A self-powered multifunctional dressing for active infection prevention and accelerated wound healing

Combined treatment strategy of hydrogel dressing and physiotherapy for rapid wound healing

Wound care for open wounds is essential for reducing pain, protecting open wounds, speeding up the healing process and avoiding scar formation. Among the various three-dimensional (3D) carrier biomaterials such as films, sponges, and hydrogels, hydrogels are chemically and physically most similar to the natural extracellular matrix (ECM). Meanwhile, hydrogels are also common 3D carriers that can be efficiently loaded with drugs or cells. In addition, it forms a protective barrier on the wound surface to prevent secondary external infections and has the effect of directing skin cell expansion, tissue infiltration, and wound closure. However, the role of functional drugs in wound healing also faces a number of issues such as resistance, dosage, activity, and stability; therefore, a richer array of therapies is needed for wound repair and other areas of development. Physiotherapy, also known as nonpharmacological therapy, is a commonly used clinical treatment. Recently, more and more physiotherapy have been used for wound repair due to their high efficiency and low irritation. In recent reports, many researchers have tended to use hydrogel dressings in combination with physiotherapy, and this combination therapy is beneficial because it can both protect the wound microenvironment and accelerates wound healing. Therefore, this paper reviews the combined use of hydrogel dressings and physiotherapy in wound healing. We present the characteristics of hydrogel and physiotherapy and focus on the progress and problems of these two combined therapies in recent years.

Exogenous electron generation techniques for biomedical applications: Bridging fundamentals and clinical practice

Endogenous bioelectrical signals are quite crucial in biological development, governing processes such as regeneration and disease progression. Exogenous stimulation, which mimics endogenous bioelectrical signals, has demonstrated significant potential to modulate complex biological processes. Consequently, increasing scientific efforts have focused on developing methods to generate exogenous electrons for biological applications, primarily relying on piezoelectric, acoustoelectric, optoelectronic, magnetoelectric, and thermoelectric principles. Given the expanding body of literature on this topic, a systematic and comprehensive review is essential to foster a deeper understanding and facilitate clinical applications of these techniques. This review synthesizes and compares these methods for generating exogenous electrical signals, their underlying principles (e.g., semiconductor deformation, photoexcitation, vibration and relaxation, and charge separation), biological mechanisms, potential clinical applications, and device designs, highlighting their advantages and limitations. By offering a comprehensive perspective on the critical role of exogenous electrons in biological systems, elucidating the principles of various electron-generation techniques, and exploring possible pathways for developing medical devices utilizing exogenous electrons, this review aims to advance the field and support therapeutic innovation.

Electrotherapy and health monitoring with piezoelectric and triboelectric technologies

The growing need for advanced therapeutic and diagnostic technologies has spurred interest in self-powered systems for electrotherapy and health monitoring. Traditional battery-dependent medical devices (MDs) face limitations, including short operational lifespans and patient discomfort, underscoring the importance of sustainable alternatives. Mechanical energy harvesting technologies, such as piezoelectric and triboelectric nanogenerators (PENGs and TENGs), have emerged as promising solutions, enabling real-time health monitoring and non-invasive electrotherapy by converting biomechanical energy into electricity. This review explores the latest advancements in PENG and TENG technologies, emphasizing their applications in wound healing, neural regeneration, and real-time physiological monitoring. Strategies to overcome hurdles are discussed, demonstrating the transformative potential of PENG and TENG systems in next-generation MDs. By integrating energy harvesting with therapeutic and monitoring functionalities, piezoelectric and triboelectric systems offer a path toward non-invasive, efficient, and patient-centric medical solutions.

Innovative Self-Powered Electrically Stimulated Fabric Dressing for Enhanced Diabetic Wound Healing

Electrical stimulation (ES) therapy has emerged as a promising method for improving wound healing by mimicking the body's natural electric fields. However, traditional ES devices often fall short in practical applications due to their bulkiness and inefficiency. Current tools for electrical stimulation are hindered by issues such as poor sustainability, limited flexibility, and inadequate biocompatibility. To address these challenges, we have developed a novel self-powered electrical stimulation fabric dressing (SESFD). This innovative dressing employs advanced electrochemical deposition technology to integrate fiber electrodes seamlessly into the fabric using standard textile manufacturing methods. Additionally, we incorporated a gel electrolyte infused with antimicrobial agents to enhance protection against bacterial infections during electrical stimulation. To evaluate the effectiveness of the SESFD in promoting healing for chronic diabetic wounds, we conducted rigorous in vivo studies. The results demonstrated that the SESFD significantly improved cell proliferation and migration within the wound tissue while effectively reducing bacterial growth. These enhancements contributed to faster wound closure, decreased inflammatory response, increased collagen deposition, and improved angiogenesis. Furthermore, the SESFD displayed excellent mechanical properties, extended discharge durability, and stable voltage output even under mechanical deformation. These attributes greatly enhance user experience and comfort for patients throughout the healing process. This study positions the SESFD as a groundbreaking solution that combines electrical stimulation with antimicrobial treatment for diabetic wound care. It represents a sustainable, flexible, and biocompatible approach to accelerating wound healing and improving treatment outcomes.

A recent review on smart sensor-integrated wound dressings: Real-time monitoring and on-demand therapeutic delivery

Wound management is a critical aspect of healthcare, necessitating continuous monitoring and timely interventions to ensure optimal healing outcomes. In recent years, the integration of sensor technology into wound dressings has emerged as a transformative approach, enabling real-time monitoring of healing parameters and facilitating on-demand treatment delivery. Sensor-based wound dressings leverage various sensing modalities, including temperature, pH, moisture, oxygen, and other biochemical markers, to provide comprehensive insights into the wound microenvironment. These dressings are equipped with miniaturized sensors capable of transmitting the data wirelessly, facilitating remote monitoring and timely interventions. Moreover, some advanced dressings incorporate responsive drug delivery systems, enabling the on-demand release of therapeutics based on real-time sensor feedback. Additionally, the incorporation of on-demand treatment mechanisms allows targeted delivery of therapeutics based on the specific needs of the wound, further enhancing the efficacy of the healing process. This comprehensive approach improves patient outcomes by promoting faster and more effective wound healing and reducing the burden through streamlined monitoring and treatment protocols. This paper presents an overview of recent advancements in sensor technology applied to wound healing, focusing on their role in monitoring wound parameters and delivering targeted therapy. These sensors leverage temperature, pH, and glucose sensing modalities to provide comprehensive insights into the healing process.

A self-powered casein hydrogel E-dressing with synergistic photothermal therapy, electrical stimulation, and antibacterial effects for chronic wound management

