Topical Antimicrobials for Burn Infections – An Update

Abstract

The relentless rise in antibiotic resistance among pathogenic bacteria and fungi, coupled with the high susceptibility of burn wounds to infection, and the difficulty of systemically administered antibiotics to reach damaged tissue, taken together have made the development of novel topical antimicrobials for burn infections a fertile area of innovation for researchers and companies. We previously covered the existing patent literature in this area in 2010, but the notable progress made since then, has highlighted the need for an update to bring the reader up to date on recent developments. New patents in the areas of topically applied antibiotics and agents that can potentiate the action of existing antibiotics may extend their useful lifetime. Developments have also been made in biofilm-disrupting agents. Antimicrobial peptides are nature’s way for many life forms to defend themselves against attack by pathogens. Silver has long been known to be a highly active antimicrobial but new inorganic metal derivatives based on bismuth, copper and gallium have emerged. Halogens such as chlorine and iodine can be delivered by novel technologies. A variety of topically applied antimicrobials include chitosan preparations, usnic acid, ceragenins and XF porphyrins. Natural product derived antimicrobials such as tannins and essential oils have also been studied. Novel techniques to deliver reactive oxygen species and nitric oxide in situ have been developed. Light-mediated techniques include photodynamic therapy, ultraviolet irradiation, blue light, low-level laser therapy and titania photocatalysis. Passive immunotherapy employs antibodies against pathogens and their virulence factors. Finally an interesting new area uses therapeutic microorganisms such as phages, probiotic bacteria and protozoa to combat infections.

Ceragenins as Mimics of Endogenous Antimicrobial Peptides

“…As mimics of AMPs, ceragenins display broad-spectrum activity against Gram-negative and positive bacteria, including activity against drug-resistant organisms [33, [52][53][54]. Studies of bacteria susceptibility to ceragenins has focused on clinical isolates and bacteria, primarily clinical isolates, endemic to specific areas of the human body.…”

Antimicrobial Nanostructured Bioactive Coating Based on Fe3O4 and Patchouli Oil for Wound Dressing

“…Bacterial colonization of wounds can increase wound severity and interfere with healing [21].Previous studies have confirmed that the modification of absorbent dressings with essential oils led to better therapeutic results, consecutive to the enhanced antimicrobial protection [22][23][24]. In the review of Sevgi et al,the essential oils from Matricaria chamomilla and tea tree as well as the extracts from Bulbine fruitescens, Eremophila longifolia and Tamarindus indica are cited as useful alternatives for the treatment wounds treatment, due to their bactericidal properties, but also to the cicatrizing, antioxidant and anti-inflammatory activities [25]. PAT has been previously demonstrated to be very active against S. aureus strains, the most potent antimicrobial compounds being pogostone and (−)- These observations suggest that the coatings could be utilized for up to 72 h, but for a safe and efficient treatment it would be recommended to replace the dressing each 24 h.…”

Innovative methods of biofilm treatment in chronic wounds

“…Ponadto stwierdzono, że podawanie probiotyków hamuje ich rozwój. Jeden z opatentowanych szczepów Bacillus coagulans w wyniku wytwarzania peptydów przeciwdrobnoustrojowych może mieć zastosowanie w miejscowym leczeniu ran zainfekowanych przez Pseudomonas i Staphylococcus [58]. Zarówno badania przedkliniczne, jak i przeprowadzane u ludzi wykazały skuteczność probiotyków w profilaktyce i terapii wielu schorzeń wywołanych przez czynniki infekcyjne, immunologiczne oraz zapalne [60].…”