Graphdiyne-modified TiO2 nanofibers with osteoinductive and enhanced photocatalytic antibacterial activities to prevent implant infection

Multiscale metal-based nanocomposites for bone and joint disease therapies

Bone and joint diseases are debilitating conditions that can result in significant functional impairment or even permanent disability. Multiscale metal-based nanocomposites, which integrate hierarchical structures ranging from the nanoscale to the macroscale, have emerged as a promising solution to this challenge. These materials combine the unique properties of metal-based nanoparticles (MNPs), such as enzyme-like activities, stimuli responsiveness, and photothermal conversion, with advanced manufacturing techniques, such as 3D printing and biohybrid systems. The integration of MNPs within polymer or ceramic matrices offers a degree of control over the mechanical strength, antimicrobial efficacy, and the manner of drug delivery, whilst concomitantly promoting the processes of osteogenesis and chondrogenesis. This review highlights breakthroughs in stimulus-responsive MNPs (e.g., photo-, magnetically-, or pH-activated systems) for on-demand therapy and their integration with biocomposite hybrids containing cells or extracellular vesicles to mimic the native tissue microenvironment. The applications of these composites are extensive, ranging from bone defects, infections, tumors, to degenerative joint diseases. The review emphasizes the enhanced load-bearing capacity, bioactivity, and tissue integration that can be achieved through hierarchical designs. Notwithstanding the potential of these applications, significant barriers to progress persist, including challenges related to long-term biocompatibility, regulatory hurdles, and scalable manufacturing. Finally, we propose future directions, including machine learning-guided design and patient-specific biomanufacturing to accelerate clinical translation. Multiscale metal-based nanocomposites, which bridge nanoscale innovations with macroscale functionality, are a revolutionary force in the field of biomedical engineering, providing personalized regenerative solutions for bone and joint diseases.

Boosting H2O2 production via two-electron oxygen reduction with O-doped g-C3N4 decorated with Ti3C2Tx quantum dots

Photocatalytic synthesis of H2O2 with g-C3N4 holds great promise for converting solar energy into chemical energy, but it remains constrained by the narrow optical absorption range and rapid charge recombination. To overcome these challenges, Ti3C2Tx MXene quantum dots (TQDs), known for their ease of carrier regulation and strong visible light absorption, were incorporated into O-doped g-C3N4 (O-CN) to form TQDs-modified O-CN (O-CN@TQDs) with a Schottky heterojunction. Attributed to such structural design, the H2O2 production was promoted through the two-step two-electron oxygen reduction pathway, with O2- serving as the primary intermediate. The photocatalytic H2O2 production rate over optimized O-CN@TQDs reached 868.9 μmol g-1 h-1 under visible light irradiation, which was 10.8 times higher than that of the pristine g-C3N4. This study underscores the potential of judiciously selecting suitable semiconductor and metal-like materials to construct Schottky heterojunctions for the efficient photocatalytic production of H2O2.

Modulating the electronic structure of graphdiyne-based nanomaterials for engineering nano-bio interfaces in biomedical applications

Graphdiyne (GDY), a two-dimensional (2D) carbon allotrope featuring a unique electronic structure, has attracted considerable attention due to its outstanding properties and potential applications in various fields, particularly in biomedicine due to its exceptional surface area, tunable electronic structure, and biocompatibility. Although promising, this field is still in the proof-of-concept stage due to incomplete understanding of the effects of structural regulation, particularly electronic structure, of GDY-based nanomaterials on their nano-bio interfaces, which seriously hinders the research of GDY-based nanomaterials in the biomedical field. To provide a comprehensive understanding of the relationship between electronic structures and nano-bio interfaces, this review focuses on the modulation of the electronic structure of GDY-based nanomaterials and its implications for engineering nano-bio interfaces for biomedical applications. Firstly, we delve into the intrinsic electronic properties of GDY, including its bandgap tunability and high carrier mobility, which are critical for its functionality in biomedical applications. We then discuss strategies for modulating these properties through oxidation, nonmetallic doping, covalent modification, and metal loading, aiming to optimize the electronic structure of GDY-based nanomaterials for superior performance in specific biomedical contexts, such as biomedical imaging, surface and interface catalysis, free radical scavenging, and drug delivery. Furthermore, we provide an overview of the methodologies for the investigation of these electronic properties, including theoretical simulation, characterization techniques, and real-time analysis of electron transfer at the nano-bio interfaces, highlighting their roles in advancing our understanding and guiding the design of novel GDY-based materials. Finally, this review provides an outlook on future research directions aimed at further optimizing the design of GDY-based nanomaterials and nano-bio interfaces, emphasizing the need for interdisciplinary collaboration to overcome current challenges and to fully realize the potential of GDY-based nanomaterials in biomedical applications. These principles are anticipated to facilitate the future development and clinical translation of precise, safe, and effective nanomedicines with intelligent theranostic features.

