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

Bacterial cellulose serves as the hydrogel’s foundational scaffold, providing a biocompatible, highly porous matrix that structurally emulates the extracellular environment crucial for cellular activities in tissue regeneration. This scaffold supports cellular attachment and migration, which are prerequisite steps in effective wound repair. The hydrogel’s matrix not only maintains a moist environment but also facilitates adequate oxygenation and nutrient exchange, both vital for sustaining cellular function within the wound milieu.

Integrating platelet-rich plasma (PRP) imbues the hydrogel with a potent cocktail of endogenous growth factors, including vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), and platelet-derived growth factor (PDGF). These bioactive molecules are essential in stimulating angiogenesis, enhancing fibroblast proliferation, and promoting re-epithelialization. Crucially, their presence mimics the biochemical microenvironment of normal cutaneous healing, which is often deficient in chronic diabetic ulcers due to dysregulated cellular signaling.

Conductive polypyrrole (PPy) enhances the hydrogel’s functional repertoire through its electrical conductivity and intrinsic antibacterial characteristics. The PPy component enables capacitive charging within the dressing, which exerts bactericidal effects by disrupting microbial membrane integrity and metabolic functions. Beyond antimicrobial action, electrical stimulation mediated by PPy actively modulates cellular behavior, promoting the growth of fibroblasts and endothelial cells—two pivotal cell types that orchestrate tissue regeneration and angiogenesis.

Comprehensive in vitro assessments underscore the PBP hydrogel’s remarkable antibacterial efficacy, achieving over 98% reduction in common diabetic wound pathogens such as Escherichia coli and Staphylococcus aureus. This substantial microbial clearance is critical for preventing persistent infections that can exacerbate inflammation and impede healing. The electroresponsive nature of the hydrogel also allows for controlled, on-demand release of growth factors, providing a dynamic treatment modality that adapts in real-time to the wound’s evolving physiological requirements.

Moreover, the hydrogel’s influence on the immune microenvironment is particularly noteworthy. It fosters a beneficial macrophage phenotypic shift from the pro-inflammatory M1 state to the reparative M2 state. This immunomodulation helps resolve chronic inflammation, a hallmark of diabetic wounds, thereby supporting progression towards tissue regeneration and remodeling phases. The capacity to tailor immune responses addresses an otherwise intractable obstacle in diabetic wound healing, spotlighting the hydrogel’s therapeutic sophistication.

In vivo experiments utilizing a diabetic mouse model demonstrated the hydrogel’s superior wound healing capabilities, especially when electrical stimulation was applied adjunctively. Treated wounds displayed expedited closure rates, markedly enhanced collagen synthesis, increased vascularization, and robust epidermal regeneration by day 14 post-treatment. The treatment’s efficacy underscores the hydrogel’s ability to recapitulate physiological healing cascades, transitioning wounds from prolonged, non-healing ulcers to actively resolving lesions.

A further advantage of this hydrogel is its maintenance of a moist, absorbent wound environment that mitigates excessive exudate and reduces levels of pro-inflammatory cytokines. These conditions collectively prevent wound desiccation, maceration, and sustained inflammatory signaling, which frequently compromise healing trajectories in chronic diabetic wounds. By creating an optimal wound niche, the PBP hydrogel facilitates cellular processes necessary for tissue repair and barrier restoration.

Distinguishing itself from conventional passive dressings, the PBP hydrogel actively participates in the wound healing journey. Its ability to imitate the sequential phases of skin repair—inflammation resolution, tissue proliferation, and remodeling—positions it as a pioneering example of bioinspired, smart therapeutic design. The electroresponsive system incorporated within the hydrogel enables clinicians to fine-tune therapeutic interventions, optimizing growth factor release in synchrony with wound status.

Sustainability and scalability have been pivotal considerations in crafting the PBP hydrogel. The bacterial cellulose component is biosynthesized via fermentation from renewable, low-cost substrates, while PRP is autologously sourced, reducing issues of immunogenicity and disease transmission. The polypyrrole is chemically polymerized utilizing low-energy methods, minimizing the environmental footprint of material production. Such eco-conscious attributes enhance the hydrogel’s potential for widespread clinical deployment.

