# The role of negative pressure wound therapy—From the perspective of drainage fluid composition

## TL;DR

This study explores how negative pressure wound therapy (NPWT) helps wounds heal by analyzing the composition of drained fluids and their effects on healing processes.

## Contribution

The study investigates the molecular and cellular components of drainage fluid during NPWT and their correlation with wound healing in a diabetic rat model.

## Key findings

- NPWT increases the levels of growth factors like PDGF, TGF-β1, EGF, VEGF, and SDF-1 during wound healing.
- Drainage fluid levels are proportional to wound healing and correlate with increased presence of EPCs, fibrocytes, and MSCs.
- NPWT significantly enhances the clearance of drainage fluid and its bioactive components.

## Abstract

Negative pressure wound therapy (NPWT) accelerates wound healing processes by promoting angiogenesis and vascularization. However, the molecular mechanisms and biological effects underpinning these processes remain unclear, while drainage fluids (and associated components) extracted by negative pressure suction are rarely investigated. This study investigated these components and explored their relationship with wound healing. To this end, a diabetic wound rat model was established, and wound exudate was collected using negative pressure wound therapy (NPWT) equipment. Platelet-derived growth factor (PDFG-BB), transforming growth factor-β (TGF-β1), epidermal growth factor (EGF), vascular endothelial growth factor-A (VEGF-A), and stromal cell-derived factor-1 (SDF-1) expression levels were investigated using quantitative reverse transcription polymerase chain reaction (RT-qPCR) and western blotting. Circulating endothelial progenitor cells (EPCs), circulating fibrocytes, and mesenchymal stem cells (MSCs) were analyzed by flow cytometry. This study observed that during wound healing, the expression levels of platelet-derived growth factor (PDGF), transforming growth factor-β (TGF-β1), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), and chemokine-1 (SDF-1) were significantly higher in the experimental group than in the control group. This expression pattern was similar to that observed in endothelial progenitor cells (EPCs), fibroblasts, and mesenchymal stem cells (MSCs). The data from this study indicate that NPWT significantly increases the clearance of drainage fluid and its related components (including growth factors, chemokines, and cells). Also, drainage fluid levels were proportional to wound healing.

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