IN-VITRO RECONSTITUTED TISSUE AS AN ALTERNATIVE TO HUMAN RESPIRATORY-TRACT

The data obtained from in vitro systems utilizing human cells and tiss ues should form a basic part of the information necessary for risk ass essment. The most important thing for such systems is, therefore, to s imulate the structures and functions of cells and tissues in the nativ e organ as closely as possible, In designing in vitro systems, there m ay be two approaches--one aiming at the growth of cells in a primarily two-dimensional fashion, the other allowing cells to form in vivo-mim icking three-dimensional architectures. In cultures in which the airwa y epithelial cells are growing in a two-dimensional fashion, some func tional and structural characteristics can be developed to a considerab le extent. However, there are some that cannot be developed or express ed under that condition but require a three-dimensional growth pattern . In this paper we explore the capacity of early to long-term passage airway epithelial cells (human and hamster) to resume architectures an d functions existing in the native tissue in the specific environments given in vitro.