Negative-pressure wound therapy induces endothelial progenitor cell mobilization in diabetic patients with foot infection or skin defects

Non healing chronic wounds are difficult to treat in patients with diabetes and can result in severe medical problems for these patients and for society. Negative-pressure wound therapy (NPWT) has been adopted to treat intractable chronic wounds and has been reported to be effective. However, the mechanisms underlying the effects of this treatment have not been elucidated. To assess the vasculogenic effect of NPWT, we evaluated the systemic mobilization of endothelial progenitor cells (EPCs) during NPWT. Twenty-two of 29 consecutive patients who presented at the clinic of Seoul National Universty Hospital between December 2009 and November 2010 who underwent NPWT for diabetic foot infections or skin ulcers were included in this study. Peripheral blood samples were taken before NPWT (pre-NPWT) and 7–14 days after the initiation of NPWT (during-NPWT). Fluorescence-activated cell sorting (FACS) analysis showed that the number of cells in EPC-enriched fractions increased after NPWT, and the numbers of EPC colony forming units (CFUs) significantly increased during NPWT. We believe that NPWT is useful for treating patients with diabetic foot infections and skin ulcers, especially when these conditions are accompanied by peripheral arterial insufficiency. The systemic mobilization of EPCs during NPWT may be a mechanism for healing intractable wounds in diabetic patients with foot infections or skin defects via the formation of increased granulation tissue with numerous small blood vessels. Orthopedic surgeons in South Korea have shown that negative-pressure wound therapy (NPWT), a strategy for treating chronic wounds in diabetic patients, mobilizes cells responsible for blood vessel reconstruction in injured tissue. Widely used to accelerate healing, NPWT entails sealing off a wound with a foam treatment, and then applying suction to remove any infected fluid. As diabetic patients with chronic non-healing wounds may also benefit from NPWT, Dong Yeon Lee and colleagues at Seoul National University examined its the physiological effects on these patients. They observed increased numbers of endothelial progenitor cells (EPCs) in blood samples collected one or two weeks after initiation of treatment. These cells are generally associated with formation of new vasculature in oxygen-deprived tissues. The researchers hypothesize that the local effects of negative pressure may directly invoke an EPC response that facilitates wound healing.