High glucose blood and bacterial infection remain major issues for the slow healing of diabetic wounds, so developing functional biosensing composite with excellent antibacterial and remarkable glucose response sensitivity is necessary and prospective. Herein, by in situ synthesis AgNPs on the surface of self-prepared PTIGA elastomers, PTIGA-AgNPs conductive composites are obtained with efficient synergistic antibacterial effect, excellent mechanical and self-healing properties. The strain of the composites can reach 1800%, and its self-healing efficiency exceeds 90% at 60 °C within 8 h. Both elastomers and composites represent excellent biocompatibility and the antibacterial rate against E. coli and S. aureus exceeded 90%. Moreover, the biosensor assembled from the conductive composites exhibits excellent glucose response sensitivity and stability, with a sensitivity coefficient of 0.518 mA mm-1 in the range of 0.2-3.6 × 10-3 m glucose concentration, as well as a low detection limit of 0.08 × 10-3 m. Furthermore, based on the remarkable antibacterial performance and bioactivity derived from GA, the composites reduce the expression of pro-inflammatory factors and promote the production of anti-inflammatory factors, and effectively promote the regeneration of skin and granulation tissue of wounds in a diabetic full-thickness skin defect model, demonstrating the enormous therapeutic potential in diabetic wound healing.

Wound healing in movable parts, including the joints and neck, remains a critical challenge due to frequent motions and poor flexibility of dressings, which may lead to mismatching of mechanical properties and poor fitting between dressings and wounds; thus, increasing the risk of bacterial infection. This study proposes a sprayable zwitterionic antibacterial hydrogel with outstanding flexibility and desirable adhesion. This hydrogel precursor is fabricated by combining zwitterionic sulfobetaine methacrylate (SBMA) with poly(sulfobetaine methacrylate-co-dopamine methacrylamide)-modified silver nanoparticles (PSBDA@AgNPs) through robust electrostatic interactions. About 150 s of exposure to UV light, the SBMA monomer polymerizes to form PSB chains entangled with PSBDA@AgNPs, transformed into a stable and adhesion PSB-PSB@Ag hydrogel at the wound site. The resulting hydrogel has adhesive strength (15-38 kPa), large tensile strain (>400%), suitable shape adaptation, and excellent mechanical resilience. Moreover, the hydrogel displays pH-responsive behavior; the acidic microenvironment at the infected wound sites prompts the hydrogel to rapidly release AgNPs and kill bacteria. Further, the healing effect of the hydrogel is demonstrated on the rat neck skin wound, showing improved wound closing rate due to reduced inflammation and enhanced angiogenesis. Overall, the sprayable zwitterionic antibacterial hydrogel has significant potential to promote joint skin wound healing.

Manipulating the dispersibility and reactivity of two-dimensional nanomaterials in collagen fibers (CFs) matrix has aroused attention in the fabrication of multifunctional collagen-based nanocomposites. Here, α‑zirconium phosphate nanoplatelets (ZrP NPs) were surface-functionalized with gallic acid (GA) to afford ZrP-GA NPs for engineering CFs matrix. The influence of ZrP-GA NPs on the ultraviolet barrier, antibacterial, and flame-retardant properties of resultant CFs matrix were investigated. Microstructural analysis revealed that ZrP-GA NPs were dispersed and bound within the collagen fibrils and onto the collagen strands in the CFs matrix. The resultant CFs matrix also maintained typical D-periodic structures of collagen fibrils and native branching and interwoven structures of CFs networks with increased porosity and enhanced ultraviolet barrier properties. Inhibition zone testing presented excellent antibacterial activities of the CFs matrix owing to surface grafting of antibacterial GA. Thanks to enhanced dispersion and binding of ZrP NPs with the CFs matrix by surface-functionalization with GA, the resultant CFs matrix reduced the peak heat release rate and the total heat release by 42.9 % and 39.0 %, respectively, highlighting improved flame-retardant properties. We envision that two-dimensional nanomaterials possess great potential in developing reasonable collagen-based nanocomposites towards the manufacture of emergent multifunctional collagen fibers-based wearable electronics.