Triboelectric nanogenerators (TENGs) have recently demonstrated great application potential for accelerating wound healing in the field of medical research due to their unique electrical stimulation effect. Among the various types of TENGs, solid-liquid TENGs have attracted much attention due to their significant advantages, such as high contact-separation efficiency and a wide range of liquid motion. Therefore, this study innovatively proposed a solid-liquid biphasic TENG electronic dressing constructed from a casein hydrogel enhanced by the metal-organic framework Zeolitic Imidazolate Framework-8 (ZIF-8). This hydrogel dressing comprised sodium caseinate (SC)/multi-walled carbon nanotubes-polydopamine@polydopamine (MWCNT@PDA)/polyacrylamide (PAM)/ZIF-8. It ingeniously integrates multiple functions such as photothermal, photodynamic antibacterial, and electrical stimulation therapies, thereby establishing a new multimodal synergistic treatment paradigm. Notably, the addition of ZIF-8 not only controlled photothermal release of antibacterial agents but also facilitates the development of a distinctive solid-liquid biphasic operational modality in TENG system, achieving a 131 V peak output voltage through significant enhancement of electrical performance parameters. In addition, the TENG-based system adopts a non-contact electrical stimulation method for wound treatment, fundamentally reducing the risk of infection caused by direct contact. Experiments using mouse fibroblasts revealed that the simultaneous real-time use of near-infrared light and TENG can significantly improve the cell migration process. Empirical studies on animals demonstrated that it could accelerate tissue regeneration and wound healing by increasing collagen deposition and angiogenesis. Based on these results, this study provides new perspectives for the developing intelligent biomedical composites for future wound management. STATEMENT OF SIGNIFICANCE: Chronic wounds have become a major threat to global medical and health fields due to pathogenic infections. Traditional wound dressings mostly focus on passive healing, which has limited effectiveness. To overcome these limitations, we developed an electronic dressing of a casein-based hydrogel TENG enhanced by a MOF. This electronic dressing combines photothermal, photodynamic antibacterial, and electrical stimulation functions and efficiently promotes wound healing through multifunctional synergy. This research provides a promising solution for diabetic wound care and a broader field of chronic wound treatment. It is a solid step in the scientific exploration of interdisciplinary integration, offering new ideas for making the wound treatment field more intelligent, efficient, and precise.

A photothermal-enhanced thermoelectric nanosheet incorporated with zwitterionic hydrogels for wound repair and bioelectronics

The new generation of smart wound dressings aims to encompass sensory restoration capabilities through multi-stimulation rather than merely focusing on skin rebuilding and repair. Wound dressings integrated with real-time measurement of wound motion can improve healing efficiency considerably by providing crucial guidance during the skin regeneration process. Herein, we report a conductive zwitterionic hydrogel dressing with photothermal and thermoelectric properties prepared using a poly(3,4-ethylenedioxythiophene)-modified polydopamine-functionalized bismuth telluride (PEDOT@PBT) sandwich-like nanosheet-incorporated poly(sulfobetaine methacrylate)/silk fibroin (PEDOT@PBT-PSBMA/SF) semi-interpenetrating polymer network hydrogel, which can accelerate chronic wound healing and monitor motion. With the incorporation of PEDOT@PBT nanosheets, the hydrogel exhibits remarkable photothermal and thermoelectric effects, endowing it with broad-spectrum antibacterial properties against Escherichia coli (E. coli, 99.02 %), Staphylococcus aureus (S. aureus, 99.14 %), and methicillin-resistant Staphylococcus aureus (MRSA, 97.70 %). Additionally, the PEDOT@PBT-PSBMA/SF hydrogel can be employed in bioelectronics because of its good conductivity (0.13 S/m). In-vivo experiments show that the PEDOT@PBT-PSBMA/SF hydrogel actively promotes the regeneration of MRSA-infected wounds through immunomodulation, collagen deposition, and vascularization. Consequently, this study presents a promising strategy for the development of next-generation multifunctional hydrogel dressings with considerable potential for application in chronic skin wound therapy and bioelectronics. STATEMENT OF SIGNIFICANCE: Thermoelectric materials are increasingly being incorporated into hydrogels to enhance tissue regeneration. However, improving the thermoelectric efficiency while effectively harnessing the generated electricity for tissue regeneration remains a significant challenge. This study presents a multifunctional hydrogel dressing that integrates advanced photothermal and thermoelectric properties with real-time motion sensing, offering a breakthrough in chronic wound therapy. The PEDOT@PBT-PSBMA/SF hydrogel demonstrates exceptional antibacterial efficacy against E. coli, S. aureus, and MRSA, along with remarkable conductivity suitable for bioelectronic applications. In vivo results highlight its ability to accelerate wound healing through immunomodulation, enhanced collagen deposition, and improved vascularization. In conclusion, this multifunctional hydrogel holds great promise for future development as an integrated platform for diabetic skin wound repair and real-time monitoring.

Anti-Infective Polyurethane Dressings via Ultrafast Laser Micro/Nanostructuring

Bacteria-associated wound infections lead to life-threatening complications such as systemic inflammatory response (SIRS) or septic shock. Even though affordable and permeable polyurethane (PU) dressings are widely used in clinical practice, their pure shielding function appears ineffective for contaminated wounds. Herein, an ultrafast laser is utilized to fabricate micro/nanostructures in PU dressings to significantly enhance drug loading capacity. In contrast to untreated areas, the laser direct writing with spatiotemporal regulation method enhances the drug loading capacity by 61 times. The anti-infective capability is demonstrated by embedding clindamycin within the PU films, indicating that laser-induced micro/nanostructured PU dressings (PU-MS) not only exhibit stable mechanical properties and biocompatiability, but also produce an obvious inhibition zone of Staphylococcus aureus in vitro. Furthermore, a rat skin wound infection model verified that PU-MS can effectively prevent bacteria-associated wound infection and SIRS, promoting wound healing. The results show that PU-MS offers considerable potential for various clinical applications, providing a new strategy for the development of advanced medical dressings.

Structural properties and sustained antimicrobial activity of thymol-loaded cellulose nanofibers from one-pot synthesis via in situ dynamic microfluidization

The physicochemical properties of cellulose nanofibers (CNFs) are significantly influenced by their production methods and surface modifications. This study presents an eco-friendly approach for synthesizing CNFs impregnated with thymol via a single-step in-situ dynamic high-pressure microfluidization process. Optimal conditions for preserving the intrinsic structure and desirable properties of CNFs were explored using various ethanol-water ratios with thymol. The physicochemical properties and characteristics of CNFs were analyzed using advanced techniques. Thymol-impregnated CNFs at an ethanol-to-water ratio of 10:90 (E10W90) demonstrated a sustained cumulative release of up to 27.5 % over 50 h and complete inhibition of bacterial growth within 3 h against S. aureus and E. coli. Density functional theory analysis indicated that thymol adsorption onto the CNF surface is facilitated by hydrogen bonding. This investigation proposes a novel, energy-efficient method for thymol impregnation, achieving prolonged antimicrobial activity without complex surface modifications.

Electroactive Electrospun Nanofibrous Scaffolds: Innovative Approaches for Improved Skin Wound Healing

The incidence and burden of skin wounds, especially chronic and complex wounds, have a profound impact on healthcare. Effective wound healing strategies require a multidisciplinary approach, and advances in materials science and bioengineering have paved the way for the development of novel wound healing dressing. In this context, electrospun nanofibers can mimic the architecture of the natural extracellular matrix and provide new opportunities for wound healing. Inspired by the bioelectric phenomena in the human body, electrospun nanofibrous scaffolds with electroactive characteristics are gaining widespread attention and gradually emerging. To this end, this review first summarizes the basic process of wound healing, the causes of chronic wounds, and the current status of clinical treatment, highlighting the urgency and importance of wound dressings. Then, the biological effects of electric fields, the preparation materials, and manufacturing techniques of electroactive electrospun nanofibrous (EEN) scaffolds are discussed. The latest progress of EEN scaffolds in enhancing skin wound healing is systematically reviewed, mainly including treatment and monitoring. Finally, the importance of EEN scaffold strategies to enhance wound healing is emphasized, and the challenges and prospects of EEN scaffolds are summarized.

A review on smart dressings with advanced features

Wound care is a multifaceted and collaborative process, and chronic wounds can have significant repercussions on a patient's well-being and impose a financial burden on the healthcare industry. While traditional wound dressings can effectively facilitate healing, their limitations in addressing the intricacies of the wound healing process remain a formidable obstacle. Smart wound dressings have emerged as a promising solution to tackle this challenge, offering numerous advantages over conventional dressings, such as real-time monitoring of wound healing and enhanced wound care management. These advanced medical dressings incorporate microelectronic sensors that can monitor the wound environment and provide timely interventions for accelerated and comprehensive healing. Furthermore, advancements in drug delivery systems have enabled real-time monitoring, targeted therapy, and controlled release of medications. Smart wound dressings exhibit versatility, as they are available in various forms and can be utilised for treating different types of acute or chronic wounds. Ultimately, the development of innovative wound care technologies and treatments plays a vital role in addressing the complexities presented by wounds and enhancing patients' quality of life. This review sheds light on the diverse types of smart dressings and their distinctive features, emphasising their potential in advancing the field of wound care.

