Quaternized chitosan/rectorite intercalative materials for a gene delivery system

Non-viral vectors have gained increasing attention in gene therapy because of their safety, but with the shortcoming of low transfection efficiency. We have developed a hybrid material as a novel non-viral vector, which combines the advantages of both biopolymer and clay in a gene delivery system. Quaternized chitosan was intercalated into the interlayers of rectorite to obtain a new polymer/layered silicate nanocomposite. In vitro and in vivo toxicity studies revealed that the nanocomposites were biocompatible and non-toxic. At the nanocomposite:pDNA mass ratio of 8:1, they achieved 100% pDNA adsorption capacity. In vitro cell transfection revealed a transfection efficiency of 32.1% at 96?h as shown by a flow-cytometric study, and the intensive green fluorescence protein (GFP) expression could last for up to 120?h. Furthermore, an in vivo transfection study showed that the most prominent GFP expression was observed in the gastric and duodenum mucosa, and good transfection efficiency was also obtained when injected into the muscle. All the results suggest that quaternized chitosan/rectorite nanocomposite is a novel and potential non-viral gene carrier.