A Host-Directed Approach to the Detection of Infection in Hard-to-Heal Wounds

Abstract

Wound infection is traditionally defined primarily by visual clinical signs, and secondarily by microbiological analysis of wound samples. However, these approaches have serious limitations in determining wound infection status, particularly in early phases or complex, chronic, hard-to-heal wounds. Early or predictive patient-derived biomarkers of wound infection would enable more timely and appropriate intervention. The observation that immune activation is one of the earliest responses to pathogen activity suggests that immune markers may indicate wound infection earlier and more reliably than by investigating potential pathogens themselves. One of the earliest immune responses is that of the innate immune cells (neutrophils) that are recruited to sites of infection by signals associated with cell damage. During acute infection, the neutrophils produce oxygen radicals and enzymes that either directly or indirectly destroy invading pathogens. These granular enzymes vary with cell type but include elastase, myeloperoxidase, lysozyme, and cathepsin G. Various clinical studies have demonstrated that collectively, these enzymes, are sensitive and reliable markers of both early-onset phases and established infections. The detection of innate immune cell enzymes in hard-to-heal wounds at point of care offers a new, simple, and effective approach to determining wound infection status and may offer significant advantages over uncertainties associated with clinical judgement, and the questionable value of wound microbiology. Additionally, by facilitating the detection of early wound infection, prompt, local wound hygiene interventions will likely enhance infection resolution and wound healing, reduce the requirement for systemic antibiotic therapy, and support antimicrobial stewardship initiatives in wound care.

Chitosan-based multifunctional oxygenating antibiotic hydrogel dressings for managing chronic infection in diabetic wounds

“…Also, wounds exudates, fluid circulation, drug degradation by host cells and bacteria, and the controlled release properties of our hydrogels, constantly dilute and inactivate a large portion of PHMB from the wound. 41–43…”

“…Also, wounds exudates, fluid circulation, drug degradation by host cells and bacteria, and the controlled release properties of our hydrogels, constantly dilute and inactivate a large portion of PHMB from the wound. [41][42][43] Swelling properties of hydrogels were assessed due to their importance in maintaining wound moisture and enhancing healing processes. 44 Results (Figure 1E) suggested that dressings utilizing MACF or MAC were able to absorb high levels of liquids which implies their ability to draw bacteria away from the wounds by entrapping wound fluids and bacteria.…”

“…Also, wounds exudates, fluid circulation, drug degradation by host cells and bacteria, and the controlled release properties of our hydrogels, constantly dilute and inactivate a large portion of PHMB from the wound. [41][42][43] Swelling properties of hydrogels were assessed due to their importance in maintaining wound moisture and enhancing healing processes. 44 Results (Fig.…”