Human tracheal epithelial cells in culture: a suitable model for testing the cytocompatibility of materials for endotracheal use

Abstract

It is well known that cuffs of endotracheal tubes can induce ischemic injuries on tracheal epithelium, as a result of mechanical hyperpressure caused by the cuff on the airway tissue. Whether or not material components are leached out and may provoke a direct toxic effect on the respiratory epithelium is much less clear. To study the cytocompatibility of such materials, we have developed an in vitro cell system using human tracheal epithelial cells, arising from trachea superficial biopsies. In culture, cells have been characterized by morphological and immunocytochemical criteria. Ultrastructural observations suggest that our culture conditions are permissive for the expression of both squamous and secretory phenotypes. We have assessed the cytocompatibility of a cuff towards epithelial cells, first, by an indirect test, and second by a direct test. By the indirect test, using material extracts, we did not find any toxic effect towards human airway epithelial cells of the cuff components. By a direct test, we found a slight cell lysis after a 24 h incubation. Our study shows that this human tracheal epithelial cell system is a useful and relevant model which could be used in a quality control procedure for testing the cytocompatibility of materials for endotracheal use.