Different Kinds of Stem Cells

The political and scientific status of adult stem cells (also called mesenchymal stem cells, or MSCs) and embryonic stem cells (escs) is quite different and in need of constant clarification. Add to these two types of cells amniotic stem cells, recently discussed by Anthony Atala (Wake Forest) as another possible source of different- and still useful- cells that are normally discarded in amniotic fluid. But there are many more types. Even within our bone marrow, stem cells have begun to differentiate into subtypes. Catherine Verfaille has identified "multipotent" cells, that can make certain tissues such as muscle, cartilage & bone (MAP stem cells); but these cells cannot make, for example, liver or bladder. The different types of stem cells will eventually be classified based upon surface antigens or other biomarkers that give us an idea of what path they have already gone down...and what they can become.

News from the Orthopaedic Research Society

The recent ORS meeting in San Diego featured pretty good weather and lots of stuff about cartilage from contributors around the world. It will take several posts to summarize. Lots of people were talking about the Osiris study on using injectable stem cells for regeneration of the meniscus, which is the cushion of the knee joint. Non medical people sometimes call this the "cartilage", but I will call it the meniscus; the cartilage on this blog is the surface coating of the bone. Anyway, the cells did nada for the meniscus, which is too bad, but the investigators noticed there was some improvement in the cartilage, which is interesting. These are allograft stem cells, they come from a dead donor. I don't know if the injected cells seed themselves and grow, or if they just produce some chemicals (growth factors) that diffuse around the knee and help the other cells. This type of "co-culture" effect has been seen in the lab in other situations. Anyway, if there is something positive put out by the injected stem cells, that would be very, very interesting.

Cartilage Regeneration

Cartilage Regeneration
Orthopaedic Research Society
The ORS is to meet next week in San Diego for it Annual Meeting.
Expect many papers concerning stem cells, joint repair, cartilage
regeneration and growth factors. Many vendors use this meeting to bring
out new products. New forms of allograft material may be introduced this
year that are both safer and easier to use than prior techniques. Keep an eye on cell based
products that may be easier to deploy that older methods of ACI.