Microfluidic devices and their applicability to cell studies

Microfluidics and microfluidic devices are the perfect platform to perform cell-, tissue-, and organ-based studies. Not only is microfluidics at the same scale as most cells and organ features but also most microfluidic physical phenomena (e.g., laminar flow, high surface to volume ratio) are closer to what is physiologically experienced by cells than with standard equipment. Microfluidics also offers other advantages: (1) the flow and level of oxygen are physiologically relevant, (2) biocompatible materials, (3) 2D/3D fabrication and assembly for 2D/3D cell culture, (4) diverse geometries and operation modes, (5) high customization of surface features, (6) compatibility with standard analytical methods, and (7) available miniaturized analytical sensors.

In this chapter, microfluidics’ suitability for cell culture applications is discussed, as well as the relevance of scale in cell–cell interactions and establishing the right cell microenvironment. Some general drawbacks of microfluidics are presented, and its impact in cell-based studies is analyzed. A summary of the main fluid and cell handling methods available in microfluidic systems is also presented. In addition a detailed overview on how microfluidics has been and can be further used in cell culture, from 2D single cells to body-on-a-chip applications, supported with relevant examples from the literature, is described. A summary of relevant (bio)sensor strategies applicable to cell culture microfluidic systems is also included. Finally, we examine the main factors hindering a wider application of microfluidics in cell culture and cell-based studies and propose a list of necessary requirements in order to “close the gap” between microfluidics’ potential and its actual use in cell culture applications.