Nonetheless, challenges remain in transitioning this promising technology from bench to bedside. Optimizing hydrogel morphology for mechanical resilience, improving production efficiency, and extending the therapeutic window of growth factor release are critical areas for ongoing investigation. Emerging manufacturing techniques, including pressurized gyration spinning, offer promising routes to scale production without compromising material integrity or bioactivity.

Ultimately, this bioinspired composite hydrogel embodies a paradigm shift in chronic wound management, harmonizing material science, bioengineering, and regenerative biology. Offering a dynamic, multipronged therapeutic solution, it holds immense promise for alleviating the burden of diabetic wounds, improving patient outcomes, and reducing the incidence of severe complications such as infections and amputations. Future research directions include refining mechanical properties, prolonging growth factor release kinetics, and conducting rigorous trials in larger animal models and human patients.

Such advancements anticipate a new generation of wound dressings that are no longer mere passive barriers but active facilitators of tissue repair. The PBP hydrogel’s adaptability and multifunctionality may redefine personalized wound care, aligning treatment strategies intricately with patient-specific wound pathophysiology. By integrating bioinspired design with smart materials technology, this innovation exemplifies how translational research can address some of medicine’s most persistent challenges.

As this hydrogel progresses toward clinical application, its impact may extend beyond diabetic wounds to other chronic and complex tissue defects where inflammation, infection, and impaired regeneration converge. The principles informing its design could inform a broader spectrum of regenerative therapies, heralding a new era in biomaterials science. With its promising preclinical results, the interdisciplinary approach embodied by the PBP hydrogel offers a beacon of hope for millions suffering from debilitating chronic wounds worldwide.

Subject of Research: Animals

Article Title: Skin Repairing Procedure Inspired Polypyrrole/Bacterial Cellulose/Platelet Rich Plasma Composite Hydrogel as Diabetes Wound Dressing

News Publication Date: 3-Nov-2025

Web References:
Journal of Bioresources and Bioproducts
DOI: 10.1016/j.jobab.2025.10.004

Image Credits: Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China

Keywords

Hydrogels, Polymer Chemistry, Molecules, Bacteria, Bacterial Defenses, Wound Healing, Biochemistry, Cell Biology

Chronic wounds, especially diabetic foot ulcers, represent a stubborn healthcare challenge due to impaired healing dynamics caused by high blood glucose, persistent inflammation, and infection. Current treatment modalities, including wound dressings and hydrogel patches, can provide symptomatic relief but fall short in offering comprehensive therapeutic management that simultaneously regulates glucose, combats deep-seated infections, and monitors healing status. Recognizing this critical gap, the Shaanxi research team designed a novel electroactive microneedle system that not only treats wounds but also acts as an intelligent sensor and stimulator within the wound microenvironment.

Drawing inspiration from the bee’s serrated stinger, the microneedle array features saw-toothed edges that anchor securely into the dermal layers of the skin. This structural design ensures the device maintains intimate contact with the wound without slipping or loosening during normal patient movements. Unlike traditional dressings that can be easily dislodged or require removal for inspection, this self-anchoring mechanism enhances both stability and compliance, enabling sustained therapeutic efficacy even during exercise or daily activities.

At the core of this technology is a temperature-sensitive hydrogel positioned at the tips of each microneedle, loaded with insulin—a critical hormone for diabetic patients. The hydrogel’s release mechanism responds dynamically to the patient’s body heat, allowing a controlled, sustained insulin delivery for up to 24 hours. This means that the drug release is finely tuned to the local physiological environment, mitigating the risk of overdose and enhancing treatment specificity. By leveraging the body’s own thermal signature as a trigger, the system achieves a smart, non-invasive drug administration protocol unlike traditional timed-release dressings.

Beneath the hydrogel, a conductive layer composed of the polymer polypyrrole envelops the polylactic acid microneedles. Polypyrrole is a biocompatible, electroresponsive material that facilitates the delivery of electrical stimulation directly to the wound site. Electrical cues have been shown to promote angiogenesis—the formation of new blood vessels—thereby accelerating tissue regeneration. Simultaneously, this conductive layer serves as a sensor by measuring minute changes in electrical resistance, which correlate with tissue viability and healing progression. Through continuous impedance monitoring, the platform provides real-time feedback on wound status, allowing for dynamic adjustments in therapy without the need to remove the device.

