Biodistribution analysis of injected human bone marrow mesenchymal stromal cells (hBMSCs) in pig femoral head by flow cytometry. hBMSCs were injected in the subchondral area of pig femoral head and analysed at different time point. (a) Blood was collected before (T0) and after injection with a kinetic of 1 minute to 24 hours. (b) Liver, lungs, spleen, and kidneys were analysed either at 30 minutes or 24 hours after injection. Periarticular muscles and round ligament were collected 30 minutes after injection. (c) Bone marrow was collected before (T0) and 24 hours after injection. Dark histogram: unstained hBMSCs; grey histogram: stained CD73-APC hBMSCs; and white histogram: negative control cells of a non-injected pig.