Self-pumping wound dressings with directional water transport ability have been widely studied for their function of directional extraction of excessive biofluid from wounds while keeping the wound in a moderately humid environment to realize rapid wound healing. However, the existing solutions have not paid close attention to the fabrication of a nonirritating hydrophobic layer facing the wounds, which may cause irritation to wounds and thereby further worsen inflammation. Herein, a flexible and elastic thermoplastic polyurethane (TPU) hydrophobic microfiber mesh (TPU-HMM) produced by melt electrospinning (MES) is reported. The TPU-HMM was compounded to a hydrophilic nanofiber membrane, which was fabricated by blending with polyamide 6 and poly(ethylene glycol) (PA6-PEG) to form a composite self-pumping dressing, for which the breakthrough pressure in a reverse direction was 12.8 times than that in a positive direction and the forward water transmission rate was increased by 700%. It shows good directional water transport ability and is expected to absorb excessive biofluid of the wounds. This solvent-free and easy-process TPU-HMM provides a new strategy for the development of functional self-pumping textiles, and the solvent-free fabrication method for fibers, which eliminates the potential toxicity brought by solvent residues, offers more possibilities for its applications in biomedicine.
Keywords: Janus dressing; directional water transport; melt electrospinning; self-pumping; thermoplastic polyurethane microfiber.