Patient tolerance study of topical chlorhexidine diphosphanilate: a new topical agent for burns

Use of magnetic nanoparticles as a drug delivery system to improve chlorhexidine antimicrobial activity

Nanotechnology offers new tools for developing therapies to prevent and treat oral infections, particularly biofilm-dependent disorders, such as dental plaques and endodontic and periodontal diseases. Chlorhexidine (CHX) is a well-characterized antiseptic agent used in dentistry with broad spectrum activity. However, its application is limited due to inactivation in body fluid and cytotoxicity toward human cells, particularly at high concentrations. To overcome these limitations, we synthesized nanosystems composed of aminosilane-coated magnetic nanoparticles functionalized with chlorhexidine (MNP@CHX). In the presence of human saliva, MNPs@CHX displayed significantly greater bactericidal and fungicidal activity against planktonic and biofilm-forming microorganisms than free CHX. In addition, CHX attached to MNPs has an increased ability to restrict the growth of mixed-species biofilms compared to free CHX. The observed depolarization of mitochondria in fungal cells treated with MNP@CHX suggests that induction of oxidative stress and oxidation of fungal structures may be a part of the mechanism responsible for pathogen killing. Nanoparticles functionalized by CHX did not affect host cell proliferation or their ability to release the proinflammatory cytokine, IL-8. The use of MNPs as a carrier of CHX has great potential for the development of antiseptic nanosystems.

Topical antimicrobial agents for pediatric burns

While topical antimicrobial agents are indicated for most if not all burn wounds, the choice of a topical agent must consider many factors such as the wound depth, anticipated time to healing, need for surgical intervention, and the known cytotoxicity of the agent. Especially relevant to the pediatric burn patient are the antimicrobial agent’s properties related to causing pain or irritation and the required frequency of application and dressings. This article will discuss the general principles surrounding the use of topical antimicrobials on burn wounds and will review the most common agents currently in use.

Topical antimicrobials for burn wound infections

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 multidrug resistance.

Silver. I: Its antibacterial properties and mechanism of action

Silver products have two key advantages: they are broad-spectrum antibiotics and are not yet associated with drug resistance. This article, the first in a two-part series, describes the main mechanism of action of this metallic element.