Engineering of a Hollow‐Structured Cu 2− X S Nano‐Homojunction Platform for Near Infrared‐Triggered Infected Wound Healing and Cancer Therapy

A strategy of "adding fuel to the flames" enables a self-accelerating cycle of ferroptosis-cuproptosis for potent antitumor therapy

Cuproptosis in antitumor therapy faces challenges from copper homeostasis efflux mechanisms and high glutathione (GSH) levels in tumor cells, hindering copper accumulation and treatment efficacy. Herein, we propose a strategy of "adding fuel to the flames" for potent antitumor therapy through a self-accelerating cycle of ferroptosis-cuproptosis. Disulfiram (DSF) loaded hollow mesoporous copper-iron sulfide (HMCIS) nanoparticle with conjugation of polyethylene glycol (PEG) and folic acid (FA) (i.e., DSF@HMCIS-PEG-FA) was developed to swiftly release DSF, H2S, Cu2+, and Fe2+ in the acidic tumor microenvironment (TME). The hydrogen peroxide (H2O2) levels and acidity within tumor cells enhanced by the released H2S induce acceleration of Fenton (Fe2+) and Fenton-like (Cu2+) reactions, enabling the powerful tumor ferroptosis efficacy. The released DSF acts as a role of "fuel", intensifying catalytic effect ("flame") in tumor cells through the sustainable Fenton chemistry (i.e., "add fuel to the flames"). Robust ferroptosis in tumor cells is characterized by serious mitochondrial damage and GSH depletion, leading to excess intracellular copper that triggers cuproptosis. Cuproptosis disrupts mitochondria, compromises iron-sulfur (Fe-S) proteins, and elevates intracellular oxidative stress by releasing free Fe3+. These interconnected processes form a self-accelerating cycle of ferroptosis-cuproptosis with potent antitumor capabilities, as validated in both cancer cells and tumor-bearing mice.

Bioclay Enzyme with Bimetal Synergistic Sterilization and Infectious Wound Regeneration

Bacteria invasion is the main factor hindering the wound-healing process. However, current antibacterial therapies inevitably face complex challenges, such as the abuse of antibiotics or severe inflammation during treatment. Here, a drug-free bioclay enzyme (Bio-Clayzyme) consisting of Fe2+-tannic acid (TA) network-coated kaolinite nanoclay and glucose oxidase (GOx) was reported to destroy harmful bacteria via bimetal antibacterial therapy. At the wound site, Bio-Clayzyme was found to enhance the generation of toxic hydroxyl radicals for sterilization via cascade catalysis of GOx and Fe2+-mediated peroxidase mimetic activity. Specifically, the acidic characteristics of the infection microenvironment accelerated the release of Al3+ from kaolinite, which further led to bacterial membrane damage and amplified the antibacterial toxicity of Fe2+. Besides, Bio-Clayzyme also performed hemostasis and anti-inflammatory functions inherited from Kaol and TA. By the combination of hemostasis and anti-inflammatory and bimetal synergistic sterilization, Bio-Clayzyme achieves efficient healing of infected wounds, providing a revolutionary approach for infectious wound regeneration.

A H₂S-Evolving Alternately-Catalytic Enzyme Bio-Heterojunction with Antibacterial and Macrophage-Reprogramming Activity for All-Stage Infectious Wound Regeneration

The disorder of the macrophage phenotype and the hostile by-product of lactate evoked by pathogenic infection in hypoxic deep wound inevitably lead to the stagnant skin regeneration. In this study, hydrogen sulfide (H2S)-evolving alternately catalytic bio-heterojunction enzyme (AC-BioHJzyme) consisting of CuFe2S3 and lactate oxidase (LOD) named as CuFe2S3@LOD is developed. AC-BioHJzyme exhibits circular enzyme-mimetic antibacterial (EMA) activity and macrophage re-rousing capability, which can be activated by near-infrared-II (NIR-II) light. In this system, LOD exhausts lactate derived from bacterial anaerobic respiration and generated hydrogen peroxide (H2O2), which provides an abundant stock for the peroxidase-mimetic activity to convert the produced H2O2 into germicidal •OH. The GPx-mimetic activity endows AC-BioHJzyme with a glutathione consumption property to block the antioxidant systems in bacterial metabolism, while the O2 provided by the CAT-mimetic activity can generate 1O2 under the NIR-II irradiation. Synchronously, the H2S gas liberated from CuFe2S3@LOD under the infectious micromilieu allows the reduction of Fe(III)/Cu(II) to Fe(II)/Cu(І), resulting in sustained circular EMA activity. In vitro and in vivo assays indicate that the CuFe2S3@LOD AC-BioHJzyme significantly facilitates the infectious cutaneous regeneration by killing bacteria, facilitating epithelialization/collagen deposition, promoting angiogenesis, and reprogramming macrophages. This study provides a countermeasure for deep infectious wound healing via circular enzyme-mimetic antibiosis and macrophage re-rousing.

Cu2-xS homojunction coatings empower titanium implants with near-infrared-triggered antibacterial and antifouling properties

For decades, implant-associated infections (IAIs) caused by pathogenic bacteria have been associated with high failure and mortality rates in implantation surgeries, posing a serious threat to global public health. Therefore, developing a functionalized biomaterial coating with anti-fouling and anti-bacterial functions is crucial for alleviating implant infections. Herein, a near-infrared-responsive anti-bacterial and anti-adhesive coating (Ti-PEG-Cu2-xS) constructed on the surface of titanium (Ti) implants is reported. This coating is composed of nano-Cu2-xS with anti-bacterial activity and super-hydrophilic polyethylene glycol (PEG). Under near-infrared irradiation, the nano-catalyst Cu2-xS on the surface of Ti-PEG-Cu2-xS induces bacterial death by catalyzing the production of singlet oxygen (1O2). The Ti-PEG-Cu2-xS coating can effectively prevent bacterial adhesion and biofilm formation. This coating combines the antibacterial mechanisms of "active attack" and "passive defense", which can kill bacteria and inhibit biofilm formation. The results of in vitro and in vivo experiments have shown that Ti-PEG-Cu2-xS exhibits excellent anti-bacterial properties under near-infrared irradiation and can effectively prevent implant-related infections caused by Escherichia coli (E. coli) ATCC 8739 and Staphylococcus aureus (S. aureus). The antibacterial efficiency of Ti-PEG-Cu2-xS coatings against E. coli was 99.96% ± 0.058% and that of S. aureus was 99.66% ± 0.26%, respectively. In addition, the Ti-PEG-Cu2-xS coating has good blood compatibility and excellent bactericidal ability. Therefore, this multifunctional coating combines a non-adhesive surface strategy and a near-infrared phototherapy sterilization method, effectively blocking the initial attachment and proliferation of bacteria on implants via photothermal/photodynamic effects and providing a promising method for preventing bacterium-induced IAIs.

