“…Mesenchymal stem cells (MSCs), as a suitable cell source, are considered as novel therapeutic agents for cartilage and bone diseases and injuries because of their special ability to differentiate into a variety of cell types and their potent capability to self-renewal and repair, as well as their high healing ability and their growth factor secretory capacity (6). MSCs have been identified in many tissues, including bone marrow, adipose tissue, and synovial tissue (6). In addition, because lack of human leucocyte antigen (HLA) class II expression, mesenchymal stem cells are also able to retain immunomodulatory activity in vivo (7).…”