Effect of Electrospun Silk Fibroin-Silk Sericin Films on Macrophage Polarization and Vascularization

Biomaterial implantation is followed by an inflammatory cascade dominated by the macrophages, which polarized to the proinflammation M1 phenotype or prohealing M2 phenotype. Generally, silk sericin (SS) is considered to be of high immunogenicity associated with native silk fibers. The blends of silk fibroin (SF) and SS in different mass ratios might elicit different host immune responses and induce macrophage phenotype switch. The objective of this study was to assess the effects of electrospun SF-SS fibrous films with different mass ratios (10:0, 9:1, 8:2, and 7:3) on the macrophage phenotypes and explore the optimal ratio of SF and SS for angiogenesis. Our results indicated that the macrophages were activated by the addition of SS. When the mass ratio of SF and SS reached 7:3, the film displayed the highest degree of vascularization. The macrophages were induced to secrete more M1 and M2 cytokines accompanying with high M2/M1 ratio. Taken together, this study provided a perspective to promote neovascularization by modulating appropriate host response and macrophage phenotypes in tissue engineering field.