Defect engineering of a TiO2 anatase/rutile homojunction accelerating sulfur redox kinetics for high-performance Na-S batteries

Room-temperature sodium-sulfur (RT Na-S) batteries have the drawbacks of the poor shuttle effect of soluble sodium polysulfides (NaPSs) as well as slow sulfur redox kinetics, which result in poor cycling stability and low capacity, seriously affecting their extensive application. Herein, defect engineering is applied to construct rich oxygen vacancies at the interface of a TiO2 anatase/rutile homojunction (OV-TRA) to enhance sulfur affinity and redox reaction kinetics. Combining structural characterizations with electrochemical analysis reveals that OV-TRA well alleviates the shuttle effect of NaPSs and precipitates the deposition and diffusion kinetics of Na2S. Consequently, S/OV-TRA provides excellent electrochemical performance with a reversible capacity of 870 mA h g-1 at 0.1 C after 100 cycles and a long-term cycling capability of 759 mA h g-1 at 1 C after 1000 cycles. This work provides an effective interfacial defect engineering strategy to promote the application of metal oxides in RT Na-S batteries.

Putting Hybrid Nanomaterials to Work for Biomedical Applications

Hybrid nanomaterials have found use in many biomedical applications. This article provides a comprehensive review of the principles, techniques, and recent advancements in the design and fabrication of hybrid nanomaterials for biomedicine. We begin with an introduction to the general concept of material hybridization, followed by a discussion of how this approach leads to materials with additional functionality and enhanced performance. We then highlight hybrid nanomaterials in the forms of nanostructures, nanocomposites, metal-organic frameworks, and biohybrids, including their fabrication methods. We also showcase the use of hybrid nanomaterials to advance biomedical engineering in the context of nanomedicine, regenerative medicine, diagnostics, theranostics, and biomanufacturing. Finally, we offer perspectives on challenges and opportunities.

Multifunctional Therapeutic Nanodiamond Hydrogels for Infected-Wound Healing and Cancer Therapy

Wound infection and tumor recurrence are the two main threats to cancer patients after surgery. Although researchers have developed new treatment systems to address the two significant challenges simultaneously, the potential side effects of the heavy-metal-ion-based treatment systems still severely limit their widespread application in therapy. In addition, the wounds from tumor removal compared with general operative wounds are more complex. The tumor wounds mainly exhibit more hemorrhage, larger trauma area, greater vulnerability to bacterial infection, and residual tumor cells. Therefore, a multifunctional treatment platform is urgently needed to integrate rapid hemostasis, sterilization, wound healing promotion, and antitumor functions. In this work, nanodiamonds (NDs), a material that has been well proven to have excellent biocompatibility, are added into a solution of acrylic-grafted chitosan (CEC) and oxidized hyaluronic acid (OHA) to construct a multifunctional treatment platform (CEC-OHA-NDs). The hydrogels exhibit rapid hemostasis, a wound-healing-promoting effect, excellent self-healing, and injectable abilities. Moreover, CEC-OHA-NDs can effectively eliminate bacteria and inhibit tumor proliferation by the warm photothermal effect of NDs under tissue-penetrable near-infrared laser irradiation (NIR) without cytotoxicity. Consequently, we adopt a simple and convenient strategy to construct a multifunctional treatment platform using carbon-based nanomaterials with excellent biocompatibility to promote the healing of infected wounds and to inhibit tumor cell proliferation simultaneously.

Antibacterial and Angiogenic (2A) Bio-Heterojunctions Facilitate Infectious Ischemic Wound Regeneration via an Endogenous-Exogenous Bistimulatory Strategy

In infectious ischemic wounds, a lack of blood perfusion significantly worsens microbe-associated infection symptoms and frequently complicates healing. To overcome this daunting issue, antibacterial and angiogenic (2A) bio-heterojunctions (bio-HJs) consisting of CuS/MXene heterojunctions and a vascular endothelial growth factor (VEGF)-mimicking peptide (VMP) are devised and developed to accelerate infectious cutaneous regeneration by boosting angiogenesis via an endogenous-exogenous bistimulatory (EEB) strategy. Assisted by near-infrared irradiation, the bio-HJ platform exhibits versatile synergistic photothermal, photodynamic, and chemodynamic effects for robust antibacterial efficacy. In addition, copper ions liberated from 2A bio-HJs elevate VEGF secretion from fibroblasts, which provokes VEGF receptors (VEGFR) activation through an endogenous pathway, whereas VMP itself promotes an exogenous pathway to facilitate endothelial cell multiplication and tube formation by directly activating the VEGFR signaling pathway. Moreover, employing an in vivo model of infectious ischemic wounds, it is confirmed that the EEB strategy can considerably boost cutaneous regeneration through pathogen elimination, angiogenesis promotion, and collagen deposition. As envisaged, this work leads to the development of a powerful 2A bio-HJ platform that can serve as an effective remedy for bacterial invasion-induced ischemic wounds through the EEB strategy.

NIR-triggered bacterial cellulose-based wound dressings for multiple synergistic therapy of infected wound

Skin wounds are repaired by a complex series of events and overlapping phases in which bacterial infection and insufficient angiogenesis at the wound site delay the healing process. Thus, functional wound dressings with enhanced antibacterial activity and angiogenic capacity have attracted attention. Herein, bacterial cellulose (BC)-based dressings were successfully fabricated by functionalization with a polydopamine (PDA) coating and copper sulfide nanoparticles (CuS NPs). Under 808 nm laser illumination, the BC/PDA/CuS composite membranes exhibited outstanding adjustable photothermal and photodynamic activities as well as controlled Cu2+ release, endowing the composite membranes with synergetic antibacterial activity. Specially, a bactericidal efficiency of 99.7 % and 88.0 % for Staphylococcus aureus and Escherichia coli was achieved after treatment with BC/PDA/CuS5 sample under NIR irradiation (0.8 W/cm2, 10 min), respectively. Moreover, the BC/PDA/CuS5 composite membrane could enhance the angiogenesis due to the released Cu2+. In vivo experiments revealed that the BC/PDA/CuS5 composite membrane dressing could accelerate the wound closure process of the full-thickness skin defects with S. aureus by synergistically reducing inflammation, enhancing collagen deposition, and promoting vascularization under NIR irradiation. Additionally, the BC/PDA/CuS5 composite membrane exhibited high biocompatibility and biosafety. This work offers a new strategy to prepare multifunctional BC-based dressing for clinical wound healing.