Mild Phototherapy Strategies for Preventing Pathogen Infection and Enhancing Cell Proliferation in Diabetic Wound

Excessive inflammation, bacterial infection, and impaired cell proliferation posed significant challenges to diabetic wound healing. There is an urgent need for an effective method that can simultaneously provide antibacterial activity and promote cell proliferation to facilitate the healing of bacteria-infected diabetic wounds. In this study, a novel nanoplatform, GDYO-VPIM-Au is designed, by co-decorating 1-vinyl-3-pentylimidazolium bromide ([VPIM]Br) and gold nanorods (Au NRs) on graphdiyne oxide (GDYO) nanosheets. GDYO-VPIM-Au exhibited excellent antibacterial properties against drug-resistant bacteria through reactive oxygen species (ROS) generation and electrostatic interactions. Moreover, GDYO-VPIM-Au with the synergistic effect of mild phototherapy therapy (mPTT) produced by Au NRs can promote efficient cell proliferation and significantly accelerate the healing of infected diabetic wounds. This work represented a promising therapeutic strategy for addressing drug-resistant bacterial infections and enhancing diabetic wound healing.

Tetrathienylethene-based porous framework composites for boosting photocatalytic antibacterial activity

In order to reduce the risk of high-threat pathogens, a photocatalytic antibacterial method with a reputation for high efficiency and sustainability has attracted widespread attention. Recently, metal-organic frameworks (MOFs) have emerged as desirable platforms for photocatalytic applications by virtue of their structural diversity and functional adjustability. Herein, we report that we have synthesized a stable and photosensitive zirconium-based MOF (Zr-MOF) with a photoactive tetrathienylethene-based organic linker, Zr-TSS-1. Compared with all-carbocyclic Zr-MOF counterparts, Zr-TSS-1 shows a substantial improvement in visible-light harvesting and free-carrier generation, enabling it to be a promising candidate for photocatalytic antibacterial applications. In order to validate the advantages of this framework as an antibacterial protective material, a composite was fabricated by incorporating robust Zr-TSS-1 onto sustainably accessible bacterial cellulose (BC) using an in situ growth method. This composite exhibits near-complete lethality toward typical Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus within 1 h under mild irradiation and preserves outstanding antibacterial capability after five cycles of reutilization. In addition, the high biocompatibility is confirmed by the low cytotoxicity toward human skin fibroblast, suggesting its potential for biomedical and healthcare applications. This research demonstrates the efficacious integration of a purposely designed photosensitive porous framework onto a sustainable substrate for synergistic functionality, paving a practical way for the development of the next-generation high-efficiency antimicrobial technology.

Controllable Fabrication of ZnO Nanorod Arrays on the Surface of Titanium Material and Their Antibacterial and Anti-Adhesion Properties

The adhesion of deleterious bacteria on titanium substrates not only causes economic losses but also endangers human life and health. The study is expected to address the challenging issues of using ZnO as an antibacterial material, including low bactericidal efficiency without lighting, susceptibility to ZnO cluster formation, and easy adhesion of bacteria to its surface. It is proposed that the prepared ZnO nanorod arrays with a hexagonal wurtzite structure on the surface of titanium-based materials can address the issue of ZnO cluster formation. Remarkably, a mere 3.49 g cm-2 of decorated Ag/AgCl achieves over 99% sterilization efficiency without lighting. The incorporation of FAS (1H,1H,2H,2H-perfluorodecyltrimethoxysilane) molecules with low surface energy enables the prepared Ti@ZnO@Ag/AgCl@FAS to attain a Cassie-Baxter wetting state, thereby imparting exceptional bacterial anti-adhesion properties exceeding 99.50%. Furthermore, antibacterial and anti-adhesion models have been proposed to elucidate the underlying mechanisms. This innovative approach is anticipated to be adaptable for application across various material substrates, which opens up a new avenue for the application of the antibacterial and bacterial anti-adhesion properties on the surface of ZnO materials.

