Developing an Artificial Synovial Membrane Model Using Hyaluronic Acid-Binding Peptides

In normal synovial membranes, CD68-fibroblast-like synoviocytes (FLSs) and CD68+ macrophage-like synoviocytes (MLSs) form a bilayer structure and secrete heteroglycans and proteins (primarily hyaluronic acid [HA] and lubricin [PRG4]) that lubricate the joint and produce synovial fluid. Notably, despite the important role of synovial membrane cells in rheumatological diseases, such as osteoarthritis (OA) and rheumatoid arthritis (RA), relatively few artificial synovial membrane models exist in the literature, and those that have been presented are often minimally biomimetic. HA is an integral part of a healthy synovial membrane and synovial fluid. Utilization of strategies introducing HA has been studied earlier; however, no such study exists utilizing endogenous HA for tissue engineering of the synovial membrane. In this study, we utilized hyaluronic acid binding peptide (HABPs) functionalized onto nanofibrous poly-ε-caprolactone (PCL) scaffolds following electrospinning. The physical properties, such as surface morphology and surface tribology, of these scaffolds were tested to ensure they exhibit characteristics reminiscent of the native synovial membranes. To further mimic the native synovial membranes, human dermal fibroblasts (hDFs) were seeded onto the surfaces of the HABP-functionalized scaffolds. In the study, the development of cells and their production of HA were tested to evaluate the therapeutic effect of artificial synovial membranes. The results showed that HABP-functionalized scaffolds aid in cell proliferation, HA retention on scaffolds, and HA secretion into the cell culture supernatant by hDFs. We conclude that HABP-functionalized artificial synovial membranes cultured with fibroblasts can serve as a suitable scaffold toward tissue engineering of human synovial membranes.