3D skin models along with skin-on-a-chip systems: A critical review

Skin is the largest organ in human body, and it plays an important role in regulating physiological microenvironments and acts as a barrier to protect human body from harmful intrusions. The demand for fully functional skin models (also called skin equivalents, SE) in an in-vivo mimicking culturing microenvironment has been increased dramatically due to the fast development in skin disease treatments and skin care products. Owing to the emerging of the concept and technology of organ-on-chips along with the three-dimensional (3D) bioprinting technology, 3D skin models and their applications have been fast evolving. In this paper, the advances in the development of 3D skin models along with skin-on-a-chip (SOC) are reviewed and commented. One of the findings with this paper is that the SOC together with the 3D bioprinting technology is promising to construct fully functional 3D skin models in the field of pharmaceutical and cosmetic industries.