Medicinal signaling cells niche in stromal vascular fraction from lipoaspirate and microfragmented counterpart

AIM: To expand our previous findings by increasing the number of patients in a study characterizing medicinal signaling cells (MSC) of stromal vascular fraction from lipoaspirate (SVF-LA) and from microfragmented lipoaspirate (SVF-MLA) applied for the treatment of osteoarthritis (OA). METHODS: Twenty OA patients, including 8 new patients, acquiring autologous microfragmented adipose tissue were enrolled. In-parallel immunophenotyping of SVF-LA and SVF-MLA was performed. The samples were incubated in a DuraClone SC prototype tube targeting the CD31, CD34, CD45, CD73, CD90, CD105, and CD146 surface markers, stained with the DRAQ7 cell nuclear dye and Live/Dead Yellow Fixable Stain, and analyzed by flow cytometry. RESULTS: The population phenotypes in SVF-LA and SVF-MLA samples included CD31(+)CD34(+)CD73(±)CD90(±)CD105(±)CD146(±) endothelial progenitors (EP), CD31(+)CD34(-)CD73(±)CD90(±)CD105(-)CD146(±) mature endothelial cells, CD31(-)CD34(-)CD73(±)CD90(+)CD105(-)CD146(+) pericytes, CD31(-)CD34(+)CD73(±)CD90(+)CD105(-)CD146(+) transitional pericytes, and CD31(-)CD34(+)CD73(high)CD90(+)CD105(-)CD146(-) supra-adventitial-adipose stromal cells. Compared with the autologous SVF-LA samples, the prevailing cell type in SVF-MLA were EP, which outnumbered leukocytes and supra-adventitial-adipose stromal cells (SA-ASC). The ratio of progenitor cells in SVF-MLA samples differed between female and male patients, showing a higher EP-pericyte and pericyte-SA-ASC ratio in men. CONCLUSION: Our results, hallmarked by EP-enriched anti-inflammatory features and indicating a possible sex-specific impact, contribute to defining the cellular composition of the clinically applied MSC serving as a regenerative cell therapy in OA.