Waterproof and Breathable Wound Dressing Composited By Expanded Polytetrafluoroethylene Backing and Hydrogel.

Wound dressings with waterproof, breathable, and bacterial-resistant properties are still rarely realized. In this work, a newly hydrogel-based dressing is designed with a backing of expanded polytetrafluoroethylene (ePTFE) film. The ePTFE grafting with polyvinylpyrrolidone (PVP) brush is composited with hydrogel successfully with an adhesion energy of ≈80 kJ m-2 . In this resultant composite, the ePTFE backing contributes excellent breathability, water resistance, and bacterial barrier property. The water vapor transmission rate of the composite is 4.83 × 103  g m-2 × 24 h, which can maintain the moist environment of wound and relieve pain by evaporating water. Notably, it can withstand 500 mm water column for over 300 s, which is obviously better than the commonly used nonwoven fabric backing materials. It can also prevent the invasion of bacteria, because the pores of ePTFE backing are smaller than those of most common bacterial. As a result, the composite with an ePTFE film backing has a positive effect in accelerating wound healing, promoting the reconstruction of intact epidermis and reducing inflammation.