The second class of wounds is the chronic wounds. Chronic wounds occur whenever the normally well-orchestrated reparative process does not proceed in a sequential and timely fashion from hemostasis and inflammation, through proliferation to remodeling. The process is necessarily complicated and can be delayed by many intrinsic and extrinsic factors along the way (1). Acute and chronic wounds pose a significant burden to patients, healthcare professionals, and the healthcare system, affecting more than 15.5 million patients and costing an estimated $ 500 billion annually (2-3). Based on their pathogenesis, there are four principle types of chronic wounds: venous ulcers, diabetic ulcers, arterial ischemic and pressure ulcers.