co.don AG engages in cell cultivation for the regenerative treatment of articular cartilage defects. Its customers include accident surgeons, orthopedic surgeons, and neurosurgeons in clinics and specialized practices. The firm's main product Spherox is a three-dimensional chondrocyte product used to treat articular cartilage defects in the knee with autologous cells by means of matrix-associated autologous chondrocyte transplantation. The company was founded in 1993 and is headquartered in Teltow, Germany.