Chitosan as a carrier for non‐viral gene transfer in a cystic‐fibrosis cell line

The gene transfer mediated by chitosan in CFBE41o(-) (a cystic-fibrosis bronchial epithelial cell line) and HEK (a human embryonic kidney cell line) has been evaluated. Polyplexes based on chitosan and PEI (polyethyleneimine) using a luciferase and enhanced green fluorescent protein reporter plasmid showed that the transfection efficacy of polyplexes in the CFBE41o(-) cell line was poor compared with that in HEK cells. In the highly differentiated cystic-fibrosis bronchial epithelial cell line the narrow-size-distributed chitosan shows enhanced transfection at a low pH compared with PEI. The enhanced transfection at lower pH could be a result of damage to the cell surface or changes in the cell-surface charge, leading to better penetration of the cell membrane.