By Jordan Sudario-Cook

Cartilage Cartilage is flexible connective tissue found mainly in joints. Produced of specialized cells called chondrocytes which originate from mesenchymal stem cells. When damaged, cartilage repairs very slowly. Many people suffer from diseases that affect the cartilage such as osteoarthritis, costochondritis, and relapsing polychondritis.

History of Cartilage Repair A Russian morphologist, Alexander Maximow, finds a precursor cell in mesenchyme that differentiates into different cells Dr. McCulloch and Dr. Till find self-renewing cells in mice bone marrow. 1970’s-Dr. Freidenstein finds the potential for multipotent marrow cells to reproduce Swedish researchers used autologous chondrocytes to repair a rabbits damaged patella calling the procedure autologous chondrocyte implantation (ACI) The ACI procedure became available for human use Current- Research for the use of mesenchymal stem cells to be used for damaged cartilage.

Current Cartilage Repair Technology Marrow Stimulation Damaged cartilage is drilled out of joint until doctors reach bone. The bone is then perforated forming a blood clot at the joint which will eventually produce fibrocartilage. Osteochondral Autografts The damaged cartilage is taken from the joint and healthy cartilage from another area replaces it. The damaged cartilage is then put into the area where the healthy cartilage was taken. Autologous Chondrocyte Implantation Small amount of healthy cartilage is taken from a joint and the chondrocytes are isolated and grown in vitro until there is enough cartilage to be implanted.

Mesenchymal Stem Cell Transplantation Mesenchymal cells taken from adipose tissue, bone marrow, or embryonic connective tissue. These cells are then cultured and made to reproduce and once there is enough to replace the cartilage, it is implanted into the joint with a growth factor to continue growth as well as a scaffold to promote the shape of the cartilage. Either while being cultured or after implantation, a signal is introduced to the mesenchymal cells to differentiate into cartilage.

Mesenchymal Stem Cell Transplantation This procedure has been mainly tested on animal subjects such as rats and goats. Recently, a couple cases have been successful in repairing menisci in patients with damaged knee cartilage. The procedure still has many years until it is used in the medical field.

Limitations The acquiring of the mesenchymal stem cells for the procedure. Hasn’t been tested on humans in a large scale yet. Cartilage formed may still not work as effectively. When procedure is available it will likely be expensive.

Future Use in the medical field. Will become the main procedure in cartilage repair. Easier way to attain the mesenchymal stem cells. Decrease in the cost of the procedure.

References s_cartilage_growth s_cartilage_growth damage.aspx damage.aspx cells.html cells.html 11. Bean, Olivia S., and Eric M. Darling. “Isolation, Characterization, and Differentiation of Stem Cells for Cartilage Regeneration.” Annals of Biomedical Engineering (2012): Print.