Solar-driven interfacial evaporation is an efficient method for purifying contaminated or saline water. Nonetheless, the suboptimal design of the structure and composition still necessitates a compromise between evaporation rate and service life. Therefore, achieving efficient production of clean water remains a key challenge. Here, a biomimetic dictyophora hydrogel based on loofah/carbonized sucrose@ZIF-8/polyvinyl alcohol is demonstrated, which can serve as an independent solar evaporator for clean water recovery. This special structural design achieves effective thermal positioning and minimal heat loss, while reducing the actual enthalpy of water evaporation. The evaporator achieves a pure water evaporation rate of 3.88 kg m-2 h-1 and a solar-vapor conversion efficiency of 97.16% under 1 sun irradiation. In comparison, the wastewater evaporation rate of the evaporator with ZIF-8 remains at 3.85 kg m-2 h-1 for 30 days, which is 16.3% higher than the light irradiation without ZIF-8. Equally important, the evaporator also showcases the capability to cleanse water from diverse sources of contaminants, including those with small molecules, oil, heavy metal ions, and bacteria, greatly improving the lifespan of the evaporator.

Bacterial infection and tissue hypoxia always prevent wound healing, so multifunctional platforms with antimicrobial and oxygen-supplying functions were developed. However, they face many difficulties such as complex preparation and low oxygen release. To address this challenge, a copper peroxide loaded gelatin/oxide dextran hydrogel (CGO) was prepared. Surprisingly, CGO hydrogel as a wound dressing not only had good biocompatibility, injectivity, and mechanical properties, but also exhibited mild photothermal properties, temperature responsiveness, and pH responsiveness. After being applied to wounds infected with bacteria, CGO hydrogel released copper peroxide under near-infrared laser irradiation, which produced copper ions and hydrogen peroxide, combined with PTT to kill bacteria. After the bacteria were cleared from the wound and the pH of the wound was changed to be acidic, CGO hydrogel released copper peroxide via pH response. Copper ions and oxygen produced from copper peroxide accelerated wound healing by promoting angiogenesis. The multi-responsive and multi-mode treatment platform provided a potential strategy for treating bacteria-infected wounds.

In diabetic patients with skin injuries, bacterial proliferation, accumulation of reactive oxygen species (ROS) in the tissues, and impaired angiogenesis make wound healing difficult. Therefore, eliminating bacteria, removing ROS, and promoting angiogenesis are necessary for treating acute diabetic wounds. In this study, benefiting from the ability of polyphenols to form a metal-phenolic network (MPN) with metal ions, TA-Eu MPN nanoparticles (TM NPs) were synthesized. The prepared photothermal agent CuS NPs and TM NPs were then loaded onto the supporting base and needle tips of PVA/HA (PH) microneedles, respectively, to obtain PH/CuS/TM microneedles. Antibacterial experiments showed that microneedles loaded with CuS NPs could remove bacteria by the photothermal effect. In vitro experiments showed that the microneedles could effectively scavenge ROS, inhibit macrophage polarization to the M1 type, and induce polarization to the M2 type as well as have the ability to promote vascular endothelial cell migration and angiogenesis. Furthermore, in vivo experiments showed that PH/CuS/TM microneedles accelerated wound healing by inhibiting pro-inflammatory cytokines and promoting angiogenesis in a diabetic rat wound model. Therefore, PH/CuS/TM microneedles have efficient antibacterial, ROS scavenging, anti-inflammatory, immunomodulatory, and angiogenic abilities and hold promise as wound dressings for treating acute diabetic wounds.

