Magnesium Phosphate Nanoparticles can be Efficiently Used In Vitro and In Vivo as Non-Viral Vectors for Targeted Gene Delivery

Magnesium phosphate (MgPi) nanoparticles (NPs) encapsulating pSV beta gal and pEGFP have been used as novel non-viral vector for targeted gene delivery. These plasmid DNA loaded magnesium phosphate nanoparticles of diameter 100-130 nm were prepared in water-in-oil microemulsion. In vitro cell viability study carried out on MCF-7, HEK, and COS-7 cells demonstrated that magnesium phosphate nanoparticles have no cytotoxic effect against cell proliferation. In vivo cytotoxicity conducted on Swiss Albino mice indicated no cytotoxic effect 3 months after intraperitoneal administration of 600 mg of void magnesium phosphate nanoparticles per Kg of body weight one-time only. In vitro transfection in COS-7 cells demonstrated that magnesium phosphate nanoparticles showed approximately 100% efficiency when compared to commercial transfecting reagent Polyfect (R) as well as the transfection efficiency of calcium phosphate (CaPi) nanoparticles recently reported. Moreover, to explore the possibility of targeting these nanoparticles to specific tissue, we have surface modified these particles by adsorbing highlyt adhesive polymer, polyacrylic acid (PAA), followed by conjugating the carboxylic groups of the polymer with p-amino-thio-beta-galactopyranoside (PAG) using a cross-linking agent 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and used these particles to target to liver in vivo successfully and more efficiently.