Alginate films augmented with chlorhexidine hexametaphosphate particles provide sustained antimicrobial properties for application in wound care

Abstract

All chronic wounds are colonised by bacteria; for some, colonisation progresses to become infection. Alginate wound dressings are used for highly exuding chronic wounds as they are very absorbent, taking up large quantities of exudate while maintaining a moist wound bed to support healing. Some alginate dressings are doped with antimicrobials, most commonly silver, but evidence regarding the efficacy of these is largely inconclusive. This manuscript describes the development and in vitro assessment of alginate materials doped with chlorhexidine hexametaphosphate (CHX-HMP), a sparingly soluble salt which when exposed to aqueous environments provides sustained release of the common antiseptic chlorhexidine. Comparator materials were a commercial silver alginate dressing material and an alginate doped with chlorhexidine digluconate (CHXdg). CHX-HMP alginates provided a dose-dependent CHX release which was sustained for over 14 days, whereas CHXdg alginates released limited CHX and this ceased within 24 h. CHX-HMP and silver alginates were efficacious against 5 major wound pathogens (MRSA, E. coli, P. aeruginosa, K. pneumoniae, A. baumannii) in a total viable count (TVC) and an agar diffusion zone of inhibition (ZOI) model. At baseline the silver alginate was more effective than the CHX-HMP alginate in the TVC assay but the CHX-HMP alginate was the more effective in the ZOI assay. After 7 days' artificial aging the CHX-HMP alginate was more effective than the silver alginate for four of the five bacteria tested in both assays. These materials may ultimately find application in the development of wound dressings for chronic wounds that provide sustained antimicrobial protection.

Antibiotic-Loaded Psyllium Husk Hemicellulose and Gelatin-Based Polymeric Films for Wound Dressing Application

“…The complex physiological process of wound healing, which includes highly coordinated hemostasis, inflammatory, proliferation, and maturation phases, is further complicated by wound infection, chronic diseases (diabetes, obesity, and cardiovascular complications), and poor care and patient lifestyle (smoking, drinking alcohol) [ 1 , 2 , 3 ]. Despite substantial progress in the discovery of healing agents, the healing of chronic wounds remains a key challenge for medical professionals [ 4 ]. Annually, more than 6.5 million patients suffer from chronic wounds in the United States, which has expanded the market of wound handling products to above 27 billion USD [ 5 ].…”

Antibacterial interactions between two monofloral honeys and several topical antiseptics, including essential oils

“…For example, honey could be combined with a silver-impregnated dressing to allow for controlled release of honey into the wound. This combination has not been reported for honey, however augmentation of silver-impregnated dressings with chlorhexidine has been demonstrated in vitro [ 40 ]. The potential remains for honey to be combined with antiseptics for topical therapeutic use.…”

Atomic Force Microscopy (AFM) on Biopolymers and Hydrogels for Biotechnological Applications—Possibilities and Limits

“…Moreover, some papers report about phase imaging to investigate alginate samples. Duckworth et al compared topography and phase images of alginate films with chlorhexidine hexametaphosphate particles as well as pure alginate films, as depicted in Figure 11 [ 169 ]. Opposite to Figure 10 , the authors here found a high roughness in both cases ( Figure 11 b,d), but only for the alginate film with chlorhexidine hexametaphosphate particles did they also find variations in stiffness, leading to variations in the phase image, while the phase image of the pure alginate film was quite even.…”

“…Lateral image dimensions are 300 nm; the z -axis represents 40° (phase images) and 10 nm (topography), respectively. Reprinted from [ 169 ], originally published under a CC-BY license.…”