Regenerative medicine is “targeted to regenerate tissues and organs that cannot be naturally regenerated and restore their functions.” Human beings have a natural regenerative ability. Skin cells are renewed in a couple of months, i.e., dead skin cells are shed, e.g., as scurf. Similarly, “old” cells from stomach, intestines, lungs and blood vessels are regenerated by being replaced with new cells. Damaged skin (e.g., cuts) and bone fractures are also replaced with new cells. However, they may not be completely restored when the number of lost cells exceeds that of regenerated cells. “Regenerative medicine” aims to restore the structure and functions of adult body parts when the body cannot achieve this on its own. Artificial feet and dentures, organ transplantation, blood transfusion, and bone marrow transplantations in leukemia treatment are examples, as well as administration of cells into blood and repair or regeneration of tissues using stem cells. These approaches are collectively termed regenerative medicine. Today, various of cells are studied in regenerative medicine. Currently, TWOCELLS is working on “regenerative medicine using MSCs.” The treatment involves extracting MSCs from the patient’s tissue, proliferating them outside (in vitro), and transplanting them back into the patient’s body.
MSCs (Mesenchymal stem cells) are adult stem cells, which can be isolated from adult human or animal tissues such as bone marrow, adipose tissue, umbilical cord, and synovium (a membrane-like tissue covering joints). MSCs retain the ability to differentiate into various mature cells, such as bone cells, cartilage cells, cardiac muscle cells, fat cells, and nerve cells. MSCs are promising in cell therapy for various diseases, and to be applied for vast number of patients near the future. Because of their character as adult stem cells, MSCs have great advantages, such as lesser ethical risks, comparing with ES cells. They also have higher safety with minimized risks of cancer formation. On the other hand, MSCs exist only 1 in 100,000 of bone-marrow cells, and the number of MSCs decreases with aging. For this reason, it used to be necessary to take large amounts of bone marrow to prepare MSCs needed for treatment. In addition, the abilities for growth and differentiation are likely to get declined through sequential passage for their expansion. These circumstances made us have developed the method for MSC super-proliferation, maintaining their adequate abilities for growth and differentiation in collaboration with Prof. Yukio Kato of Hiroshima University (he was also appointed as a director of TWOCELLS). In this way, we have been engaging in extensive research and development, aiming the realization and spread of regenerative medicine.
Synovial-derived MSCs cultured in serum-free medium.