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Hydrogel materials have proven valuable in wound healing, but improving the safety of these hydrogels is still challenging. Therefore, designing multifunctional natural polymeric-based hydrogels with excellent mechanical properties to replace toxic or potentially risky, refractory chemical polymer-based hydrogels such as polyacrylamide and polyethylene glycol is of particular significance. Here, a green starch-based hydrogel (Starch@Ca/CGC hydrogel) with injectability, self-healing, and instant adhesion was constructed by coordination interaction, electrostatic interaction, and intramolecular and intermolecular hydrogen bonds. Therein, natural bioactive small molecules gallic acid (GA) and carvacrol (CA) were coordinated with metal ions by the ultrasonic-triggered self-assembly and ionic cross-linking codriven strategy to prepare Cu-gallic acid-carvacrol nanospheres (CGC NPs), which conferred the hydrogel with near-infrared light (NIR)-controlled CA release and photothermal synergistic sterilization properties, as well as antioxidant and anti-infection capabilities. More importantly, the multifunctional hydrogel platforms could completely cover an irregular wound shape to prevent secondary injury and significantly accelerate wound healing under NIR with more skin appendages like hair follicles and blood vessels appearing. Therefore, it is expected that this starch-based hydrogel could serve as a competitive multifunctional dressing in the biomedical field, including bacteria-derived wound infection and other tissue repair.

[Display omitted] Early diagnosis of bacterial infection and tracking of treatment effect are of great importance for developing a "sense-and-treat" integrated system. Herein, we developed a bacteria-triggered, portable, wearable and colorimetric film-based band-aid (FBA) for closed-loop monitoring and light-controlled therapy of wound infection. FBA with high photothermal conversion efficiency of 52.56% was prepared by wrapping Bi 2 S 3 nanoflowers (BS NFs) loaded with rhodium nanoparticles (Rh NPs) and bromothymol blue (BTB) into LB agar film, integrating bacteria-triggered color change, photothermal/photodynamic therapy (PTT/PDT) synergistic bactericidal therapy and agar-based band aid in one intelligent system. Initially, FBA effectively simulates the pH sensing mechanism, and monitors the occurrence of bacterial infections within 5 min through color changes of Staphylococcus aureus (S. aureus) from blue to yellow and Escherichia coli (E. coli) from yellow to blue. Additionally, the short-term and controlled antibacterial strategy of "one light dual-mode responses" (photothermal and photodynamic responses) was implemented with the introduce of near-infrared (NIR). Ultimately, the effectiveness of FBA was fully validated in the monitoring and treating of S. aureus -infected mouse wounds. Notably, the designed FBA decisively abandoned off-target side effects maximizing the treatment effect and nakedly tracking therapeutic situation in real time, contributing an effective antibacterial alternative strategy for reducing the use of antibiotics. To the best of our knowledge, such integrated system is still unreported on film-fixed model. In view of the advantages of the low cost and convenience of the simple device, the integrated design is expected to provide a solution for the development of a closed-loop biomedical system combining diagnosis and treatment. [ABSTRACT FROM AUTHOR]

The goal of regenerative wound healing dressings is to restore tissue function back to normal physiological activity and accelerate skin tissue regeneration at wound sites. The optimal strategy to achieve this purpose requires a balance between material functionality, degradation, safety, and tissue regrowth. Herein, for the first time, an ultrasonic‐triggered irreversible tending to equilibrium self‐assembly and ionic cross‐linking codriven strategy is proposed for producing multifunctional cinnamaldehyde‐tannic acid‐zinc acetate nanospheres (CA‐TA‐ZA NSs), realizing the fusion of hydrophilic and hydrophobic drug‐food small molecules. Moreover, a novel "all‐in‐one" chitosan (CS)‐based hydrogel functionalized by introducing drug‐food small molecules self‐assembled CA‐TA‐ZA NSs to the 3D network structures of CS is designed, integrating excellent antibacterial, antioxidant, anti‐inflammatory and reducing oxidative stress damage abilities. Additionally, the multifunctional CS‐based hydrogel can realize rapid in situ gelation at wound sites and completely cover the irregular wounds. All of these superiorities enable the CS‐based hydrogel to clean the wound microenvironment, induce skin tissue remodeling, promote blood vessel repair and hair follicle regeneration, restore the immune system back to normal physiological activity, and accelerate wound healing. Therefore, this study offers a new perspective for the design of advanced functional materials with great application potential in the biomedical field. [ABSTRACT FROM AUTHOR]

