Title : Self-pumping scaffolds for skin tissue engineering: A systematic review
Abstract:
Background: Effective wound healing depends on maintaining a balanced local environment at the wound site. Excessive wound exudate can prolong inflammation, increase infection risk, cause maceration of surrounding tissue, and interfere with cell migration and extracellular matrix formation. Although conventional absorbent dressings can temporarily retain wound fluid, they may become saturated and often fail to provide continuous, directional exudate transport. Self-pumping wound dressings have therefore emerged as advanced biomaterial systems designed to transfer excess fluid away from the wound while preserving adequate moisture for tissue repair. These dressings may also function as platforms for drug delivery and biological stimulation. This systematic review aimed to examine recent progress in their design, fabrication, fluid-transport mechanisms, and regenerative effects.
Materials and Methods: A systematic search was conducted using PubMed, Scopus, and Google Scholar. Studies published between 2022 and 2025 were screened, with emphasis on self-pumping, asymmetric, Janus, and directionally transporting wound dressings developed for skin tissue engineering and wound healing. The included studies were assessed according to fabrication method, structural organization, surface wettability, exudate-transport mechanism, incorporated therapeutic agents, carrier systems, and reported cellular or tissue-level outcomes.
Results: The reviewed studies showed that self-pumping wound dressings are commonly fabricated by electrospinning, freeze-drying, or a combination of both techniques. Most systems contain two or three functionally distinct layers arranged to create a wettability gradient. Typically, a hydrophobic or less-wettable layer is positioned away from the wound, whereas a hydrophilic layer remains close to the wound surface. This asymmetric organization generates capillary pressure and promotes unidirectional movement of exudate toward the external absorbent region. Hydrogels, nanofibrous membranes, porous sponges, and composite scaffolds were frequently used as structural components. Fluid transfer was further improved through interconnected pores, aligned microchannels, conical channels, or differences in pore size between adjacent layers. Several dressings were loaded with therapeutic compounds, including curcumin, antioxidants, and antibacterial agents, to reduce oxidative stress, limit microbial contamination, and support tissue repair. Micro- and nanoparticle systems, such as PLGA particles and microspheres, were also incorporated to protect bioactive compounds and provide sustained or controlled release. In addition to exudate drainage, these dressings were reported to reduce reactive oxygen species and inflammatory mediators within the wound microenvironment. These effects may contribute to macrophage phenotype regulation, improved angiogenesis, enhanced fibroblast migration and proliferation, increased collagen deposition, re-epithelialization, and, in some models, hair follicle regeneration.
Conclusion: Self-pumping wound dressings represent a promising generation of multifunctional biomaterials that combine directional exudate transport, moisture regulation, and therapeutic delivery. Their ability to modify both the physical and biological wound environment may offer advantages over passive absorbent dressings. However, differences in material composition, testing methods, and evaluation criteria currently limit direct comparison among studies. Further research is needed to standardize performance assessment, examine long-term biosafety, and validate these systems in large-animal models and human clinical trials.
Keywords: Self-pumping wound dressings; Directional fluid transport; Wound exudate management; Skin regeneration; Drug delivery; Advanced biomaterials.