Flexible sensors, as a significant component of flexible electronics, have attracted great interest the realms of human-computer interaction and health monitoring due to their high conformability, adjustable sensitivity, and excellent durability. In comparison to wearable sensor-based in vitro health monitoring, the use of implantable flexible sensors (IFSs) for in vivo health monitoring offers more accurate and reliable vital sign information due to their ability to adapt and directly integrate with human tissue. IFSs show tremendous promise in the field of health monitoring, with unique advantages such as robust signal reading capabilities, lightweight design, flexibility, and biocompatibility. Herein, a review of IFSs for vital signs monitoring is detailly provided, highlighting the essential conditions for in vivo applications. As the prerequisites of IFSs, the stretchability and wireless self-powered properties of the sensor are discussed, with a special attention paid to the sensing materials which can maintain prominent biosafety (i.e., biocompatibility, biodegradability, bioresorbability). Furthermore, the applications of IFSs monitoring various parts of the body are described in detail, with a summary in brain monitoring, eye monitoring, and blood monitoring. Finally, the challenges as well as opportunities in the development of next-generation IFSs are presented.

The global pandemic and excessive use of antibiotics have raised concerns about environmental health, and efforts are being made to develop alternative bactericidal agents for disinfection. Metal-based nanomaterials and their derivatives have emerged as promising candidates for antibacterial agents due to their broad-spectrum antibacterial activity, environmental friendliness, and excellent biocompatibility. However, the reported antibacterial mechanisms of these materials are complex and lack a comprehensive understanding from a coherent perspective. To address this issue, a new perspective is proposed in this review to demonstrate the toxic mechanisms and antibacterial activities of metal-based nanomaterials in terms of energy conversion and electron transfer. First, the antimicrobial mechanisms of different metal-based nanomaterials are discussed, and advanced research progresses are summarized. Then, the biological intelligence applications of these materials, such as biomedical implants, stimuli-responsive electronic devices, and biological monitoring, are concluded based on trappable electrical signals from electron transfer. Finally, current improvement strategies, future challenges, and possible resolutions are outlined to provide new insights into understanding the antimicrobial behaviors of metal-based materials and offer valuable inspiration and instructional suggestions for building future intelligent environmental health.

Cationic surfactant-stabilized oil-in-water emulsions pose a significant challenge in separation due to the presence of surfactants. Herein, we develop a collagen-fiber-based CFM-PMDA-TiO2 membrane with unique infiltration properties capable of efficiently separating cationic surfactant-stabilized oil-in-water emulsions by exploiting the charge-demulsification effect. The membrane exhibits superhydrophilic and submerged superoleophobic properties, making it highly suitable for separating a wide range of commercially available cationic surfactant-stabilized oil-in-water microemulsions and nanoemulsions, which demonstrates an exceptional separation efficiency as high as 99.86% and an impressive flux of up to 1436.40 L m-2 h-1. Furthermore, even after a strong subjecting of the membrane to sandpaper abrasion and a full 15 time use, the separation efficacy of oil-in-water emulsions is retained, highlighting the durability, reusability, and economic viability. We propose that these features are enabled by the electrostatic interactions triggered from pyromellitic dianhydride (PMDA) and superhydrophilic-superoleophobic membrane intensified by the TiO2 on the unique collagen fiber membrane. Outcomes emphasize the versatility and potential of our membrane in addressing emulsified oily wastewater hurdles.