Skin-inspired elastomer-hydrogel Janus fibrous membrane creates a superior pro-regenerative microenvironment toward complete skin regeneration

The complete regeneration of deep cutaneous wounds remains a challenge. Development of advanced biomaterials that more closely resemble the natural healing environments of skin is a promising strategy. In the present study, inspired by the human skins, an elastomer-hydrogel bilayer fibrous membrane was fabricated for cutaneous wound healing. The elastomer layer, made of poly (trimethylene carbonate) (PTMC), mimics human epidermis, including a similar wettability (around 80°), a compact structure, flexibility, excellent moisture retention, and bacterial pathogen blocking. The hydrogel fiber layer that directly contacts the wound surface was made of hydrophilic gelatin hydrogel fibers, providing an advanced pro-regeneration microenvironment for wound healing, including a moist environment and a mesh-like structure and patterns. Bioactive agents (e.g. stem cell-derived exosomes) could be feasibly incorporated into the hydrogel fiber layer to further enhance the therapeutic outcome. In vivo studies demonstrated that such biomimetic elastomer-hydrogel hybrid fibrous membrane could dramatically enhance the skin regeneration as evidenced by faster wound closure rates, enhanced vascularization, promoted collagen deposition, reduced inflammation, and promoted skin appendage regeneration. Our work provides a new avenue for designing biomimetic wound dressings for cutaneous wound healing.

A dynamically phase-adaptive regulating hydrogel promotes ultrafast anti-fibrotic wound healing

Achieving rapid and scar-free wound repair is a key goal in the field of regenerative medicine. Herein, a dynamically Schiff base-crosslinked hydrogel (F/R gel) with phase-adaptive regulating functions is constructed to integratedly promote rapid re-epithelization with suppressed scars on chronic infected wounds. Specifically, the gel effectively eliminates multidrug-resistant bacterial biofilm at infection stage via antimicrobial activity of ε-polylysine firstly dissociated from hydrogel matrix in infectious microenvironment, and interrupts the severe oxidative stress-inflammation cycle at wound site by the released ceria nanozyme, thus stimulating a pro-regenerative environment to ensure tissue repair. Subsequently, fibroblast growth factor/c-Jun siRNA co-loaded microcapsules gradually disintegrate to release drugs, facilitating neoangiogenesis and cell proliferation but simultaneously blocking c-Jun overexpression for fibrotic scar suppression. Notably, the F/R gel facilitates normal-like skin regeneration with no perceptible scars formed on infected male mouse wound and female rabbit ear wound models. Our work offers a promising regenerative strategy emphasizing immunomodulatory and fibroblast subtype modulation for scarless wound repair.

Interpretable Machine Learning for Evaluating Nanogenerators' Structural Design

The limited battery life in modern mobile, wearable, and implantable electronics critically constrains their operational longevity and continuous use. Consequently, as a self-powered technology, triboelectric nanogenerators (TENGs) have emerged as a promising solution to this. Traditional approaches for evaluating TENG structural design typically require manual, repetitive, time-consuming, and high-cost finite element modeling or experiments. To overcome this bottleneck, we developed a fully automated platform that leverages machine learning (ML) techniques. Our framework contains an artificial neuron network-based surrogate model that can provide accurate and reliable performance predictions for any structural parameters and a TreeSHAP interpretable ML model that can generate precise global and local insights for TENG structural parameters. Our platform shows broad adaptability to multiple TENG structures. In summary, our platform is an integrated platform that utilizes interpretable ML techniques to solve the complex multidimensional TENG structural evaluation problem, marking a significant advancement in TENG design and supporting sustainable energy solutions in mobile electronics.

Functional hydrogels for accelerated wound healing: advances in conductive hydrogels and self-powered electrical stimulation

Compared to traditional dressings, hydrogel dressings not only protect the wound surface and prevent bacterial infection but also possess excellent moisturizing properties, which can provide an optimal moist environment for wound healing, and exhibit good biocompatibility, making them considered the best wound treatment materials. This review focuses on the research status and application progress of various functional hydrogel dressings, such as hemostatic, antimicrobial, anti-inflammatory, antioxidant, and conductive hydrogels. It proposes the combination of conductive hydrogels with flexible solar cells to form self-powered devices. Compared to traditional externally powered devices, this approach can reduce carbon footprints by utilizing clean energy, aligning with carbon neutrality policy requirements. Additionally, it eliminates the need for frequent battery replacement or power connections, effectively saving labor and operational costs. Self-powered devices can convert solar energy into electrical energy, which is conducted to the wound site through hydrogels, generating continuous electrical stimulation (ES). This electrical stimulation guides the directional migration of keratinocytes and fibroblasts toward the center of the wound; activates the MAPK/ERK signaling pathway to accelerate the cell cycle process, and upregulates the expression of vascular endothelial growth factor, thereby inducing endothelial cell proliferation and lumen formation. These multiple mechanisms work synergistically to promote wound healing. Finally, the review provides an outlook on the emergence and applications of multifunctional hydrogels and stimuli-responsive hydrogels, highlighting common challenges in the future development of hydrogels, such as weak mechanical strength and poor long-term stability, as well as feasible solutions to these issues.

Hybrid Molecules of Benzothiazole and Hydroxamic Acid as Dual-Acting Biofilm Inhibitors with Antibacterial Synergistic Effect against Pseudomonas aeruginosa Infections

The ubiquitous opportunistic pathogen Pseudomonas aeruginosa (P. aeruginosa) causes biofilm-associated drug-resistant infections that often lead to treatment failure. Targeting the bacterium's quorum sensing (QS) and iron homeostasis presents a promising strategy to combat biofilm formation. This study synthesized benzothiazole-conjugated hydroxamic acid derivatives as dual-acting biofilm inhibitors, and compound JH21 was identified as the hit compound with potent submicromolar biofilm inhibitory activity (IC50 = 0.4 μM). Further mechanistic studies demonstrated not only that the production of virulence was decreased through mainly inhibiting QS system but also that JH21 competed for iron with the high-affinity siderophore pyoverdine, inducing iron deficiency and inhibiting biofilm. Moreover, JH21 significantly enhanced the efficacy of tobramycin and ciprofloxacin by 200- and 1000-fold, respectively, in a mouse wound infection model. These results emphasized the feasibility of dual-acting biofilm inhibitors against resistant P. aeruginosa infections and the potential of JH21 as a novel antibacterial synergist.

Electroactive Dressing with Selective Sorption of Exudate Enables Treatment of Complicated Wound

Exudate management and cell activity enhancement are vital to complicated wound healing. However, current exudate management dressings indiscriminately remove exudate, which is detrimental to cell activity enhancement. Herein, a novel class of electroactive bilayer (cMO/PVA) dressing is developed by constructing manganese oxide nanoneedle-clusters decorated commercial carbon cloth (MO), in situ casting polyvinyl alcohol (PVA) hydrogel, and finally charging. Benefitting from the hierarchical nanoneedle-cluster structure of MO, abundant active sites are sufficiently exposed to achieve high area-specific capacitances (e.g., 1881.3 mF cm-2), thereby establishing the long-lasting electric field for cMO/PVA dressing. Such a unique cMO/PVA dressing can realize extraordinary selective sorption toward noxious substances over nutrient substances during exudate management. Meanwhile, its long-term electrical stimulation therapy can promote cell proliferation and migration and enhance antibacterial property. As a result, our multifunctional cMO/PVA dressing can rapidly repair full-thickness wounds in type II diabetic rats, offering an advanced strategy for the treatment of complicated wounds.

