Joris van Dongen

225 tSVF enriched facial lipofilling with PRP BACKGROUND Lipofilling has rapidly become a popular treatment modality for facial rejuvenation to restore loss of volume and to decrease aging related skin characteristics e.g. wrinkles, pigmentation spots, pores or rosacea. 1 In literature, these effects are mainly ascribed to the presence of adipose tissue-derived stromal cells (ASCs) which reside in the stromal vascular fraction (SVF) of adipose tissue. The precursors of (cultured) ASCs are attached around vessels as peri-adventitial cells and pericytes. 2,3 ASCs secrete a plethora of growth factors, cytokines and proteins which could enhance tissue regeneration based on angiogenesis and matrix remodeling. 4,5 In this way, autologous lipofilling might reverse loss of facial skin elasticity. To enhance the regenerative effects of lipofilling, different additives have been advocated to use such as platelet-rich plasma (PRP) or SVF to increase the number of ASCs. SVF can be isolated by means of enzymatic or mechanical isolation. Enzymatic dissociation yields a single cell suspension of SVF (cSVF) without cell-cell communications and extracellular matrix, while mechanical dissociation results mainly in a SVF with intact cell-cell interactions including extracellular matrix (tissue-SVF (tSVF)). 6,7 The use of tSVF might be advantageous over cSVF because intact cell-cell interactions warrant retention of ASCs after injection. Additionally, an intact native network of extracellular matrix binds and releases cells as well as trophic factors and thus preserves the regenerative function of tSVF. In contrast to mechanical isolation, enzymatic isolation is time-consuming, expensive and clinical use of enzymes is forbidden by law in an increasingly number of countries. 6 PRP is defined as a portion of plasma of blood having a platelet concentration above baseline. Platelets serve as a source of regenerative growth factors and cytokines. 8 These regenerative factors have shown to influence ASCs in dose-dependent fashion in animal and in vitro studies. 9-11 A concentration of platelets above baseline results in increased cell proliferation and RNA expression of genes related to angiogenesis, matrix remodeling and wound healing. 9-11 To date, clinical studies using PRP as additive to autologous lipofilling have shown to reduce postoperative recovery time and showed preliminary evidence of increased dermal wound healing. 12-15 Plasma also contains fibrinogen, that will form fibrin fibers after activation with thrombin. Fibrin clots entrap platelet-released trophic factors and also serve as transient scaffolds for tissue repair. We hypothesized that tSVF augments the therapeutic benefit of PRP-supplemented lipofilling in treatment of aged facial female skin.