It has been increasingly realized that the conventional planar cell cultures and the animals do not necessarily reproduce human physiology in vitro due to their limited structural and functional complexity and the genetic difference, respectively, oftentimes leading to inaccurate prediction of drug, chemical, and toxin effects as well as biased outcomes of biological investigations. Miniaturized physiological systems are therefore proposed as alternative platforms that are anticipated to bridge the gap between currently available models and the human body.
