In vitro multilineage potential and immunomodulatory properties of adipose derived stromal/stem cells obtained from nanofat lipoaspirates

Background: Among stem cell sources for regenerative therapy, human adipose derived stromal/stem cells (hASCs) have attracted a lot of attention over the last decade. hASCs are easily accessible, available in high numbers and their use does not pose ethical concerns. These cells can be obtained with minimal manipulation methods and have been used extensively in the autologous setting. However, the methods for tissue harvesting and grafting remain a crucial issue. This study aims at evaluating the biological features of hASCs obtained with nanofat, a novel liposuction technique, and at comparing them with hASCs obtained with the classical Coleman technique of adipose tissue harvesting. Materials and Methods: The nanofat methodology is a procedure alternative to the classical Coleman technique of fat harvesting and is characterized by the use of a thinner cannula. We analyzed hASCs derived from lipoaspirate samples collected using these two techniques. We assessed the immunophenotype, the rate of cell proliferation, adipogenic, osteogenic and chondrogenic differentiation potential and immunomodulatory properties of nanofat- and Coleman-processed hASCs. Results: Both liposuction procedures enabled isolation and expansion of hASCs with high efficiency. The immunophenotypic characterization showed an antigen profile similar to the pattern expressed by mesenchymal stem cells. hASCs obtained with the two methods displayed multilineage differentiation potential into the adipogenic, osteogenic and chondrogenic commitments. Finally, both nanofat- and Coleman-derived hASCs displayed immunomodulatory properties, as evidenced by their tolerogenic phenotype and their ability to inhibit lymphocyte proliferation in vitro. Conclusions: These results indicate that the stem cell component in the stromal vascular fraction is preserved in lipoaspirates obtained with the nanofat technique.