Development and Validation of an In Vitro Test Method for the Assessment of Superabsorbent Wound Dressings

The aim of the study was to develop and validate an exuding wound model and an in vitro test method that mimics how superabsorbent polymer (SAP) wound dressings behave in situ.

Artificial human legs were placed in an upright position. Synthetic, adult human tissue, consisting of multiple discrete layers and designed to mimic living skin tissue, was fixed onto the vertical model. Simulated wound exudate (SWE) was pumped, so that it exuded from the skin at low, medium and high flow rates. SAPs were used to ‘dress’ the model and exudate was recovered over a 24-hour period. The method was performed by multiple operators across different research sites. Concurrent absorption under pressure studies were performed according to a modified EN 13726 method.

SAPs demonstrated reduced fluid absorption capabilities in the simulated wound model compared to the volumes obtained using the modified EN 13726 test method. The model was able to differentiate between the absorption potential of different NPWT devices and SAPs and thus offers a product comparison methodology that better mimics a clinical exuding wound than current fluid absorption methods.

Clinicians are required to make daily decisions relating to fluid handling of exuding wounds, with the aim of supporting moist wound healing while reducing the development of peri-wound maceration. Physical product support data is typically limited to horizontal fluid absorption and retention studies. Data from this method aims to better inform clinicians about SAP dressing performance, resulting in improved patient care. It would also be expected that other dressing types would exhibit a reduced fluid handling capacity in this model compared to EN 13726.