Air-Liquid Interface Culture of Serially Passaged Human Nasal Epithelial Cell Monolayer forIn VitroDrug Transport Studies

Abstract

The objective of this study was to establish a drug transport study using human nasal epithelial (HNE) cell monolayers cultured by the air-liquid interface (ALI) method using serum-free medium (BEGM:DME/F12, 50:50). The cells were developed and characterized in comparison to those that have been previously cultured by the liquid-covered culture (LCC) method. The epithelial cell monolayer cultured by the ALI method resulted in a significantly higher transepithelial electrical resistance value (3,453 ± 302 ohm × cm²) that was maintained (>1,000 ohm × cm²) for up to 20 days compared with that cultured by the LCC method. Observation by scanning electron microscopy revealed mature cilia after 2 weeks in the ALI culture, while flatten unhealthy ciliated cells were observed in the LCC method. After 21 days, higher level of MUC5AC and 8 mRNA were expressed in ALI culture which confirmed the secretory differentiation of HNE monolayers in vitro. No significant difference in the permeability coefficients of a model hydrophilic marker (¹⁴C-mannitol) and a lipophilic drug (budesonide) was observed between the two conditions on day 7. The passage 2–3 of the HNE monolayer using ALI condition retained the morphology and differentiated features of normal epithelium. Thus it would be a suitable model for in vitro nasal drug delivery studies.