Platelets as Regulators of Wound Healing

Wound healing occurs through a well-orchestrated series of events encompassing hemostasis, inflammation, cellular proliferation and tissue remodeling. Platelets are specialized vascular secretory cells that rapidly accumulate at sites of injury, quickly becoming the most prevalent cell type. They undergo expansive activation within damaged tissue, initiated by the exposure of extracellular matrix proteins and by the local generation of thrombin. Platelets contain numerous granule types which hold more than 300 biological active components. The content of these granules are released upon platelet activation. A wealth of studies now demonstrates that the contents of these granules are able to regulate most stages of wound healing. In the past two decades an increased understanding of the physiological roles of platelets in wound healing has led to the idea of using platelet products as therapeutic tools to enhance skin repair. This article highlights the mechanisms by which platelets enhance wound closure and discusses the clinical effect of platelet therapy on wound healing.