Figure 4.

An illustration of three scaffold characteristics that have a fundamental role in the response of cells. One important property is the microstructure of scaffolds that may influence cell infiltration (central scaffold SEM image reprinted with permission from [38], copyright (2012) Elsevier). Magnified SEM image shows the microstructure of a collagen-based scaffold. The chemical composition is another important property that can alter cell-scaffold adhesion. The chemical structure represents a hyaluronic acid disaccharide unit, n~5000 (Reprinted with permission from [138], copyright 1972 Nature Publishing Group). The mechanical property of the scaffold also plays an important role in cell response by influencing cell proliferation, differentiation and migration (the graph shows a typical stress-strain curve of a ductile material).