omitted] •Ascorbic acid modified chitosan was coated on Fe3O4 nanoparticles as pDNA nanocarriers•The nanoparticles were characterized by FE-SEM, FT-IR, XRD, VSM, and DLS•The MTT assay confirmed biocompatibility of the nanocarriers to Vero and EPC cells•The loaded pDNA contents were released successfully in intestinal environment