Glucose-primed PEEK orthopedic implants for antibacterial therapy and safeguarding diabetic osseointegration

Diabetic infectious microenvironment (DIME) frequently leads to a critical failure of osseointegration by virtue of its main peculiarities including typical hyperglycemia and pathogenic infection around implants. To address the plaguing issue, we devise a glucose-primed orthopedic implant composed of polyetheretherketone (PEEK), Cu-chelated metal-polyphenol network (hauberk coating) and glucose oxidase (GOx) for boosting diabetic osseointegration. Upon DIME, GOx on implants sostenuto consumes glucose to generate H2O2, and Cu liberated from hauberk coating catalyzes the H2O2 to highly germicidal •OH, which massacres pathogenic bacteria through photo-augmented chemodynamic therapy. Intriguingly, the catalytic efficiency of the coating gets greatly improved with the turnover number (TON) of 0.284 s-1. Moreover, the engineered implants exhibit satisfactory cytocompatibility and facilitate osteogenicity due to the presence of Cu and osteopromotive polydopamine coating. RNA-seq analysis reveals that the implants enable to combat infections and suppress pro-inflammatory phenotype (M1). Besides, in vivo evaluations utilizing infected diabetic rat bone defect models at week 4 and 8 authenticate that the engineered implants considerably elevate osseointegration through pathogen elimination, inflammation dampening and osteogenesis promotion. Altogether, our present study puts forward a conceptually new tactic that arms orthopedic implants with glucose-primed antibacterial and osteogenic capacities for intractable diabetic osseointegration.

Photocatalytic Antimicrobials: Principles, Design Strategies, and Applications

Nowadays, the increasing emergence of antibiotic-resistant pathogenic microorganisms requires the search for alternative methods that do not cause drug resistance. Phototherapy strategies (PTs) based on the photoresponsive materials have become a new trend in the inactivation of pathogenic microorganisms due to their spatiotemporal controllability and negligible side effects. Among those phototherapy strategies, photocatalytic antimicrobial therapy (PCAT) has emerged as an effective and promising antimicrobial strategy in recent years. In the process of photocatalytic treatment, photocatalytic materials are excited by different wavelengths of lights to produce reactive oxygen species (ROS) or other toxic species for the killing of various pathogenic microbes, such as bacteria, viruses, fungi, parasites, and algae. Therefore, this review timely summarizes the latest progress in the PCAT field, with emphasis on the development of various photocatalytic antimicrobials (PCAMs), the underlying antimicrobial mechanisms, the design strategies, and the multiple practical antimicrobial applications in local infections therapy, personal protective equipment, water purification, antimicrobial coatings, wound dressings, food safety, antibacterial textiles, and air purification. Meanwhile, we also present the challenges and perspectives of widespread practical implementation of PCAT as antimicrobial therapeutics. We hope that as a result of this review, PCAT will flourish and become an effective weapon against pathogenic microorganisms and antibiotic resistance.

Engineered Bio-Heterojunction with Infection-Primed H2 S Liberation for Boosted Angiogenesis and Infectious Cutaneous Regeneration

Photodynamic therapy (PDT) acts as a powerful weapon against infectious diseases for its enormous antimicrobial activity that quickly elicits storms of reactive oxygen species (ROS). Nevertheless, redundant ROS during treatment inevitably bring detriments in revascularization. To address this dilemma, an innovative P-N bio-heterojunction (bio-HJ) material consisting of p-type copper sulfide (p-CuS), n-type bismuth sulfide (n-Bi2 S3 ), and lactate oxidase (LOx) for effective treatment of recalcitrant infectious wounds by promoting angiogenesis is devised. LOx exhausts lactic acid accumulated in infection environment and converts it to hydrogen peroxide (H2 O2 ), which subsequently yields bactericidal hydroxyl radicals (·OH) via Fenton-like reactions. Ultimately, the P-N bio-HJs exert synergistic photothermal, photodynamic, and chemodynamic effects for rapid bacterial annihilation. Moreover, in vitro and RNA-seq analyses reveal that the crafted bio-HJs dramatically expedite the proliferation of L929 cells and promote angiogenesis by up-regulating angiogenic gene expression in hypoxia-inducible factor-1 (HIF-1) signaling pathway, which may ascribe to the evolution of H2 S in response to the infection microenvironment. Critically, results of in vivo experiments have authenticated that the bio-HJs significantly boost healing rates of full-thickness wounds by slaughtering bacteria, elevating angiogenesis, and promoting cytothesis. As envisioned, this work furnishes a novel tactic for the effective treatment of bacteria-invaded wound using H2 S-liberating P-N bio-HJs.

Near-Infrared-Induced NO-Releasing Photothermal Adhesive Hydrogel with Enhanced Antibacterial Properties

Bacterial infection and the development of antibiotic-resistant bacteria have decreased the effectiveness of traditional antibiotic treatments for wound healing. The design of a multifunctional adhesive hydrogel with antibacterial activity, self-healing properties, and on-demand removability to promote wound healing is highly desirable. In this work, a photothermal cyclodextrin with a NO-releasing moiety has been incorporated within an oxidized sodium alginate conjugated polyacrylamide (OS@PA) hydrogel to get a photothermal NO-releasing GSNOCD-OS@PA hydrogel. Such a multifunctional hydrogel has the unique feature of combined antibacterial activity as a result of a controlled photothermal effect and NO gas release under an 808 near-infrared laser. Because of oxidized sodium alginate (OSA), the hydrogel matrix easily adheres to the skin under twisted and bent states. In vitro cytotoxicity analysis against 3T3 cells showed that the hydrogels OS@PA and GSNOCD-OS@PA are noncytotoxic under laser exposure. The temperature-induced NO release by GSNOCD-OS@PA reached 31.7 mg/L when irradiated with an 808 nm laser for 10 min. The combined photothermal therapy and NO release from GSNOCD-OS@PA effectively reduced viability of both Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) to 3 and 5%, respectively. Importantly, the phototherapeutic NO-releasing platform displayed effective fibroblast proliferation in a cell scratch assay.

