Abstract
Wound healing is a well-orchestrated process, with various cells and growth factors coming into the wound bed at a specific time to influence the healing. Understanding the wound healing process is essential to generating wound healing products that help with hard-to-heal acute wounds and chronic wounds. The 2D scratch assay whereby a wound is created by scratching a confluent layer of cells on a 2D substrate is well established and used extensively but it has a major limitation—it lacks the complexity of the 3D wound healing environment. Established 3D wound healing models also have many limitations. In this paper, we present a novel 3D wound healing model that closely mimics the skin wound environment to study the cell migration of fibroblasts and keratinocytes. Three major components that exist in the wound environment are introduced in this new model: collagen, fibrin, and human foreskin fibroblasts. The novel 3D model consists of a defect, representing the actual wound, created by using a biopsy punch in a 3D collagen construct. The defect is then filled with collagen or with various solutions of fibrinogen and thrombin that polymerize into a 3D fibrin clot. Fibroblasts are then added on top of the collagen and their migration into the fibrin—or collagen—filled defect is followed for nine days. Our data clearly shows that fibroblasts migrate on both collagen and fibrin defects, though slightly faster on collagen defects than on fibrin defects. This paper shows the visibility of the model by introducing a defect filled with fibrin in a 3D collagen construct, thus mimicking a wound. Ongoing work examines keratinocyte migration on the defects of a 3D construct, which consists of collagen-containing fibroblasts. The model is also used to determine the effects of various growth factors, delivered in the wound defects, on fibroblasts’ and keratinocytes’ migration into the defects. Thus this novel 3D wound healing model provides a more complex wound healing assay than existing wound models.
Highlights
Wound healing is a complex process that consists of four main stages: hemostasis, inflammation, proliferation, and remodeling of the tissue [6,21]
We created a scratch in a confluent layer of fibroblasts seeded on collagen, fibrin, or polystyrene and measured the fibroblasts migration over two days
We have found that taking a condition medium from a 2D scratched wound healing increased the migration rate slightly but not statistically significantly (Figures 4 and 5) over untreated 3D collagen models, suggesting that some factors released from scratched wounds might be affecting cell migration
Summary
Wound healing is a complex process that consists of four main stages: hemostasis, inflammation, proliferation, and remodeling of the tissue [6,21]. Five to seven days after the initial injury, fibroblasts migrate to the wound site, secreting new collagen, and keratinocytes migrate from the wound edge and form a thin epithelial cell layer to close the wound [6,21]. Various growth factors secreted by invading cells such as macrophages, fibroblasts, and keratinocytes play an essential role during this process [6,21]. Examples of these growth factors include epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and platelet-derived growth factor (PDGF) [1,2,10,14]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
