Abstract
A human nasal epithelial cell culture model has been adapted to observe transport and metabolism of drugs, e.g., peptides. Human nasal epithelial cells, isolated by protease treatment of human nasal conchae, grew to confluency after 6-8 days using DMEM supplemented with 1% nonessential amino acids, 1% glutamine, 10% FCS and 1% antibiotics. These cultures expressed microvilli and actively beating cilia as documented by light microscopy and scanning electron microscopy (SEM). Tight junctions were confirmed by dome formation and positive actin staining using FITC-labelled phalloidin. Preliminary transport studies, carried out with FITC-labelled Dex-tran (FD 4, MW 4400) and Sulforhodamine (SR 101, MW 607), demonstrated the intact barrier function of the cultured monolayer, grown on filter membranes. In addition, the cultured cells metabolized Leu-Enkephalin to Des-Tyr-Leu-Enkephalin demonstrating the presence of aminopeptidase, a naturally occurring enzyme in the human nasal mucosa.