Ultra-stretchable, tissue-adhesive, shape-adaptive, self-healing, on-demand removable hydrogel dressings with multiple functions for infected wound healing in regions of high mobility

Bacterial infection in the most mobile area usually leads to delayed healing and functional restriction, which has been a long-term challenge in clinic. Developing hydrogel-based dressings with mechanical flexibly, high adhesive and anti-bacterial properties, will contribute to the healing and therapeutic effects especially for this typical skin wound. In this work, composite hydrogel named PBOF through multi-reversible bonds between polyvinyl alcohol, borax, oligomeric procyanidin and ferric ion demonstrated a 100 times ultra-stretch ability, 24 kPa of highly tissue-adhesive, rapid shape-adaptability within 2 min and self-healing feature within 40 s, was designed as the multifunctional wound dressing for the Staphylococcus aureus-infected skin wound in the mice nape model. Besides, this hydrogel dressing could be easily removed on-demand within 10 min by water. The rapid disassembly of this hydrogel is related to the formation of hydrogen bonds between polyvinyl alcohol and water. Moreover, the multifunctional properties of this hydrogel include strong anti-oxidative, anti-bacteria and hemostasis derived from oligomeric procyanidin and photothermal effect of ferric ion/polyphenol chelate. The killing ratio of the hydrogel on Staphylococcus aureus in infected skin wound reached 90.6% when exposed to 808 nm irradiation for 10 min. Simultaneously, reduced oxidative stress, suppressed inflammation, and promoted angiogenesis all together accelerated wound healing. Therefore, this well-designed multifunctional PBOF hydrogel holds great promise as skin wound dressing especially in the high mobile regions of the body. STATEMENT OF SIGNIFICANCE: An ultra-stretchable, highly tissue-adhesive, and rapidly shape-adaptive, self-healing and on-demand removable hydrogel based on multi-reversible bonds among polyvinyl alcohol, borax, oligomeric procyanidin and ferric ion is designed as dressing material for infected wound healing in the movable nape. The rapid on-demand removal of the hydrogel relates to the formation of hydrogen bonds between polyvinyl alcohol and water. This hydrogel dressing shows strong antioxidant capacity, rapid hemostasis and photothermal antibacterial ability. This is derived from oligomeric procyanidin and thephotothermal effect of ferric ion/polyphenol chelate, which eliminates bacterial infection, reduces oxidative stress, regulates inflammation, promotes angiogenesis, and finally accelerates the infected wound healing in movable part.

Cu-GA-coordination polymer nanozymes with triple enzymatic activity for wound disinfection and accelerated wound healing

During the past few years, bacterial infection and oxidative stress have become important issues for wound healing. However, the emergence of numerous drug-resistant superbugs has had a serious impact on the treatment of infected wounds. Presently, the development of new nanomaterials has become one of the most important approaches to the treatment of drug-resistant bacterial infections. Herein, coordination polymer copper-gallic acid (Cu-GA) nanorods with multi-enzyme activity is successfully prepared for efficient wound treatment of bacterial infection, which can effectively promote wound healing. Cu-GA can be efficiently prepared by a simple solution method and had good physiological stability. Interestingly, Cu-GA shows enhanced multienzyme activity (peroxidase, glutathione peroxidase, and superoxide dismutase), which can produce a large number of reactive oxygen species (ROS) under acidic conditions while scavenging ROS under neutral conditions. In acidic environment, Cu-GA possesses POD (peroxidase)-like and glutathione peroxidase (GSH-Px)-like catalytic activities that is capable of killing bacteria; but in neutral environment, Cu-GA exhibits superoxide dismutase (SOD)-like catalytic activity that can scavenge ROS and promote wound healing. In vivo studies show that Cu-GA can promote wound infection healing and have good biosafety. Cu-GA contributes to the healing of infected wounds by inhibiting bacterial growth, scavenging reactive oxygen species, and promoting angiogenesis. STATEMENT OF SIGNIFICANCE: Cu-GA-coordinated polymer nanozymes with multienzyme activity were successfully prepared for efficient wound treatment of bacterial infection, which could effectively promote wound healing. Interestingly, Cu-GA exhibited enhanced multienzyme activity (peroxidase, glutathione peroxidase, and superoxide dismutase), which could produce a large number of reactive oxygen species (ROS) under acidic conditions and scavenge ROS under neutral conditions. In vitro and in vivo studies demonstrated that Cu-GA was capable of killing bacteria, controlling inflammation, and promoting angiogenesis.

Nanomaterials for the treatment of bacterial infection by photothermal/photodynamic synergism

In the past few decades, great progress has been made in the field of nanomaterials against bacterial infection. However, with the widespread emergence of drug-resistant bacteria, people try their best to explore and develop new antibacterial strategies to fight bacteria without obtaining or increasing drug resistance. Recently, multi-mode synergistic therapy has been considered as an effective scheme for the treatment of bacterial infections, especially the combination of photothermal therapy (PTT) and photodynamic therapy (PDT) with controllable, non-invasive, small side effects and broad-spectrum antibacterial characteristics. It can not only improve the efficiency of antibiotics, but also do not promote antibiotic resistance. Therefore, multifunctional nanomaterials which combine the advantages of PTT and PDT are more and more used in the treatment of bacterial infections. However, there is still a lack of a comprehensive review of the synergistic effect of PTT and PDT in anti-infection. This review first focuses on the synthesis of synergistic photothermal/photodynamic nanomaterials and discusses the ways and challenges of photothermal/photodynamic synergism, as well as the future research direction of photothermal/photodynamic synergistic antibacterial nanomaterials.

In Situ Fabrication of Silver Peroxide Hybrid Ultrathin Co-Based Metal-Organic Frameworks for Enhanced Chemodynamic Antibacterial Therapy

Bacterial-induced infectious diseases have always caused an unavoidable problem and lead to an increasing threat to human health. Hence, there is an urgent need for effective antibacterial strategies to treat infectious diseases. Current methods are often ineffective and require large amounts of hydrogen peroxide (H₂O₂), with harmful effects on normal healthy tissue. Chemodynamic therapy (CDT) provides an ideal infection microenvironment (IME)-activated paradigm to tackle bacterial-related diseases. To take full advantage of the specificity of IME and enhanced CDT for wounds with bacterial infection, we have designed an intelligent antibacterial system that exploits nanocatalytic ZIF-67@Ag₂O₂ nanosheets. In this system, silver peroxide nanoparticles (Ag₂O₂ NPs) were grown on ultrathin zeolitic imidazolate framework-67 (ZIF-67) nanosheets by in situ oxidation, and then, ZIF-67@Ag₂O₂ nanosheets with the ability to self-generate H₂O₂ were triggered by the mildly acidic environment of IME. Lamellar ZIF-67 nanosheets were shown to rapidly degrade and release Co²⁺, allowing the conversion of less reactive H₂O₂ into the highly toxic reactive oxygen species hydroxyl radicals (^•OH) for enhanced CDT antibacterial properties. In vivo results revealed that the ZIF-67@Ag₂O₂ nanosheet system exhibits excellent antibacterial performance against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The proposed hybrid strategy demonstrates a promising therapeutic strategy to enable antibacterial agents with IME-responsive nanocatalytic activity to circumvent antibiotic resistance against bacterial infections.

