Skin wounds have a tremendous negative impact on healthcare systems and the economy worldwide. It was reported recently that nearly one billion people suffer from acute and chronic wounds globally. This enormous number translates into huge financial expenditures. It was estimated that in developed countries, the expenditures associated with chronic wound management accounted for as much as 3% of total healthcare spending. For instance, in the United States, the overall costs associated with chronic wounds is approximated to be 50 billion USD per year. The situation is likely to be aggravated by low healing rates. In fact, it was reported that publicly available healing rates for skin wounds were significantly overestimated. In particular, the data from randomized-controlled studies provides an average healing rate of 40%, whereas the reported rate is usually greater than 90%. The classification of skin wounds into acute and chronic is based on the pathogenesis and consequences. Acute wounds undergo a series of molecular events that eventually result in the regaining of structural integrity. By contrast, chronic wounds fail to resolve and are characterized by pathologic processes, such as continuous inflammation, persistent infections and necrosis.
