Skin substitutes for burn wound closure
After a burn, wound closure is a critical part of recovery. Burns that destroy part of the upper layer of skin, the epidermis, can usually heal without skin grafting. However, when burns destroy both layers of skin, the epidermis and the dermis, skin grafting is required for healing. In patients with very large burns, skin substitutes can help speed healing and recovery by providing additional material for skin grafting.
Engineered skin substitutes are made through a process called “tissue engineering.” This involves the isolation of cells from a patient’s unburned skin. These cells are combined with a “scaffold,” such as collagen, to provide structural support, and are cultured in the lab to form a skin-like tissue.
Skin substitutes previously developed by scientists at Shriners Hospitals for Children — Cincinnati were made using two critical cell types: keratinocytes from the epidermis (upper skin layer) and fibroblasts from the dermis (lower skin layer). Clinical trials showed the potential for engineered skin to help healing in patients with very large burns. However, the color of the healed skin substitutes was not a good match for the patients’ natural skin color, and structures such as hair were not present.
Current studies are developing and testing more complex skin substitutes that include other cell types, in addition to keratinocytes and fibroblasts. Next-generation skin substitutes will contain melanocytes, which are pigment-producing cells, to regulate skin color, and hair follicle stem cells, for regrowth of hair. This research will lead to skin substitutes that look and function more like natural skin.
Scarring is a natural part of the healing process. Unfortunately, burns can result in abnormal scars including hypertrophic scars that reduce overall quality of life. Hypertrophic scars are thick, raised scars that can be itchy, painful, and restrict a patient’s range of motion. Researchers are studying two of the most common treatments—compression garments and laser therapy–to help determine the best way to treat and prevent hypertrophic scars after burns.
Immunology, inflammation, and infection
Research at Shriners Hospitals for Children — Cincinnati aims to understand how the body’s immune system responds to burn injury and fights infection. Burn injury can cause massive changes to the entire immune system, resulting in reduced immune function, increased susceptibility to infection, and excessive inflammation, which can lead to death if not properly controlled. Research seeks to understand these processes for development of better therapies for burn patients.
Meeting the nutritional needs of burn patients can be challenging because of the metabolic changes that occur after burns. Nutrition researchers have studied and tested formulations with various levels and types of proteins, fats, vitamins, minerals, probiotics, and fiber to determine the best combination to help improve recovery in burn patients. One formulation developed at Shriners Hospitals for Children — Cincinnati has been commercially developed and is being sold under the trade name IMPACT™. It is currently used to improve outcomes in surgical and trauma patients.
Nutrition researchers and clinicians are interested in the development of nutritional supplements that reduce inflammation and fight infections in burned individuals. Dietary components that boost immune function are called immunonutrients. Recent studies showed that some of the nutrients supplied in IMPACT™ might be immunonutrients. Some immunonutrients, such as fish oil and arginine, may help reduce inflammation and fight wound infection. They could potentially be used to help diseases involving inflammation, such as cardiovascular disease and type II diabetes. Current studies aim to test immunonutrients in humans to determine their safety and effectiveness.
Sleep is also vital for optimum recuperation from injury and illness. For patients with severe burns, getting sufficient sleep is difficult. Studies at Shriners Hospitals for Children — Cincinnati are unraveling the causes and effects of sleep deficiency after burns.
Researchers evaluate sleep using a painless test called polysomnography, which involves measuring brain waves, muscle tension, and eye movements using electrodes attached to the face and head. This test has been used to show that burn injury affects a patient’s internal clock, known as the circadian rhythm. This contributes to sleep deprivation, a problem that continues long after the burn wound has healed.
The Cincinnati’s research team is examining different types of interventions, such as sleep medications and alternative medicine approaches, to increase the time spent in deep, restorative sleep. This research will help determine new approaches for maximizing the quality of sleep, and, consequently, improve the outcomes in children recovering from burns.