Human Plasma Protein Cocktail Decreases Burn Wound Expansion and Bacterial Growth

Abstract

Background: Burn injuries lead to hemolysis and inflammation, simultaneously releasing reactive oxygen species (ROS) and toxic extracellular components such as hemoglobin, heme, and iron. Although the body naturally counteracts this toxicity by increasing the production of plasma scavenger proteins such as haptoglobin (Hp), hemopexin (Hpx), and transferrin (Tf), this protective response takes several hours to reach its peak. In the case of more severe burns, these plasma proteins may be depleted. Iron also serves as a nutrient for growing pathogens, potentially leading to subsequent infection. Methods: We tested the effect of a human plasma protein cocktail consisting of Hp, Hpx, and Tf on hydrogen peroxide (H₂O₂)-induced ROS injury in vitro and a burn injury mouse model of full-thickness wounds using different delivery routes of the protein cocktail. In addition, the antibacterial properties of the protein cocktail were assessed against Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus). Results: Metabolic activity of human fibroblasts decreased significantly after 1000 μM of H₂O₂ treatment for 24 hours, while the protein cocktail significantly reversed this effect in a dose-dependent manner. In the burn injury animal model, after 3 days, wound expansion and iron deposition were significantly reduced via daily treatment with the protein cocktail. This further led to better and more complete wound healing in these mice. Histologically, burn wounds were not entirely closed in the control group, unlike protein cocktail-treated wounds. Therefore, wound width was significantly larger in the control group. In bacterial zone inhibition assays against P. aeruginosa and S. aureus, the protein cocktail had minimal effect on bacterial inhibition when used alone; however, the protein cocktail, when used in conjunction with minimum doses of gentamicin, inhibited bacterial growth significantly. Conclusions: Using the scavenger plasma protein cocktail may reduce ROS injury, wound expansion, and bacterial growth in both in vitro and in vivo burn injury models. This approach could be potentially used in infected bacterial burn injury animal models and sets the stage for future application in burn injury patients for wound management and promotion of healing.