Treatment Strategies for Infected Wounds

Abstract

The treatment of skin wounds is a key research domain owing to the important functional and aesthetic role of this tissue. When the skin is impaired, bacteria can soon infiltrate into underlying tissues which can lead to life-threatening infections. Consequently, effective treatments are necessary to deal with such pathological conditions. Recently, wound dressings loaded with antimicrobial agents have emerged as viable options to reduce wound bacterial colonization and infection, in order to improve the healing process. In this paper, we present an overview of the most prominent antibiotic-embedded wound dressings, as well as the limitations of their use. A promising, but still an underrated group of potential antibacterial agents that can be integrated into wound dressings are natural products, especially essential oils. Some of the most commonly used essential oils against multidrug-resistant microorganisms, such as tea tree, St. John's Wort, lavender and oregano, together with their incorporation into wound dressings are presented. In addition, another natural product that exhibits encouraging antibacterial activity is honey. We highlight recent results of several studies carried out by researchers from different regions of the world on wound dressings impregnated with honey, with a special emphasis on Manuka honey. Finally, we highlight recent advances in using nanoparticles as platforms to increase the effect of pharmaceutical formulations aimed at wound healing. Silver, gold, and zinc nanoparticles alone or functionalized with diverse antimicrobial compounds have been integrated into wound dressings and demonstrated therapeutic effects on wounds.

Keywords: Manuka honey; antibacterial activity essential oils; antibiotics; nanoparticles; wound healing; wound infection.

Figure 1

The four stages of wound repair.

Figure 2

Illustration of the continuum from contamination to wound infection. Contamination is represented by the existence of non-replicating bacteria and is a common circumstance in chronic wounds; wound contamination does not promote impaired healing. Colonization is the occurrence of replicating microorganisms without triggering host responses. Acute colonization is characterized by the manifestation of replicating bacteria resulting in moderate local reaction; this increase of bioburden can delay wound healing. Infection occurs when microorganisms are multiplying and have entered the tissue, producing a systemic host response.

Figure 3

Properties of an ideal wound dressing.