Fig. 1From: The impact of collagen membranes on 3D gingival fibroblast toroidsFormation of gingival fibroblast toroids. Human gingival fibroblasts were seeded into agarose molds and evenly settled into toroid-shaped recesses. After 24 h, toroids contracted to a compact 3D structure where the lumen is not visible anymore. HE-stained toroids show numerous basophilic cell nuclei of similar shapes and even distributionBack to article page