The demographic shift and the increasing prevalence of chronic wounds represent major challenges for modern health care systems. Classic chronic wounds (venous ulcer, arterial ulcer, mixed ulcer, diabetic foot ulcer) persist for months or years with a very slow or even no healing progress. Patients suffer from pain and immobility, which dramatically reduces their quality of life. Complications such as infections or tissue necrosis can lead to a bad outcome and amputation of extremities.