Three Dimensional Cell Culture: The Importance of Microenvironment in Regulation of Function

Abstract

The basic principle of three-dimensional (3D) cell cultures is to place cells in conditions that induce formation of multicellular, tissue-like structures developing in X, Y, and Z planes. The 3D structures are characterized by establishment of adhesion complexes and tissue polarity, and by changes in cytoskeletal structure and cell volume that are significantly different from those found in cells cultured as monolayers (2D). As a result, the phenotypes, function, and regulation of signaling pathways under 2D and 3D conditions are fundamentally different. The science, as well as the art, of 3D cultures center around the recapitulation of physiological behaviors found in the organism, where reciprocal and dynamic cell–cell and cell–ECM interactions affect intracellular biochemical and structural signals, and hence influence gene expression and homeostasis. The 3D culture systems provide unique opportunities to mimic many aspects of developmental and pathological phenomena, to elucidate molecular mechanisms, and to produce tissues for transplantation purposes. With apologies to many colleagues whose works are not cited, this chapter relies heavily on the examples from the authors' laboratories using mammary epithelial cells. This is partly because we are most familiar with this tissue and also, many of the details for mammary models have been worked out in nearly three decades. As such, the experience with mammary acinus is used as a possible road map for other tissues. Keywords: Biomaterial; Extracellular Matrix (ECM); Hydrogel; Mechanical Stress; Tissue Bioengineering