Modified cotton gauze dressings that selectively absorb neutrophil elastase activity in solution

Abstract

Dressings for chronic human wounds have been aimed at protection, removal of exudate, and improved appearance. However since the time of ancient Greece wound care and dressing strategies have primarily relied on empiricism. Recent studies have shown that chronic wounds contain high levels of tissue and cytokine destroying proteases including collagenase and neutrophil elastase. Therefore we sought to develop an effective wound dressing that could absorb elastase through affinity sequestration. Cotton gauze was modified by oxidation, phosphorylation, and sulfonation to enhance elastase affinity by ionic or active site uptake. Type VII absorbent cotton gauze was oxidized to dialdehyde cotton which was subsequently converted in part to the bisulfite addition product. Gauze preparations were also phosphorylated and carboxymethylated. Modified cotton gauzes were compared with untreated gauze for reduction of elastase activity in buffered saline. Solutions of elastase that were soaked in oxidized, sulfonated, and phosphorylated cotton gauze showed reduced elastase activity. The initial velocities (v(o)) and turnover rates of elastase showed significant decreases compared with solutions taken from untreated gauze. The reduction in enzyme activity with dialdehyde cotton gauze was confirmed in solution by determining elastase inhibition with dialdehyde starch. The dialdehyde cotton gauze also decreased elastase activity in human wound fluid in a dose response relation based on weight of gauze per volume of wound fluid. Absorbency, pH, air permeability and strength properties of the modified gauze were also compared with untreated cotton gauze. This report shows the effect of reducing elastase activity in solution with cotton containing aldehydic or negatively charged cellulose fibers that may be applicable to treatment modalities in chronic wounds.

Human neutrophil elastase and collagenase sequestration with phosphorylated cotton wound dressings

“…The dressing's mechanism of action may also be through other cellular or biochemical events that modulate protease levels. Previously reported active wound dressings designed to redress the biochemical imbalance of the chronic wound in this manner are composed of collagen and oxidized regenerated cellulose, 20 nanocrystalline silver-coated high density polyethylene, 21 deferrioxamine-linked cellulose, 22 electrophilic and ionically derivatized cotton, 23 peptide 24 or carbohydrate-conjugates, 25 and sulfonated ion exchange derivatives of hydrogel polymers. 26 Cotton dressings are still a standard in chronic wound care, 23 and improvement in cotton dressing finishes to enhance absorbency, gelation, and elasticity have been reported.…”

“…Previously reported active wound dressings designed to redress the biochemical imbalance of the chronic wound in this manner are composed of collagen and oxidized regenerated cellulose, 20 nanocrystalline silver-coated high density polyethylene, 21 deferrioxamine-linked cellulose, 22 electrophilic and ionically derivatized cotton, 23 peptide 24 or carbohydrate-conjugates, 25 and sulfonated ion exchange derivatives of hydrogel polymers. 26 Cotton dressings are still a standard in chronic wound care, 23 and improvement in cotton dressing finishes to enhance absorbency, gelation, and elasticity have been reported. [23][24][25]27 Here, we report the design and assessment of phosphorylated cotton wound dressings that significantly enhance the removal of both human neutrophil elastase and collagenase from wound fluid.…”

“…26 Cotton dressings are still a standard in chronic wound care, 23 and improvement in cotton dressing finishes to enhance absorbency, gelation, and elasticity have been reported. [23][24][25]27 Here, we report the design and assessment of phosphorylated cotton wound dressings that significantly enhance the removal of both human neutrophil elastase and collagenase from wound fluid.…”

A Review on Antimicrobial Silver Absorbent Wound Dressings Applied to Exuding Wounds

“…Thus, gauzes tend to be dry rather than maintaining the moist environment to facilitate wound healing. In addition, cotton gauze is easily to adhere to the wound and requires frequent changes, causing trauma and pain to the patients [58].…”

Phosphorylation of Cotton Cellulose with Baker's Yeast Hexokinase

“…Chemical phosphorylation usually is a rather complicated process, requiring several protection and deprotection steps. [6,7] Enzymatic phosphorylation can make the synthesis more efficient, eliminating many of these steps. The introduction of phosphate groups into cellulose will provide a polymer highly reactive toward various chemical compounds.…”