Matrix expression and proliferation of primary gingival fibroblasts in a three-dimensional cell culture model

The growth of cultured primary human gingival fibroblasts and the three-dimensional arrangement of the extracellular matrix in a polyester carrier system was investigated using various histological techniques. The results were compared with monolayer cultures. Collagen types I, III, V, and VI were investigated by conventional and fluorescence microscopy, scanning and transmission electron microscopy, and confocal laser scanning microscopy. Human gingival fibroblasts were obtained from tissue biopsies of five donors and were cultivated up to 5 weeks under three-dimensional culture conditions. The cells displayed an elongated, spindle-like or stellate morphology resembling the in vivo situation. Collagen type I revealed thick fiber bundles, and collagens type III and V were distributed as fine fibrils or small bundles throughout the culture system. Frequently, the fibers were oriented parallel to the long axis of the cells. Type VI collagen formed thin fibers and revealed a reticular pattern. In histological sections the cultured cells exhibited a morphology clearly different from that of cells cultured in monolayers. Their shape and spatial distribution resembled that of cells in tissue biopsies more closely. The culture system presented here promotes a dynamic model for performing studies for instance on the interactions of cultured cells with extracellular matrix molecules, on the pathogenesis of inflammatory processes or on the interactions with biomaterials, thus providing qualitative and quantitative information.