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The emerging mechanically active wound dressing has been perceived as one of the most effective strategies to accelerate wound closure in a non‐invasive manner. However, the development of wound dressing with body temperature‐stimulated shrinkage behavior and superior mechanical capability is still a severe challenge. Here, a thermal‐shrinkable, stretchable, and tough fibrous tape is developed via the construction of "stiff‐elastic" binary component, as well as manipulation of the fiber stretching and phase separation. The resultant polyurethane (PU)/polyvinyl butyral (PVB) fibrous membrane (FM) shows a rapid and considerable shrinkage of 70.0% after exposure at 37 °C for 12 h. The shrunk PU/PVB FMs exhibit excellent mechanical performance including high elongation of 364.4%, large toughness of 26.6 MJ m−3 and rapid thermal‐recoverable capability with 80.4% and 71.8% restoration of stress and dissipated energy respectively. The in vivo study in rat full‐thickness skin model with 2 cm‐diameter circular wounds demonstrates that the thermal‐shrinkable PU/PVB FMs can enhance wound contraction and healing. Furthermore, the ex vivo rabbit organ model indicates the possibility of thermal‐shrinkable PU/PVB FMs in defect contraction of diverse tissues. This work may offer a promising way in the development of body temperature‐triggered mechanically active fibrous dressings for defects repair. [ABSTRACT FROM AUTHOR]

Smart wound dressings capable of detecting, monitoring, and regulating complicated dynamic healing processes hold tremendous potential in wound healing and tissue reconstruction. Micro/nanofiber‐based materials are regarded as one of the most promising candidates to develop smart wound dressings owing to their remarkable features including architectural mimicry of extracellular matrix, tunability in structural assembly, and diversity in functionality. Herein, the latest progress of smart micro/nanoscale fiber‐based materials in terms of composition engineering, structural design, and applications in wound management is comprehensively reviewed. This work begins with the advances in smart fibers including stimuli‐responsive fibers, shape memory fibers, and conductive fibers. Then, the structural design of fiber‐based materials from conventional 2D fibrous membrane to emerging 3D fibrous sponge/hydrogel is thoroughly discussed. Furthermore, the applications of smart micro/nanofibrous materials as wound dressings in stimuli‐responsive drug delivery, biomechanical stimulation, electrical stimulation, and wound monitoring are highlighted. Finally, the article offers perspectives on the existing challenges and future directions of smart fibrous materials for wound management. [ABSTRACT FROM AUTHOR]

Fibrous patches capable of withstanding bursting force and recruiting endogenous stem cells are of great demand for wound treatment. A programmable strategy for development of radially gradient nanofibrous patches with rapid deployment property, robust bursting bearing capability, and excellent mesenchymal stem cell (MSC) recruitment capability, is demonstrated. Benefiting from the royal water lily‐like radially branched architecture, the gradient fibrous (GF) patches exhibit fast deployment in aqueous solution (2 s), high bursting strength of 4.6 N, as well as "center‐to‐periphery" gradient immobilization of stromal‐cell‐derived factor 1α (SDF1α). The SDF1α gradient patches direct MSC migration from the periphery to the center along the aligned nanofibers, resulting in a 4.2 times higher migrated cell number and 2.6 times greater maximum migration distance than random fibrous patches with homogenous SDF1α. The gelatin methacryloyl coated GF patches respond to matrix metalloproteinase‐9 for "on‐demand" release of anti‐inflammatory drug diclofenac sodium (DS). Furthermore, repair of the mouse full‐thickness skin incision validates that SDF1α/DS/GF patches are able to provide feasible microenvironment to attenuate inflammation and improve endogenous MSC recruitment, leading to accelerated wound healing. This work may open a new pathway for development of smart tough fibrous patches for stimulating endogenous repair mechanisms during tissue regeneration. [ABSTRACT FROM AUTHOR]

[Display omitted] Diabetic wound treatment remains a major challenge due to the difficulties of eliminating bacterial biofilm and relieving wound hypoxia. To address these issues simultaneously, a multifunctional Dex-SA-AEMA/MnO 2 /PDA (DSAMP) hydrogel platform was developed with excellent biocompatibility and porous structure. The hydrogel could absorb the exudate, maintain humidity and permeate oxygen, which was prepared by encapsulating polydopamine (PDA) and manganese dioxide (MnO 2) into Dex-SA-AEMA (DSA) hydrogel by UV irradiation. With the addition of PDA, the DSAMP hydrogel was proved to eliminate the biofilm after NIR photodynamic therapy (PTT, 808 nm) irradiation at 54 °C. Furthermore, in order to mitigate hypoxia wound microenvironment, MnO 2 nanoparticles were added to convert the endogenous hydrogen peroxide (H 2 O 2) into oxygen (O 2 , 16 mg L−1). The diabetic wound in vivo treated by DSAMP hydrogel was completely healed on 14 days. It was revealed that the DSAMP hydrogel possessed a great potential as dressing for diabetic chronic wound healing. [ABSTRACT FROM AUTHOR]

