Initial interaction of fluticasone propionate with ciliated respiratory epithelium

Background Inhaled Fluticasone Propionate (FP) is widely used in the treatment of patients with asthma and COPD. Little is known of the initial interaction of inhaled FP particles with the ciliated respiratory epithelium. In this study we demonstrate a novel interaction between FP particles and rapidly moving cilia. Methods Ciliated epithelial cell cultures from healthy volunteers were grown at air-liquid interface (ALI). FP 2mg/ml was nebulized on to the apical surface of ciliated cell cultures using a bespoke system that allowed observation in real time by high-speed video microscopy. Results Flixotide particles were observed to impact on the ciliated cultures. Particles were transported around the culture well by the motile cilia. A number of FP particles bound to the tips of rapidly moving cilia. Binding occurred as early as 5 minutes after nebulization but continued to occur over time. Although the number of particles bound to cilia reduced over time some were still present at 48 hours. Binding of FP particles significantly (P Conclusion Binding of FP to cilia may result in retention of steroid particles in ciliated epithelial airways.