Lubricin structural and functional characteristics, its participation in maintaining articular cartilage tribological parameters

Articular cartilage is constantly exposed to high loads. Wearing out of joints due to aging, as well as their poor functioning, is a common problem leading to a significant decline in the qualityof human life. Lubricin is one of the main components of the biological lubrication system, it is a surface-active mucinous glycoprotein, which plays an important role in cartilage integrity. Its main function is to protect the cartilage surfaces from excessive friction - a necessary condition for maintaining the health of mammal joints. Moreover, lubricin has growth-regulating properties, it participates in the maturation of the subchondral bone and prevents cell adhesion. Although the molecule of lubricin was discovered almost half a century ago, there is still not much data available. The molecule has a great potential in medical applications. Studying lubricin can help solve problems caused by joint diseases, such as osteoarthritis. This review presents up-to-date information about structural and functional features of lubricin, its role in maintaining the integrity of articular cartilage, which can serve as a basis for the development of chondroprotectors or as a material to improve existing joint prostheses.