Because of increasing antibiotic resistance, careful construction of an efficient phototherm-nanozyme-hydrogel synergistic antibacterial platform is imperative for the treatment of bacteria-infected wounds. In this study, a carrageenan-based hydrogel embedded with polyethylene glycol dicarboxylic acid (COOH-PEG-COOH)-functionalized zirconium-ferrocene metal-organic frames nanosheets (PEG@Zr-Fc MOF hydrogel) was successfully constructed through COOH-PEG-COOH modification and physical assembly. The PEG@Zr-Fc MOF hydrogel could capture Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria through reactive oxygen species (ROS) destruction and kill some bacteria by disintegration of H 2 O 2 into toxic hydroxyl radicals (•OH). Significantly, by introducing the photothermal performance of the PEG@Zr-Fc MOF hydrogel, the catalytic activity of the target material could be improved to achieve a synergistic sterilization effect. The wound infection model experiment confirmed that the PEG@Zr-Fc MOF hydrogel had powerful bactericidal activity and could achieve a rapid tissue repair effect. More importantly, the PEG@Zr-Fc MOF hydrogel had negligible biological toxicity and reduced the risk of inflammation. This study reveals that phototherm-nanozyme-hydrogel synergy holds great potential for bacterial wound infection therapy. Additionally, this is the first study to use two-dimensional MOF nanozymes in combination with hydrogel for antimicrobial therapy. Bacteria-infected wound is one of the serious threats to public health, and this topic has attracted tremendous attention worldwide in recent decades. Although numerous traditional therapeutic strategies that depend on antibiotics have been developed and applied for treating bacteria-infected wound disease, the effect of wound treatment is becoming increasingly unsatisfactory due to bacterial resistance. The present study provides a feasible method to treat bacterial wound infection by constructing a carrageenan-based hydrogel embedded with polyethylene glycol dicarboxylic acid (COOH-PEG-COOH) functionalized zirconium-ferrocene metal organic frame nanosheets (PEG@Zr-Fc MOF hydrogel). The experiments with the wound infection model confirmed that the PEG@Zr-Fc MOF hydrogel had powerful bactericidal activity and could achieve a rapid tissue repair. This strategy provides a promising avenue to further accelerate the development of antibacterial therapy in biomedical fields. [Display omitted] [ABSTRACT FROM AUTHOR]

Bacterial infection can cause chronic nonhealing wounds, which may be a great threat to public health. It is highly desirable to develop an injectable wound dressing hydrogel with multifunctions including self‐healing, remodeling, antibacterial, radical scavenging ability, and excellent photothermal properties to promote the regeneration of damaged tissues in clinical practice. In this work, dopamine‐modified gelatin (Gel‐DA) is employed for the first time as a biotemplate for enhancing the biomineralization ability of gelatin to synthesize dopamine‐modified gelatin@Ag nanoparticles (Gel‐DA@Ag NPs). Further, the prepared Gel‐DA@Ag NPs with antioxidant activity and near‐infrared (NIR) laser irradiation synergistic antibacterial behavior are fixed in the guar gum based hydrogels through the formation of borate/didiol bonds to possess remolding, injectable, and self‐healing performance. In addition, the multifunctional hydrogels can completely cover the irregular wound shape to prevent secondary injury. More importantly, these hydrogel platforms under NIR can significantly accelerate wound healing with more skin appendages like hair follicles and blood vessels appearing. Therefore, it is expected that these hydrogels can serve as competitive multifunctional dressings in biomedical field, including bacteria‐derived wound infection and other tissue repair related to reactive oxygen species overexpression. [ABSTRACT FROM AUTHOR]

