Exploring exudate absorption via sessile droplet dynamics in porous wound dressings

Abstract

Chronic wounds, typically defined as those that fail to reduce in size by at least 40% within a month, present a significant global socioeconomic challenge. In clinical practice, it is widely recognized that maintaining an optimal moisture balance in the wound while managing excess exudate is crucial for wound healing. Therefore, the selection of wound dressings is a key tool in wound management, which is based on their ability to sustain this delicate equilibrium. However, there is a notable lack of fundamental studies on the interaction between wound exudate and dressings, which limits the availability of evidence-based guidance for clinical practitioners. Thus, the present investigation explores how wound exudate interacts with different commercially available wound dressings to optimize wound management through a deep understanding of exudate-air interface dynamics in contact with the dressing material. Employing high-resolution imaging, the research delves into the behaviour of quasi-sessile droplets on various porous materials, analysing the impacts of exudate viscosity, blood sugar levels, and exudate volume. The findings reveal that droplet absorption rates depend on exudate properties and dressing materials. Notably, cellulose-based dressings outperform alginate and polyester-based alternatives in terms of wettability and imbibition capacity, with a performance improvement of at least 48%. Furthermore, increased exudate viscosity and elevated blood sugar are associated with longer absorption times, with increases of $\approx$ 51% and $\approx$ 38%, respectively. The study also identifies that absorption completion time increases exponentially with fibre diameter but decreases with greater pore radius and higher porosity. The overall findings can aid clinicians with quantitative insights to optimize the selection of wound dressings, thereby enhancing the healing of chronic wounds.