Joris van Dongen

17 General introduction and outline of the thesis FAT procedure using additional validation techniques, while chapter 5 shows the immunomodulative effect of SVFon chondrocytes. In chapter6 , an extensive overview is given of protocols to use and validate the FAT procedure. A decrease in skin quality can be caused by a physiological process i.e. ageing or pathophysiological processes e.g. scarring or fibroproliferative diseases. Although the mechanism of (patho)-physiological processes affecting skin quality differs highly, many studies suggest that lipofilling or any component of adipose tissue e.g. SVF provides skin rejuvenation regardless the nature of decreased skin quality. In chapter 7 an extensive overview is given of the role of lipofilling as anti-scarring treatment. In this review, both the clinical evidence as well as the mechanism of action based on in vitro and animal experiments is described. In chapter 8 , a multicenter prospective randomized placebo-controlled trial is performed to study the effect of SVF on scarring in a mamma-reduction model. Of each patient, one breast serves as control, while the wound of the other breast receives SVF. We hypothesized that early intervention to improve wound healing would result in a less visible scar. In chapter 9 , a randomized placebo-controlled trial is performed investigating the effect of lipofilling on facial skin rejuvenation due to ageing. Our hypothesis is that the addition of platelet-rich plasma, a known stimulator of ASCs, results in an improved skin elasticity in comparison with lipofilling alone. To further increase skin elasticity, we hypothesized that the addition of SVF to facial lipofilling in combination with platelet-rich plasma would benefit. Chapter 10 shows the results of a randomized placebo-controlled trial comparing SVF in combination with lipofilling and platelet-rich plasma to lipofilling and platelet- rich plasma alone. SVF is obtained by means of the FAT procedure. Chapter 11 systematically describes the clinical evidence of using adipose tissue as a treatment for facial skin rejuvenation due to ageing. SVF is believed to be pro-regenerative by secreting a plethora of released factors by ASC. Additionally, SVF contains extracellular matrix which is able to bind and release secreted factors by ASCs and thus functions as a natural scaffold to guide tissue regeneration. In chapter 12 , an off the shelve product is created based on gelated extracellular matrix incubated with released factors from ASCs. We hypothesized that this hydrogel would be able to stimulate important processes regarding wound healing and skin rejuvenation i.e. angiogenesis as well as fibroblast migration and proliferation. In chapter 13 , the toxicity of the hydrogel as a 3D in vitro culture model was studied. Finally, in chapter14 , the findings of this thesis and implications are being summarised and discussed as well as directions for future perspectives are underlined.