Figure 7

Schematic drawings of the proposed mechanism. Layer 1/4 had higher sericin than layer 2/3. Consequently, released sericin fragments are expected to be higher in layer 1/4 than in layer 2/3. The behaviour of macrophage with sericin differed according to the concentration. A high concentration of sericin increased the level of TNF-α expression in macrophages compared with a low concentration of sericin. The expression of osteogenic genes in osteoblasts was dependent on the concentration of applied TNF-α.