Figure 2. Reconstructing the breast. Schematic of 3D microfabrication procedure used to build the mammary epithelial tissues. Preadipocytes are seeded in unpolymerized collagen. Cavities of collagen gel are generated by molding the cell-gel mixture around a patterned elastomeric stamp. In the presence of differentiation medium (DM), preadipocytes are induced to differentiate into adipocytes. Epithelial cells are then embedded into the cavities, which form hollow tubules conforming to the size and shape of the collagen cavities.