Recent advances in in vitro skin-on-a-chip models for drug testing

IntroductionThe skin is an organ that has the largest surface area and provides a barrier against external environment. While providing protection, it also interacts with other organs in the body and has implications for various diseases. Development of physiologically realistic in vitro models of the skin in the context of the whole body is important for studying these diseases and will be a valuable tool for pharmaceutical, cosmetics, and food industry.Area coveredThis article provides an overview of the skin structure, physiology, as well as drug metabolism in the skin, and dermatological diseases. We summarize various in vitro skin models currently available, as well as novel in vitro models based on organ-on-a-chip technology. We also explain the concept of multi-organ-on-a-chip and describe recent developments in this field aimed at recapitulating the interaction of the skin with other organs in the body.Expert opinionRecent developments in the organ-on-a-chip field have enabled the development of in vitro model systems that resemble human skin more closely than conventional models. In the near future, we will be seeing various model systems that allow researchers to study complex diseases in a more mechanistic manner, which will help the development of new pharmaceuticals for such diseases.