ABSTRACT
Background: Improving oxygen delivery to challenging wound types has been shown to optimize and accelerate several key contributors to healing. This study aims to compare selective skin substitutes and primary dressings and evaluate their ability to transfer oxygen to the wound. Methods: Visual and quantitative methods were employed to measure gas and fluid movement across several skin substitutes, including a bilayer nylon and silicone dressing coated with porcine gelatin and aloe vera (CNS), a porous bovine collagen-glycosaminoglycan (GAG) matrix dressing coated with silicone (UBC), and a urethane biodegradable temporizing matrix (PFD). Results: Fluids did not move across solid silicone membranes or urethane foam while oxygen movement across solid silicone membranes was inversely proportional to the thickness of the membrane. Oxygen moved across the coated nylon and silicone dressing 5.63 times faster than across the bovine-GAG scaffold and 2.0 times faster than the biodegradable temporizing matrix of polyurethane. Conclusions: The coated nylon and silicone matrix functioned like a membrane oxygenator, potentially augmenting atmospheric oxygen delivery to healing wounds.
ABSTRACT
Introduction: New treatments that promote wound healing while preventing scar formation are needed. One option in topical wound healing is the use of temporary dressings that allow the natural healing process with minimal scar formation. Methods: We evaluated the temporary wound dressings PermeaDerm C, and a PermeaDerm C derivative coated with the anti-scarring agent, salinomycin (PermeaDerm D) in a pig model of wound healing to show the efficacy of these wound dressings in vivo. Results: Porcine fibroblasts grow well in the presence of PermeaDerm C or PermeaDerm A, and salinomycin reduces excessive myofibroblast formation in porcine fibroblasts in vitro. In vivo, wounds treated with PermeaDerm C and PermeaDerm A did not show abnormal or unwanted healing patterns up to 8 weeks post-wound formation. Wounds covered with either PermeaDerm C or PermeaDerm A showed a more mature wound-healing phenotype than the control wounds. Conclusions: PermeaDerm C and PermeaDerm A allowed wound healing, revealing the potential of both PermeaDerm C and PermeaDerm A to promote effective healing while preventing excessive scar formation.
ABSTRACT
Introduction: New options are needed to improve wound healing while preventing excessive scar formation. Temporary primary dressings are important options in topical wound management that allow the natural healing process. Methods: We evaluated a novel primary dressing consisting of a biosynthetic, variable porosity, matrix-containing gelatin and Aloe Vera extract and a derivative dressing coated with the anti-scarring agent salinomycin for their ability to promote cell growth, reduce myofibroblast formation, and regulate cytokine production. In addition, salinomycin-coated primary dressings were tested for antimicrobial activity. Results: Both primary wound dressings permitted cell growth and attenuated TGFß-induced scar-forming myofibroblast formation. The primary wound dressings also reduced IL-6 production by 50%, IL-8 by 20%, MCP-1 by 75%, and GRO by 60% in human mesenchymal stem cells treated with TGFß. Salinomycin coating of the dressing showed antimicrobial activity by preventing Staphylococcus aureus growth. Conclusions: Both primary wound dressings support the growth of human fibroblasts and stem cells, as well as reduce inflammatory cytokine production, demonstrating their potential to serve as temporary wound dressings.
ABSTRACT
OBJECTIVE: To compare PermeaDerm to first temporary biosynthetic skin substitute (Biobrane, cleared by the Food and Drug Administration in 1979). METHODS: Different temporary skin substitutes (Biobrane, PermeaDerm, and PermeaDerm derivatives) were tested for physical differences, impact on healing wounds, inflammatory response, and ability to allow adequate growth of dermal fibroblasts and mesenchymal stem cells without accumulation of excessive scar-forming myofibroblasts. Proliferation of fibroblasts and stem cells on various skin substitutes was measured, and myofibroblast marker accumulation was evaluated by the expression of α-smooth muscle actin and fibronectin. Fibroblast migration was measured by tracking viable cells with MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] dye. RESULTS: In vivo testing shows PermeaDerm works well as a temporary skin substitute, performing better than Biobrane with respect to inflammation and fluid accumulation. Tissue culture techniques revealed that cells on PermeaDerm grow in a more uniform fashion and migrated to a greater extent than cells on Biobrane. Furthermore, cells grown in the presence of PermeaDerm expressed lower levels of the myofibroblast markers α-smooth muscle actin and fibronectin than cells grown on Biobrane. CONCLUSION: PermeaDerm with variable porosity possesses all attributes and properties known to be important for a successful temporary skin substitute and enables the clinician to control porosity from essentially zero to what the wound requires. The ability of the clinician to minimize wound desiccation without fluid accumulation is related to the reduction of punctate scarring.
