A Self‐Pumping Dressing for Draining Excessive Biofluid around Wounds

Abstract

dressing for its intrinsic hydrophilicity. The left biofluid continuously hydrates the wound and complicates the healing process. [7] Therefore, it is urgently needed to develop a new wound dressing to effectively remove the excessive biofluid.Bio-interface plays a significant role in the interaction between biofluid and biomaterial. [8] Surface wettability of wound dressings can generally affect the wetting behavior of biofluid around wounds. Hydrophilic materials, like most conventional dressings, easily get wetted by biofluid thus overhydrating wound. [7] In contrast, as the waterproof outer layer of dressings, hydrophobic materials prevent unexpected contacting of external fluid with the wounds, but they cannot facilitate biofluid removal. [9][10][11] Recently, several materials with asymmetric wettability have shown their unique capability to transfer water droplet, for instance, a polyester fabric with wettability gradient, [12] a polyurethane (PU)/polyvinyl acetate composite fibrous film, [13] and a one-side fluorinated cotton fabric membrane. [14] Therefore, the control of surface wettability may offer an opportunity to design wound dressings with the capability of effective biofluid management.Herein, we electrospan a hydrophobic PU nanofiber array onto a hydrophilic microfiber network, constructing a selfpumping dressing as a biofluid pump (Figure 1a). Such a selfpumping dressing can unidirectionally drain the excessive biofluid from its hydrophobic side to hydrophilic side, thereby preventing the biofluid from wetting the wound. In an infected wound model, we demonstrated a faster wound healing treated by this self-pumping dressing than the conventional dressing. This study provides a new clue to manage excess biofluid around wounds to promote faster wound healing.Medical gauze is a conventional dressing for its economic cost, flexible and tough network structure, and super absorbing capability. [15] Bundles (diameter = 259.0 ± 59.3 µm) of cotton microfibers (diameter = 16.9 ± 2.6 µm) interpenetrate each other (Figure 1b-d) and form a superhydrophilic network (Figure 1d, inset) in medical gauze, suitable for serving as a supporting framework and the source of pumping force as well. PU is a hydrophobic (Figure 1g, inset) biocompatible medical material with easy processing property, [16] expected to be an ideal candidate for preparing a separate layer to prevent biofluid wetting. Here we electrospan a thin layer of hydrophobic PU nanofiber array (diameter = 220.0 ± 40.0 nm; Figure 1e-g) onto a cotton medical gauze (Figure 1b-d) to form a self-pumping dressing Excessive biofluid around wounds often causes infection and hinders wound healing. However, the intrinsic hydrophilicity of the conventional dressing inevitably retains excessive biofluid at the interface between the dressing and the wound. Herein, a self-pumping dressing is reported, by electrospinning a hydrophobic nanofiber array onto a hydrophilic microfiber network, which can unidirectionally drain excessive biofluid away from wounds and finall...

Responsive Porous Microcarriers With Controllable Oxygen Delivery for Wound Healing

“…Wound healing acts a pivotal part in tissue repair and clinical treatment, since these wounds caused by trauma or resections would be life-threatening themselves or result in some severe complications. [1][2][3][4][5][6][7][8][9][10] Oxygen, which is a key factor to maintain the normal cell growth and respiration, has demonstrated to be essential in tissue generation and restoration. [11,12] Therefore, attempts to promote wound healing for tissue repair can tend to focus on the study of oxygen and oxygen-delivering microcarriers to some extent.…”

Advances and Impact of Antioxidant Hydrogel in Chronic Wound Healing

“…A wound is a defect or breakage of the skin caused by physical or thermal damage or the presence of underlying medical or physiological conditions, which may render the area physiologically unstable and even lead damage to normal body processes . Wound healing is the result of a series of biological molecules and stem cells working together to promote wound repair at all levels, which is considered to be one of the most complex dynamic biological processes .…”

Omniphobic ZIF‐8@Hydrogel Membrane by Microfluidic‐Emulsion‐Templating Method for Wound Healing

“…They are often fabricated in the form of membrane, sponges, and fiber mat with large surface‐to‐volume ratios, to absorb biofluids effectively 7. However, most hydrophilic dressings have small apparent water contact angle (CA); after they are wet, excessive biofluids can be pinned firmly to the porous surface of the dressing 8. The unabsorbed biofluids may overhydrate the wound, which could cause maceration of tissue edges, vulnerability against microbial invasion, bacterial colonization, and damage of the extracellular matrix, even tissue 9–12…”

“…Alternatively, porous wound dressing made from intrinsic hydrophobic polymers exhibits a large apparent water CA, blocking bacteria from adhesion and colonization while eliminating the overhydration issue 13. Owing to their hydrophobicity, the exudate cannot be absorbed 8. More importantly, most bactericidal active ingredients are water‐soluble; thus, it is ineffective to encapsulate and release them from hydrophobic polymers.…”

“…This attribute allows the fabrication of anti‐fouling dressings that prevent microbial invasion by inhibiting their adhesion, and release bactericidal agents to kill them simultaneously 14,15. The applications of superwettability surfaces for wound healing have been inadequate;8,24 wound dressings that combine the advantages of controlled release property of hydrogels and antibacterial property of omniphobic surfaces are still desired.…”