Joris van Dongen

90 Chapter 4 ABSTRACT Background Adipose tissue has beenwidelyused in regenerative surgery for its therapeutic potential. The therapeutic potential of adipose tissue is often ascribed to the stromal vascular fraction (SVF), which can be mechanically isolated. Mechanical isolation results in SVF containing intact cell-cell communication including extracellular matrix and is therefore named tissue-SVF (tSVF). Objectives The Fractionation of Adipose Tissue (FAT) procedure, a procedure to mechanically isolate tSVF, is evaluated using a new disposable one-hole fractionator and compared to the former reusable three-hole fractionator. Methods The composition of tSVF obtained by the one-hole fractionator was histologically and histochemically compared to unprocessed adipose tissue. The number of viable nuclear cells in tSVF obtained by the onehole and three-hole fractionator as well as unprocessed adipose tissue were compared after enzymatic isolation and tested for colony forming unit capacity. Flow cytometry was used to compare different cell compositions based on surface marker expression between tSVF isolated by both types of fractionators. Results Fractionation of adipose tissue with the one-hole fractionator condenses vasculature and extracellular matrix by disrupting adipocytes. The number of viable nuclear cells in tSVF obtained by both fractionators was comparable and significantly higher than unprocessed lipoaspirate. Furthermore, tSVF isolated by both types of fractionators showed similar cell compositions and comparable colony forming unit capacities. Conclusion The FAT procedure with a disposable one-hole fractionator effectively isolates tSVF with a comparable cell count and cell composition in comparison with the three-hole reusable fractionator. A disposable one-hole fractionator, however, is safer and more user friendly.