Protamine nanoparticles for improving shRNA-mediated anti-cancer effects.

Protamine nanoparticles were designed by encapsulating small hairpin RNA (shRNA)-expressing plasmid DNA targeting the Bcl-2 gene (shBcl-2) to silence apoptosis-related Bcl-2 protein for improving the transfection efficiency and cytotoxicity in cancer therapy. Our findings demonstrated that the obtained protamine nanoparticles possessed excellent characterizations of small particle size, homogenous distribution, positive charge, and high encapsulation efficiency of gene. shBcl-2 loaded in nanoparticles (NPs) was protected effectively from the degradation of DNase I and serum. More importantly, it significantly improved the efficiency of transfection of shRNA in vitro in A549 cells and increased its cytotoxicity and induced more cell apoptosis by silencing Bcl-2.