In this work, the authors performed a detailed in vitro characterization of the biological properties of micro-fragmented adipose tissue (MFAT) obtained from eight volunteers who underwent liposuction and provided material generated using the Lipogems device. MFAT cluster size varied from sample to sample with 51-76% being within the expected range of 0.3-0.75mm. Conditioned medium obtained from Lipogems samples showed a high capacity for secretion of important anti-inflammatory (interleukin-1 receptor-α antagonist), pro-regenerative factors such as hepatocyte growth factor and regenerative molecules such as transforming growth factor-β. In addition, the conditioned medium of all samples was able to stimulate angiogenesis in vitro, intracellular cell signalling associated with cell proliferation through ERK1/2 phosphorylation and block lipopolysaccharide-induced pro-inflammatory interleukin 1-β signalling in macrophages.
All samples were able to produce large quantities of colony forming units from the mesenchymal stem cells isolated following collagenase digestion-an indication of the viability and potential to secrete paracrine inducing molecules. In conclusion, although there was significant heterogeneity between samples from different individuals, the majority were highly biologically active and this study therefore provides a basis for understanding the mechanisms responsible for the incredible regenerative and pain-relieving capacity of MFAT in current therapeutics such as orthopaedic practice.