Practice Innovations
Lactate is a key player in cellular homeostasis and exerts powerful pleiotropic effects on wound healing. These properties have been exploited by next-generation synthetic Cellular, Acellular, Matrix-like Products (CAMPs) to help re-establish the healing cascade and afford hard-to-heal wounds the ability to heal. Here, we present the acronym RACE to describe lactate’s effects on the wound-healing cascade and comment on four patients that exemplify each effect. Ten main topics were identified and integrated into the RACE acronym. The acronym consists of the following elements: R - Reactive oxygen species generation for signal transduction, Redox homeostasis, Reduction of pH, and Reduction of inflammation; A - Angiogenesis stimulation; C - Collagen upregulation and Cell migration and attachment; and E - ECM deposition and boosting Energy availability. A case series of 3 patients illustrates these concepts. The first patient is a 71-year-old female with diabetes, hypertension, and a 2-year-old pyoderma gangrenosum ulcer. Multiple attempts to heal her wound failed due to the inflammatory nature of the ulcer. However, the wound healed after 5 weekly applications when switched to PLA matrices. Interestingly, the erythematous halo of the ulcer completely disappeared after 3 weeks, demonstrating lactate's powerful immunomodulatory and redox homeostasis effects. Patient number 2 is a 66-year-old male with poorly controlled diabetes and a foot ulcer with a history of repeated infections. Multispectral imaging after the application of PLA matrices showed increases in the oxygen saturation of the wound bed and peri-wound tissue. This was matched with an increased healing rate and a switch of the wound’s tissue from fibrous, necrotic to granular. After 8 weeks, the wound was fully closed without further infection episodes, probably due to the PLA pH shifting effect. Finally, patient 3 is an 89-year-old frail patient with a history of frequent difficult-to-heal skin tears due to tissue atrophy. PLA matrices led to the complete healing of tears in only 2 weeks, with adequate restoration of the skin integrity, showcasing the effects of lactate to recruit cells and allowing them to use the molecule as metabolic fuel.
Methods: A literature review was performed to identify the effects of lactate on wound healing.
Results:
Discussion: Despite traditionally being regarded as a waste product of cellular metabolism, lactate is a pleiotropic signalling molecule. The RACE to Heal acronym offers an easy way to remember its key effects in the healing cascade.