This multifunctional microneedle patch thus synthesizes three crucial elements into a streamlined interface: targeted drug delivery, therapeutic electrical stimulation, and in situ wound monitoring. The implications for diabetic wound care are profound. Since diabetic wounds often become chronic due to a vicious cycle of hyperglycemia, infection, and impaired blood flow, a dressing that can simultaneously break this cycle by delivering insulin, promoting blood vessel growth, and providing continuous diagnostic data offers unmatched potential for improved outcomes.

The research team elaborates on the fabrication process, beginning with biodegradable polylactic acid microneedles engineered for optimal skin penetration and minimal discomfort. These needles are then coated with a layer of polypyrrole to endow the array with electrical conductivity and biocompatibility. The final step involves applying the insulin-loaded, temperature-responsive hydrogel to the needle tips, creating a composite structure that is both smart and multifunctional. The serrated needle design not only enhances anchorage but also aids in painless penetration, ensuring effective drug delivery to the intended dermal layers.

Beyond the immediate therapeutic benefits, the system’s ability to continuously map wound healing progression through electrical resistance measurements represents a significant step toward personalized and data-driven wound care. The device’s sensors provide clinicians with crucial, timely insights, enabling intervention before complications arise. According to Prof. Xinhua Liu, the corresponding author, chronic wound management has historically been a reactive process heavily reliant on visual assessments. This innovation pivots the paradigm toward proactive and precise treatment guided by objective, real-time data.

Looking ahead, the researchers are proactively expanding the platform’s sensing capabilities. Future iterations aim to incorporate additional parameters such as humidity levels and biochemical markers within wound exudate, providing an even richer dataset for monitoring infection, moisture balance, and metabolic activity. Complementing these advancements, the team is developing artificial intelligence algorithms capable of analyzing longitudinal sensor data to predict wound trajectory and automatically adjust treatment protocols—including insulin dosing and electrical stimulation intensity—tailored to each patient’s healing response.

Flexibility and comfort are also focal points in ongoing development. To ensure the microneedle patch remains safely in place during a patient’s daily routine, including walking or exercising, material innovation is harnessed to improve elasticity and wearability. These enhancements aim to maximize patient adherence and comfort without compromising the device’s therapeutic functions. Such considerations underscore the translation of cutting-edge technology into clinically viable, user-friendly solutions.

In essence, this bee-stings-inspired microneedle platform epitomizes the future of wound care—a seamless integration of therapy, monitoring, and adaptive intervention. It transforms a simple dressing into a sophisticated navigator of the healing process, making strides toward truly personalized, real-time wound management driven by data and patient-specific physiology. This breakthrough embodies a convergence of materials science, bioengineering, and clinical insight, heralding new possibilities for chronic wound treatment globally.

As chronic diabetic wounds continue to impose enormous clinical and economic burdens worldwide, innovations like this provide a beacon of hope. By harnessing biomimicry and smart materials, the Shaanxi University team has redefined what a wound dressing can achieve, blending the biological elegance of nature’s design with cutting-edge electroactive technology. Their work, published in the prestigious International Journal of Extreme Manufacturing, sets a new benchmark for multifunctional, intelligent medical devices that can adapt, respond, and heal alongside the patient.

Prof. Liu emphasizes that the platform is not merely a passive treatment device but a proactive tool capable of sensing, deciding, and acting autonomously, minimizing the need for clinician intervention and potentially transforming wound management paradigms. Such technology aligns with the broader aim of moving toward integrated digital health solutions that leverage real-time data and machine intelligence to optimize patient outcomes. It represents a milestone not just in wound care but in the evolution of smart biomedical devices designed for chronic disease management.

Subject of Research: Intelligent electroactive microneedle platform for chronic diabetic wound management integrating drug delivery, electrical stimulation, and real-time monitoring.

Article Title: Bee-stings-inspired intelligently-sensitive electroactive microneedle with serrated structure for advanced electrical-stimulation-intervened chronic wound-management

News Publication Date: 14-Jul-2025

Web References: DOI link

Image Credits: By Huie Jiang, Jiamin Zhang, Lijuan Chen, Qian Zhang, Fengqian Yang, Yifan Fei, Xing Chen and Xinhua Liu

Keywords

Chronic wound healing, diabetic foot ulcers, electroactive microneedles, drug delivery, electrical stimulation, biosensing, polypyrrole, polylactic acid, temperature-sensitive hydrogel, insulin release, biomimicry, real-time monitoring, personalized medicine, smart wound dressing