Drug-Free Antimicrobial Nanomotor for Precise Treatment of Multidrug-Resistant Bacterial Infections

Manufacturing heteronanostructures with specific physicochemical characteristics and tightly controllable designs is very appealing. Herein, we reported NIR-II light-driven dual plasmonic (AuNR-SiO₂-Cu₇S₄) antimicrobial nanomotors with an intended Janus configuration through the overgrowth of copper-rich Cu₇S₄ nanocrystals at only one high-curvature site of Au nanorods (Au NRs). These nanomotors were applied for photoacoustic imaging (PAI)-guided synergistic photothermal and photocatalytic treatment of bacterial infections. Both the photothermal performance and photocatalytic activity of the nanomotors are dramatically improved owing to the strong plasmon coupling between Au NRs and the Cu₇S₄ component and enhanced energy transfer. The motion behavior of nanomotors promotes transdermal penetration and enhances the matter-bacteria interaction. More importantly, the directional navigation and synergistic antimicrobial activity of the nanomotors could be synchronously driven by NIR-II light. The marriage of active motion and enhanced antibacterial activity resulted in the expected good antibacterial effects in an abscess infection mouse model.

Reduced graphene oxide-enriched chitosan hydrogel/cellulose acetate-based nanofibers application in mild hyperthermia and skin regeneration

Asymmetric wound dressings have captured researchers' attention due to their ability to reproduce the structural and functional properties of the skin layers. Furthermore, recent studies also report the benefits of using near-infrared (NIR) radiation-activated photothermal therapies in treating infections and chronic wounds. Herein, a chitosan (CS) and reduced graphene oxide (rGO) hydrogel (CS_rGO) was combined with a polycaprolactone (PCL) and cellulose acetate (CA) electrospun membrane (PCL_CA) to create a new NIR-responsive asymmetric wound dressing. The rGO incorporation in the hydrogel increased the NIR absorption capacity and allowed a mild hyperthermy effect, a temperature increase of 12.4 °C when irradiated with a NIR laser. Moreover, the PCL_CA membrane presented a low porosity and hydrophobic nature, whereas the CS_rGO hydrogel showed the ability to provide a moist environment, prevent exudate accumulation and allow gaseous exchanges. Furthermore, the in vitro data demonstrate the capacity of the asymmetric structure to act as a barrier against bacteria penetration as well as mediating a NIR-triggered antibacterial effect. Additionally, human fibroblasts were able to adhere and proliferate in the CS_rGO hydrogel, even under NIR laser irradiation, presenting cellular viabilities superior to 90 %. Altogether, our data support the application of the NIR-responsive asymmetric wound dressings for skin regeneration.

Endoplasmic reticulum-targeted NIR-II phototherapy combined with inflammatory vascular suppression elicits a synergistic effect against TNBC

Recurrence and metastasis are the main reasons for failure in the treatment of triple-negative breast cancer (TNBC). Phototherapy, one of the most well-known potent cancer treatment models is highlighted by ablating primitive tumors with immunogenic cell death (ICD) and is associated with endoplasmic reticulum (ER) stress to elicit long-lasting anti-tumor immunity. However, the provoked inflammatory response after phototherapy will stimulate angiogenesis, which provides nutrition for tumor recurrence. Here, an ER-targeted nanoplatform was constructed based on hollow mesoporous Cu_2-XS (HMCu_2-XS) nanoparticles to suppress recurrence and metastasis of TNBC by combining photo-ablation and microenvironment remodeling. Profiting from the metal ion coordination and large hollow space, HMCu_2-XS can be easily modified with p-toluenesulfonamide for ER-targeting and quantitatively loaded celecoxib (CXB) as a vascular inhibitor, thus obtaining ER-HMCu_2-XS/CXB. ER-HMCu_2-XS showed great photothermal and photodynamic efficiency for ablating 4T1 tumors and inducing ICD under NIR-II laser irradiation. Compared with non-ER-targeted nanosystems, the ER-targeted nanosystem elicited stronger ICDs and recruited more immune cells. Moreover, the thermal-responsively released CXB successfully inhibited angiogenesis after photothermal therapy. The data showed that the ER-HMCu_2-XS/CXB mediated the triplicate therapeutic effect of photo-ablation, immune response activation, and vascular suppression effectively, preventing the recurrence and metastasis of TNBC. In conclusion, this work provides a synergistic strategy to enhance therapeutic outcomes in TNBC.

Nanocatalytic Hydrogel with Rapid Photodisinfection and Robust Adhesion for Fortified Cutaneous Regeneration

Chronic inflammation caused by invasive bacterial infections severely interferes with the normal healing process of skin regeneration. Hypoxia of the infection microenvironment (IME) seriously affects the antibacterial effect of photodynamic therapy in phototherapy. To address this serious issue, a nanocatalytic hydrogel with an enhanced phototherapy effect consisting of a hydrogel polyvinyl alcohol (PVA) scaffold, MXene/CuS bio-heterojunction, and polydopamine (PDA) for photothermal antibacterial effects and promoting skin regeneration is designed. The MXene/CuS bio-heterojunction has a benign photothermal effect. Singlet oxygen (¹O₂) and hydroxyl radicals (·OH) were generated under near-infrared light, which made the hydrogel system have good antioxidant and antibacterial properties. The addition of PDA further improves the biocompatibility and endows the nanocatalytic hydrogel with adhesion. Additionally, in vivo assays display that the nanocatalytic hydrogel has good skin regeneration ability, including ability to kill bacteria, and promotes capillary angiogenesis and collagen deposition. This work proposes an approach for nanocatalyzed hydrogels with an activated IME response to treat wound infections by enhancing the phototherapeutic effects.

Polysaccharide-based nanocarriers for efficient transvascular drug delivery

Polysaccharide-based nanocarriers (PBNs) are the focus of extensive investigation because of their biocompatibility, low cost, wide availability, and chemical versatility, which allow a wide range of anticancer agents to be loaded within the nanocarriers. Similar to other nanocarriers, most PBNs are designed to extravasate out of tumor vessels, depending on the enhanced permeability and retention (EPR) effect. However, the EPR effect is compromised in some tumors due to the heterogeneity of tumor structures. Transvascular transport efficacy is decreased by complex blood vessels and condensed tumor stroma. The limited extravasation impedes efficient drug delivery into tumor parenchyma, and thus affects the subsequent tumor accumulation, which hinders the therapeutic effect of PBNs. Therefore, overcoming the biological barriers that restrict extravasation from tumor vessels is of great importance in PBN design. Many strategies have been developed to enhance the EPR effect that involve nanocarrier property regulation and tumor structure remodeling. Moreover, some researchers have proposed active transcytosis pathways that are complementary to the paracellular EPR effect to increase the transvascular extravasation efficiency of PBNs. In this review, we summarize the recent advances in the design of PBNs with enhanced transvascular transport to enable optimization of PBNs in the extravasation of the drug delivery process. We also discuss the obstacles and challenges that need to be addressed to clarify the transendothemial mechanism of PBNs and the potential interactions between extravasation and other drug delivery steps.