Advances in Triboelectric Nanogenerators for Microbial Disinfection

The global COVID-19 pandemic has highlighted the pivotal role of microbial disinfection technologies, driving the demand for innovative, efficient, and sustainable solutions. Triboelectric technology, known for efficiently converting ambient mechanical energy into electrical energy, has emerged as a promising candidate to address these needs. Self-powered electro-based microbial disinfection using triboelectric nanogenerators (TENGs) has emerged as a promising solution. TENGs have demonstrated effective disinfection capabilities in various settings, including water, air, surfaces, and wounds. This review explores the advancements in TENG-based microbial disinfection, highlighting its mechanisms and applications. By utilizing triboelectric technology, it provides comprehensive insights into the development of sustainable and efficient solutions for microbial control across diverse environments.

Nanozyme-based wearable biosensors for application in healthcare

Recent years have witnessed tremendous advances in wearable sensors, which play an essential role in personalized healthcare for their ability for real-time sensing and detection of human health information. Nanozymes, capable of mimicking the functions of natural enzymes and addressing their limitations, possess unique advantages such as structural stability, low cost, and ease of mass production, making them particularly beneficial for constructing recognition units in wearable biosensors. In this review, we aim to delineate the latest advancements in nanozymes for the development of wearable biosensors, focusing on key developments in nanozyme immobilization strategies, detection technologies, and biomedical applications. The review also highlights the current challenges and future perspectives. Ultimately, it aims to provide insights for future research endeavors in this rapidly evolving area.

Self-powered biomedical devices: biology, materials, and their interfaces

Integrating biomedical electronic devices holds profound promise for advancements in healthcare and enhancing individuals' quality of life. However, the persistent challenges associated with the traditional batteries' limited lifespan and bulkiness hinder these devices' long-term functionality and consistent power supply. Here, we delve into the biology and material interfaces in self-powered medical devices by summarizing the intrinsic electric demands in humans, analyzing material and biological mechanisms for electricity generation and storage, and discussing the pathways toward self-chargeable powering. As a result, the current challenges in material designs and biological integrations emerged to shape the future directions in advancing self-powered medical devices. This paper calls on the community to integrate biology and material science to develop self-powering medical devices and improve their clinical prospects.

Ultrasound-responsive microfibers promoted infected wound healing with neuro-vascularization by segmented sonodynamic therapy and electrical stimulation

Bacteria-infected wounds pose challenges to healing due to persistent infection and associated damage to nerves and vessels. Although sonodynamic therapy can help kill bacteria, it is limited by the residual oxidative stress, resulting in prolonged inflammation. To tackle these barriers, novel 4 octyl itaconate-coated Li-doped ZnO/PLLA piezoelectric composite microfibers are developed, offering a whole-course "targeted" treatment under ultrasound therapy. The inclusion of Li atoms causes the ZnO lattice distortion and increases the band gap, enhancing the piezoelectric and sonocatalytic properties of the composite microfibers, collaborated by an aligned PLLA conformation design. During the infection and inflammation stages, the piezoelectric microfibers exhibit spatiotemporal-dependent therapeutic effects, swiftly eliminating over 94.2 % of S. aureus within 15 min under sonodynamic therapy. Following this phase, the microfibers capture reactive oxygen species and aid macrophage reprogramming, restoring mitochondrial function, achieving homeostasis, and shortening inflammation cycles. As the wound progresses through the healing stages, bioactive Zn2+ and Li + ions are continuously released, improving cell recruitment, and the piezoelectrical stimulation enhances wound recovery with neuro-vascularization. Compared to commercially available dressings, our microfibers accelerate the closure of rat wounds (Φ = 15 mm) without scarring in 12 days. Overall, this "one stone, four birds" wound management strategy presents a promising avenue for infected wound therapy.

Metal-organic frameworks as thermocatalysts for hydrogen peroxide generation and environmental antibacterial applications

Reactive oxygen species (ROS) are highly reactive, making them useful for environmental and health applications. Traditionally, photocatalysts and piezocatalysts have been used to generate ROS, but their utilization is limited by various environmental and physical constraints. This study introduces metal-organic frameworks (MOFs) as modern thermocatalysts efficiently producing hydrogen peroxide (H2O2) from small temperature differences. Temperature fluctuations, abundant in daily life, offer tremendous potential for practical thermocatalytic applications. As proof of concept, MOF materials coated onto carbon fiber fabric (MOF@CFF) created a thermocatalytic antibacterial filter. The study compared three different MOFs (CuBDC, MOF-303, and ZIF-8) with bismuth telluride (Bi2Te3), a known thermocatalytic material. ZIF-8 demonstrated superior H2O2 generation under low-temperature differences, achieving 96% antibacterial activity through temperature variation cycles. This work advances potential in thermoelectric applications of MOFs, enabling real-time purification and disinfection through H2O2 generation. The findings open interdisciplinary avenues for leveraging thermoelectric effects in catalysis and various technologies.

Rapidly self-crosslinking sodium alginate hydrogel for infected wounds

The risks associated with wound infections are significant, making a snug-fitting hydrogel dressing an optimal choice for wound management. For it, we employed the self-cross-linking method of oxidized sodium alginate (SCSA), incorporating clarithromycin (Cla) and basic fibroblast growth factor (bFGF) to formulate a rapidly forming, bacteriostatic, and wound-healing hydrogel (SCSA@C/b). Bacteriostatic and cytocompatibility assays demonstrated that SCSA@C/b exhibits exceptional antibacterial activity alongside strong biocompatibility. A fractional infected wound model showed that SCSA@C/b accelerated healing of infected wounds by approximately three days compared to the healing time of the control group, with nearly complete wound recovery. H&E staining and SEM analysis of the healed wound sections revealed significant pro-healing effects. Thus, SCSA@C/b is a promising medicinal hydrogel for encouraging wound healing in contaminated areas.

Electrical Stimulation Therapy - Dedicated to the Perfect Plastic Repair

Tissue repair and reconstruction are a clinical difficulty. Bioelectricity has been identified as a critical factor in supporting tissue and cell viability during the repair process, presenting substantial potential for clinical application. This review delves into various sources of electrical stimulation and identifies appropriate electrode materials for clinical use. It also highlights the biological mechanisms of electrical stimulation at both the subcellular and cellular levels, elucidating how these interactions facilitate the repair and regeneration processes across different organs. Moreover, specific electrode materials and stimulation sources are outlined, detailing their impact on cellular activity. The future development trends are projected from two perspectives: the optimization of equipment performance and the fulfillment of clinical demands, focusing on the feasibility, safety, and cost-effectiveness of technologies.

Bacterial nanocelluloses as sustainable biomaterials for advanced wound healing and dressings

Wound healing remains a significant clinical challenge, calling for innovative approaches to expedite the recovery process and improve patient outcomes. Bacterial nanocelluloses (BNCs) have emerged as a promising solution in the field of wound healing and dressings due to their unique properties such as high crystallinity, mechanical strength, high purity, porosity, high water absorption capacity, biodegradability, biocompatibility, sustainability, and flexibility. BNC-based materials can be applied for the treatment of different types of wounds, from second-degree burns to skin tears, biopsy sites, and diabetic and ischemic wounds. BNC-based dressings have exceptional mechanical properties such as flexibility and strength, which ensure proper wound coverage and protection. The renewable nature, eco-friendly production process, longer lifespan, and potential for biodegradability of BNCs make them a more sustainable alternative to conventional wound care materials. This review aims to provide a detailed overview on the application of BNC-based composites for wound healing and dressings via highlighting their ability as a carrier for delivery of different types of antimicrobial compounds as well as their direct effect on the healing process. Besides, it mentions some of the in vivo and clinical studies using BNC-based dressings and describes challenges related to the application of these materials as well as their future directions.