[Display omitted] Infected wounds show delayed and incomplete healing processes and even render patients at a high risk of death due to the formed bacterial biofilms in the wound site, which protect bacteria against antimicrobial treatments and immune response. Nitric oxide based therapy is considered a promising strategy for eliminating biofilms and enhancing wound healing, which encounters a significant challenge of controlling the NO release behavior at the wound site. Herein, a kind of phenylalanine based poly(ester urea)s with high thermal stability are synthesized and fabricated to electrospun films as NO loading vehicle for infected wound treatment. The resultant films can continuously and stably release nitric oxide for 360 h with a total concentration of 1.15 μmol L−1, which presents obvious advantages in killing the bacteria and removing biofilms. The results exhibit the films have no cytotoxicity and may accelerate the wound repair without causing inflammation, hemolysis, or cytotoxic reactions as well as stimulate the proliferation of fibroblasts and increase the synthesis of collagen. Therefore, the films may be a suitable NO releasing dressing for removing biofilms and repairing infected wounds. [ABSTRACT FROM AUTHOR]

Electrospun micro/nanofibrous membranes (EFMs) have been widely investigated as local drug delivery systems. Multiple drugs can be simultaneously incorporated into one EFM to create synergistic effects, reduce side effects, and play their respective roles in the complex physiological processes of tissue regeneration and postoperative adhesion prevention. Due to the versatile electrospinning techniques, sustained and programmed release behaviors of multiple drugs could be achieved by modulating the structure of the EFMs and the location of the drugs. In this review, various multidrug incorporation approaches based on electrospinning are overviewed. In particular, the advantages and limitations of each drug incorporation technique, the methods to control drug release and the effect of one drug release on another are discussed. Then the applications of multidrug-loaded EFMs in regenerative medicine, including wound healing, bone regeneration, vascular tissue engineering, nerve regeneration, periodontal regeneration and adhesion prevention are comprehensively reviewed. Finally, the future perspectives and challenges in the research of multidrug-loaded EFMs are discussed. Unlabelled Image • Multiple drugs can be simultaneously loaded into electrospun fibrous membranes. • Various drug release profiles can be obtained by different electrospinning methods. • Multiple drugs have synergistic therapeutic efficacy in regenerative medicine. [ABSTRACT FROM AUTHOR]

The objective of this research study is to develop novel composite nanofibers based on methacrylamide chitosan (ChMA)/poly(ε-caprolactone) (PCL) materials by the dual crosslinking and coaxial-electrospinning strategies. The prepared ChMA/PCL composite nanofibers can sequentially deliver tannic acid and curcumin drugs to synergistically inhibit bacterial reproduction and accelerate wound healing. The rapid delivery of tannic acid is expected to inhibit pathogenic microorganisms and accelerate epithelialization in the early stage, while the slow and sustained release of curcumin is with the aim of relieving chronic inflammatory response and inducing dermal tissue maturation in the late stage. Meanwhile, dual-drugs sequentially released from the membrane exhibited a DPPH free radical scavenging rate of ca. 95 % and an antibacterial rate of above 85 %. Moreover, the membrane possessed great biocompatibility in vitro and significantly inhibited the release of pro-inflammatory factors (IL-1β and TNF-α) in vivo. Animal experiments showed that the composite membrane by means of the synergistic effect of polyphenol drugs and ChMA nanofibers, could significantly alleviate macrophage infiltration and accelerate the healing process of wounds. From the above, the as-prepared ChMA-based membrane with a stage-wise release pattern of drugs could be a promising bioengineered construct for wound healing application. • Dual-crosslinked ChMA/PCL composite nanofibers was fabricated. • The composite nanofibers can sequential delivery of curcumin and tannic acid. • The sample had great antioxidant, antibacterial and anti-immunology activities. • The synergistic effects of ChMA and polyphenols enhanced wound healing efficiency. [ABSTRACT FROM AUTHOR]

Hydrogel has emerged as one of the most promising dressings for wound healing owing to the creation of moist environment. However, it suffers from poor water retention capability and weak mechanical property. Therefore, development of dressings with durable moisture retention, robust mechanical property, and self-healing performance is urgently needed in practical applications. Herein, we developed a bilayered composite dressing consisting of breathable and hydrophobic polyurethane/polydimethylsiloxane (PU/PDMS) nanofibrous membrane and double-crosslinked chitosan-based hydrogel with dynamic Schiff base bonds and non-dynamic photo-crosslinking bonds. Combined with the nanofibrous membrane as protection and mechanical support, the bilayered hydrogel composites presented enhanced water retention capability to provide sustained moist environment, excellent stretchable and compressive performance to bear deformation, fast self-healing and good cyclic resilience to endure frequent movements. The in vivo study indicated their effective therapeutic effect in a rat model with full-thickness skin wounds. This study demonstrated that the hydrogel/nanofibrous membrane composite represented a promising candidate as dressing material for wound healing. [Display omitted] [ABSTRACT FROM AUTHOR]

Bacterial biofilm often exists in non-healing wounds, and if it cannot be removed promptly, further complications will occur. Bioactive biodegradable wound dressings with the ability to kill bacteria, eliminate biofilms and prevent infections are expected to solve this problem. This study reports the development of a new l -tryptophan and l -phenylalanine-based poly(ester urea)s which aims at fabricating electrospun composite mat with nitric oxide releasing capability for infected wound treatment. The designed l -tryptophan and l -phenylalanine based poly(ester urea)s owned adjustable degradability and good biocompatibility, indicating it could be an ideal biomaterial for wound repair. The electrospun mat was an ideal cargo for steady and continuous delivery with a total concentration of 0.8 μmol/L of NO. The mats showed obvious advantages in killing the bacteria and destructing biofilms. Such electrospun mats could promote proliferation and improve collagen deposition as well as accelerate wound healing. It suggests that the fabric mats can act as a suitable candidate in infected-wound care applications. [Display omitted] [ABSTRACT FROM AUTHOR]