CVUs develop as a consequence of impaired venous drainage of the lower extremities, mainly due to venous reflux or venous outflow obstruction. The increased venous pressure causes micro-circulatory disturbances, initiating a cascade of pathophysiological events that lead to tissue breakdown and the development of painful wounds. To date there is no conclusive evidence that any particular dressing, topical agent or systemic agent can effectively improve venous ulcer healing. For severely affected patients, surgical interventions aiming at eliminating the cause of the venous hypertension are often the last hope.

CVUs develop as a consequence of impaired venous drainage of the lower extremities, mainly due to venous reflux or venous outflow obstruction. The increased venous pressure causes micro-circulatory disturbances, initiating a cascade of pathophysiological events that lead to tissue breakdown and the development of painful wounds. To date there is no conclusive evidence that any particular dressing, topical agent or systemic agent can effectively improve venous ulcer healing. For severely affected patients, surgical interventions aiming at eliminating the cause of the venous hypertension are often the last hope.

During the course of diabetes mellitus, DFUs represent the most common and severe complication, affecting 15 % of diabetic patients in their lifetime. DFUs are the major cause of hospitalization of diabetic patients. It is estimated that approximately 50-70 % of total lower limb amputations are due to DFUs. This number is expected to increase further, reflecting the increasing number of diabetic patients from 463 million in 2019 to 700 million by 2045 and obese patients, as predicted by the International Diabetes Federation (IDF).

ACLF is a condition characterized by an acute hepatic decompensation in patients with chronic liver disease, which is accompanied by multi-organ failure and a profound systemic inflammatory response. Non-manageable organ damages and secondary infections account for a poor short-term survival with 30-day lethality rates ranging up to 77 %, depending on the number of extrahepatic organ failures. ACLF requires intensive care, in most of the cases, liver transplantation would be the only effective treatment option. However, it is restricted by the limited availability of donor organs.

RDEB is an inherited, clinically and genetically heterogenous severe skin disorder. The disease affects about 500,000 individuals worldwide. EB patients suffer from extremely fragile skin and mucosa, caused by cytoskeletal disorganization followed by the loss of anchorage of the epidermis to the underlying dermis. Thus, even a minor mechanical trauma or friction can lead to blisters, erosions and open, slowly healing wounds. The life expectancy of EB patients is highly dependent on the subtype, inheritance pattern and severity of the disease. In its severest forms, EB can lead to death in early childhood or increase the risk of dying from metastatic skin carcinoma in early adulthood.

Limbal stem cells (LSCs) are crucial for the regular physiological regeneration of the transparent anterior part of human eye, i.e. the corneal epithelium. Damage to the limbus, the area which forms the border between cornea and sclera, may cause a lack of LSCs leading to LSCD. Typical symptoms of LSCD involve corneal conjunctivalization, neovascularization and scarring as well as chronic ocular inflammation. This contributes to a loss of corneal transparency and may finally lead to profound vision impairment or even blindness. Conventional treatment options for corneal disorders like LSCD include transplantation of limbal auto- or allografts. However, limbal donor tissue is limited and transplantation is associated with a high risk of rejection.

Clinical success of transplantation has been described to be associated with the percentage of stem cells, characterized by expression of p63. Being a transcription factor, purification for p63 is unfortunately not feasible due to its intracellular location, but co-expression with the membrane-bound ABC transporter ABCB5 has been recently found allowing for monoclonal antibody-based LSC sorting. Besides its advantage in terms of purification, a central role of ABCB5 in corneal development and repair has been shown so far by various authors. This suggests that the natural stem cell pool could potentially be restored by topical administration of ABCB5+ LSCs to the eye affected with LSCD, leading to regeneration of the corneal tissue to improve or restore vision.