HUMAN TRACHEAL EPITHELIAL-CELLS IN CULTURE - A SUITABLE MODEL FOR TESTING THE CYTOCOMPATIBILITY OF MATERIALS FOR ENDOTRACHEAL USE

It is well known that cuffs of endotracheal tubes can induce ischemic injuries on tracheal epithelium, as a result of mechanical hyperpressu re caused by the cuff on the airway tissue. Whether or not material co mponents are leached out and may provoke a direct toxic effect on the respiratory epithelium is much less clear. To study the cytocompatibil ity of such materials, we have developed an in vitro cell system using human tracheal epithelial cells, arising from trachea superficial bio psies. 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 squa mous and secretory phenotypes. We have assessed the cytocompatibility of a cuff towards epithelial cells, first, by an indirect test, and se cond 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 lysi s after a 24 h incubation. Our study shows that this human tracheal ep ithelial cell system is a useful and relevant model which could be use d in a quality control procedure for testing the cytocompatibility of materials for endotracheal use.