Bacterial infections are a serious threat to wound healing and skin regeneration. In recent years, photothermal therapy (PTT) has become one of the most promising tools in the treatment of infectious diseases. However, wound dressings with photo-responsive properties are currently still limited by the difficulties of biosafety and thermal stability brought by the introduction of photosensitizers or photothermal agents. Therefore, how to improve the therapeutic efficiency and biosafety from material design is still a major challenge at present. In this study, the carboxymethyl chitosan (CMCS) and protocatechuic aldehyde (PA) hydrogels based on horseradish peroxidase (HRP) and hydrogen peroxide (H2O2) enzymatic catalysis was developed. Therein, HRP and H2O2 catalyzed cross-linking while polymerizing PA, which not only endowed the hydrogels with photothermal responsiveness but also with good biosafety through this enzyme-catalyzed green approach. Meanwhile, the hydrogels possessed highly efficient bacteriostatic ability with the assistance of near infrared (NIR). Moreover, the ultra-rapid gelation, strong tissue adhesion, high swelling ability, good antioxidant property and hemostatic property of the CMCS-PA hydrogels based on HRP/H2O2 enzymatic catalysis were suitable for the treatment of skin wounds. Meanwhile, NIR-assistant CMCS-PA hydrogels based on HRP/H2O2 enzymatic catalysis reduced inflammation, decreased bacterial infection, and promoted collagen deposition and angiogenesis, which showed remarkable therapeutic effects in a skin wound infection model. All results indicate that this green approach to introduce photothermal property by HRP-catalyzed PA polymerization endows the hydrogels with efficient photothermal conversion efficiency, suggesting that they are promising to provide new options for replacing photothermal agents and photosensitizers. STATEMENT OF SIGNIFICANCE: In recent years, wound dressings with photo-responsive properties are currently still limited by the difficulties of biosafety and thermal stability brought by the introduction of agent photosensitizers or photothermal agents. In this study, the carboxymethyl chitosan and protocatechuic aldehyde hydrogels based on horseradish peroxidase and hydrogen peroxide enzymatic catalysis was developed. The photothermal properties of hydrogels were transformed from absent to present just by horseradish peroxidase-catalyzed protocatechuic aldehyde polymerization in a green approach. Meanwhile, the hydrogels possessed highly efficient bacteriostatic ability with the assistance of near infrared. The green approach of introducing photothermal properties from material design solves the biosafety challenge. Therefore, this study is expected to provide new options for alternative photothermal agents and photosensitizers.

Wound infections are an escalating clinical challenge with continuous inflammatory response and the threat of drug-resistant bacteria. Herein, a series of self-healing conductive hydrogels were designed based on carboxymethyl chitosan/oxidized sodium alginate/polymerized gallic acid/Fe3+ (CMC/OSA/pGA/Fe3+, COGFe) for promoting infected wound healing. The Schiff base and catechol-Fe3+ chelation in the dynamical dual network structure of the hydrogels endowed dressings with good toughness, conductivity, adhesion, and self-healing properties, thus flexibly adapting to the deformation of skin wounds. In terms of ultraviolet (UV) resistance and scavenging of reactive oxygen species (ROS), the hydrogels significantly reduced oxidative stress at the wound site. Additionally, the hydrogels with photothermal therapy (PTT) achieved a 95% bactericidal rate in 5 min of near-infrared (NIR) light radiation by disrupting the bacterial cell membrane structure through elevated temperature. Meanwhile, the inherent antimicrobial properties of GA could reduce healthy tissue damage caused by excessive heat. The composite hydrogels could effectively promote the proliferation and migration of fibroblasts and possess good biocompatibility and hemostatic effect. In full-thickness infected wound repair experiments in rats, the COGFe5 hydrogel combined with NIR effectively killed bacteria, modulated macrophage polarization (M1 to M2 phenotype) to improve the immune microenvironment of the wound, and shortened the repair time by accelerating the expression of collagen deposition (TGF-β) and vascular factors (CD31). This combined therapy might provide a prospective strategy for infectious wound treatment.

The healing of a wound under tension (hereafter, \"tension wound\") often coincides with the development of hypertrophic scars in clinical settings. Currently, compress bandages offer a potential alternative for the healing of tension wounds; however, their application in surgery is limited due to their prefabricated patch form. To overcome this, a tension-shielding hydrogel system was designed using photocurable catechol-grafted hyaluronic acid and tannic-acid silver nanoparticles (hereafter, \"HTA system\"). The hydrogel exhibited tension-shielding capacity, reducing wound tension via shape-fixation and ultimately reducing scar formation. The HTA hydrogel exhibited superior photothermal antibacterial efficacy, self-healing properties, and effective dissipation of energy, thereby promoting tissue regeneration. The hydrogel significantly inhibited the mechanotransduction pathway, thus preventing Engrailed-1 activation and reducing the fibrotic response. The HTA hydrogel system, therefore, provides a treatment strategy for tension wounds, burn wounds and other wounds that are prone to form hypertrophic scars via creating a tension-free local environment. STATEMENT OF SIGNIFICANCE: In our study, we presented a wound-dressing hydrogel system (HTA) that exhibit shape-fixing capacity in tension wound model. Here, we designed and modified a tension regulator, applied it to mice, and furthermore, established a tension wound model in mice with adjustable tension. Outcomes showed that the HTA hydrogel system can effectively form a shape-fixed environment on tension wounds and dynamic wounds, thus promoting scarless healing. Additionally, HTA performs injectability, rapid crosslinking, biocompatibility, wet adhesion, hemostasis and photothermal antibacterial properties. We believe this research has various potential clinical applications, including scarless-healing in tension wounds, treatment of acute bleeding, treatment of infected wounds, and even internal organ repair.