Photonic double-network hydrogel dressings for antibacterial phototherapy and inflammation regulation in the general management of cutaneous regeneration

The treatment of festering pathogenic bacteria-induced skin wounds with increased inflammation is an ongoing challenge. The traditional antibacterial photothermal therapy always results in localized hyperthermia (over 50 °C), which inevitably delays tissue recovery. To address this serious issue, we devise a novel photonic hydrogel by integrating urchin-like Bi₂S₃ nano-heterojunctions (nano-HJs) into double-network hydrogels for infected skin regeneration. The synergy of NIR-triggered heat and ROS enables the hydrogels to achieve a rapid germicidal efficacy against bacteria within 15 min at mild temperature (below 50 °C). In vitro cell analysis results revealed that the photonic hydrogels exhibit superior cytocompatibility even after NIR illumination. More importantly, an in vivo study demonstrated that the photonic hydrogel dressings have a robust ability of accelerating contagious full-thickness wound regeneration through debriding abscesses, eliminating pathogens, improving collagen deposition, promoting angiogenesis, and adjusting the inflammation state. This photonic hydrogel system provides a general management strategy for the remedy of infectious wounds, where the incorporation of nano-HJs endows the hydrogels with the photodisinfection ability; in addition, the multifunctional hydrogels alleviate the damage from overwhelming heat towards surrounding tissues during phototherapy and steer the inflammation during the process of tissue regeneration. Accordingly, this work highlights the promising application of the photonic hydrogels in conquering refractory pathogen-invaded infection.

An Overview of Antitumour Activity of Polysaccharides

Cancer incidence and mortality are rapidly increasing worldwide; therefore, effective therapies are required in the current scenario of increasing cancer cases. Polysaccharides are a family of natural polymers that hold unique physicochemical and biological properties, and they have become the focus of current antitumour drug research owing to their significant antitumour effects. In addition to the direct antitumour activity of some natural polysaccharides, their structures offer versatility in synthesizing multifunctional nanocomposites, which could be chemically modified to achieve high stability and bioavailability for delivering therapeutics into tumor tissues. This review aims to highlight recent advances in natural polysaccharides and polysaccharide-based nanomedicines for cancer therapy.

Engineering of Defect-Rich Cu2WS4 Nano-homojunctions Anchored on Covalent Organic Frameworks for Enhanced Gaseous Elemental Mercury Removal

Fabricating two-dimensional transition-metal dichalcogenide (TMD)-based unique composites is an effective way to boost the overall physical and chemical properties, which will be helpful for the efficient and fast capture of elemental mercury (Hg⁰) over a wide temperature range. Herein, we constructed a defect-rich Cu₂WS₄ nano-homojunction decorated on covalent organic frameworks (COFs) with abundant S vacancies. Highly well-dispersed and uniform Cu₂WS₄ nanoparticles were immobilized on COFs strongly via an ion pre-anchored strategy, consequently exhibiting enhanced Hg⁰ removal performance. The saturation adsorption capacity of Cu₂WS₄@COF composites (21.60 mg·g^-1) was 9 times larger than that of Cu₂WS₄ crystals, which may be ascribed to more active S sites exposed in hybrid interfaces formed in the Cu₂WS₄ nano-homojunction and between Cu₂WS₄ nanoparticles and COFs. More importantly, such hybrid materials reduced adsorption deactivation at high temperatures, having a wide operating temperature range (from 40 to 200 °C) owing to the thermostability of active S species immobilized by both physical confined and chemical interactions in COFs. Accordingly, this work not only provides an effective method to construct uniform TMD-based sorbents for mercury capture but also opens a new realm of advanced COF hybrid materials with designed functionalities.

Surface Bandgap Engineering of Nanostructured Implants for Rapid Photothermal Ion Therapy of Bone Defects

Bone defects are seriously threatening the health of orthopedics patients and it is difficult for implants to accelerate bone regeneration without using bone growth factors. Herein, a fast photothermal ion therapeutic strategy is developed based on the bandgap engineering of nanostructured TiO₂ through (Si/P)-dual elemental doping by micro-arc oxidation treatment of titanium implants. The (Si/P)-dual doping can tune the surface bandgap structure of TiO₂ by decreasing bandgap and broadening valence band simultaneously, which is confirmed by density functional theory calculations. It not only endows the implants with a mildly photothermal effect under near-infrared (NIR) light irradiation, but also creates an (Si/P) ion-rich microenvironment around the implants. This photothermal ion microenvironment can tune the behaviors of osteoblasts by promoting p38/Smad and ERK signaling pathways of osteoblasts, thus significantly upregulating the expression of osteogenesis genes by the synergistic action of mild photothermal stimulation and increased release of Si/P ions. The in vivo results are also in good agreement with in vitro tests, i.e., under NIR light irradiation, the photothermally responsive TiO₂ enhances the bone formation and osteointegration with implants. Therefore, this kind of photothermal ion strategy is a promising remote and noninvasive therapeutic mode for promoting bone regeneration of Ti implants.

H2O2-activated in situ polymerization of aniline derivative in hydrogel for real-time monitoring and inhibition of wound bacterial infection

Wound is highly susceptible to bacterial infection, which can cause chronic wound and serial complications. However, timely treatment is hampered by the lack of real-time monitoring of wound status and effective therapeutic systems. Herein, in situ biosynthesis of functional conjugated polymer in artificial hydrogel was developed via the utilization of biological microenvironment to realize monitoring in real time of wound infection and inhibition of bacteria for the first time. Specially, an easily polymerizable aniline dimer derivative (N-(3-sulfopropyl) p-aminodiphenylamine, SPA) was artfully in situ polymerized into polySPA (PSPA) in calcium alginate hydrogel, which was initiated via the catalysis of hydrogen peroxide (H₂O₂) overexpressed in infected wound to produce hydroxyl radical (•OH) by preloaded horseradish peroxidase (HRP). Benefitting from outstanding near infrared (NIR) absorption of PSPA, such polymerization can be ingeniously used for real-time monitoring of H₂O₂ via naked-eye and photoacoustic signal, as well as NIR light-mediated photothermal inhibition of bacteria. Furthermore, combining the persistent chemodynamic activity of •OH, the in vivo experimental data proved that the wound healing rate was 99.03% on the 11th day after treatment. Therefore, the present work opens the way to manipulate in situ biosynthesis of functional conjugated polymer in artificial hydrogels for overcoming the issues on wound theranostics.

Near-infrared II plasmonic porous cubic nanoshells for in vivo noninvasive SERS visualization of sub-millimeter microtumors

In vivo surface-enhanced Raman scattering (SERS) imaging allows non-invasive visualization of tumors for intraoperative guidance and clinical diagnostics. However, the in vivo utility of SERS is greatly hampered by the strong optical scattering and autofluorescence background of biological tissues and the lack of highly active plasmonic nanostructures. Herein, we report a class of porous nanostructures comprising a cubic AuAg alloy nanoshell and numerous nanopores. Such porous nanostructures exhibit excellent near-infrared II plasmonic properties tunable in a broad spectral range by varying the pore features while maintaining a small dimension. We demonstrate their exceptional near-infrared II SERS performance varying with the porous properties. Additionally, near-infrared II SERS probes created with porous cubic AuAg nanoshells are demonstrated with remarkable capability for in vivo visualization of sub-millimeter microtumors in a living mouse model. Our near-infrared II SERS probes hold great potentials for precise demarcation of tumor margins and identification of microscopic tumors.

