Gene Expression and Pulmonary Toxicity of Chitosan-graft-Polyethylenimine as Aerosol Gene Carrier

Chitosan-graft-polyethylenimine (CHI-g-PEI) copolymer has been used for theimprovement of low transfection efficiency of chitosan. The present study aims to test thepulmonary toxicity and efficiency of CHI-g-PEI as an aerosol gene carrier. Mice were exposedto aerosol containing green-fluorescent protein (GFP)-polyethylenimine (PEI) or GFP-CHIg-PEI complexes for 30 min during the development of our nose-only exposure chamber(NOEC) system. CHI-g-PEI-mediated aerosol delivery demonstrated 15.65% enhancementof the fluorescence intensity. Compared to PEI, CHI-g-PEI showed no significant pulmonarytoxicity. In summary, using CHI-g-PEI is safe and shows high transfection in aerosol genedelivery to animals, and enhanced efficiency was achieved through our aerosol gene deliverysystem. Therefore, CHI-g-PEI and this system would be applicable to future study for aerosolgene therapy.