ADIPOSE-DERIVED MULTIPOTENT STROMAL CELLS IN REGENERATIVE MEDICINE

Beside adipose tissue had been considered a discard product for many years, recently its role as regenerative agent has been widely recognized. Adipose tissue is a connective tissue constituted of adipocytes interspersed with collagen fibers and stromal vascular fraction (SVF), composed of adipose-derived multipotent stromal cells (ASCs), pre-adipocytes, fibroblasts, vascular endothelial cells and immune cells. The regenerative role is played specifically by the SVF and, inside it, especially by the ASCs, by secreting angiogenetic, anti-apoptotic, antiinflammatory and immunomodulatory growth factors. Surgeons use different strategies to reconstruct or repair damaged tissues and organs through adipose tissue. Among them, the most effective are the autologous fat transfer and tissue engineering. In the autologous fat transfer, autologous adipose tissue is harvested from one part of the body, purified through some processing techniques and reinjected where necessary. In tissue engineering, some scaffolds made of natural or synthetic materials are used in combination with ASCs and, sometimes, growth factors to repair or reconstruct tissues. The first experimental part of this doctoral thesis analyzes the in vitro performances of one automated closed device and two different disposable kits to process adipose tissue in comparison with the enzymatic digestion, which is the gold-standard technique. All three methods produce micrografts rich of ASCs. Parameters such as ASCs phenotype, viability, growth and replicative rate have been observed. The second experimental part of this thesis analyzes the in vitro and in vivo performances of different formulations of hyaluronic acid, a natural and very promising material to regenerate tissues, when combined with ASCs. Parameters such as ASCs viability, interaction with the hyaluronic acid material and adipogenesis have been observed.