From microchannels to microphysiological systems: Development of application specific devices

Abstract Microphysiological systems are an emerging field of biomimetic technologies which utilize microfluidics to reconstitute tissue functions within an in vitro environment. Microfluidic organ-on-a-chip platforms exist at the intersection of biology and engineering, straddling the forefront of cutting edge biological research, fluidics, and microfabrication technologies to emulate complex in vitro tissue systems within a highly controllable, accessible, and observable, in vitro environment. Although the advance of cell culture technologies from comparatively rudimentary conventional 2D petri dish based cultures to sophisticated 3D tissue engineering may seem futuristic, the microfluidic engineering concepts behind organ-on-a-chip technologies have deep historical roots which span over half a century. In this paper, we will discuss the shortcomings of conventional cell culture and organ modeling platforms which contributed to the demand for in vitro tissue engineering, as well as provide a background in the technological foundations of microfluidics. We will further recount a brief history of microfluidic cell culture, with emphasis on important developments in fabrication practices and methods of engineering biologically relevant microenvironmental conditions, before discussing the present state of organ specific microfluidic platforms and the future directions that the field may take to overcome present challenges.