Evidence of oxidative stress in chronic venous ulcers

James, Tim; Hughes, Margaret; Cherry, George W.; Taylor, Richard

doi:10.1046/j.1524-475x.2003.11304.x

Cited by 122 publications

(85 citation statements)

References 24 publications

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“…3B). Because of prolonged inflammation (25), human chronic wounds experience three to four times higher oxidative stress (26) and oxidative damage (27) than acute wounds. To mimic this scenario, we investigated the effect of immobilized QHREDGS peptide on DHEK survival following a 2-h treatment with 2 mM H 2 O 2 (an exposure four times higher than used for the HEK survival assay) after DHEKs were allowed to attach to the chitosan-collagen films for 4 h (Fig.…”

Section: Immobilized Qhredgs Peptide Promotes Diabetic Human Primarymentioning

confidence: 99%

Diabetic wound regeneration using peptide-modified hydrogels to target re-epithelialization

Xiao

Reis

Feric

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

127

156

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There is a clinical need for new, more effective treatments for chronic wounds in diabetic patients. Lack of epithelial cell migration is a hallmark of nonhealing wounds, and diabetes often involves endothelial dysfunction. Therefore, targeting re-epithelialization, which mainly involves keratinocytes, may improve therapeutic outcomes of current treatments. In this study, we present an integrin-binding prosurvival peptide derived from angiopoietin-1, QHREDGS (glutamine-histidine-arginine-glutamic acid-aspartic acid-glycine-serine), as a therapeutic candidate for diabetic wound treatments by demonstrating its efficacy in promoting the attachment, survival, and collective migration of human primary keratinocytes and the activation of protein kinase B Akt and MAPK p42/44 . The QHREDGS peptide, both as a soluble supplement and when immobilized in a substrate, protected keratinocytes against hydrogen peroxide stress in a dose-dependent manner. Collective migration of both normal and diabetic human keratinocytes was promoted on chitosan-collagen films with the immobilized QHREDGS peptide. The clinical relevance was demonstrated further by assessing the chitosan-collagen hydrogel with immobilized QHREDGS in full-thickness excisional wounds in a db/db diabetic mouse model; QHREDGS showed significantly accelerated and enhanced wound closure compared with a clinically approved collagen wound dressing, peptide-free hydrogel, or blank wound controls. The accelerated wound closure resulted primarily from faster re-epithelialization and increased formation of granulation tissue. There were no observable differences in blood vessel density or size within the wound; however, the total number of blood vessels was greater in the peptide-hydrogeltreated wounds. Together, these findings indicate that QHREDGS is a promising candidate for wound-healing interventions that enhance reepithelialization and the formation of granulation tissue.

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Section: Immobilized Qhredgs Peptide Promotes Diabetic Human Primarymentioning

confidence: 99%

Diabetic wound regeneration using peptide-modified hydrogels to target re-epithelialization

Xiao

Reis

Feric

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

127

156

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“…6 The prolonged inflammatory phase characteristic of chronic wounds results in an over exuberant response of neutrophils. 7 Neutrophils contain and release high concentrations of proteases, 8 and free radical generating enzymes 9 that have been implicated in mediating tissue damage associated with chronic wounds and other major chronic inflammatory diseases including rheumatoid arthritis, 10 chronic obstructive pulmonary disease, 11 and adult respiratory distress syndrome. 12 Since neutrophils mediate a variety of chemotactic, proteolytic, and oxidative events that have destructive activities in chronic wounds, therapeutic interventions have been proposed to remedy the proteolytic and oxidative mechanisms of neutrophil activity within the wound environment as part of a wound bed management strategy.…”

Section: Introductionmentioning

confidence: 99%

Human neutrophil elastase and collagenase sequestration with phosphorylated cotton wound dressings

Edwards

Howley

2007

J Biomedical Materials Res

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The design and preparation of wound dressings that redress the protease imbalance in chronic wounds is an important goal of wound healing and medical materials science. Chronic wounds contain high levels of tissue and cytokine-destroying proteases including matrix metalloprotease and neutrophil elastase. Thus, the lowering of excessive protease levels in the wound environment by wound dressing sequestration prevents the breakdown of extracellular matrix proteins and growth factors necessary for wound healing. Phosphorylated cotton wound dressings were prepared to target sequestration of proteases from chronic wound exudate through a cationic uptake binding mechanism involving salt bridge formation of the positively charged amino acid side chains of proteases with the phosphate counterions of the wound dressing fiber. Dressings were prepared by applying sodium hexametaphosphate and diammonium phosphate in separate formulations to cotton gauze by pad/dry/cure methods. Phosphorylated cotton dressings were assessed for their ability to lower elastase and collagenase activity. The phosphorylated cotton dressings lowered elastase and collagenase activity 40-80% more effectively than the untreated cotton wound dressings under conditions that mimic chronic wound exudate. Efficacy of the phosphorylated cotton was found to be related to the level of phosphorylation and a lower pH due to protonated phosphate at the surface of the dressing. The capacity of the modified gauze to sequester continued elastase secretions similar to that found in a chronic wound over a 24-h period was retained within a 80% retention of elastase sequestration and was dose-dependent.

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“…ROS, including free radicals have been implicated in several pathogenic events including impaired wound healing due to the release of free radicals from neutrophils trapped within the wound area (29). Therapeutic intervention with hyperbaric oxygen additionally increases ROS levels and impairs wound healing.…”

Section: Discussionmentioning

confidence: 99%

Bereiter‐Hahn

Bernd

Beschmann

et al. 2014

Acta Med. (Hradec Kralove, Czech Repub.)

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Summary: Egg-oil (Charismon © ) is known for its beneficial action in wound healing and other skin irritancies and its antibacterial activity. The physiological basis for these actions has been investigated using cells in culture: HaCaT-cells (immortalized human keratinocytes), human endothelial cells in culture (HUVEC), peripheral blood mononuclear lymphocytes (PBML) and a full thickness human skin model (FTSM). Emphasis was on the influence of egg-oil on cell migration and IL-8 production in HaCaT cells, respiration, mitochondrial membrane potential, reactive oxygen (ROS) production and proliferation in HUVEC and HaCaT cells, cytokine and interleukin production in PBML and UV-light induced damage of FTSM. IL-8 production by HaCaT cells is stimulated by egg-oil whilst in phythemagglutinin-activated PBMLs production of the interleukins IL-2, IL-6, IL-10 and IFN-γ and TFN-α is reduced. ROS-production after H 2 O 2 stimulation first is enhanced but later on reduced. Respiration becomes activated due to partial uncoupling of the mitochondrial respiratory chain and proliferation of HaCaT and HUVEC is reduced. Recovery of human epidermis cells in FTSM after UV-irradiation is strongly supported by egg-oil. These results support the view that egg-oil acts through reduction of inflammatory processes and ROS production. Both these processes are equally important in cellular aging as in healing of chronic wounds.

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Evidence of oxidative stress in chronic venous ulcers

Cited by 122 publications

References 24 publications

Diabetic wound regeneration using peptide-modified hydrogels to target re-epithelialization

Diabetic wound regeneration using peptide-modified hydrogels to target re-epithelialization

Human neutrophil elastase and collagenase sequestration with phosphorylated cotton wound dressings

Cellular Responses to Egg-Oil (Charismon©)

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