Antibacterial wound dressings can effectively avoid the residual of antibacterial nanomaterials for injection in vivo , reduce their biological toxicity to normal cells and tissues, making them be widely applied in biomedical field. Herein, an approach of combining ion-crosslinking, in-situ reduction and microwave-assisted methods was employed to prepare chitosan-copper-gallic acid nanocomposites (CS-Cu-GA NCs) with dual-functional nano-enzyme characteristics (oxidase- and peroxidase-like functions). The oxidase-like activity of CS-Cu-GA NCs can facilitate the production of hydrogen peroxide (H 2 O 2) when it contacted with physiologically relevant antioxidants (AH 2) in bacteria. Subsequently, H 2 O 2 was catalyzed to generate hydroxyl radicals (OH) under the peroxidase-like activity of CS-Cu-GA NCs. Furthermore, CS-Cu-GA NCs integrate the inherent antibacterial properties of chitosan, Cu NPs and Cu2+. Animal experiments revealed that the antibacterial dressing incorporating CS-Cu-GA NCs exhibited its effective promotion of S. aureus -infected wounds healing, as well as no damage to normal tissues. Besides, the antibacterial dressing was prepared to a band aid with excellent water swelling and antibacterial properties, which was further fixed in a medical tape to construct a portable antibacterial product that can be applied to the surface of human skin and showed excellent waterproof performance, providing a new insight for the construction of clinical antibacterial wound healing products. Unlabelled Image • CS-Cu-GA NCs with oxidase-like and peroxidase-like functions were fabricated. • Oxidase- and peroxidase-like CS-Cu-GA NCs had strong antibacterial property. • CS-Cu-GA NCs combined the inherent antibacterial functions of CS, Cu NPs, Cu2+. • Biocompatible CS-Cu-GA NCs antibacterial dressing promoted wounds healing. • A portable multifunctional antibacterial product was constructed. [ABSTRACT FROM AUTHOR]

Nature-derived bioactive components and photothermal synergistic therapy bring potential strategies for fighting bacterial infection and accelerating would healing by virtue of their excellent therapeutic efficiencies and ignorable side effects, where photothermal property not only acts as sterilization energy but also as a doorkeeper to control the natural component release. Herein, by integrating the excellent antibacterial property of cinnamaldehyde (CA) and the outstanding photothermal performance of copper sulfide nanoparticles (CuS NPs), a multifunctional nanoplatform of SiO 2 @CA@CuS nanospheres (NSs) is constructed with silica nanosphere (SiO 2 NSs) as carrier. SiO 2 @CA@CuS NSs exhibit photothermal property, bacterial absorption capacity, extraordinary antibacterial activity and antioxidant property. Mechanism characteriazation and antibacterial experiment indicate that positive charged SiO 2 @CA@CuS can adhere to the negative charged surface of bacteria, and quickly kill bacteria through the synergistic action of the released CA and heat produced under near infrared light (NIR) irradiation at 980 nm. The sterilization efficiencies for Escherichia coli (E. coli) and S. aureus reach 99.86% and 99.84%, respectively. Furthermore, NIR-regulated SiO 2 @CA@CuS perform great biocompatibility, as well as effective effects for accelerating S. aureus -infected wound healing at a low photothermal temperature (45 °C) relying on synergistic sterilization and anti-oxidation. [Display omitted] • Mesoporous silica loaded with CA performs electropositive. • Photothermal energy: antibacterial energy and a doorkeeper of cinnamaldehyde. • NIR-induced cinnamaldehyde release and photothermal synergistic therapy. • Promoting blood vessel growth and accelerating infected-wound healing. [ABSTRACT FROM AUTHOR]

