The role of adipose stem cells seeded on a cross-linked bovine tendon collagen and glycosaminoglycan (chondroitin-6-sulfate) scaffold in the treatment of ulcers of the lower limbs.

Stem cells have the ability to regenerate themselves and to differentiate in one, or several, differently specialized cells. They are present in many human adult tissues, such as blood, bone marrow, adipose tissue, musculoskeletal tissue, epidermis, brain and vascular tissue, and they are important for tissue repairing and for maintaining cellular homeostasis (regenerative capacity). It has been shown that these stem cells are able to differentiate, through specific stimuli, not only in the cells of the tissue from which they were isolated, but also in other not related phylogenetically to the tissue in which they reside. One of the main source of stem cells is adipose tissue, in which recent studies have demonstrated the presence of multipotent and pluripotent stem cells, all able to regenerate themselves and to differentiate in various specialized cell types. Fat transfer, an easy technique, with limited invasiveness, executable in Day-Hospital, repeatable and with high compliance and poor in complication, has always aroused great interest in Plastic Surgery. Adipose tissue has been used previously by some authors for the treatment of post traumatic lesion, bed sores at first stage or skin ulcers of various ethioloy. In these studies, however, fat was always used in combination with other regenerative factors, such as mesenchymal cells or platelet rich plasma. ADSCs contribute to healing of the ulcer through stimulation of processes that involve the formation of a neo-epithelial barrier similar to the skin, together with angiogenetic factors and antiapoptotic factors such as monobutyril, VEGF, leptin, and KGF. In our project we want to strengthen the usefulness of a regenerative intervention in the treatment of pathological conditions like chronic ulcers refractory to conventional treatments, using an alternative model of wound dressing. The purpose is to use a cross-linked bovine tendon collagen and glycosaminoglycan (chondroitin-6-sulfate) scaffold sprinkled with ADSCs taken from each patient, for the treatment of chronic lesions. Previous studies have demonstrated the adhesion and survival of ADSCs in this kind of scaffold, but never tried this model in vivo (animal/human).