Protamine sulfate–calcium carbonate–plasmid DNA ternary nanoparticles for efficient gene delivery

Abstract

Ternary nanoparticles, protamine sulfate–calcium carbonate–plasmid DNA (PS–CaCO₃–DNA), were prepared for efficient gene delivery. By adding the cationic polypeptide PS in the co-precipitation system of calcium carbonate and DNA, PS–CaCO₃–DNA nanoparticles could be formed by self-assembly facilely. The effect of PS on the properties of the ternary nanoparticles was studied by varying the PS amount in the nanoparticles. The size and ζ-potential measurements indicated that the ternary nanoparticles with an appropriate PS amount exhibited a decreased size and an increased ζ-potential. The in vitro gene transfections mediated by different nanoparticles in 293T cells and HeLa cells were carried out in the presence of 10% fetal bovine serum, using pGL3-Luc and pEGFP-C1 as reporter plasmids. As compared with both PS–DNA nanoparticles and CaCO₃–DNA nanoparticles, PS–CaCO₃–DNA nanoparticles exhibited significantly enhanced gene delivery efficiency, which was higher than that of Lipofectamine 2000–DNA. Confocal microscopy observation showed that PS–CaCO₃–DNA nanoparticles could efficiently deliver DNA to cell nuclei. These results indicated that the ternary PS–CaCO₃–DNA nanoparticles prepared in this study have promising applications in gene delivery.