Stem Cells are cells in our bodies as children and adults which are important for the growth and healing potential of our body. These cells are one generation from some of the youngest cells present when we are developing in the womb, as an embryo. These stem cells can be found in multiple area of the body as adults and are named based upon the location where they can be obtained.
Stem cells have the ability to perform four functions which are important for regenerative potential: the ability to reproduce (proliferatory potential), the ability to differentiate and mature into a different number of cell lines (multipotentiality), the ability to mobilize in situations of blood vessel formation, and the ability to activate and control cells within their environment (trophic functions). Although all four of these functions can be used to the advantage of regenerative medicine, most scientists have sought to utilize the ability of stem cells to mature into a cell needed for repair. Stem cells also have ability to release growth factors and signaling molecules at a region of healing. For orthopaedic purposes, the mesenchymal stem cell has garnered the most interest due to its direct path to change into cells important for orthopaedic purposes.
Mesenchymal stem cells (MSCs) can be isolated from the bone marrow, lining of a joint (synovial tissue), lining around bones (periosteum), and fat. Cells obtained from different sites are slightly different. The peripheral blood stem cell (PBSC) is a cell that which is present within the blood stream and originates from the bone marrow. In laboratory studies, bone marrow derived, adipose derived, periosteum derived, and synovial derived MSCs as well as PBSCs have illustrated the ability to turn into bone cells, cartilage cells, and fat cells. Additionally, scientists have been able to turn bone marrow derived MSCs and PBSCs into brain cells, heart cells, and liver cells in laboratory study.
Progress with stem cells has been exciting in scientific laboratories and animal studies. However, some work is still required to apply what we have learned to patient care on a daily basis. The Food and Drug Administration (FDA) regulates the use of stem cells to treat patients. They have set up mechanisms to ensure that treatments utilizing stem cells are safe and useful for patients. Treatments involving bone marrow aspirate are currently the only treatments which orthopaedic surgeons can offer patients outside of clinical trials.
Bone marrow aspirate contains platelets and a patient’s own stem cells, which have the ability to replicate themselves or differentiate into various tissue types. Bone marrow aspirate can assist in treating certain injuries. Sometimes when an injury occurs, the number of stem cells available for tissue regeneration is inadequate. By using bone marrow aspirate, additional stem cells and growth factors can be placed at a site of injury to improve the overall healing process.
Bone marrow aspirate is a complex mixture of platelets, red blood cells, white blood cells, red blood precursor cells, and white blood precursor cells. Initially, the white blood precursor cells were thought to be cells that nurtured the growth of red blood cells alone. These cells were initially termed plastic-adherent cells due to this physical property of the cells. Later, these cells were found to have the ability to reproduce and change into cells of other types, thus acquiring the name mesenchymal stem cells. Initially isolated only on their ability to stick to tissue culture surfaces, when scientists studied these cells they found a broad mixture of cells which had the ability to turn into a number of different cell types. Since bone marrow aspirate and bone marrow aspirate concentrate contains platelets and mesenchymal stem cells, it is a combination growth factor therapy and cell therapy, utilizing the regenerative potential of platelet-rich plasma (PRP) and Mesenchymal Stem Cells.
Platelet-rich plasma a growth factor/cytokine therapy. It involves the isolation of platelets from a patient’s own blood and placing it at a given location. Platelets are found in our blood. They contain growth factors and other signaling molecules which are instrumental in the body’s normal healing response. Growth factors and cytokines are proteins which signal cells in our body. These molecules tell our body to grow or stimulate our body to heal in scenarios. When you have an injury, such as a cut on your skin, platelets are some of the first responders to arrive on the scene to stop the bleeding and stimulate other cells in your body to begin the healing process. Platelet-rich plasma is a tissue product that is made from a patient’s own blood; it is an autograft tissue.
Blood contains red blood cells, white blood cells, and platelets. These elements are suspended in a fluid called plasma. Platelet-rich plasma is made by first taking a small amount of blood from the blood stream. The blood is placed into a device that spins, also known as a centrifuge. The centrifuge separates the blood into layers through spinning. The layer including plasma and platelets is captured. This solution can then be placed at a site where healing or a response of the body is desired.
A complete evaluation of an injury or condition is necessary before Dr Anz can decide if PRP therapy is a consideration for treatment. If it is determined to be an option, the PRP therapy procedure will be scheduled, potentially on the day of evaluation or at a later date. PRP may not provide instant relief for the patient, as treatment with PRP seeks to improve the biology of healing or reduce inflammation related to a mechanical issue. During the procedure, Dr. Anz will inject the PRP solution into the injured area. In certain scenarios, PRP is used to augment a surgical procedure. Dr. Anz will discuss the benefits of using PRP in a given surgical procedure if it will improve the result after surgery.
For additional information, or if you would like to schedule an appointment with Dr. Adam W. Anz, orthopedic surgeon and sports medicine specialist, please contact his Gulf Breeze, FL office today.
Medical doctors often use the term biologics to refer to natural products that are harvested and used to augment a medical process. These products include tissues from a patient’s own body (often called autograft) and tissues from another patient’s body (often called allograft). These products can encompass a wide spectrum of tissues. For the purposes of orthopedics, therapies can be classified into three main categories:
- Growth Factory Therapies
- Cell Therapies
- Tissue Therapies
Growth factor therapies involve the harvest and delivery of growth factors to a site, such as in the setting of using platelet-rich plasma to augment healing after a partial tear of a tendon. Cell therapies involve the harvest and delivery of cells to a site, such as in the setting of cartilage repair with peripheral blood stem cells. Tissue therapies involve utilizing tissue to repair or augment a repair, such as in the setting of a meniscal allograft transplant. Many factors have effects on function, the potential for success, and the FDA regulatory concerns related to these treatments. There is a spectrum of treatments available within biologics. Similar to golf clubs in a golf bag, there are different therapies available for different patient problems.
Food and Drug Administration Regulation
It is important to understand the regulatory affairs concerning biologics in order to understand the potential for how they can be used to help patients. This is especially important for stem cell therapies, as cells are living biologic products. In 1997, the United States Food and Drug Administration (FDA) set forth in the Code of Federal Regulations Title 21 Part 1271, an approach to articles containing or consisting of all human cells, tissues, and cellular/tissue based products intended for implantation, transplantation, infusion, or transfer into a human recipient. These articles were abbreviated HCT/P’s, and the FDA employed a tiered approach to regulation of these articles, based on the FDA’s assessment of patient risk.
Low-risk biologics were set to be regulated by the Public Health Service Act 361 which required only that treatments be prepared involving techniques aimed to prevent the introduction, transmission, or spread of communicable diseases. These products do not require pre-market clinical studies or approval before they can be offered to patients. Higher risk products are regulated under Public Health Service Act 351, whereby they must also undergo animal and human clinical studies in order to prove that they are safe and worthwhile to be used in patient care. This hurdle prevents physicians from offering some stem cell treatments to patients such as cultured stem cell treatments, certain stem cell treatments from fat and blood, and stem cell treatments involving allograft stem cells.