(WHS-L4.05) DISCARDED WOUND DRESSINGS: AN UNTAPPED SOURCE OF PREDICTIVE AND MONITORING BIOMARKERS OF MULTIPLE TYPES OF WOUNDS
Thursday, May 16, 2024
10:30 AM – 11:30 AM East Coast USA Time
Purpose: The purpose of our study was to utilize discarded wound dressings in order to identify potential predictive and diagnostic biomarkers of different wound types by the proteomic analysis of cells and exosomes captured from wound exudate.
Methods: We solubilized biomaterial from discarded wound dressings from patients with pyoderma gangrenosum, diabetic foot ulcer, venous leg ulcer and acute wounds left to heal by secondary intention. Patients were followed weekly for 4 weeks and change in wound size measured by EKARE inSight imaging equipment at each visit, at which point the wound dressing was collected. Cells from each dressing were then isolated, number of viable cells quantified and immunophenotyping using flow cytometry. Differential centrifugation was then used to isolate exosomes from each specimen, with exosomes purified using magnetic beads and validated by western blotting and FACS flow cytometry. Next, all samples were lysed and normalized to total protein, followed by trapped ion mobility spectrometry analysis of cellular and exosomal proteome. Lastly, we utilized mass-to-charge ratio (m/z) to identify and quantify relative peptide species, followed by analysis of hierarchical clustering of samples and functional annotation of identified clusters.
Results: Although we were able to isolate viable cells and exosomes from multiple types of wound dressings, foam and alginate dressings yielded highest levels of viable cells (5.8-7.9 x 107 cells). Next, from immunophenotyping, we were able to determine those wounds which exhibited higher levels of gamma/delta T-cells (CD45+CD3+TCRg/d+) also exhibited trends towards reductions in wound size. Numbers of dendritic (CD45+-CD11c+), macrophages -CD11+), neutrophils (-CD66b+) or either CD4+/CD8+ T-cells did not correlate with the surrogate healing outcome at week 4, nor where their relative numbers able to predict healing outcome from week 1 samples. Next, we were able to validate previous proteomic profiling reports of wound exudate that associated with poor healing outcomes (CTSG, LCN2, DEF1, MMP9, HBA, HBB, CAMP, VTN, among others). Lastly, our data suggests that healing wounds exhibit higher levels of ALB, SERPING1, CERU, CO3, POSTN, FN1, FGA (among others) in their week 1 dressings, and may act to serve as potential predictive biomarkers of healing wounds.
Conclusions: Together, our innovative approach to proteomic profiling of various types of wound dressings has demonstrated reproducible and encouraging results and we anticipate that higher recruitment (expected n=30 from each wound type), will shed light on variability in healing outcomes and identify other potential biomarkers.