New Advances in Periodontal Functional Materials Based on Antibacterial, Anti-Inflammatory, and Tissue Regeneration Strategies

With the global population aging, awareness of oral health is rising. Periodontitis, a widespread bacterial infectious disease, is gaining attention. Current novel biomaterials address key clinical issues like bacterial infection, gum inflammation, tooth loosening, and loss, focusing on antibacterial, anti-inflammatory, and tissue regeneration properties. However, strategies that integrate the advantages of these biomaterials to achieve synergistic therapeutic effects by clearing oral biofilms, inhibiting inflammation activation, and restoring periodontal soft and hard tissue functions remain very limited. Recent studies highlight the link between periodontitis and systemic diseases, underscoring the complexity of the periodontal disease. There is an urgent need to find comprehensive treatment plans that address clinical requirements. Whether by integrating new biomaterials to enhance existing periodontal treatments or by developing novel approaches to replace traditional therapies, these efforts will drive advancements in periodontitis treatment. Therefore, this review compares novel biomaterials with traditional treatments. It highlights the design concepts and mechanisms of these functional materials, focusing on their antibacterial, anti-inflammatory, and tissue regeneration properties, and discusses the importance of developing comprehensive treatment strategies. This review aims to provide guidance for emerging periodontitis research and to promote the development of precise and efficient treatment strategies.

Sponge-like inorganic-organic S-scheme heterojunction for efficient photocatalytic hydrogen evolution

Covalent organic frameworks (COFs)-based S-scheme heterojunction photocatalysts have gained considerable attention for photocatalytic hydrogen evolution. However, challenges such as limited interfacial contact and low stability persist, primarily due to uneven inorganic semiconductor coverage on the COFs surface. Therefore, constructing inorganic-organic S-scheme heterojunction photocatalysts via the in-situ growth of COFs on inorganic semiconductor surfaces shows great promise. Herein, we successfully developed a sponge-like TiO2@BTTA S-scheme heterojunction with a tight contact interface by in-situ growing COF (referred to as BTTA) on the surface of sponge-like TiO2 (referred to as ST). Density Functional Theory (DFT) calculations confirmed that the ST@BTTA hybrids exhibit the optimal adsorption and desorption capabilities for H2O and H2 molecules, respectively. Notably, the ST@BTTA-120 S-scheme heterojunction photocatalyst demonstrates an outstanding hydrogen production rate under simulated sunlight irradiation, surpassing pristine ST and BTTA by factors of 10.3 and 2.6, respectively. The enhanced photocatalytic performance is attributed to improved solar energy utilization efficiency, a larger specific surface area, and an increased interfacial contact area between ST and BTTA. X-ray photoelectron spectroscopy (XPS) and electron spin resonance (ESR) analyses further verify the S-scheme carrier transfer mechanism in the ST@BTTA hybrids. This research provides a valuable method for designing efficient S-scheme heterojunction photocatalysts with closely integrated interfaces for photocatalytic hydrogen production via water splitting.

Atomic layer deposition paves the way for next-generation smart and functional textiles

As technology evolves and consumer needs diversify, textiles have become crucial to determining the future of fashion, sustainability, and functionality. Functional textiles, which not only provide comfort and aesthetics as traditional textiles but also endow textiles with special functions such as antibacterial, anti-odor, moisture absorption and perspiration, anti-ultraviolet (UV), flame-retardant, self-cleaning, and anti-static properties through technological innovation and upgrading, have attracted increasing attention because they satisfy the specific needs of people in different environments and occasions. However, functionality often occurs at the expense of comfort in existing functional products. Endowing textiles with excellent multi-functionality with marginal effects on comfort and wearability properties continues to be a challenge. Atomic layer deposition (ALD) paves the way for creating functional fabrics by enabling the formation of highly conforming inorganic/organic coatings over a large area with precise atomic-level film thickness control from a self-limiting reaction mechanism. Therefore, this paper introduces the reaction mechanism of ALD and the unique advantages of depositing inorganic nanofilms on fiber and textile surfaces. The factors influencing ALD and the commonly used ALD-derived technologies are then discussed. Subsequently, the research progress and breakthroughs in inorganic nanofilms prepared by ALD in conferring multifunctional properties on textile surfaces, such as antimicrobial, UV-resistant, heat-insulating, multifunctional wetting, structural coloring, thermoelectric elements, and flexible sensing, are reviewed. Finally, future developments and possible challenges of ALD for the large-scale production of multifunctional fabrics are proposed, which are expected to promote the development of next-generation advanced functional textiles.

