What Is the Composition of Bone Marrow Aspirate (BMA)?

BMA is derived from a patient’s bone marrow. It contains a heterogeneous mix of stem and progenitor cells, platelets and white blood cells—each making their own contribution to the healing process.

The chart below outlines key components of iliac-crest-derived bone marrow.

Components of iliac-crest-derived bone marrow

Stem Cells

Stem cells can differentiate into many different types of cells. There are several types of stem cells, including hematopoietic and mesenchymal. They vary in differentiation potential and the terminal cell types they can become. 

Hematopoietic stem cells (HSCs) typically differentiate into blood and vasculature cell components. Mesenchymal stem cells (MSCs) have the capability to differentiate into many different cell types responsible for repair or growth of bone, cartilage, muscle, marrow, tendons, ligaments and connective tissue.4,5,6,7 

Endothelial Progenitor Cells

Endothelial progenitor cells also retain the ability to differentiate into other cell types, but to a lesser extent than stem cells. Progenitor cells are capable of releasing BMP-2 and BMP-6, two bone morphogenetic proteins that play a role in bone formation.3

This chart demonstrates the differentiation potential of both stem cells and progenitor cells.

Stem Cells Versus Progenitor Cells

Neuringer IP and SH Randell, “Stem Cells and Repair of Lung Injuries.” Respiratory Research 2004; 5:6.

Platelets and Growth Factors

Platelets are rich in growth factors, which plays a critical role in the process of stem cell differentiation. Growth factors instruct stem cells to differentiate through proteins, which bind to receptors on the surface of the cell. A signal is delivered to the nucleus to turn off or turn on certain genes, which generates the proteins that dictate cell differentiation.

Lymphocytes and Granulocytes

Lymphocytes are small white blood cells that play a large role in immune response by protecting the body from disease. Lymphocytes also support the growth of endothelial progenitor cells, which can stimulate angiogenesis, release BMP-2 and BMP-6 and up-regulate the production of BMP-2.8

Granulocytes are a type of white blood cell filled with granules that digest microorganisms. Granulocytes release growth factors that support the development of new blood vessels (angiogenesis) necessary to support tissue regeneration and bone formation.9

Why Concentrated BMA?

Concentrated BMA delivers a highly concentrated sample of stem cells, progenitor cells and growth factors directly to the application site, harnessing the body’s biologic potential.

How Does Concentrated BMA Compare to Allografts and Xenografts?

An allograft is a transplant of an organ or tissue from one individual to another of the same species with a different genotype. For example, a transplant from one person to another person who is not an identical twin is an allograft. Allografts account for many human transplants, including those from cadavers, related living donors and unrelated living donors. Also known as an allogeneic graft or a homograft, a xenograft is tissue taken from a donor of one species and grafted into a recipient of another species—called also heterograft. They are stripped of their cell content due to the risk of an immune reaction upon implantation and are typically used as a biological scaffold.

The advantages of concentrated BMA over allografts and xenografts may include:

  • Less risk of immune response39,41
  • Higher heterogeneity of stem cells to support tissue regeneration57
  • Inexpensive alternative treatment40

Potential risks include:

  • Bruising
  • Pain at aspiration site
  • Excessive bleeding
  • Infection
  • Transient neuropathy

Why the Harvest® Bone Marrow Aspirate Concentrate (BMAC®) System?

Used for over a decade, the Harvest BMAC system offers the highest stem cell concentration and yield as compared to five other systems, as shown by the data here.

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