Preparation and evaluation of chitosan-DNA-FAP-B nanoparticles as a novel non-viral vector for gene delivery to the lung epithelial cells

Gene delivery using cationic polymers such as chitosan shows good biocompatibility, but reveals low transfection efficiency. Fibronectin Attachment Protein of Mycobacterium bovis (FAP-B) which is responsible for the attachment of many Mycobacteria on the Fibronectin molecule of epithelial cell membrane can be considered as a new targeting ligand and can improve transfection rates in epithelial cells. In this study, chitosan-DNA nanoparticles were prepared using coacervation process. The effect of stirring speed and charge ratio (N/P) on the size and zeta potential of nanoparticles were evaluated. FAP-B ligand was added to nanoparticles at the specific condition to form chitosan-DNA-FAP-B nanoparticles via electrostatic attraction. Transfection efficiency of the final nanoparticles was investigated in A549 (alveolar epithelial cells). Cell viability was investigated using MTT assay. The optimum speed of stirring which was yielded the smallest chitosan-DNA nanoparticles with a narrow distribution (227±43 nm), was 500 rpm with the corresponding N/P ratio of 20. Chitosan-DNA-FAP-B nanoparticles presented the size of 279±27 nm with transfection efficiency about 10-fold higher than chitosan-DNA nanoparticles and resulted in 97.3% cell viability compared to 71.7% using Turbofect controls. Chitosan-DNA-FAP-B nanoparticles showed good transfection efficiency without cell toxicity. They have small particle size around 279 nm which make them a promising candidate as a novel non-viral gene vector for gene delivery to lung epithelial cells.