OBJECTIVE: To investigate the effect of 12-alkylated chitosan nanoparticles enfolding antisense endothelin converting enzyme RNA expression plasmid on airway hyperresponsiveness in asthmatic mouse models.

METHODS: Forty Balb/c mice were randomly divided into four groups: control, chitosan nanoparticles, normal saline and plasmid groups. Mice in the chitosan nanoparticles, normal saline and plasmid groups were subjected to sensitization by an intraperitoneal injection with ovalbumin (0, 14 days) and motivation by aerosol inhalation of ovalbumin (24, 25, 26 days) to induce asthma models. Mice in the control group were subjected to sensitization and motivation by the perfusion of normal saline. At 24hours before the first excitation, mice in the control, chitosan nanoparticles, normal saline and plasmid groups were perfused with normal saline via airway, 12-alkylated chitosan nanoparticles, normal saline and antisense endothelin converting enzyme RNA. At 48 hours after the last excitation, the airway reactivity of mice was detected. After 28 days, bronchoalveolar lavage  fluid cytology, lung histopathology, cytokines in spleen cell culture supernatant were detected.