Biodistribution analysis of injected autologous pig bone marrow mesenchymal stromal cells (BMSCs) in pig femoral head by flow cytometry. Characterization of pig BMSCs in vitro with (a) osteoblastic differentiation with an extensive mineralized matrix of calcium hydroxyapatite crystals stained in red by Alizarin Red S, (b) adipocyte differentiation with adipocytes containing lipid droplets in the cytoplasm stained in red by Oil Red O, and (c) chondrogenic differentiation with chondrocyte-like cells stained by hematoxylin in purple and surrounded by glycosaminoglycan-rich extracellular matrix stained in blue by Alcian Blue. (d) Biodistribution analysis by flow cytometry follow-up during 24 hours (n = 1) of autologous labeled DiOC18-FITC BMSCs injected in subchondral area of pig femoral head. Dark histogram: unstained pig BMSCs; grey histogram: stained DiOC18-FITC pig BMSCs; and white histogram: negative control cells of a non-injected pig. DiOC18, 3, 3′-dioctadecyloxacarbocyanine perchlorate; FITC, fluorescein isothiocyanate.