Aqueous-Aqueous Triboelectric Nanogenerators Empowered Multifunctional Wound Healing System with Intensified Current Output for Accelerating Infected Wound Repair

Triboelectric nanogenerators (TENGs) have emerged as promising devices for generating self-powered therapeutic electrical stimulation over multiple aspects of wound healing. However, the challenge of achieving full 100% contact in conventional TENGs presents a substantial hurdle in the quest for higher current output, which is crucial for further improving healing efficacy. Here, a novel multifunctional wound healing system is presented by integrating the aqueous-aqueous triboelectric nanogenerators (A-A TENGs) with a functionalized conductive hydrogel, aimed at advancing infected wound therapy. The A-A TENGs are founded on a principle of 100% contact interface and efficient post-contact separation of the immiscible interface within the aqueous two-phase system (ATPS), enhancing charge transfer and subsequently increasing current performance. Leveraging this intensified current output, this system demonstrates efficient therapeutic efficacies over infected wounds both in vitro and in vivo, including stimulating fibroblast migration and proliferation, boosting angiogenesis, enhancing collagen deposition, eradicating bacteria, and reducing inflammatory cells. Moreover, the conductive hydrogel ensures the uniformity and integrity of the electric field covering the wound site, and exhibits multiple synergistic therapeutic effects. With the capability to realize accelerated wound healing, the developed "A-A TENGs empowered multifunctional wound healing system" presenting an excellent prospect in clinical wound therapy.

Biomimetic poly(thioctic acid)-based bioadhesive hydrogels for wet adhesion, expeditious hemostasis and enhanced wound healing

The bioadhesive hydrogels have been viewed as promising substitutes for surgical sutures in wound closure. However, current bioadhesives face challenges such as weak wet adhesion and hemostatic performance, which hinder their wider clinical application. In this study, a novel poly(thioctic acid)Li+/caffeic acid-grafted sericin (CAS) (PTALi-CAS) supramolecular hydrogel was prepared using facile one-pot method. Among the PTALi-CAS hydrogels with varying CAS content, the PTALi-7%CAS hydrogels exhibited the highest adhesion strength (32.02 ± 2.28 kPa) and could adhere on surfaces of various organs in moist environments. It is noteworthy that the microstructure of the PTALi-7%CAS hydrogels after stretching closely resemble those of mussel byssal adhesion proteins. Additionally, the PTALi-7%CAS hydrogels exhibited rapid hemostatic properties in rat hemorrhage models and significantly accelerated the wound healing in rat skin incision experiments. Therefore, this study proposes a promising approach for developing a versatile hydrogel to aid in healing traumatic wounds.

Thermoelectric Materials and Devices for Advanced Biomedical Applications

Thermoelectrics (TEs), enabling the direct conversion between heat and electrical energy, have demonstrated extensive application potential in biomedical fields. Herein, the mechanism of the TE effect, recent developments in TE materials, and the biocompatibility assessment of TE materials are provided. In addition to the fundamentals of TEs, a timely and comprehensive review of the recent progress of advanced TE materials and their applications is presented, including wearable power generation, personal thermal management, and biosensing. In addition, the new-emerged medical applications of TE materials in wound healing, disease treatment, antimicrobial therapy, and anti-cancer therapy are thoroughly reviewed. Finally, the main challenges and future possibilities are outlined for TEs in biomedical fields, as well as their material selection criteria for specific application scenarios. Together, these advancements can provide innovative insights into the development of TEs for broader applications in biomedical fields.

Recent advances in reactive oxygen species (ROS)-responsive drug delivery systems for photodynamic therapy of cancer

Reactive oxygen species (ROS)-responsive drug delivery systems (DDSs) have garnered significant attention in cancer research because of their potential for precise spatiotemporal drug release tailored to high ROS levels within tumors. Despite the challenges posed by ROS distribution heterogeneity and endogenous supply constraints, this review highlights the strategic alliance of ROS-responsive DDSs with photodynamic therapy (PDT), enabling selective drug delivery and leveraging PDT-induced ROS for enhanced therapeutic efficacy. This review delves into the biological importance of ROS in cancer progression and treatment. We elucidate in detail the operational mechanisms of ROS-responsive linkers, including thioether, thioketal, selenide, diselencide, telluride and aryl boronic acids/esters, as well as the latest developments in ROS-responsive nanomedicines that integrate with PDT strategies. These insights are intended to inspire the design of innovative ROS-responsive nanocarriers for enhanced cancer PDT.

A Mg Battery-Integrated Bioelectronic Patch Provides Efficient Electrochemical Stimulations for Wound Healing

Bioelectronic patches hold promise for patient-comfort wound healing providing simplified clinical operation. Currently, they face paramount challenges in establishing long-term effective electronic interfaces with targeted cells and tissues due to the inconsistent energy output and high bio interface impedance. Here a new electrochemical stimulation technology is reported, using a simple wound patch, which integrates the efficient generation and delivery of stimulation. This is realized by employing a hydrogel bioelectronic interface as an active component in an integrated power source (i.e., Mg battery). The Mg battery enhances fibroblast functions (proliferation, migration, and growth factor secretion) and regulates macrophage phenotype (promoting regenerative polarization and down-regulating pro-inflammatory cytokines), by providing an electric field and the ability to control the cellular microenvironment through chemical release. This bioelectronic patch shows an effective and accelerated wound closure by guiding epithelial migration, mediating immune response, and promoting vasculogenesis. This new electrochemical-mediated therapy may provide a new avenue for user-friendly wound management as well as a platform for fundamental insights into cell stimulation.

Photothermal Fish Gelatin-Graphene Microneedle Patches for Chronic Wound Treatment

Microneedles are demonstrated as an effective strategy for chronic wound treatment. Great endeavors are devoted to developing microneedles with natural compositions and potent functions to promote therapeutic effects for wound healing. Herein, a novel graphene oxide-integrated methacrylated fish gelatin (GO-FGelMA) microneedle patch encapsulated with bacitracin and vascular endothelial growth factor (VEGF) is developed for chronic wound management. As the natural components and porous structures of FGelMA, the fabricated microneedle patches display satisfactory biocompatibility and drug-loading ability. Owing to the integration of graphene oxide, the microneedle patches can realize promoted drug release via near-infrared (NIR) irradiation. Besides, the encapsulated bacitracin and VEGF endow the microneedle patches with the ability to inhibit bacterial growth and promote angiogenesis. It is demonstrated that the GO-FGelMA microneedle patches with efficient drug release exert a positive influence on the wound healing process through reduced inflammation, enhanced wound closure, and improved tissue regeneration. Thus, it is believed that the proposed drugs-loaded GO-FGelMA microneedle patches will hold great potential in future chronic wound treatment.

A bioabsorbable mechanoelectric fiber as electrical stimulation suture

In surgical medicine, suturing is the standard treatment for large incisions, yet traditional sutures are limited in functionality. Electrical stimulation is a non-pharmacological therapy that promotes wound healing. In this context, we designed a passive and biodegradable mechanoelectric suture. The suture consists of multi-layer coaxial structure composed of (poly(lactic-co-glycolic acid), polycaprolactone) and magnesium to allow safe degradation. In addition to the excellent mechanical properties, the mechanoelectrical nature of the suture grants the generation of electric fields in response to movement and stretching. This is shown to speed up wound healing by 50% and reduce the risk of infection. This work presents an evolution of the conventional wound closure procedures, using a safe and degradable device ready to be translated into clinical practice.

