Micropatterned composite membrane guides oriented cell growth and vascularization for accelerating wound healing

Skin defect is common in daily life, but repairing large skin defects remains a challenge. Using biomaterials to deliver biochemical or physical factors to promote skin tissue regeneration is of great significance for accelerating wound healing. Specific surface micropatterns on biomaterials could affect cell behavior and tissue regeneration. However, few studies have focused on the construction of wound healing biomaterials with surface micropatterns and their role in skin tissue regeneration. In the present study, gelatin-polycaprolactone/silk fibroin composite membranes with different micropatterns were fabricated by photolithography, including line, grid and plane micropatterns. In vitro cell experiments demonstrated that the line micropattern on the composite membrane could guide cell-oriented growth, and more importantly, promote the expression of angiogenesis-related markers and alpha-smooth muscle actin (alpha-SMA) at both gene level and protein level. In the rat full-thickness skin defect model, the composite membrane with line micropatterns increased alpha-SMA production and neovascularization in wounds, leading to accelerated wound contraction and healing. The current study not only suggests that composite membranes with specific micropatterns can be promising wound repair materials but also provides new insights into the importance of biomaterial surface topology for tissue regeneration.