Rapid sterilisation and diabetic cutaneous regeneration using cascade bio-heterojunctions through glucose oxidase-primed therapy

The cutaneous wound in diabetic patients frequently encounters intractable pathogenic infections due to the hyperglycemia micromilieu which is conducive to bacterial growth and multiplication. Despite the extensive clinical use of antibiotics to treat bacterial infections, the emergence of drug-resistant and super pathogens as well as the potential side effects of antibiotics have elicited alarming challenges to public health. To address this daunting concern, we devise and develop a photo-activated cascade bio-heterojunctions (C-bio-HJs) for rapid sterilization and diabetic cutaneous regeneration. In the designed C-bio-HJs, photo-generated electron-hole pairs of graphite-phase carbon nitride (g-C₃N₄) are effectively separated with the marriage of molybdenum disulfide (MoS₂), which achieves the augmented photodynamic antibacterial effect. Moreover, glucose oxidase (GOx) tethered on the bio-HJs catalyzes glucose into hydrogen peroxide (H₂O₂) in diabetic wounds for starvation therapy. Furthermore, Mo⁴⁺ enables the catalysis of H₂O₂ into a highly effective hydroxyl radical (·OH) for chemodynamic-photothermal combined antibacterial therapy. Both in vitro and in vivo results authenticate the cascading antibacterial properties and skin regeneration-promoting effects of the C-bio-HJs, which provide a facile strategy to combat diabetic wound healing through the synergistic GOx-primed dynamic therapies.

Minimally invasive nanomedicine: nanotechnology in photo-/ultrasound-/radiation-/magnetism-mediated therapy and imaging

Traditional treatments such as chemotherapy and surgery usually cause severe side effects and excruciating pain. The emergence of nanomedicines and minimally invasive therapies (MITs) has brought hope to patients with malignant diseases. Especially, minimally invasive nanomedicines (MINs), which combine the advantages of nanomedicines and MITs, can effectively target pathological cells/tissues/organs to improve the bioavailability of drugs, minimize side effects and achieve painless treatment with a small incision or no incision, thereby acquiring good therapeutic effects. In this review, we provide a comprehensive review of the research status and challenges of MINs, which generally refers to the medical applications of nanotechnology in photo-/ultrasound-/radiation-/magnetism-mediated therapy and imaging. Additionally, we also discuss their combined application in various fields including cancers, cardiovascular diseases, tissue engineering, neuro-functional diseases, and infectious diseases. The prospects, and potential bench-to-bedside translation of MINs are also presented in this review. We expect that this review can inspire the broad interest for a wide range of readers working in the fields of interdisciplinary subjects including (but not limited to) chemistry, nanomedicine, bioengineering, nanotechnology, materials science, pharmacology, and biomedicine.

Heterostructured Metal-Organic Frameworks/Polydopamine Coating Endows Polyetheretherketone Implants with Multimodal Osteogenicity and Photoswitchable Disinfection

Clinically, bacteria-induced contagion and insufficient osseointegrative property inevitably elicit the failure of orthopedic implants. Herein, a heterostructured coating consisting of simvastatin (SIM)-laden metal-organic frameworks and polydopamine nanolayers is created on a porous bioinert polyetheretherketone implant. The heterostructured coating significantly promotes cytocompatibility and osteogenic differentiation through multimodal osteogenicity mechanisms of zinc ion (Zn²⁺ ) therapy, SIM drug therapy, and surface micro-/nano-topological stimulation. Under the illumination of near-infrared (NIR) light, singlet oxygen (¹ O₂ ) and local hyperthermia are produced; besides, NIR light dramatically accelerates the release of Zn²⁺ ions from heterostructured coatings. Gram-positive and -negative bacteria are effectively eradicated by the synergy of photothermal/photodynamic effects and photo-induced accelerated delivery of Zn²⁺ ions. The superior osteogenicity and osseointegration, as well as photoswitchable disinfection controlled by NIR light are corroborated via in vivo results. This work highlights the great potential of photoresponsive heterostructured orthopedic implants in treatment of the noninvasive bone reconstruction of bacteria-associated infectious tissues through multimodal phototherapy and photoswitchable ion-therapy.

Development of a magnetic MoS2 system camouflaged by lipid for chemo/phototherapy of cancer

Untargeted release of traditional chemotherapeutic drugs can damage normal tissues in the body and cause serious side effects for patients. Therefore, the research of targeted drug delivery system based on nanomaterials has become a hot topic in the field of cancer therapy. Magnetic molybdenum disulfide (mMoS₂) was modified by liposomes with a cell membrane-like structure to prepare nanocarrier complex (mMoS₂-Lipid) with high biocompatibility and stability. Then, combined photo-chemotherapeutic therapy was realized both in vitro and in vivo by its ultra-high photothermal conversion efficiency and excellent drug loading profile of mMoS₂-Lipid. The characterization showed that the lamellar magnetic molybdenum disulfide modified by liposomes was not easy to aggregate in physiological solution, and had a lower non-specific protein adsorption rate, which was beneficial for biomedical application. In vitro cell experiments exhibited a successful cellular uptake profile of MCF-7 cells with no significant cytotoxicity, while a concentration dependent cytotoxicity for both chemotherapy alone and photo-chemotherapy combined therapy. Compared with the unmodified mMoS₂, mMoS₂-Lipid injected into mice through tail vein can accumulate more in the tumor site, and in vivo anti-tumor studies have shown that the synergistic treatment of the mMoS₂-Lipid has an obvious inhibitory effect on the tumor with less toxic and side effects on mice. In conclusion, mMoS₂-Lipid treatment system provides a safe, rapid and effective choice for the treatment of breast cancer in the future.

