Osteochondral unit-on-a-chip (OC-OoCs) are regarded as a promising platform for investigating the complex physiology of the osteochondral unit and its pathophysiology in disorders such as osteoarthritis (OA) and osteochondritis dissecans (OCD). The biomechanical heterogeneity of the osteochondral layers, which is critical to joint function, can be precisely engineered within OC-OoCs, making them ideal tools for studying physiological activities. In OA, multiple forms of endochondral ossification, including chondrocalcinosis and osteophyte formation, disrupt the normal tissue relationship of cartilage, subchondral bone plate, and subchondral trabecular bone. Additionally, cellular and molecular communication networks between cartilage and subchondral bone are altered due to increased vascularization, porosity, microcracks, and fissures. Recapitulating these key physiological factors is therefore a critical objective in OC-OoC design. This review summarizes the current advancements in OC-OoCs technology for bone and cartilage research and, from the aspects of both physiology of disease and engineering, highlights OC-OoCs' potential to advance our understanding of OA and facilitate the development of new therapeutic solutions.
Liu et al. (Wed,) studied this question.