Stem Cells:  The Repairmen of the Body

Stem Cell ImageStem cells are cells that can renew themselves and turn into other cells (differentiate).  Most of what you’ve heard about stem cells is about embryonic stem cells.  Despite ethical issues, the good thing about stem cells from embryos is that they have great growth potential.  However, believe it or not, there is much much more published data on the properties of adult stem cells.

What are adult stem cells?  They are the “Repairmen of the Body”.  They live inside all of us in various tissues, poised to leap into action to repair damage as it occurs.  The problem is that as we age or get big injuries, we often can’t muster enough of these cells to the site to fully repair the area.

There are many types of adult stem cells.

The most common is known as a hematopoetic stem cells (HSC-CD 34+).  While these are easy to obtain from IV blood or bone marrow and are very plentiful, outside of a handful of cardiac and vascular applications, they are not well studied as being effective in treating a broad range of disease.  Despite this, the vast majority of what you see being billed as “stem cells” (where the cells are injected the same day as collected from bone marrow or blood) are these less useful cells.  The type of adult stem cell that is most often seen in research as being associated with tissue repair is a mesenchymal stem cell (MSC).

For orthopedic applications, two main types of MSC’s have been used, bone marrow derived and adipose derived.  Bone marrow stem cells are taken via a needle through a bone marrow aspirate.  The bone marrow aspiration procedure sounds like a big deal, but is consistently described by patients as very comfortable.  The second type of MSC is derived from fat tissue (adipose).  This can be obtained via liposuction.  For orthopedic applications, fat derived MSC’s consistently and dramatically under perform bone marrow derived cells.  In studies of cartilage repair, bone repair, and soft-tissue repair, bone marrow derived MSC’s are much more adept at these tasks.  This makes sense, as they perform this function naturally (homologous) everyday.  For example, if you break a bone, it’s these bone marrow MSC’s that help mend that bone.  In addition, for surgical micro fracture to repair small amounts of knee cartilage damage, it’s bone marrow MSC’s that are released to do that job.

Learn More about Stem Cells on the International Cellular Medicine Society’s website.