Microfabricated three-dimensional environments for single cell studies

!Received 24 February 2006; accepted 6 March 2006; published 7 April 2006"#DOI: 10.1116/1.2190698$Most of what is known about cells and their functionalregulation has been derived from cell cultures performed onat, mostly rigid culture surfaces, such as the ubiquitous dishintroduced by Julius Petri in 1877. However, results obtainedin two-dimensional cell cultures !2D" often lacked the powerto predict, for example, the toxicity of drugs in a wholeorganism