Light driven water oxidation on silica supported NiO-TiO2 heteronanocrystals yields hydrogen peroxide

Decomposition of nickel nitrate hexahydrate in the presence of rod-shape anatase TiO2 nanocrystals led to the formation of NiO-TiO2 heteronanocrystals confirmed with powder X-ray diffraction and electron microscopy. The heteronanocrystals were supported on amorphous fumed silica to provide a heterogeneous photocatalyst material SiO2/NiO-TiO2. The aqueous suspension of the catalyst, under argon atmosphere, irradiated with a Xe arc lamp led to the formation of H2O2 with trace gaseous product formation. We observed an initial rate of formation of H2O2 of 1.8 μmol g-1 min-1 that decays toward a steady-state concentration of 52 μM. Addition of AgNO3 to the aqueous suspension gave fast reduction of silver ion, and higher initial rates of formation and steady state concentrations of H2O2. We report the concentration dependence of water oxidation versus [AgNO3] with the fastest initial rate of formation of H2O2 as 9.1 μmol g-1 min-1 and a steady-state concentration of 174 μM.

Semiconductor photocatalytic antibacterial materials and their application for bone infection treatment

Bacterial infection in bone tissue engineering is a severe clinical issue. Traditional antimicrobial methods usually cause problems such as bacterial resistance and biosecurity. Employing semiconductor photocatalytic antibacterial materials is a more controlled and safer strategy, wherein semiconductor photocatalytic materials generate reactive oxygen species under illumination for killing bacteria by destroying their cell membranes, proteins, DNA, etc. In this review, P-type and N-type semiconductor photocatalytic materials and their antibacterial mechanisms are introduced. Type II heterojunctions, P-N heterojunctions, type Z heterojunctions and Schottky junctions have been reported to reduce the recombination of carriers, while element doping, sensitization and up-conversion luminescence expand the photoresponse range. Furthermore, the applications of semiconductor photocatalytic antibacterial materials in bone infection treatment such as osteomyelitis treatment, bone defect repair and dental tissue regeneration are summarized. Finally, the conclusion and future prospects of semiconductor photocatalytic antibacterial materials in bone tissue engineering were analyzed.

Bacterial cell wall-specific nanomedicine for the elimination of Staphylococcus aureus and Pseudomonas aeruginosa through electron-mechanical intervention

Personalized synergistic antibacterial agents against diverse bacterial strains are receiving increasing attention in combating antimicrobial resistance. However, the current research has been struggling to strike a balance between strain specificity and broad-spectrum bactericidal activity. Here, we propose a bacterial cell wall-specific antibacterial strategy based on an in situ engineered nanocomposite consisting of carbon substrate and decorated TiOx dots, termed TiOx@C. The fiber-like carbon substrate of TiOx@C is able to penetrate the bacterial membrane of Pseudomonas aeruginosa (P. aeruginosa), but not that of Staphylococcus aureus (S. aureus) due to its thicker bacterial wall, thus achieving bacterial wall specificity. Furthermore, a series of experiments demonstrate the specific electro-mechanical co-sterilization effect of TiOx@C. On the one hand, TiOx@C can disrupt the electron transport chain and block the energy supply of S. aureus. On the other hand, TiOx@C capable of destroying the membrane structure of P. aeruginosa could cause severe mechanical damage to P. aeruginosa as well as inducing oxidative stress and protein leakage. In vivo experiments demonstrate the efficacy of TiOx@C in eliminating 97% of bacteria in wounds and promoting wound healing in wound-infected female mice. Overall, such a bacterial cell wall-specific nanomedicine presents a promising strategy for non-antibiotic treatments for bacterial diseases.

Employing Copper-Based Nanomaterials to Combat Multi-Drug-Resistant Bacteria

The rise of multi-drug-resistant (MDR) bacteria poses a severe global threat to public health, necessitating the development of innovative therapeutic strategies to overcome these challenges. Copper-based nanomaterials have emerged as promising agents due to their intrinsic antibacterial properties, cost-effectiveness, and adaptability for multifunctional therapeutic approaches. These materials exhibit exceptional potential in advanced antibacterial therapies, including chemodynamic therapy (CDT), photothermal therapy (PTT), and photodynamic therapy (PDT). Their unique physicochemical properties, such as controlled ion release, reactive oxygen species (ROS) generation, and tunable catalytic activity, enable them to target MDR bacteria effectively while minimizing off-target effects. This paper systematically reviews the mechanisms through which Cu-based nanomaterials enhance antibacterial efficiency and emphasizes their specific performance in the antibacterial field. Key factors influencing their antibacterial properties-such as electronic interactions, photothermal characteristics, size effects, ligand effects, single-atom doping, and geometric configurations-are analyzed in depth. By uncovering the potential of copper-based nanomaterials, this work aims to inspire innovative approaches that improve patient outcomes, reduce the burden of bacterial infections, and enhance global public health initiatives.

