We could write a book chapter on the specifics of bone marrow and PRP and why it is considered the optimum tissue to use in treating orthopedic injuries, as well as the most FDA compliant, but I will try to stick to the most salient points.

Tissues regulated by the FDA fall under what is known as the Code of Federal Regulations, or CFR.

In November of 2017 the FDA issued two separate guidances under section21 CFR 1271.    On the day these were released the FDA commissioner made a statement regarding what he considers “bad actors” in the stem cell world.  In one statement he opined, “… the rapid growth and promise of this field has increasingly sowed the ground for the entry of some unscrupulous actors…”.

He went on to say, “To be clear, we remain committed to ensuring that patients have access to safe and effective regenerative medicine products as efficiently as possible.  We are also committed to making sure we take action against products being marketed that pose a significant risk to their safety.”

So to this point we are well within the “safe and effective” category under the FDA guidance for two main reasons; bone marrow concentrate or aspirate/BMC/BMA, and platelet rich plasma/PRP, are minimally manipulated, and are homologous.

What does that all mean?  Let’s start with “minimal manipulation”.  It means that cells are either centrifuged as in the case of PRP to concentrate platelets, or bone marrow to concentrate mesenchymal stem cells.   Or bone marrow is extracted using a special needle that requires no centrifuging at all.  In either case, the cells are not grown in a lab and expanded, and nothing is added to them that would change their original function in the body.

Per the FDA:

“1) For structural tissue, processing that does not alter the original relevant characteristics of the tissue relating to the tissue’s utility for reconstruction, repair, or replacement;

2) For cells or nonstructural tissues, processing that does not alter the relevant biological characteristics of cells or tissues.”

What is meant by the term homologous use?  The prefix homo in Latin means ‘same’, or ‘similar’.  There are two types of tissue the FDA address; structural tissue, and cells or nonstructural tissue.  This is where things can get a little muddy in terms of interpretation, especially for those clinics looking to justify using adipose tissue and placenta or cord umbilical based therapies, or those looking to treat a myriad of non-orthopedic diseases.

Per the FDA:

“What is the definition of homologous use?

Homologous use means the repair, reconstruction, replacement, or supplementation of a recipient’s cells or tissues with an HCT/P (human cells or tissues) that performs the same basic function or functions in the recipient as in the donor (21 CFR 1271.3(c)), including when such cells or tissues are for autologous use. We generally consider an HCT/P to be for homologous use when it is used to repair, reconstruct, replace, or supplement”

To quickly distill in all down, bone marrow and peripheral blood are considered cells or nonstructural tissues by the FDA.  Our purpose in using these is for their growth factor potential with PRP, and stem/progenitor cell and growth factor potential with bone marrow, for the purposes of aiding in orthopedic type tissue healing and regeneration.  If we however, manipulated adipose tissue (fat) for example, we would be using what is considered a structural type of tissue to accomplish something that should be accomplished by cells (stem cells and growth factors), healing and regeneration.  It’s a slippery slope when we start to stray away from the FDA guidance like so many “stem cell” clinics have done.

I hope this was an informative and approachable introduction to FDA guidance.

Dr. P