In an era marked by an ever-increasing global incidence of infected wounds, the demand for innovative and multifunctional wound care solutions has never been more critical. Despite over 300 million surgeries conducted annually worldwide, postoperative infections remain alarmingly prevalent, impacting between 5 to 20 percent of patients. These infections not only prolong patient recovery but also escalate healthcare costs and burden medical systems globally. Traditional wound dressings, though widespread, often fall short in striking a delicate balance between protection, comfort, and active healing functionalities. Addressing this pressing challenge, an interdisciplinary team led by researchers from The Hong Kong Polytechnic University has pioneered a groundbreaking bionic cooling skin designed to revolutionize infected wound management.
This novel skin-mimetic dressing represents a leap forward by seamlessly integrating passive cooling capabilities with potent antibacterial activity and mechanical properties akin to natural skin. The design employs a hierarchical Janus nanofiber structure engineered through a sophisticated combination of solvent welding technology and the incorporation of visible light-responsive metal–organic frameworks (MOFs). The Janus architecture manifests dual functionality: a hydrophobic outer layer that passively cools wounds by reflecting sunlight and emitting mid-infrared radiation, and a hydrophilic inner layer that promotes moisture management while anchoring antibacterial nanoparticles for on-demand infection control.
The underlying fabrication strategy is both innovative and meticulous. By applying solvent welding to electrospun polyvinylidene fluoride (PVDF) nanofibers, researchers achieved strong physical bonds that endow the dressing with tensile strength approximating 21.6 MPa and a failure strain nearing 54%. These mechanical metrics closely mimic the elasticity and resilience of human skin, an essential attribute to ensure patient comfort and dressing durability during movement. The Fe-modified zeolitic imidazolate framework-8 (Fe-ZIF8) nanoparticles integrated on the hydrophilic side serve a dual purpose by narrowing the bandgap to enable visible light activation and by generating reactive oxygen species (ROS) under illumination, effectively eradicating bacteria in situ.
From a photophysical standpoint, density functional theory (DFT) simulations alongside ultraviolet photoelectron spectroscopy (UPS) measurements illustrate that Fe doping shrinks the ZIF8 bandgap from an inert 5.15 eV to a visible light-active 2.56 eV. This modification empowers the photocatalytic Fe-N4 coordination centers to efficiently produce ROS, particularly initiating the oxygen radical cascade necessary for disinfection. Under white light exposure, this mechanism translates to near-complete bacterial eradication—achieving an impressive 97.1% antibacterial efficacy against Staphylococcus aureus, a notorious pathogen in postoperative infections. This efficacy parallels that of traditional antibiotic treatments, but without the risk of resistance or systemic side effects.
The Janus nanofiber skin’s thermal management prowess derives from its superior mid-infrared emissivity, measured at 80.7% within the atmospheric transparency window of 7–14 micrometers. This radiative cooling effect, demonstrated to reduce surface temperature by approximately 4°C under simulated sunlight, is critical in mitigating hyperthermia at wound sites, thereby promoting an optimal healing microenvironment. Importantly, in vivo tests on rat models under authentic outdoor sunlight conditions confirmed a tangible cooling benefit, reducing skin temperature by an average of 1.7°C—even amidst fluctuating solar irradiance levels between 115 and 195 W/m².
Beyond its multifunctionality, the dressing excels in physiological compatibility. Its breathable structure facilitates air permeability exceeding 1.8 mL per second and maintains a water vapor transmission rate above 12.5 kilograms per square meter per day, preventing maceration while supporting gaseous exchange essential for tissue repair. Simultaneously, particulate filtration efficiency surpassed 99.8%, underscoring its protective barrier efficacy against environmental contaminants. Cytocompatibility assays confirmed minimal cytotoxicity, as evidenced by sustained fibroblast (NIH3T3) viability across five days, ensuring the material’s safety for prolonged wound contact.
