Topical Antimicrobials for Burn Wound Infections

Abstract

Throughout most of history, serious burns occupying a large percentage of body surface area were an almost certain death sentence because of subsequent infection. A number of factors such as disruption of the skin barrier, ready availability of bacterial nutrients in the burn milieu, destruction of the vascular supply to the burned skin, and systemic disturbances lead to immunosuppression combined together to make burns particularly susceptible to infection. In the 20th century the introduction of antibiotic and antifungal drugs, the use of topical antimicrobials that could be applied to burns, and widespread adoption of early excision and grafting all helped to dramatically increase survival. However the relentless increase in microbial resistance to antibiotics and other antimicrobials has led to a renewed search for alternative approaches to prevent and combat burn infections. This review will cover patented strategies that have been issued or filed with regard to new topical agents, preparations, and methods of combating burn infections. Animal models that are used in preclinical studies are discussed. Various silver preparations (nanocrystalline and slow release) are the mainstay of many approaches but antimicrobial peptides, topical photodynamic therapy, chitosan preparations, new iodine delivery formulations, phage therapy and natural products such as honey and essential oils have all been tested. This active area of research will continue to provide new topical antimicrobials for burns that will battle against growing multi-drug resistance.

Evaluation of genipin-crosslinked chitosan hydrogels as a potential carrier for silver sulfadiazine nanocrystals

“…Usually skin wounds are rich in exudation and proteins, and consist of avascular necrotic tissues, which limit the effective permeation of systemically administered antibiotics [4,5]. Subsequently, topical antibacterial preparations are more suitable in these cases.…”

LL-37-Derived Peptides Eradicate Multidrug-Resistant Staphylococcus aureus from Thermally Wounded Human Skin Equivalents

“…Other topical disinfectants, such as chlorhexidine (13), silver sulfadiazine (14), and iodine preparations (15), can be very painful when applied to open wounds (16), and the scientific evidence for the efficacy of these agents in wounds is scarce. Clearly, there is an urgent need for novel antimicrobial agents that can be applied topically to (i) prevent colonization and (ii) eliminate infectious agents in burn wounds (17).…”

Synergistic Combination of Chitosan Acetate with Nanoparticle Silver as a Topical Antimicrobial: Efficacy against Bacterial Burn Infections

“…Unfortunately, due to the excessive use of antibiotics, some bacteria have evolved to become antibiotic resistant, and this has led to the present time being described as the "end of the antibiotic era" (26,34). Thus, the search for novel, more efficient antibacterial burn dressings has been the subject of intense and continuing research efforts (14,20,27). In addition, it has recently been recognized that certain bacterial strains, such as Pseudomonas aeruginosa, have the ability to establish themselves in biofilms (2,28,47), which are complex structures consisting of bacterial cells embedded in an extracellular matrix of hydrated extrapolymeric substances and permanently attached to surfaces (13).…”