Novel sulfonated hydrogel composite with the ability to inhibit proteases and bacterial growth

Abstract

There is a growing interest in the development of wound dressings that possess functionality beyond providing physical protection and an optimal moisture environment for the wound. To this end, a novel dressing material based on a sulfonated triblock polymer has been developed. This versatile polymer possesses an ion-exchange capability that is amenable to binding and controlled release of a variety of therapeutic agents. This sulfonated polymer offers several advantages over existing commercial hydrogels used as wound dressings. These include (1) hydrophilicity that is proportional to sulfonation level, (2) easy preparation of fabric supported dressings (e.g., polyester, cotton, nylon), (3) excellent mechanical integrity of the materials when hydrated, (4) stability to a variety of chemistries, and (5) stability to a variety of sterilization methodologies. In this study, polymer was coated onto a polyester fabric and then modified by ion exchange to prepare the sodium, silver, or doxycycline salts. These sulfonated triblock polymer formulations were then evaluated for their capacity to sequester the neutrophil proteases, elastase, and collagenase-2 (MMP-8). Several of the formulations were found to sequester significant amounts of either elastase or collagenase. These formulations were demonstrated to be tested against a commercially available dressing that is currently marketed for its protease-inhibiting capability. The experimental dressing was statistically superior to the commercial dressing at inhibiting MMP-8 and elastase under the same conditions.

Positively and negatively charged ionic modifications to cellulose assessed as cotton-based protease-lowering and hemostatic wound agents

“…For example sulfonation and carboxymethylation finishes on cotton dressings are effective in removing elastase (Edwards et al 2001). A sulfonated polymer hydrogel also removes elastase from the wound bed (Vachon and Yager 2006). Interestingly carboxy methyl benzylamide sulfonate dextran previously has been shown to inhibit elastase, and may utilize ionic binding to facilitate enzyme uptake (Meddahi et al 1996).…”

“…In a healthy person healing occurs in 21 days from coagulation, and the remodeling phase consisting of scar transformation based on collagen synthesis continues for months following injury Cellulose (2009) 16:911-921 913 selectively bind the enzyme to the wound dressing in the presence of other wound proteins that promote wound healing. Mechanism-based dressings include and are composed of collagen and oxidized regenerated cellulose (Cullen et al 2002), nanocrystalline silver-coated high density polyethylene (Wright et al 2002), deferroxamine-linked cellulose (Meyer-Ingold et al 2000), electrophilic and ionically derivatized cotton (Edwards et al 2001), peptide (Edwards et al 1999) or carbohydrate conjugates (Edwards et al 2002), and bisphosphonate MMP inhibitors (Rayment et al 2008) and sulfonated ion exchange derivatives of hydrogel polymers (Vachon and Yager 2006). We discuss here the relative activities of two negatively charged cellulose fibers for their abilities to sequester proteases.…”

Sulphonated biomaterials as glycosaminoglycan mimics in wound healing

“…The use of styrene sulphonate technology in wound healing applications is best exemplifi ed by the work of Vachon (Vachon and Wnek, 2004;Vachon, 2006;Vachon and Yager, 2006). In practical terms, however, the Vachon technology falls signifi cantly short of the biomimetic aspirations that underpin the hydrogel-based approach and was not driven by any biomimetic consideration.…”

“…In a series of patents assigned to Aegis Biosciences, he describes the use of sulphonated styrene copolymer compositions in wound dressings, claiming their usefulness for inhibiting elastase and collagenase and for promoting angiogenesis in a wound (Vachon and Wnek, 2004;Vachon, 2006). In a subsequent publication he describes the applicability of his invention (Vachon and Yager, 2006). The material is based on a sulphonated triblock polymer and can be prepared with a range of sulphonation levels and thus hydrophilicities.…”

A study of diffusion in poly(ethyleneglycol)-gelatin based semi-interpenetrating networks for use in wound healing

“…Other polymer based wound dressings have further been utilized as conduits for antimicrobials and analgesics. Ag + and doxycycline have been incorporated into sulfonated elastomers [4] and minocycline has been included in chitosin-polyurethane films [5] to reduce bacterial growth, while bupivacaine-loaded poly(acrylamide(A)-co-monomethyl itaconate) hydrogels have been generated to provide prolonged pain relief [6]. …”