Stem cells and diabetic foot ulcers
Diabetic foot ulcers (DFUs) are a significant and rapidly growing complication of diabetes. The International Working Group on the Diabetic Foot describes a diabetic foot ulcer (DFU) as a full-thickness wound or sore located below the ankle in a person with diabetes. These ulcers are associated with diabetic peripheral neuropathy (loss of feeling) and peripheral arterial disease (poor blood flow). Foot ulcers are the most prevalent foot complication, with a yearly incidence of around two to four percent and a lifetime incidence between 15 and 25 percent.
Over half of diabetic patients who develop a single ulcer will likely develop another one which in the majority of cases will become a chronic non-healing ulcer. One-third will progress to lower extremity amputation. The most common reasons foot ulcers develop are peripheral neuropathy, foot deformities, minor foot trauma, and peripheral artery disease.
Diabetic peripheral neuropathy, present in 60 percent of diabetic persons and 80 percent of diabetic persons with a foot ulcer have the greatest risk of foot ulceration. Once the skin is ulcerated, it can become infected and lead to an amputation or even death. Only two thirds of foot ulcers eventually heal and up to 40 percent can reoccur and 28 percent may result in some form of lower extremity amputation. Every year, more than 1 million people with diabetes lose a part of their leg. This occurs every 20 seconds somewhere in the world. Eighty five percent of all amputations are preceded by an ulcer and can be prevented. The five-year death rate following a diabetic foot ulcer or amputation is almost 50 percent and it is higher for persons with prostate cancer and breast cancer. Prevention of foot ulcers are very important and a major priority in diabetic foot care.
Over past decades, the outcome for patients with DFUs have not improved, despite advances in wound care. Current treatment guidelines for DFUs recommend debridement, management of infection, improving blood flow to the foot, and taking the pressure of the foot to promote healing. However, ischemia (no blood flow), infection, neuropathy, and metabolic disorders such as diabetes frequently delay wound healing.
Use of stem cells is becoming a promising therapeutic strategy to treat diabetic foot ulcers. Stem cell therapy, also known as regenerative medicine, promotes the repair response of diseased, dysfunctional or injured tissue using stem cells. Stem cells are the body’s raw materials — cells from which all other cells with specialized functions are made. Under the right conditions in the body or a lab, stem cells divide to form more cells called daughter cells. These daughter cells can become more stem cells (self-renewal) or be manipulated to specialize (differentiation) into specific types of cells with a specific function, such as skin cells for wound healing, blood cells, brain cells, heart muscle cells or bone cells. No other cell in the body has the natural ability to generate new cell types. This is why stem cells are so important.
Stem cells come from several sources in the body. Some come from embryos (new babies in the womb) that are three to five days old. These are pluripotent (ploo-RIP-uh-tunt) stem cells, meaning they can divide and become any type of cell. Stem cells are also found in small numbers in most adult tissues, such as bone marrow or fat. Compared with embryonic stem cells, adult stem cells are less and have a limited ability to change into other types of cells. The third type of stem cells are perinatal stem cells. These are found in amniotic fluid as well as umbilical cord blood. They also have the ability to change into specialized cells. Recent advances in under- standing the cellular and molecular complexities of wound healing have identified clotting (coagulation), inflammation, cell movement (migration), and cell growth (proliferation) as critical steps required for tissue remodeling and wound healing. Stem cells are a promising treatment for diabetic foot ulcers because they are capable of targeting and by-passing the underlying abnormal healing mechanisms and damaged (deranged) cell signaling in these wounds to promote healthy wound healing. Stem cells make (synthesize) and secrete chemicals called cytokines that promote cell recruitment, immunomodulation, extracellular matrix remodeling, angiogenesis, and neuro-regeneration, all of which promote wound healing. This means, that the cytokines cause an increase in the number of healing cells and growth factors in the area, improving the immune functioning, improving the growth and function of skin cells, new blood vessels and nerves in the wound that all lead to wound healing. Stem cells are also capable of changing into various cell types, such as new skin cells – myofibroblasts, keratinocytes, pericytes, and endothelial cells that are needed for wound healing.
This is a very exciting topic and all the uses of stem cells are yet to be discovered. Definitely more research is needed in this area and we eagerly await the time when stem cells are readily available for healing diabetic foot ulcers. Until then, it is vital for all diabetics to do all they can to prevent diabetic foot ulcers by:
• Ensuring their blood sugar is under control by healthy eating, exercise and taking medication;
• Checking their feet daily if they can see well or have a family member do it;
• Protecting the feet and avoid injury by wearing correct style and size shoes and not soaking the feet in hot water;
• Providing care for the feet regularly, and seeing a podiatrist at least once per year for regular examination and care. If there is a problem or concern with the feet, seek medical care right away.
• For more information or to see a podiatrist visit Bahamas Foot Centre Rosetta Street, telephone 325-2996 or Bahamas Surgical Associates Centre, Albury Lane, telephone 394-5820 or email firstname.lastname@example.org or visit www.apma.org.