Musculoskeletal Care of the Mature Patient
Generating cartilage from stem cells
What is the real story of stem cell therapy for osteoarthritis? Last week, I promised you more on stem cells so here goes.
Generating cartilage using adult human cartilage cells is very challenging as osteoarthritic patients have cartilage that is not readily responsive to the usual growth factors. Degeneration of cartilage is known to be an aberrant, cell-mediated, functional degradation of tissue in response to structural failure linked to aging, genetics, inadequate metabolite transport, loading history, and other environmental factors. Stem cells have been found in numerous adult tissues including bone marrow, adipose tissue, central nervous system, heart muscle and more. It is widely accepted that stem cells play a major role in regeneration following injury. The problem is that cartilage doesn’t naturally heal after we reach age 40, because resident stem cells lose their ability to proliferate and differentiate about that age.
There are three potential avenues for obtaining stem cells. The first, embryonic, have the attraction of being relatively pristine but political and ethical interests have made this resource unattainable. Autologous stem cells from fat or bone marrow seem to have the most promise for now. To increase the number of stem cells recovered from the bone marrow, the material would best be treated with growth factors, cytokines and chemokines however governmental regulations as well as sterility concerns preclude this step.
Enter the stem cell available from adipose tissue. By performing liposuction and concentrating the materials recovered in a centrifuge with a filter, one has a resource for stem cells to ad to a matrix and provide stem cells a “home” in which to grow. That’s what vet-stem has been doing in animals for seven years and is preparing to offer in humans once licensed and built. The final obstacle is the FDA approval process in that there will be no approval until clinical trials have established human efficacy. Until then an interested patient would have to look outside the United States but patient beware. In osteoarthritis, there has been no scientific clinical proof up until now that a biologic knee or hip resurfacing will soon replace a joint prosthesis in clinical practice