Articular cartilage is a connective tissue with low self-regeneration potential due to its avascular nature and lack of progenitor cells. Furthermore, this tissue is characterized by a dense and specific extracellular matrix (ECM). Fibronectin is a key constituent of the pericellular ECM, assembled into a fibrillar matrix through a cell-mediated process. Specifically, fibronectin links cell surface integrin receptors with collagens and others ECM proteins ^[1]. Although fibronectin is essential in chondrocytes condensation during cartilage development, its role during chondrogenic differentiation of mesenchymal stem cells (MSCs) has not been demonstrated.

In this study, we evaluate the chondrogenic potential of fibronectin bound at the surface of a nanofibrous substrate (NFM). For that, anti-fibronectin antibody was immobilized at the surface of NFMs, capable to selectively immobilize human fibronectin from platelet lysates (PL). The maximum immobilization capacity of anti-fibronectin antibody was 8 mg/mL. The chondrogenic potential of the immobilized autologous fibronectin was further assessed by culturing human bone marrow-derived MSCs during 28 days, without further induction. Unfunctionalized NFMs cultured under standard chondrogenic differentiation medium, basal medium with and without supplementation of human fibronectin were used as controls. The biological results indicate that NFMs functionalized with PL-derived fibronectin were able to conduct the chondrogenesis of MSCs, being as effective as the standard differentiation condition. Therefore, fibronectin also plays an important role in the chondrogenic differentiation of MSCs.

^[1] P. Singh, et al., J Cell Sci, 2014;