Calcium phosphate/octadecyl-quatemized carboxymethyl chitosan nanoparticles: an efficient and promising carrier for gene transfection.

Calcium phosphate (CaP) has been widely used as the vector for gene transfection in the past three decades. However, clinical application is still not popular due to the poor-controlling of DNA/CaP complexes preparation, cytotoxicity and its low transfection efficiency. In this study, a novel amphipathic octadecyl-quatemized carboxymethyl chitosan (OQCMC) derivative from chitosan was combined with calcium phosphate to synthesize CaP/OQCMC nanoparticles (CaP/OQCMC NPs). The nanoparticles were 122-177 nm in diameter exhibited neutral zeta potential (from -0.115 mV to 0.216 mV), and they were applied as DNA vectors for DNA loading and in vitro transfection. The results showed that CaP/OQCMC NPs displayed high DNA loading capacity and enhanced transfection efficiency with extremely low cytotoxicity. In addition, both CaP and OQCMC are biocompatible and biodegradable, thus the as-prepared CaP/OQCMC NPs are promising in gene delivery.