Post-operative pathogenic infections in liver transplantation seriously threaten human health. It is essential to develop novel methods for the highly sensitive and rapid detection of Staphylococcus aureus (S. aureus). Interestingly, the combination of the property of bacteria to secrete hydrogen peroxidase, bacterial metabolism-triggered-chemiluminescence (CL)-based bioassays can be as a candidate point-of-care testing (POCT) for the detection of S. aureus against the CL substrate Luminol and hydrogen peroxide without excitation light sources. Here, a CL-based strategy with stable and visualized CL intensity was fabricated according to a hybrid biomimetic enzyme of copper-Hemin metal-organic framework, which enhances the biological enzyme activity while improving the stability and sensitivity of the assay. By further integrating S. aureus-specific capture and one-step separation of the antibody-modified Fe3O4 NPs (Fe3O4 NPs@Ab), the portable device integrated smartphone enables CL-based POCT for specific detection of S. aureus in the range of 101-106 CFU/mL with a limit of detection as low as 1 CFU/mL. Specifically, S. aureus can be eliminated after detection with high antibacterial efficiency due to the excellent photothermal properties of Fe3O4 NPs@Ab. The developed multifunctional platform has the advantages of simplicity of operation and low cost, indicating great potential in clinical applications.

To better treat bacteria-infected wounds and promote healing, new wound dressings must be developed. In this study, we obtained PA@Fe by chelating iron trivalent ions (Fe3+) with protocatechualdehyde (PA), which has a catechol structure. Subsequently, we reacted it with ethylene glycol chitosan (GC) via a Schiff base reaction and loaded vancomycin to obtain an antibacterial Gel@Van hydrogel with a photothermal response. The as-prepared Gel@Van hydrogel exhibited good injectability, self-healing, hemostasis, photothermal stability, biocompatibility, and antioxidant and antibacterial properties. Moreover, Gel@Van hydrogel achieved highly synergistic antibacterial efficacy through photothermal and antibiotic sterilization. In a mouse skin-damaged infection model, Gel@Van hydrogel had a strong ability to promote the healing of methicillin-resistant Staphylococcus aureus (MRSA)-infected wounds, indicating the great potential application value of Gel@Van hydrogel in the field of treating and promoting the healing of infected wounds.

Bacterial infection and oxidative stress impede clinical wound healing. Herein, the plant-derived cowberry extract (CE) was first explored as a natural photothermal agent and antioxidant to deal with bacterial infection and oxidative stress. After loading in the carboxymethyl chitosan (CMCs)/oxidized dextran (Odex) hydrogel, the photothermal effect of CE was highly enhanced by CMCs. The controlled temperature induced by CE-containing hydrogel under NIR laser irradiation could rapidly (10 min) and effectively kill Staphylococcus aureus (S. aureus, 99.3 %) and Escherichia coli (E. coli, 94.6 %). Besides, this hydrogel exhibited a fast gelation and hemostasis abilities, high stability, adhesion and ROS scavenging capabilities, as well as good injectability and biocompatibility. Above superior properties make this hydrogel to accelerate the wound healing in S. aureus-infected mice, and it is expected to be a potential clinical wound dressing.

Wound infection is a predominant etiological factor contributing to delayed wound healing in open wounds. Hence, it holds paramount clinical significance to devise wound dressings endowed with superior antibacterial properties. In this study, a Schiff base-crosslinked aerogel comprising sodium alginate oxide (OSA), carboxymethyl chitosan (CMCS), and Nb2C@Ag/PDA (NAP) was developed. The resultant OSA/CMCS-Nb2C@Ag/PDA (OC/NAP) composite aerogel exhibited commendable attributes including exceptional swelling characteristics, porosity, biocompatibility, and sustained antimicrobial efficacy. In vitro antimicrobial assays unequivocally demonstrated that the OC/NAP composite aerogel maintained nearly 100 % inhibition of Staphylococcus aureus and Escherichia coli under an 808 nm laser even after 25 h. Crucially, the outcomes of in vivo infected wound healing experiments demonstrated that the wound healing rate of the OC/NAP composite aerogel group reached approximately 100 % within a span of 14 days, which was significantly greater than that of the blank control group. In vitro and in vivo hemostatic experiments also revealed that the composite aerogel had excellent hemostatic properties. The results of this study demonstrate the remarkable potential of OC/NAP aerogel as a multifunctional clinical wound dressing, especially for infected wounds.