PCL/EUG scaffolds with tunable stiffness can regulate macrophage secretion behavior.

Osteoarthritis (OA) is a prevalent joint disorder worldwide. Recent studies suggested that macrophages play an important role in the progression of OA. However, the detailed pathology related to macrophages is still ambiguous, especially those related to mechanotransduction. In this study, PCL/EUG composite scaffolds were first fabricated by electrospinning. The stiffness of as-fabricated scaffolds was controlled by adjusting the PCL-versus-EUG ratio. The mechanical properties, structural characterics and chemical composition of the scaffolds were investigated using various materials characterization techniques. The results showed that the stiffness of the scaffolds was in the same range as the cartilage tissues with OA. Confocal microscope and RT-PCR were performed to investigate the macrophages cultured on the scaffolds. Significant morphological change of cells was observed. The expression of inflammatory and fibrosis-related cytokines increases as the scaffold stiffness decreases, similar to the trend observed in OA progression.