Dressings with pH Sensors
Wound healing involves a complex sequence of biochemical processes leading to a significant variation in the levels of glucose, oxygen, pH, and other metabolic parameters. The pH level rises to 8 before falling to 5 or 6 during wound healing. A sustained high pH level is a signal that wound healing is stalled. Researchers from Empa's Laboratory for Biomimetic Membranes and Textiles teamed up with ETH Zurich, Centre Suisse d'Electronique et de Microtechnique, and University Hospital Zurich to develop a high-tech system that incorporates a customized fluorescent sensor in the dressing to monitor pH changes in wound fluids. The sensors are composed of benzalkonium chloride and pyranine. Benzalkonium chloride is a substance also used for conventional medical soap to combat bacteria, fungi, and other microorganisms. Pyranine is a dye that glows at pH levels between 5.5 and 7.5 in the visible or ultraviolet (UV) range. Weaker and stronger changes in color intensity can signal whether the wound fluid is alkaline or acidic. It might one day even be possible to read the signals with the aid of a smartphone camera. Combined with a simple app, wound care clinicians would have a tool that enables them to easily and conveniently read the wound status "from outside," even without a UV lamp.
Substance P in Tears as a Biomarker of Neuropathy
Substance P is a neuropeptide that acts as a neurotransmitter and is also involved in maintenance and nutrition of the cornea. The cornea has a rich network of fine nerves, which play critical roles in protecting and healing the surface of the eye. Corneal nerve fiber density, measured by confocal microscopy can predict diabetes-related damage to the peripheral nerves; one of the most common diabetes complications that causes symptoms, including pain and numbness of the hands and feet.
Researchers from the University of New South Wales, Sydney, Australia, had discovered that tear samples from patients with diabetes show low levels of substance P. The researchers measured substance P levels in the natural tear film in the eyes of 9 adults with diabetes and a control group of 17 nondiabetic subjects. Patients with diabetes had substantially lower levels of substance P in tear film samples compared to healthy controls. On confocal microscopy, the diabetic patients also had a significantly lower corneal nerve fiber density, indicating loss of corneal nerve fibers. High levels of substance P may be related to early damage to the corneal nerves contributing to the development of corneal ulcers and poor wound healing in patients with diabetes. Substance P levels were positively correlated with the corneal nerve fiber density measurement suggesting that the neuropeptide in tears may be a potential biomarker for corneal nerve health. Tear analysis may become a useful, noninvasive test for assessing the risk of peripheral neuropathy in patients with diabetes.
Mitochondria-targeted Antioxidant to Treat Diabetic Wounds
Researchers from the Lomonosov Moscow State University have tested the use of mitochondria-targeted antioxidant to treat diabetic wounds in mice. The experiments on cell cultures, along with detailed histologic examination of these wounds have shown that SkQ1 improved wound epithelization and granulation tissue formation stimulated vascularization in all the major steps of wound healing. It provides further evidence that reactive oxygen species produced in mitochondria play an important role in pathogenesis of diabetic wounds.
Ficin for Wound Healing
Enzymes, such as trypsin, chymotrypsin, or collagenase are used to necrotic tissues and fibrin clots and they have been used for wound treatment. Voronezh State University researchers have explored the use of ficin to treat biofilms formed by Staphylococcus. Ficin is an enzyme derives from figs latex and belongs to a family of proteases that also includes papain derived from papaya latex and bromelase extracted from pineapple stem. The advantage of a plant enzyme is less allergenic and cytotoxic compared to bacterial or animal proteins.
ReCell to Accelerate Healing of Donor Sites
Avita, a regenerative medicine company focused on the treatment of wounds and skin defects, is using its ReCell medical device to promote healing and minimize scarring. A small sample of skin is first collected from an area of normal skin. While the clinician prepares the affected area to be treated, the sample is processed using ReCell to generate a "spray suspension" (or RES – Regenerative Epithelial Suspension) of healthy skin cells. This suspension, containing all the necessary elements for the promotion of skin growth and regeneration, is then sprayed by the clinician onto the wound to be treated. The company presented data from 2 trials conducted at leading burns centers across the United States, including successful results from its pivotal trial needed for premarket approval with the Food and Drug Administration. Results of the latest randomized controlled trial involving 106 patients who received skin grafts showed that ReCell accelerated healing of split-thickness donor sties by 30.7%. The median time to complete reepithelialization was 9.0 days in the ReCell-treated group, compared with 13.0 days in the control group treated with hydrocolloid dressings.