Electrical Stimulating Redox Membrane Incorporated with PVA/Gelatin Nanofiber for Diabetic Wound Healing

Chronic wounds adversely affect the quality of life. Although electrical stimulation has been utilized to treat chronic wounds, there are still limitations to practicing it due to the complicated power system. Herein, an electrostimulating membrane incorporated with electrospun nanofiber (M-sheet) to treat diabetic wounds is developed. Through the screen printing method, the various alternate patterns of both Zn and AgCl on a polyurethane substrate, generating redox-mediated electrical fields are introduced. The antibacterial ability of the patterned membrane against both E. coli and S. aureus is confirmed. Furthermore, the poly(vinyl alcohol) (PVA)/gelatin electrospun fiber is incorporated into the patterned membrane to enhance biocompatibility and maintain the wet condition in the wound environment. The M-sheet can improve cell proliferation and migration in vitro and has an immune regulatory effect by inducing the polarization of macrophage to the M2 phenotype. Finally, when applied to a diabetic skin wound model, the M-sheet displays an accelerated wound healing rate and enhances re-epithelialization, collagen synthesis, and angiogenesis. It suggests that the M-sheet is a simple and portable system for the spontaneous generation of electrical stimulation and has great potential to be used in the practical wound and other tissue engineering applications.

Obstructed vein delivery of ceftriaxone via poly(vinyl-pyrrolidone)-iodine-chitosan nanofibers for the management of diabetic foot infections and burn wounds

Superficial skin injuries especially burn injuries and unhealed diabetic foot open wounds remain troubling for public health. The healing process is often interrupted by the invasion of resistant pathogens that results in the failure of conventional procedures outside the clinical settings. Herein, we designed nanofibers dressing with intrinsic antibacterial potential of poly(vinyl-pyrrolidone)-iodine/ poly (vinyl)-alcohol by electrospinning with chitosan encapsulating ceftriaxone (CPC/NFs). The optimized electrospun CPC/NFs exhibited smooth surface morphology with average diameter of 165 ± 7.1 nm, drug entrapment and loading efficiencies of 76.97 ± 4.7 % and 8.32 ± 1.73 %, respectively. The results displayed smooth and uniformed fibers with adequate thermal stability and ensured chemical doping. The enhanced in vitro antibacterial efficacy of CPC/NFs against resistant E. coli isolates and biosafety studies encourage the use of designed nanofibers dressing for burn injuries and diabetic foot injuries. In vivo studies proved the healing power of dressing for burn wounds model and diabetic infected wounds model. Immunofluorescence investigation of the wound tissue also suggested promising healing ability of CPC/NFs. The designed approach would be helpful to treat these infected skin open wounds in the hospitals and outside the clinical settings.

α-Lactalbumin based scaffolds for infected wound healing and tissue regeneration

Interruption of wound healing by multi-drug resistant-bacterial infection is a harmful issue for the worldwide health care system, and conventional treatment approaches may not resolve this issue due to antimicrobial resistance. So, there is an unmet need to develop scaffolds with intrinsic wound healing properties to combat bacterial-infected wounds. Inspired by the α-lactalbumin's (Lalb's) ability to promote collagen synthesis, we herein electrospun Lalb with cephalexin (CPL) and epigallocatechin (EP) to produce nanofibers (CE-Lalb NFs) to solve this issue. The CE-Lalb NFs were prepared using the electrospinning technique and subjected to physicochemical characterizations, in vitro, and in vivo assessments. The CE-Lalb NFs promoted fibroblast migration, proliferation, and collagen synthesis, while CPL/EP annihilated MRSA and E. coli infections. Physicochemical characterizations proved the successful fabrication and doping of CE-Lalb NFs. Antimicrobial assays and fractional inhibitory concentration index (FICI) declared synergistic antibacterial activity of CE-Lalb NFs against MRSA and E. coli. The in vivo and immunohistochemical data evidenced its exceptional potential for wound healing, promoting growth factor, collagen synthesis, and reduced scar formation. The presence of mature collagen, fewer inflammatory cytokines, increased expression of blood vessels, and low expression of IL-6 at the wound site support in vitro and in vivo results. In our view, the tailored scaffold is the next step for personalized wound dressings that could meet patients with infected wounds' unmet needs by the subscription of noninvasive and easily navigable therapeutic options.

A three-dimensional printable conductive composite dressing for accelerating wound healing under electrical stimulation

In this study, a bioink based on poly(vinyl alcohol) (PVA) and κ-carrageenan network was prepared using conductive polymer (PEDOT:PSS) as conducting medium, and (+)-Catechin-loaded mesoporous ZnO (CmZnO) as antibacterial and anti-inflammatory active medium. 3D conductive composite dressing was further fabricated by an extrusion 3D printing technology. Our results showed that the as-obtained composite dressing had suitable conductivity, efficient blood clotting capacity, and good adhesiveness. It also showed that the as-fabricated conductive composite had 92.9 % and 95.6 % antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), respectively. Furthermore, the conductive dressing with an optimal electrical stimulation (ES) parameter showed in vivo blood clotting capacity, and it enhanced in vivo wound healing process in a full-thickness skin defect model than commercial dressings by upregulating the gene expression of growth factors including CD-31 and downregulating inflammatory factor expression of IL-6.

Transpiration-Inspired Fabric Dressing for Acceleration Healing of Wound Infected with Biofilm

In chronic wound management, efficacious handling of exudate and bacterial infections stands as a paramount challenge. Here a novel biomimetic fabric, inspired by the natural transpiration mechanisms in plants, is introduced. Uniquely, the fabric combines a commercial polyethylene terephthalate (PET) fabric with asymmetrically grown 1D rutile titanium dioxide (TiO2) micro/nanostructures, emulating critical plant features: hierarchically porous networks and hydrophilic water conduction channels. This structure endows the fabric with exceptional antigravity wicking-evaporation performance, evidenced by a 780% one-way transport capability and a 0.75 g h-1 water evaporation rate, which significantly surpasses that of conventional moisture-wicking textiles. Moreover, the incorporated 1D rutile TiO2 micro/nanostructures present solar-light induced antibacterial activity, crucial for disrupting and eradicating wound biofilms. The biomimetic transpiration fabric is employed to drain exudate and eradicate biofilms in Staphylococcus aureus (S. aureus)-infected wounds, demonstrating a much faster infection eradication capability compared to clinically common ciprofloxacin irrigation. These findings illuminate the path for developing high-performance, textile-based wound dressings, offering efficient clinical platforms to combat biofilms associated with chronic wounds.

Water-powered, electronics-free dressings that electrically stimulate wounds for rapid wound closure

Chronic wounds affect ~2% of the U.S. population and increase risks of amputation and mortality. Unfortunately, treatments for such wounds are often expensive, complex, and only moderately effective. Electrotherapy represents a cost-effective treatment; however, its reliance on bulky equipment limits its clinical use. Here, we introduce water-powered, electronics-free dressings (WPEDs) that offer a unique solution to this issue. The WPED performs even under harsh conditions-situations wherein many present treatments fail. It uses a flexible, biocompatible magnesium-silver/silver chloride battery and a pair of stimulation electrodes; upon the addition of water, the battery creates a radial electric field. Experiments in diabetic mice confirm the WPED's ability to accelerate wound closure and promote healing by increasing epidermal thickness, modulating inflammation, and promoting angiogenesis. Across preclinical wound models, the WPED-treated group heals faster than the control with wound closure rates comparable to treatments requiring expensive biologics and/or complex electronics. The results demonstrate the WPED's potential as an effective and more practical wound treatment dressing.

