Cytotoxicity testing with three-dimensional cultures of transfected pulp-derived cells

SV40 large T-antigen-transfected bovine pulp-derived cells were grown three -dimensionally on polyamide meshes. For optimal cell growth, various cell n umbers and mesh coatings were tested. Next the three-dimensional cultures w ere used in a dentin barrier test device, and the system was evaluated by t esting a set of dental filling materials. After 24 hr exposure with or with out perfusion of the pulpal part of the test device, cell survival was eval uated using an WITT assay. In all experiments pulp-derived cells transfecte d with SV40 large T-antigen grew three-dimensionally on polyamide meshes an d showed growth kinetics similar to those on cell culture plates with lag, log, and plateau phases (reached after about 14 days of incubation), Cross- sections of the three-dimensional cell cultures revealed about 15 to 20 cel l layers. In vitro cytotoxicity tests resulted in cell survival rates which are in good agreement with in vivo data and with results obtained from cyt otoxicity tests with three-dimensional cultures of human foreskin fibroblas ts.