Fluorescence and Scanning Electron Microscopy of Chitosan/DNA Nanoparticles for Biological Applications

Polysaccharides and other cationic polymers have been recently used in pharmaceutical research and industry for their properties to control the release of antibiotics, DNA, proteins, peptide drugs or vaccines and have been also extensively studied as non viral DNA carriers for gene delivery and therapy. Among them, chitosan is one of the most used because it promotes long term release of incorporated drugs. The preparation of chitosan and chitosan/DNA nanoparticles of definite size and shape by using a novel and simple osmosis-based method is reported. The average diameter (measured by DLS) of chitosan nanoparticles is 45 ± 9 nm while that of chitosan/DNA is 38 ± 4 nm. The chitosan/DNA nanoparticles have a spherical morphology as also revealed by scanning electron microscopy (SEM). Varying solvent, temperature and membrane cut-off several nanostructured systems with different size and shape may be obtained for further use in biotechnological applications.