Abstract
Organ-on-a-chip (OoC) models are bioengineered tissue constructs integrated with microfluidics that recapitulate the key features of the physiology of human organs and tissues with applications related to drug development and personalized medicine. The characterization of OoCs relies on conventional labor-intensive approaches despite the many years of research in the field. The physical environment of the tissue constructs, functionality, and metabolic activity of the cells must be monitored to ensure the behavior of the cells, and the cellular environments represent in vivo physiology. Current efforts focus on monitoring these parameters, particularly with in-line biosensors integrated with OoCs. In this review, we describe the recent advances in different biosensing modalities applied to monitor the environment and functionality of OoC models and offer suggestions for future directions in OoC applications.