From a wound healing perspective, this biomimetic skin accelerates tissue regeneration drastically. Employing rat models with infected wounds, the research demonstrated near-complete closure within 11 days—more than twice the healing speed seen with untreated or purely PVDF-treated wounds. This outstanding performance is not solely physical; extensive transcriptomic analyses including RNA sequencing and quantitative PCR revealed the dressing’s molecular influence on repair pathways. Notably, angiogenesis-related genes (Vcam1, Vegfd, Vegfb, Vegfc) and cell migration markers (Cemip, Cemip2) were markedly upregulated, fostering neovascularization critical for nutrient supply and cellular recruitment.
Concurrently, antimicrobial peptides such as cathelicidin and hepcidin exhibited increased expression, enhancing innate immunity at the wound site. Equally important, genes encoding pro-inflammatory cytokines (Ilrun, Madcam1, TNF-α) were downregulated, reducing deleterious inflammation that can impede healing. Gene Ontology and KEGG pathway enrichment analyses pinpointed the activation of pivotal signaling networks—PI3K-Akt, HIF-1, and NF-kappa B—that synergistically modulate angiogenesis, inflammatory response, oxidative stress, and cellular proliferation. Histological examination corroborated these findings, revealing well-organized collagen deposition with uniform architecture (34.06 ± 8.29%) and epidermal thickness (89.50 ± 13.60 µm) nearly double that of normal skin, indicative of robust tissue remodeling without fibrotic scarring.
The convergence of these properties signals a paradigm shift in wound care technology. The bionic cooling skin epitomizes a holistic approach whereby structural biomimicry meets functional material engineering to yield a dressing that is protective, comfortable, actively antimicrobial, and regenerative. Its architecture deftly leverages nanotechnology and photocatalysis for temporally regulated antibacterial activity, while passive infrared radiation and hydrophobic surfaces maintain thermal homeostasis and moisture control. Collectively, these design features address long-standing clinical challenges, positioning this smart dressing as a potent candidate to supersede existing products that necessitate compromises between protection, convenience, and healing efficacy.
Looking forward, the implications of this research resonate throughout biomedical material science and clinical practice. This development not only facilitates superior outcomes for patients afflicted by infected wounds but also pioneers a sophisticated blueprint for future smart dressings that dynamically respond to environmental and biological stimuli. By integrating multi-omic insights with cutting-edge nanofabrication, the study unlocks unprecedented opportunities for personalized wound management tailored to the microenvironmental needs of each injury. Such advancements herald transformative possibilities spanning chronic wound care, postoperative recovery, and beyond.
In summary, this bionic cooling skin designed by researchers from The Hong Kong Polytechnic University and their collaborators exemplifies the forefront of interdisciplinary innovation. Combining Janus nanofiber architecture, visible-light photocatalytic MOFs, and solvent-welding nanomanufacturing, the dressing achieves a unique trifecta of passive cooling, active antibacterial defense, and skin-like mechanical conformity. Its validated performance in animal models and molecular repair mechanisms underscores its readiness to reshape clinical paradigms in infected wound healing. As global healthcare seeks solutions that are both patient-friendly and functionally superior, this intelligent biomaterial stands poised to make a profound impact.
Subject of Research:
Bionic wound dressing integrating passive thermal management and active antibacterial function for infected wound healing.
Article Title:
Bionic Cooling Skin for Infected Wound Healing
News Publication Date:
28-May-2026
Web References:
https://doi.org/10.1007/s40820-026-02240-6
Image Credits:
Shuo Shi, Huiqun Zhou, Yang Ming, Xiong Zhou, Hanbai Wu, Haipeng Ren, Lung Chow, Jing Su, Daming Chen, Bin Fei, Joselito M. Razal, Xungai Wang*.
Keywords
Bionic skin, Janus nanofiber, metal–organic frameworks, reactive oxygen species, photocatalysis, wound healing, passive cooling, antibacterial dressing, biomimicry, tissue regeneration, mid-infrared emissivity, multifunctional biomaterials
