title: Enhancement of magnetofection efficiency using chitosan coated superparamagnetic iron oxide nanoparticles and calf thymus DNA.
abstract: Superparamagnetic iron oxide nanoparticles (MNPs) were prepared and coated with chitosan (CS). The chitosan-magnetic iron oxide nanoparticles (CS-MNPs) were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometry (VSM), and the morphology of the particles was studied by transmission electron microscopy (TEM). Our findings show that the magnetic particles were monodisperse (10nm mean diameter) and exhibited superparamagnetic behavior. The interaction between the particles and calf-thymus DNA (DNA) in physiological buffer was studied with UV-vis, fluorescence and circular dichroism spectroscopy and zeta potential. Spectroscopic studies were indicated DNA conformational changes in the presence of CS-MNPs. Binding and thermodynamic parameters at different temperatures were calculated using the Stern-Volmer, Hill, Scatchard and Van't Hoff equations. The binding process was spontaneous and interactions were electrostatic with the appropriate binding constant (Kb=4.52×103M-1, 3.69×103M-1and 3.02×103M-1at 300K, 310K and 320K, respectively). Zeta potential measurements of DNA continually increased with the addition of CS-MNPs, supporting our thermodynamic findings. Moreover, CS-MNPs were able to quench the fluorescence of DNA-intercalated ethidium bromide (DNA-EB) by a static quenching mechanism. Cytotoxicity studies show that the DNA-CS-MNP system is biocompatible with a human foreskin fibroblast cell line, HFFF2. Collectively, these results suggest that surface cationic magnetic chitosan-iron oxide nanoparticles can potentially enhance magnetofection efficiency.
authors.affiliation: Nanotechnology and Advanced Materials, Materials and Energy Research Center, Karaj, Iran.
authors.forename: Z
authors.initials: Z
authors.lastname: Sohrabijam
authors.affiliation: Nanotechnology and Advanced Materials, Materials and Energy Research Center, Karaj, Iran. Electronic address: saeidifar@merc.ac.ir.
authors.forename: M
authors.initials: M
authors.lastname: Saeidifar
authors.affiliation: Nanotechnology and Advanced Materials, Materials and Energy Research Center, Karaj, Iran.
authors.forename: A
authors.initials: A
authors.lastname: Zamanian
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D048271:Chitosan / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000009:adverse effects / Q000737:chemistry*; D004247:DNA / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D006801:Humans; D058185:Magnetite Nanoparticles / Q000009:adverse effects / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D020099:Coated Materials, Biocompatible; D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; C000499:ferric oxide; D004247:DNA; D048271:Chitosan; C427203:calf thymus DNA
keywords: Calf thymus DNA; Chitosan; Gene delivery; Magnetofection; Superparamagnetism