Calcium phosphate nanoparticles as novel non-viral vectors for targeted gene delivery.

Calcium phosphate nanoparticles present a unique class of non-viral vectors, which can serve as efficient and alternative DNA carriers for targeted delivery of genes. In this study we report the design and synthesis of ultra-low size, highly monodispersed DNA doped calcium phosphate nanoparticles of size around 80 nm in diameter. The DNA encapsulated inside the nanoparticle is protected from the external DNase environment and could be used safely to transfer the encapsulated DNA under in vitro and in vivo conditions. Moreover, the surface of these nanoparticles could be suitably modified by adsorbing a highly adhesive polymer like polyacrylic acid followed by conjugating the carboxylic groups of the polymer with a ligand such as p-amino-1-thio-beta-galactopyranoside using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride as a coupling agent. We have demonstrated in our studies that these surface modified calcium phosphate nanoparticles can be used in vivo to target genes specifically to the liver.