Polysaccharide nanogel gene delivery system with endosome-escaping function: Co-delivery of plasmid DNA and phospholipase A2.

We developed a novel gene delivery system capable of endosome disruption using a polysaccharide-based cationic nanogel composed of a hexadecyl group-bearing cationic cycloamylose nanogel (C16-catCA nanogel) and phospholipaseA(2) (PLA(2)) to hydrolyze membrane phospholipids. C16-catCA nanogel formed nanoparticles with PLA(2) and pDNA by hydrophobic and electrostatic interactions. Both pDNA and PLA(2) were effectively internalized into cells by the C16-catCA nanogel. In addition, the pDNA expression level was enhanced when complexed with specific concentrations of PLA(2). PLA(2) complexed with C16-catCA nanogel also showed a similar hemolytic activity against red blood cells to that observed using native PLA(2). These results suggest that the C16-catCA nanogel/PLA(2) complex possesses membrane disruption ability when delivered into cells and triggers the subsequent release of pDNA from the endosome to the cytoplasm. This is the first report of co-delivery of pDNA and PLA(2) using the same carrier to achieve effective gene delivery.