Hydrogen Peroxide Generation of Copper/Ascorbate Formulations on Cotton: Effect on Antibacterial and Fibroblast Activity for Wound Healing Application

Abstract

Greige cotton (unbleached cotton) is an intact plant fiber that retains much of the outer cotton fiber layers. These layers contain pectin, peroxidases, and trace metals that are associated with hydrogen peroxide (H2O2) generation during cotton fiber development. When greige cotton is subjected to a nonwoven hydroentanglement process, components of the outer cotton fiber layers are retained. When hydrated, this fabric can generate H2O2 (5–50 micromolar). This range has been characterized as inducing accelerated wound healing associated with enhanced cell signaling and the proliferation of cells vital to wound restoration. On the other hand, H2O2 levels above 50 micromolar have been associated with bacteriostatic activity. Here, we report the preparation and hydrogen peroxide activity of copper/ascorbate formulations, both as adsorbed and in situ synthesized analogs on cotton. The cooper/ascorbate-cotton formulations were designed with the goal of modulating hydrogen peroxide levels within functional ranges beneficial to wound healing. The cotton/copper formulation analogs were prepared on nonwoven unbleached cotton and characterized with cotton impregnation titers of 3–14 mg copper per gram of cotton. The copper/ascorbate cotton analog formulations were characterized spectroscopically, and the copper titer was quantified with ICP analysis and probed for peroxide production through assessment with Amplex Red. All analogs demonstrated antibacterial activity. Notably, the treatment of unbleached cotton with low levels of ascorbate (~2 mg/g cotton) resulted in a 99 percent reduction in Klebsiella pneumoniae and Staphylococcus aureus. In situ synthesized copper/ascorbate nanoparticles retained activity and did not leach out upon prolonged suspension in an aqueous environment. An assessment of H2O2 effects on fibroblast proliferation are discussed in light of the copper/cotton analogs and wound healing.

Ascorbic Acid as an Adjuvant to Unbleached Cotton Promotes Antimicrobial Activity in Spunlace Nonwovens

“…The application process and ascorbic acid stoichiometry were found to confer activity at add-on amounts of less than one percent. Moreover, the antibacterial activity observed is consistent with previous levels of hydrogen peroxide observed within a range reported to be antibacterial [ 7 , 8 ]. This led to an investigation of the mechanism of action of multiple ascorbic acid-based dressing formularies that could potentially be used as barrier fabrics for antimicrobial and antiviral activity.…”

“…The molecular mechanism is well characterized: in the presence of metal ions such as copper or iron, ascorbic acid ((R)-5-[(S)-1,2,-dihydroxyethyl]-3,4-dihydroxyfuran-2(5H)-one) behaves as a pro-oxidant by cooperatively binding metal ions to form an organometallic bivalent complex, metal-dihydroxyfuranone complex (MDC); under aerobic conditions, MDC binds oxygen (O 2 ), the core oxygen atoms of hydrogen peroxide, which can then dismutate by way of a protonated reactive oxygen species (ROS) to form hydrogen peroxide as the end product [ 14 ]. The initiation of this molecular mechanism in the spunlaced fabric is conceivable both in light of the levels of hydrogen peroxide demonstrated in the treated fabrics and consistent with the presence of the transition metal ions previously characterized in these types of cotton fabrics [ 7 ]. An interesting finding of this work is the relative efficacy of the ascorbic acid nonwoven formulations considering previously published studies that highlight their partial antibacterial efficacy.…”

<p>Potential Applications of Nanomaterials and Technology for Diabetic Wound Healing</p>

“…Currently, the antibacterial nanoparticles used in wound healing are silver nanoparticles, gold nanoparticles, copper nanoparticles, nano-bioactive glass particles, etc. [142][143][144][145][146][147] Among different metal nanoparticles, AgNP is the most active nanoparticle due to its unique anti-inflammatory properties and antibacterial activity against natural and nosocomial strains of multidrug-resistant (MDR) microorganisms, promoting wound healing. 148 The mechanisms of antimicrobial action of AgNPs are of two types, (a) the inhibitory action and (b) the bactericidal action.…”

Therapeutic Potential of Reactive Oxygen Species: State of the Art and Recent Advances

“…142 A steady-state delivery system in which the desired H 2 O 2 concentration was initially reached by the addition of exogenous H 2 O 2 and then maintained by further addition of glucose oxidase was also developed and allowed to better control the final hydrogen peroxide concentration. 177 On the other hand, biomaterial-releasing ROS have been emerging at the forefront of tissue engineering research, with, for instance, solid peroxide scaffolds (e.g., containing sodium percarbonate, magnesium peroxide, or calcium peroxide), 178 hydrogen peroxide-releasing greige cotton nonwoven fibers, 179 and glucose oxidase-conjugated hydrogels 180 being recently developed. Compared with other delivery systems, three-dimensional scaffolds would better suit the needs of tissue engineering, offering support for cells to grow and increasing localization at the transplantation site.…”