Embedding AIE-type Ag28Au1 nanoclusters within ZIF-8 for improved photodynamic wound healing through bacterial eradication

Designing antibacterial agents with rapid bacterial eradication performance is paramount for the treatment of bacteria-infected wounds. Metal nanoclusters (NCs) with aggregation-induced emission (AIE) have been considered as novel photodynamic antibacterial agents without drug resistance, but they suffer from poor photostability and low charge carrier separation efficiency. Herein, we report the design of a photodynamic antibacterial agent by encapsulating AIE-type AgAu NCs (Ag28Au1 NCs) into a zeolitic Zn(2-methylimidazole)2 framework (ZIF-8). The encapsulation of AIE-type Ag28Au1 NCs into porous ZIF-8 could not only enhance the photostability of Ag28Au1 NCs by inhibiting their aggregation but also promote the separation of photoinduced charge carriers, resulting in the rapid generation of destructive reactive oxygen species (ROS) for bacterial killing under visible-light irradiation. Consequently, the as-designed photodynamic Ag28Au1 NCs@ZIF-8 antibacterial agent could rapidly eliminate 97.7% of Escherichia coli (E. coli) and 91.6% of Staphylococcus aureus (S. aureus) within 5 min in vitro under visible light irradiation. Furthermore, in vivo experimental results have highlighted the synergistic effect created by AIE-type Ag28Au1 NCs and ZIF-8, enabling Ag28Au1 NCs@ZIF-8 to effectively eradicate bacteria in infected areas, reduce inflammation, and promote the generation of blood vessels, epithelial tissue, and collagen. This synergistic effect promoted the healing of S. aureus-infected wound, with nearly 100% of wound recovery within 11 days. This work may be interesting because it sheds light on the design of metal NC-based photodynamic nanomedicine for bacteria-infected disease treatment.

Micro-environment-triggered chemodynamic treatment for boosting bacteria elimination at low-temperature by synergistic effect of photothermal treatment and nanozyme catalysis

An injectable hydrogel dressing, Zr/Fc-MOF@CuO2@FH, was constructed by combing acid-triggered chemodynamic treatment (CDT) with low-temperature photothermal treatment (LT-PTT) to effectively eliminate bacteria without harming the surrounding normal tissues. The Zr/Fc-MOF acts as both photothermal reagent and nanozyme to generate reactive oxygen species (ROS). The CuO2 nanolayer can be decomposed by the acidic microenvironment of the bacterial infection to release Cu2+ and H2O2, which not only induces Fenton-like reaction but also enhances the catalytic capability of the Zr/Fc-MOF. The generated heat augments ROS production, resulting in highly efficient bacterial elimination at low temperature. Precisely, injectable hydrogel dressing can match irregular wound sites, which shortens the distance of heat dissipation and ROS diffusion to bacteria, thus improving sterilization efficacy and decreasing non-specific systemic toxicity. Both in vitro and in vivo experiments validated the predominant sterilization efficiency of drug-resistant methicillin-resistant Staphylococcus aureus (MRSA) and kanamycin-resistant Escherichia coli (KREC), presenting great potential for application in clinical therapy.

4D hydrogels: fabrication strategies, stimulation mechanisms, and biomedical applications

Shape-morphing hydrogels have emerged as a promising biomaterial due to their ability to mimic the anisotropic tissue composition by creating a gradient in local swelling behavior. In this case, shape deformations occur due to the non-uniform distribution of internal stresses, asymmetrical swelling, and shrinking of different parts of the same hydrogel. Herein, we discuss the four-dimensional (4D) fabrication techniques (extrusion-based printing, dynamic light processing, and solvent casting) employed to prepare shape-shifting hydrogels. The important distinction between mono- and dual-component hydrogel systems, the capabilities of 3D constructs to undergo uni- and bi-directional shape changes, and the advantages of composite hydrogels compared to their pristine counterparts are presented. Subsequently, various types of actuators such as moisture, light, temperature, pH, and magnetic field and their role in achieving the desired and pre-determined shapes are discussed. These 4D gels have shown remarkable potential as programmable scaffolds for tissue regeneration and drug-delivery systems. Finally, we present futuristic insights into integrating piezoelectric biopolymers and sensors to harvest mechanical energy from motions during shape transformations to develop self-powered biodevices.

A Wearable Self-Charging Electroceutical Device for Bacteria-Infected Wound Healing

The prolonged wound-healing process caused by pathogen infection remains a major public health challenge. The developed electrical antibiotic administration typically requires metal electrodes wired to a continuous power supply, restricting their use beyond clinical environments. To obviate the necessity for antibiotics and an external power source, we have developed a wearable synergistic electroceutical device composed of an air self-charging Zn battery. This battery integrates sustained tissue regeneration and antibacterial modalities while maintaining more than half of the initial capacity after ten cycles of chemical charging. In vitro bacterial/cell coculture with the self-charging battery demonstrates inhibited bacterial activity and enhanced cell function by simulating the endogenous electric field and dynamically engineering the microenvironment with released chemicals. This electroceutical device provides accelerated healing of a bacteria-infected wound by stimulating angiogenesis and modulating inflammation, while effectively inhibiting bacterial growth at the wound site. Considering the simple structure and easy operation for long-term treatment, this self-charging electroceutical device offers great potential for personalized wound care.

Achieving Self-Reinforcing Triboelectric-Electromagnetic Hybrid Nanogenerator by Magnetocaloric and Magnetization Effects of Gadolinium

Triboelectric-electromagnetic hybrid nanogenerator (TEHG) has emerged as a promising technology for distributed energy harvesting. However, currently reported hybrid generators are straightforward combinations of two functional components. Moreover, inevitable heat from friction intensifies material abrasion and degrades the performance of polymer-based triboelectric nanogenerators (TENGs). Here, a self-reinforcing TEHG (SR-TEHG) that harnesses the magnetocaloric and magnetization effects of gadolinium (Gd), is proposed. The synergy between TENG and electromagnetic generator (EMG) renders them an indivisible unit. Leveraging Gd's magnetocaloric effect, an efficient heat transfer mechanism is constructed to cool the tribolayer and strengthen the device's electrical stability. After 80 h of continuous operation, the optimized TENG occupies a charge decay rate of only 0.32% per hour, significantly outperforming most existing TENGs. Additionally, Gd's magnetization effect boosts the power of EMG by ≈80.84%. This work provides a universal solution in hybrid generators where internal components reinforce each other, achieving a synergistic effect of 1 + 1 > 2.

Recent advances in harnessing biological macromolecules for wound management: A review

Wound dressings (WDs) are an essential component of wound management and serve as an artificial barrier to isolate the injured site from the external environment, thereby helping to prevent exogenous infections and supporting healing. However, maintaining a moist wound environment, providing protection from infection, good biocompatibility, and allowing for gas exchange, remain a challenge in device design. Functional wound dressings (FWDs) prepared from hybrid biological macromolecule-based materials can enhance efficacy of these systems for skin wound management. This review aims to provide an overview of the state-of-the-art FWDs within the field of wound management, with a specific focus on hybrid biomaterials, techniques, and applications developed over the past five years. In addition, we highlight the incorporation of biological macromolecules in WDs, the emergence of smart WDs, and discuss the existing challenges and future prospects for the development of advanced WDs.