Multi-activity cobalt ferrite/MXene nanoenzymes for drug-free phototherapy in bacterial infection treatment

Drug-free antibacterial strategies are of great significance for pathogenic bacterial infection treatment in clinical practice. Phototherapy with antibacterial function plays a vital role in mainstream germicidal research. However, phototherapy could lead to residual heat and excess reactive oxygen species (ROS), which are the main side-effects during antibacterial treatment. Unique CoFe₂O₄/MXene (CM) nanoenzymes, which were fabricated with electrostatic interactions, have been designed to conquer those challenges caused by side-effects of phototherapy in our research. The CM nanoenzymes possess many promising properties including photothermal and photodynamic induced phototherapy and mimic peroxidase (POD), glutathione oxidase (GSHOx), and catalase (CAT). Upon treatment with near-infrared (NIR) light, CM nanoenzymes can create a local high-temperature circumstance as well as raise bacterial membrane permeability. Furthermore, the photodynamic process and multi-enzyme-mimicking activities of CM enzymes boost the interbacterial ROS level. Herein, bacteria can hardly survive in synergistic phototherapy and multi-enzyme-mimicking catalytic therapy in vitro and in vivo. Meanwhile, the CM nanoenzymes exhibit excellent biocompatibility in vitro and in vivo. Overall, this research establishes a strong foundation for effectively employing nanoenzymes, leading to a new way to cure bacterial infections.

The CM nanoenzymes are synthesized with electrostatic interactions. Bacteria can hardly survive synergistic phototherapy and multi-enzyme-mimicking catalytic therapy with CM, which reinforces the foundation of drug-free antibacterial strategies.

Hydrogen-bond super-amphiphile based drug delivery system: design, synthesis, and biological evaluation

Drug delivery systems (DDSs) show great application prospects in tumor therapy. So far, physical encapsulation and covalent grafting were the two most common strategies for the construction of DDSs. However, physical encapsulation-based DDSs usually suffered from low drug loading capacity and poor stability, and covalent grafting-based DDSs might reduce the activity of original drug, which greatly limited their clinical application. Therefore, it is of great research value to design a new DDS with high drug loading capacity, robust stability, and original drug activity. Herein, we report a super-amphiphile based drug delivery system (HBS-DDS) through self-assembly induced by hydrogen bonds between amino-substituted N-heterocycles of the 1,3,5-triazines and hydrophilic carmofur (HCFU). The resulting HBS-DDS had a high drug loading capacity (38.1%) and robust stability. In addition, the drug delivery system exhibited pH-triggered size change and release of drugs because of the pH responsiveness of hydrogen bonds. In particular, the anticancer ability test showed that the HBS-DDS could be efficiently ingested by tumor cells, and its half-maximal inhibitory concentration (IC50 = 3.53 μg mL-1) for HeLa cells was close to that of free HCFU (IC50 = 5.54 μg mL-1). The hydrogen bond-based DDS represents a potential drug delivery system in tumor therapy.

Bimetal metal-organic framework domino micro-reactor for synergistic antibacterial starvation/chemodynamic therapy and robust wound healing

Antibacterial chemodynamic therapy (aCDT) has captured considerable attention in the treatment of pathogen-induced infections due to its potential to inactivate bacteria through germicidal reactive oxygen species (ROS). However, the lifespan of ROS generated by CDT is too short to achieve the efficacy of complete sterilization; thus, residual bacteria inevitably reproduce and cause super-infections. To address this concern, we devise an innovative bimetal, metal-organic framework (BMOF) domino micro-reactor (BMOF-DMR), consisting of Cu/Zn-rich BMOF and glucose oxidase (GOx), via electrostatic self-assembly. GOx catalyzes conversion of glucose into H₂O₂, and the Cu²⁺ ions then convert H₂O₂ into ˙OH to kill bacteria, thereby showing a domino effect. Accordingly, the BMOF-DMR not only blocks the nutrient/energy supply for bacteria, but also triggers a Fenton(-like) reaction and glutathione (GSH) depletion in a self-generating H₂O₂ microenvironment, all leading to high-efficiency bactericidal performance through synergistic starvation/chemodynamic therapy. Remarkably, in vitro and in vivo assessments demonstrate that the BMOF-DMR has superior cytocompatibility and exhibits robust ability to accelerate infectious full-thickness cutaneous regeneration through eradicating bacteria, promoting epithelialization of the wound beds and facilitating angiogenesis from the antibacterial activity and delivery of bimetal elements. The advantage of this antibacterial platform is that it suppresses bacterial metabolism by blocking the energy supply, which might prevent secondary infections from residual bacteria. As envisaged, the use of such a micro-reactor with starvation/chemodynamic therapy is a promising approach for combating bacterial skin wounds.

Bioactive Anti-Inflammatory Thermocatalytic Nanometal-Polyphenol Polypeptide Scaffolds for MRSA-Infection/Tumor Postsurgical Tissue Repair

Postsurgical tumor recurrence, infection, and tissue defect are still the challenges in clinical medicine. The development of multifunctional biomaterial scaffolds with a microenvironment-responsive tumor-infection therapy-tissue repair is highly desirable. Herein, we report a bioactive, injectable, adhesive, self-healing, antibacterial, and anti-inflammatory metal-polyphenol polypeptide nanocomposite scaffold (PEAPF) with temporal-spatial-controlled inflammation-triggered therapeutic properties for efficient infection and postsurgical tumor therapy and skin repair. PEAPF scaffolds showed sustained and inherent inflammation-triggered Fenton catalysis and mild thermochemical effect for specifically inhibiting tumor recurrence in vitro and in vivo. The PEAPF scaffolds significantly facilitated skin tissue regeneration in MRSA-infected chronic wounds and postsurgical tissue defects after tumor resection. This study presents the multifunctional scaffold-based safe and efficient therapeutic strategy to prevent local tumor recurrence and enhance postsurgical tissue regeneration.

Photo-Activated Nanofibrous Membrane with Self-Rechargeable Antibacterial Function for Stubborn Infected Cutaneous Regeneration

For quick disinfection treatment, phototherapy, including photothermal therapy and photodynamic therapy, has emerged as a promising alternative to conventional methods. However, the bactericidal effect of phototherapy, which only works upon light, is short-lived. The remaining bacteria in situ may repopulate when the irradiation of light is withdrawn. To address this refractory concern, an antibacterial fibrous membrane consisting of electrospun poly (polycaprolactone) scaffolds and polydopamine (pDA) coated MXene/Ag₃ PO₄ bioheterojunctions (MX@AgP bio-HJs) is devised and developed. Upon near-infrared (NIR) illumination, the MX@AgP nanoparticle (NP) in nanofibrous electrospun membranes exert the excellent bactericidal effect of phototherapy and release Ag⁺ ions which stop the remaining bacteria from multiplying in the dark state. When removing NIR light, pDA in situ reduces Ag⁺ ions to Ag⁰ NPs to realize the self-rechargeability of Ag⁺ ions and provides enough Ag⁺ ions for the second phototherapy. In vivo results show that photoactivated nanofibrous membranes can re-shape an infected wound microenvironment to the regenerative microenvironment through killing bacteria, ceasing bleeding, increasing epithelialization, and collagen deposition on the wound bed, as well as promoting angiogenesis. As predicted, the proposal work offers potential prospects for nanofibrous membranes with NIR-assisted "self-rechargeable" antibacterial properties to treat bacteria-infected full-thickness wounds.