Engineering Microphysiological Systems for Aging Research: A Focus on the Materials Science Perspective

Aging is a process that spans all systems, from materials to biological constructs, and compromises their function considerably. Materials experience aging as a gradual loss of their properties through a series of structural, time-dependent changes. Biological aging is similar, yet more complex and multifactorial in many aspects. Aging-induced diseases in different organs and systems such as the brain, vasculature system, and skin, have been studied extensively using in vitro and in vivo platforms; however, both hold limitations, namely physiological relevance and experimental control, respectively. Microphysiological systems (MPSs) are a new generation of in vitro platforms that integrate relevant physiological aspects, specifically in the microenvironment of cells and tissue, that provide a more accurate model of diseases. Several 2D and 3D MPSs for studying aging-induced diseases and conditions have been developed recently, each one studying vastly different aging phenomena but relying on similar design parameters. This review explores the role of materials science in upholding the higher physiological accuracy of MPSs, as well as the limitation current biomaterials hold with respect to the dynamic environment they are designed to mimic. From material properties and fabrication techniques to the most recent advances in MPSs, this review aims to highlight the central role that materials scientists play in addressing current limitations in the field.