With the increasingly serious problem of antimicrobial resistance and the lack of clinical response strategies, the development of new antibacterial materials is imminent. Herein, a VIS/NIR co-irradiation photodynamic-photothermal and oxidase-like synergistic antibacterial platform of transition metal sulfide/TiO 2 nanofibers (TMSs/TiO 2 NFs) is proposed to fight bacterial infection. On one hand, three-dimensional (3D) MoS 2 nanoflowers load can quickly capture the photogenerated electrons of two-dimensional (2D) TiO 2 nanofibers, inhibit the recombination of electron-hole pairs and greatly increase the yield of reactive oxygen species (ROS), thereby overcoming the UV sterilization defects of pure TiO 2 , endowing TiO 2 excellent photodynamic antibacterial ability in the long-wavelength region. On other hand, with the combination of MoS 2 and TiO 2 , the photothermal effect of the 3D/2D heterostructure (MoS 2 /TiO 2 NFs) was significantly enhanced and the local temperature rose to above 50 °C in a short time, which was enough to induce the inactivation of bacterial protein, thereby providing an efficient secondary sterilization effect. In addition, MoS 2 /TiO 2 NFs has fascinating oxidase-like activity, which further accelerated the oxidation of physiologically relevant antioxidants in bacteria. In the end, MoS 2 /TiO 2 NFs exerted outstanding antibacterial efficiencies against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) through the synergy of photodynamic-photothermal and oxidase-like performance. Meanwhile, MoS 2 /TiO 2 NFs antibacterial platform effectively accelerated the healing of S. aureus -infected wounds and showed negligible toxicity and hemolysis on normal cells and tissues. Hence, this study contributed an effective alternative strategy for reducing the use of antibiotics, providing new ideas for application of semiconductor nanomaterials in collaborative combination therapy. [Display omitted] • The 3D/2D TMSs/TiO 2 NFs (MoS 2 /TiO 2 NFs) heterojunctions are successfully prepared in situ. • MoS 2 /TiO 2 NFs heterojunctions are demonstrated to increases the yield of ROS. • MoS 2 /TiO 2 NFs show enhanced photodynamic-photothermal and oxidase-like properties. • MoS 2 /TiO 2 NFs process charming sterilization activity. • MoS 2 /TiO 2 NFs antibacterial agent accelerate S. aureus- infected wound healing. [ABSTRACT FROM AUTHOR]

In recent years, nanozyme-photothermal therapy (NPT) has attracted enormous interests owing to their enhanced therapeutic effects and less adverse effects in the treatment of infectious diseases. However, the development of nanozyme-photothermal agents (NPAs) that can rapidly, efficiently and synergistically combating pathogenic bacteria remains a huge challenge due to the limitation of size effect. Herein, by decorating platinum nanozymes on Zn-based photosensitizer, we report a novel metal-organic framework (MOF)-derived hybrid nanozymes antibacterial strategy for enhanced NPT. This strategy can not only prevent the aggregation of platinum nanozymes and effectively reduce the mass transfer resistance during the kinetic reaction, but also inhibit the photoelectron-hole recombination in the process of photothermal therapy (PTT) and improve the photothermal conversion performance. In the presence of a low concentration of hydrogen peroxide (H 2 O 2), the superior nanocatalytic activity of the MOF-derived hybrid nanozymes can effectively catalyze the release of H 2 O 2 to generate toxic hydroxyl radical (•OH), resulting in the increase of bacterial membrane permeability and thermal sensitivity. Once the near-infrared laser is introduced, the nanozyme-photothermal antibacterial platform can play the role of "nanoknife" to further induce the death of the damaged bacteria by physical cutting. In vitro and vivo in antibacterial assays confirm that the MOF-derived hybrid nanozymes have excellent antibacterial properties, which can serve as an antibacterial candidate with negligible adverse effect. Therefore, this work will open a new avenue for MOF-derived hybrid nanozymes in biomedical application. [Display omitted] • The MOF-derived hybrid nanozymes antibacterial strategy was used to enhance the nanozyme-photothermal therapy. • The PEG@Zn/Pt–CN nanozyme-photothermal antibacterial platform processed excellent ROS-released and NIR-responsive property. • The PEG@Zn/Pt–CN nanozyme-photothermal antibacterial platform could kill 98.74% E. coli and 99.63% S. aureus. • Wound infection model experiments confirmed the antibacterial activity and the rapid tissue repair effect. [ABSTRACT FROM AUTHOR]