DNA encapsulated magnesium and manganous phosphate nanoparticles: potential non-viral vectors for gene delivery

Nanoparticles of Mg and Mn (II) phosphates encapsulating pDNA were prepared. The sizes of these DNA loaded particles in aqueous dispersion were about 100-130 nm diameter, and they aggregated with the progression of time. Although magnesium phosphate nanoparticles were crystalline, the manganous phosphate nanoparticles were found to be amorphous in nature. Nanoparticle dissolution and pDNA release were studied using atomic absorption spectroscopy and gel electrophoresis experiments. These inorganic phosphate nanoparticles dissolved in mild acidic pH ( approximately 5) releasing pDNA indicating that DNA release in the endosomal compartment is possible. In vitro transfection in HeLa cells demonstrated that while magnesium phosphate nanoparticles showed 100% efficiency, manganous phosphate nanoparticles exhibited about 85% transfection efficiency compared to that of 'polyfect', as control.