A Closer Look At The Role Of Collagen In Healing Complex Diabetic Foot Ulcerations
Currently, in the United States, the Centers for Disease Control and Prevention (CDC) reports there are approximately 25.8 million people with diabetes mellitus, which is 8.3 percent of the population.1 This number is estimated to grow to 44 million by the year 2034.
One of the most feared complications for the patient with diabetes is amputation. More than 60 percent of non-traumatic lower limb amputations occur in people with diabetes and these are preceded by diabetic foot ulcerations about 85 percent of the time.2 To complicate things further, approximately 15 percent of people with diabetes will develop foot ulceration in their lifetime.3 Patients with diabetes have multi-organ comorbidities that contribute to further complications, delayed healing and an increased risk of infection. Accordingly, it is imperative that we prevent diabetic foot wounds from occurring and heal the wounds we cannot prevent as expeditiously as possible.
It is important to understand the wound healing process so we can fully understand the optimal ways to heal these complex diabetic foot ulcerations. The wound healing process occurs in three phases. The initial inflammatory phase lasts about three to four days from the onset of injury. In this phase, platelets begin to form a clot and produce thrombin, which subsequently initiates the formation of fibrin. The platelets also release growth factors, which are essential for wound healing. White blood cells (neutrophils and macrophages) enter the wound to eliminate bacteria and necrotic tissue, and provide defense against infection.
The wound then moves into the proliferative phase, which begins approximately four days after injury and usually lasts three weeks. Growth factors stimulate the mitosis of fibroblasts and other cells (i.e. epithelial). Wound contraction and building of the collagen framework takes place as well as neovascularization and epithelialization.
The remodeling phase is the last stage of the wound healing process and can take up to two years to complete. This phase involves collagen synthesis and breakdown. The ultimate goal of wound healing is to restore the functional barrior of skin and increase the tensile strength of the scar.
How Collagen Can Speed Wound Healing
Collagen plays an important role in the wound healing process. Originally thought to be the framework of wound healing and the provider of structural support for all other processes to take place, collagen controls many other cellular functions necessary to heal a wound. These functions include cell shape and differentiation as well as migration and synthesis of a number of proteins.4
Patients with diabetes stall in the first stage of wound healing and cannot lay down collagen. Collagen affects every phase of wound healing. The hyperglycemia caused by decreased insulin availability and increased resistance to insulin can affect the cellular response to tissue injury.5 In diabetes mellitus, insulin is not in adequate supply, energy from carbohydrates cannot enter cells, the body cannot synthesize protein and lipolysis occurs.6
It is no surprise that wound care companies are focusing a lot of attention on collagen-based wound dressings. Currently, there are numerous types of collagen dressings available. These vary in the type of collagen as well as the concentration of collagen in the dressing. The collagen can come from a variety of sources such as bovine, equine and porcine. Many of the current collagen dressings also contain antimicrobial agents. These dressings are designed to increase fibroblast production. Several of the collagen dressings can also inhibit excess matrix metalloproteinases (MMPs). This is especially important in chronic wounds as the elevated levels of MMPs in these wounds degrade collagen.