Tailored gelatin methacryloyl-based hydrogel with near-infrared responsive delivery of Qiai essential oils boosting reactive oxygen species scavenging, antimicrobial, and anti-inflammatory activities for diabetic wound healing

The management of diabetic wounds poses a substantial economic and medical burden for diabetic patients. Oxidative stress and persistent bacterial infections are considered to be the primary factors. Qiai essential oil (QEO) exhibits various pharmacological characteristics, including inflammatory-reducing, antibacterial, and antioxidant properties. Nevertheless, the hydrophobic nature and propensity for explosive release of this substance present constraints on its potential for future applications. Here, we developed a stimulus-responsive hydrogel to overcome the multiple limitations of QEO-based wound dressings. The QEO was encapsulated within graphene oxide (GO) through repeated extrusion using an extruder. Subsequently, QEO@GO nanoparticles were incorporated into a Gelatin-methacryloyl (GelMA) hydrogel. The QEO@GO-GelMA hydrogel demonstrated controlled release ablation, photothermal antibacterial effects, and contact ablation against two representative bacterial strains. It effectively reduced reactive oxygen species (ROS) generation, promoted angiogenesis, and decreased levels of the pro-inflammatory cytokine interleukin-6 (IL-6), thereby accelerating the healing process of diabetic wounds. In addition, in vitro and in vivo tests provided further evidence of the favorable biocompatibility of this multifunctional hydrogel dressing. Overall, the QEO@GO-GelMA hydrogel provides numerous benefits, encompassing antimicrobial properties, ROS-scavenging abilities, anti-inflammatory effects, and the capacity to expedite diabetic wound healing. These attributes make it an optimal choice for diabetic wound management.

Seconds Timescale Synthesis of Highly Stretchable Antibacterial Hydrogel for Skin Wound Closure and Epidermal Strain Sensor

Effective wound healing is critical for patient care, and the development of novel wound dressing materials that promote healing, prevent infection, and are user-friendly is of great importance, particularly in the context of point-of-care testing (POCT). This study reports the synthesis of a hydrogel material that can be produced in less than 10 s and possesses antibacterial activity against both gram-negative and gram-positive microorganisms, as well as the ability to inhibit the growth of eukaryotic cells, such as yeast. The hydrogel is formed wholly based on covalent-like hydrogen bonding interactions and exhibits excellent mechanical properties, with the ability to stretch up to more than 600% of its initial length. Furthermore, the hydrogel demonstrates ultra-fast self-healing properties, with fractures capable of being repaired within 10 s. This hydrogel can promote skin wound healing, with the added advantage of functioning as a strain sensor that generates an electrical signal in response to physical deformation. The strain sensor composed of a rubber shell realizes fast and responsive strain sensing. The findings suggest that this hydrogel has promising applications in the field of POCT for wound care, providing a new avenue for improved patient outcomes.

Enhanced heterogeneous interface to construct intelligent conductive hydrogel gas sensor for individualized treatment of infected wounds

In this study, we developed an enhanced heterogeneous interface intelligent conductive hydrogel NH3 sensor for individualized treatment of infected wounds. The sensor achieved monitoring, self-diagnosis, and adaptive gear adjustment functions. The PPY@PDA/PANI(3/6) sensor had a minimum NH3 detection concentration of 50 ppb and a response value of 2.94 %. It also had a theoretical detection limit of 49 ppt for infected wound gas. The sensor exhibited a fast response time of 23.2 s and a recovery time of 42.9 s. Tobramycin (TOB) was encapsulated in a self-healing QCS/OD hydrogel formed by quaternized chitosan (QCS) and oxidized dextran (OD), followed by the addition of polydopamine-coated polypyrrole nanowires (PPY@PDA) and polyaniline (PANI) to prepare electrically conductive drug-loaded PPY@PDA/PANI hydrogels. The drug-loaded PPY@PDA/PANI hydrogel was combined with a PANI/PVDF membrane to form an enhanced heterogeneous interfacial PPY@PDA/PANI/PVDF-based sensor, which could adaptively learn the individual wound ammonia response and adjust the speed of drug release from the PPY@PDA/PANI hydrogel with electrical stimulation. Drug release and animal studies demonstrated the efficacy of the PPY@PDA/PANI hydrogel in inhibiting infection and accelerating wound healing. In conclusion, the gas-sensitive conductive hydrogel sensing system is expected to enable intelligent drug delivery and provide personalized treatment for complex wound management.

Electrical Stimulation for Immunomodulation

The immune system plays a key role in the development and progression of numerous diseases such as chronic wounds, autoimmune diseases, and various forms of cancer. Hence, controlling the behavior of immune cells has emerged as a promising approach for treating these diseases. Current modalities for immunomodulation focus on chemical based approaches, which while effective have the limitations of nonspecific systemic side effects or requiring invasive delivery approaches to reduce the systemic side effects. Recent advances have unraveled the significance of electrical stimulation as an attractive noninvasive approach to modulate immune cell phenotype and activity. This review provides insights on electrical stimulation strategies employed for regulating the behavior of macrophages, T and B cells, and neutrophils. For obtaining a better understanding, two major types of electrical stimulation sources, conventional and self-powered sources, that have been used for immunomodulation are extensively discussed. Next, the strategies of electrical stimulation that may be applied to cells in vitro and in vivo are discussed, with a focus on conventional and stimuli-responsive self-powered sources. A description of how these strategies influence the polarization, phagocytosis, migration, and differentiation of immune cells is also provided. Finally, recent developments in the use of highly localized and efficient platforms for electrical stimulation based immunomodulation are also highlighted.

Next-generation of smart dressings: Integrating multiplexed sensors and theranostic functions

Non-healing wounds represent a significant burden for healthcare systems and society, giving rise to severe economic and human issues. Currently, the use of dressings and visual assessment represent the primary and standard care for wounds. Conventional dressings, like cotton gauze, provide only passive physical protection. Besides, they end up paradoxically hampering the wound-healing process by producing tissue damage and pain when removed during routine check-ups. In response to these limitations, researchers, engineers, and technologists are developing innovative dressings that incorporate advanced diagnostic and therapeutic functionalities, coined as "smart dressings". Now, the maturation of smart dressing is bringing them closer to real-life applications, leading to an exciting new generation of these devices. The next generation of smart dressings is capable of monitoring in real-time multiple biomarkers while including pro-healing capabilities in a single platform. Such multiplexed and theranostic smart dressings are expected to offer a timely biomarker-directed diagnosis of non-healing wounds while enabling rapid, automated, and personalized treatments of infection and chronicity. Herein, we provide an insightful overview of these advantageous devices, delving into the diverse spectrum of possible engineering strategies. This encompasses the use of electrochemical and optical platforms with diverse multiplexing architectures, such as multi-zone sensing arrays and multi-layered devices. Open or closed-loop theranostic mechanisms using various stimuli-responsive materials that could be internally or externally controlled are also included. Finally, a critical discussion on the main challenges and future directions of smart dressings is also offered.

Biopolymer-Assembled Porous Hydrogel Microfibers from Microfluidic Spinning for Wound Healing

Hydrogels are considered as a promising medical patch for wound healing. Researches in this aspect are focused on improving their compositions and permeability to enhance the effectiveness of wound healing. Here, novel prolamins-assembled porous hydrogel microfibers with the desired merits for treating diabetes wounds are presented. Such microfibers are continuously generated by one-step microfluidic spinning technology with acetic acid solution of prolamins as the continuous phase and deionized water as the dispersed phase. By adjusting the prolamin concentration and flow rates of microfluidics, the porous structure and morphology as well as diameters of microfibers can be well tailored. Owing to their porosity, the resultant microfibers can be employed as flexible delivery systems for wound healing actives, such as bacitracin and vascular endothelial growth factor (VEGF). It is demonstrated that the resultant hydrogel microfibers are with good cell-affinity and effective drug release efficiency, and their woven patches display superior in vivo capability in treating diabetes wounds. Thus, it is believed that the proposed prolamins-assembled porous hydrogel microfibers will show important values in clinic wound treatments.