Adipose tissue stromal vascular fraction:redrawing the lines

The research performed in this thesis aimed to investigate the difference in clinical effect of stromal vascular fraction on decreased skin quality due to a pathological cause (scarring/wounds) or physiological cause (ageing). Stromal vascular fraction of adipose tissue consist of all cell types including adipose derived stromal cells within adipose tissue except for the adipocytes itself. In the past years, the stromal vascular fraction has shown to harbour a high regenerative potential and can be isolated by enzymatic isolation. However, enzymatic isolation is time-consuming and expensive. In this thesis, we have developed an intra-operative mechanical isolation procedure to isolate the stromal vascular fraction, without the use of enzymes. In this way, our mechanical isolation procedure was able to isolate a highly viable stromal vascular fraction containing unaffected adipose derived stromal cells within 20 min. Using this mechanical isolation procedure, the effect of mechanically isolated stromal vascular fraction has been investigated to improve skin quality in patients. Research in this thesis has shown that the stromal vascular fraction was not able to improve decreased skin quality due to ageing in female patients; no improvement in skin texture or elasticity was shown. On the other hand, the stromal vascular fraction was able to improve wound healing after a bilateral mamma-reduction model. After 6 months, a fast healing occurred in the scars of the breasts that received stromal vascular fraction compared to the other control breast. However, after 12 months the increased wound healing rate was not visible in a difference in scar appearance. In vitro studies in this research showed that the clinical effect of a faster wound healing is probably ascribed to adipose derived stromal cells in the stromal vascular fraction which stimulate angiogenesis, decrease fibrosis and act anti-inflammatory. Additionally, it also contains extracellular matrix which is able to bind and release secreted factors by adipose derived stromal cells and thus functions as a natural scaffold to guide tissue regeneration