title: Microtechnology-based three-dimensional spheroid formation.
abstract: This article highlights the current state of three-dimensional spheroid/tissue formation technologies offering a new experimental platform that is both as reproducible as conventional in vitroexperiments and highly correlated to in vivo conditions. Three-dimensional tissue exhibit higher biological functions and reflect the in vivo context more precisely than classical two-dimensional cultures or monolayers. The applications cover highly efficient drug screening, regenerative medicine and fundamental biological research. Numerous three-dimensional spheroid and tissue formation devices have been developed over the past six decades. In early studies, mass production of spheroids using shaking, and non-adhesive surfaces and scaffolds in flasks was conducted. With the emergence of micro/nano fabrication technology and fundamental understanding of micro/nano fluidics, micro/nano devices capable of forming three-dimensional spheroids in a well-controlled manner have been extensively studied. The cell species composing spheroids include hepatic cells, cancer cells, primary cells and, more recently, stem cells. Formation of hetero-spheroids composed of different cells has also been attempted to further resemble the in vivo conditions. These new trends in spheroid research are particularly highlighted in this review.
authors.affiliation: Department of Mechanical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan. ota-mikilab@keio.to
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ota
authors.forename: Norihisa
authors.initials: N
authors.lastname: Miki
mesh_terms: D006801:Humans; D055616:Microtechnology / Q000379:methods*; D018874:Spheroids, Cellular / Q000166:cytology*; D023822:Tissue Engineering / Q000379:methods* / Q000639:trends