Topography immune-responsive silk films for skin regeneration

Area of Science:

• Biomaterials Science
• Immunology
• Regenerative Medicine

Background:

• Scar formation and chronic wounds are significant public health issues linked to immune dysregulation.
• The role of topography in influencing immune responses and wound healing remains underexplored in current wound dressing designs.

Purpose of the Study:

• To investigate the impact of hierarchical topography on silk fibroin films for wound healing applications.
• To explore how engineered surface structures modulate macrophage behavior and subsequent cellular responses.

Main Methods:

• Fabrication of silk fibroin films with hierarchical structures using soft lithography and femtosecond laser ablation.
• Assessment of macrophage (RAW264.7) morphology and phenotypic polarization (M1/M2) in response to the hierarchical topography.
• Evaluation of fibroblast (L929) gene expression related to extracellular matrix production and wound healing.

Main Results:

• Hierarchical topography induced significant changes in macrophage morphology and promoted M1/M2 polarization.
• The dynamic M1 to M2 macrophage transition facilitated by the topography enhanced fibroblast expression of key healing markers (FN, coll-I, TGF-β1, α-SMA).
• In vivo studies demonstrated that SF films with hierarchical structures promoted full-thickness wound repair by regulating inflammation and enhancing neovascularization and collagen deposition.

Conclusions:

• Engineered hierarchical topography on silk fibroin films offers a novel strategy for developing immunomodulatory wound dressings.
• This approach effectively controls cellular behavior, leading to improved wound healing outcomes.
• Surface topography is a critical design element for advanced wound healing materials.