Turning waste into insight: a novel proteomic approach to non-invasive wound biomarker discovery.

Chronic wounds such as diabetic foot ulcers (DFUs) and venous leg ulcers (VLUs) are a growing public health burden, contributing to significant morbidity, healthcare costs, and mortality. Current management strategies are hampered by the inability to accurately predict healing trajectories or identify early treatment failures. Here, we present a novel, non-invasive proteomic approach that leverages routinely discarded wound dressings to profile the wound microenvironment across soluble, cellular, and extracellular vesicle (EV) compartments. Using a cohort of DFU and VLU patients (n=16), we performed spatially resolved, longitudinal sampling over four weeks and identified distinct proteomic signatures associated with healing versus non-healing outcomes. Mass spectrometry revealed over 1,000 unique proteins from viable cells and EVs, as well as 489 proteins identified from soluble wound fluid. Our methodology captured immune cell phenotypes, enabling insight into tissue-specific immune responses without the need for biopsy. Longitudinal surveillance revealed patient-specific protein trajectories that correlated with wound size changes, supporting the feasibility of biomarker-based monitoring. Notably, differences in keratinocyte activation markers, acute phase proteins, and EV-associated stress proteins distinguished healing from non-healing wounds. These findings demonstrate the utility of discarded dressings as a rich, untapped source of diagnostic and prognostic biomarkers. This platform has strong potential to inform future "smart" wound care technologies, including dressings capable of real-time biosensing or therapeutic EV delivery. Larger validation studies will be essential to translate these findings into clinical tools for precision wound care.