There is an urgent need to develop a series of multifunctional materials with good biocompatibility, high mechanical strength, hemostatic properties, antiadhesion, and anti-infection for applications in wound care. However, successfully developing multifunctional materials is challenging. In this study, two superhydrophobic composite coatings with good biocompatibility, high mechanical strength, strong antifouling and blood repellency, fast hemostasis, and good antibacterial activity are prepared on cotton fabric surface by simple, green, and low-cost one-step dip-coating technology. The results discussed in the manuscript reveals that the two superhydrophobic composite coatings can maintain good mechanical stability, strong water repellency, and durability under various types of mechanical damage, high-temperature treatment, and long-term strong light irradiation. The coatings also exhibit good repellency to various solid pollutants, highly viscous liquid pollutants, and blood. In vitro and in vivo hemostatic experiments show that both composite coatings have good hemostatic and anticlot adhesion properties. More importantly, this superhydrophobic coating prevents bacterial adhesion and growth and released Cu2+ and Zn2+ ions and chitosan to achieve bactericidal properties, thereby protecting injured skin from bacterial infection. The two superhydrophobic coatings enhance the antifouling, antiadhesion, hemostatic, and antibacterial functions of blood-repellent dressings and therefore have broad application prospects in medical and textile fields.

Functional face masks that can effectively remove particulate matter and pathogens are critical to addressing the urgent health needs arising from industrial air pollution and the COVID-19 pandemic. However, most commercial masks are manufactured by tedious and complicated network-forming procedures (e.g., meltblowing and electrospinning). In addition, the materials used (e.g., polypropylene) have significant limitations such as a lack of pathogen inactivation and degradability, which can cause secondary infection and serious environmental concerns if discarded. Here, we present a facile and straightforward method for creating biodegradable and self-disinfecting masks based on collagen fiber networks. These masks not only provide superior protection against a wide range of hazardous substances in polluted air, but also address environmental concerns associated with waste disposal. Importantly, collagen fiber networks with naturally existing hierarchical microporous structures can be easily modified by tannic acid to improve its mechanical characteristics and enable the in situ production of silver nanoparticles. The resulting masks exhibit excellent antibacterial (>99.99%, 15 min) and antiviral (>99.999%, 15 min) capabilities, as well as high PM_2.5 removal efficiency (>99.9%, 30 s). We further demonstrate the integration of the mask into a wireless platform for respiratory monitoring. Therefore, the smart mask has enormous promise for combating air pollution and contagious viruses, managing personal health, and alleviating waste issues caused by commercial masks.

A novel injectable hydrogel dressing (GA@AgNPs-SA) with long-term antimicrobial effect is developed that can accelerate the closure of bacteria-infected wounds. The hydrogel dressing was prepared by cross-linking sodium alginate molecular chains and gallic acid functionalized silver nanoparticles (GA@AgNPs) via calcium ions to form a three-dimensional network. The hydrogel dressing demonstrates excellent biocompatibility and can achieve a sustainable release of silver ions, ensuring a long-term antibacterial activity and inhibiting biofilm formation. Moreover, an in vivo study demonstrates that the GA@AgNPs-SA hydrogel can effectively decrease the expression of IL-6 and TNF-α to alleviate the inflammatory response, and promote angiogenesis by upregulating CD31, α-SMA and VEGF expression, thus significantly accelerating the repair of infected wounds. Given these interesting properties, this antibacterial hydrogel has great potential for application in the clinical care of bacteria-infected wounds.

Skin-mountable electronics are considered to be the future of the next generation of portable electronics, due to their softness and seamless integration with human skin. However, impermeable materials limit device comfort and reliability for long-term, continuous usage. The recent emergence of permeable skin-mountable electronics has attracted tremendous attention in the soft electronics field. Herein, we provide a comprehensive and systematic review of permeable skin-mountable electronics. Typical porous materials and structures are first highlighted, followed by discussion of important device properties. Then, we review the latest representative applications of breathable skin-mountable electronics, such as bioelectrical sensors, temperature sensors, humidity and hydration sensors, strain and pressure sensors, and energy harvesting and storage devices. Finally, a conclusion and future directions for permeable skin electronics are provided.