Bringing Porous Framework Materials toward Photocatalytic H2O2 Production

Photocatalytic H2O2 production driven by renewable solar energy is a promising and sustainable approach, with porous framework materials such as metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and hydrogen-bonded organic frameworks (HOFs) emerging as highly efficient catalysts. This Review first presents the current research state of porous framework materials in H2O2 photosynthesis, focusing on the progress in H2O2 production across different porous frameworks and mechanism insights gained through advanced techniques. Furthermore, a systematic categorization of material modifications aimed at enhancing the photocatalytic efficiency is provided, linking structural modifications to improved H2O2 production performance. Key factors such as charge carrier separation and transfer, reaction pathways, and material stability are comprehensively analyzed. Finally, the challenges related to stability, scalability, and cost-effectiveness, are discussed alongside opportunities for future advancements. This Review aims to provide insights into understanding and optimizing porous framework materials for efficient and scalable H2O2 photosynthesis.

Black Phosphorus Nanosheet-Based Composite Biomaterials for the Enhanced Repair of Infectious Bone Defects

Infectious bone defects pose significant challenges in orthopedic practice, marked by persistent bacterial infection and ongoing inflammatory responses. Recent advancements in bone tissue engineering have led to the development of biomaterials with both antibacterial properties and the ability to promote bone regeneration, offering new solutions to these complex issues. Black phosphorus nanosheets (BPNS), a unique two-dimensional material, demonstrate exceptional biocompatibility, bioactivity, and antibacterial properties. Their combination of osteogenic, antibacterial, and anti-inflammatory effects positions BPNS as an ideal candidate for addressing bone defects complicated by infection. This Review explores the potential of BPNS-based composite biomaterials in repairing infectious bone defects, discussing their molecular mechanisms for antibacterial activity, including intrinsic antibacterial properties, photothermal therapy (PTT), photodynamic therapy (PDT), and drug delivery. The application of BPNS in treating infectious bone defects, through hydrogels, scaffolds, coatings, and fibers, is also discussed. The Review emphasizes the transformative role of BPNS in bone tissue engineering and advocates for continued research and development in this promising field.

Graphdiyne biomaterials: from characterization to properties and applications

Graphdiyne (GDY), the sole synthetic carbon allotrope with sp-hybridized carbon atoms, has been extensively researched that benefit from its pore structure, fully conjugated surfaces, wide band gaps, and more reactive C≡C bonds. In addition to the intrinsic features of GDY, engineering at the nanoscale, including metal/transition metal ion modification, chemical elemental doping, and other biomolecular modifications, endowed GDY with a broader functionality. This has led to its involvement in biomedical applications, including enzyme catalysis, molecular assays, targeted drug delivery, antitumor, and sensors. These promising research developments have been made possible by the rational design and critical characterization of GDY biomaterials. In contrast to other research areas, GDY biomaterials research has led to the development of characterization techniques and methods with specific patterns and some innovations based on the integration of materials science and biology, which are crucial for the biomedical applications of GDY. The objective of this review is to provide a comprehensive overview of the biomedical applications of GDY and the characterization techniques and methods that are essential in this process. Additionally, a general strategy for the biomedical research of GDY will be proposed, which will be of limited help to researchers in the field of GDY or nanomedicine.

Nanozyme-Based Strategies against Bone Infection

Nanozymes are a class of nanomaterials that exhibit catalytic functions analogous to those of natural enzymes. They demonstrate considerable promise in the biomedical field, particularly in the treatment of bone infections, due to their distinctive physicochemical properties and adjustable catalytic activities. Bone infections (e.g., periprosthetic infections and osteomyelitis) are infections that are challenging to treat clinically. Traditional treatments often encounter issues related to drug resistance and suboptimal anti-infection outcomes. The advent of nanozymes has brought with it a new avenue of hope for the treatment of bone infections.

Multi-Functional Bio-HJzyme Engineered Polyetheretherketone Implant with Cascade-Amplification Therapeutic Capabilities Toward Intractable Implant-Associated Infections

Intractable implant-associated infections (IAIs) are the primary cause of prosthetic implant failure, particularly in the context of diabetes mellitus. There is an urgent need to design and construct versatile engineered implants integrated with cascade amplification therapeutic modality to significantly improve the treatment of diabetic IAIs. To address this issue, a multi-functional MXene/Ag3PO4@glucose oxidase bio-heterojunction enzyme (M/A@GOx bio-HJzyme) coating is developed, which is decorated with an inert sulfonated polyetheretherketone implant (SP-M/A@G) via hydrothermal treatment and layered deposition. The decorated bio-HJzyme coating promoted cellular adhesion and proliferation of osteoblast cells on the implant. Simultaneously, upon 808 nm near-infrared (NIR) light irradiation, the decorated coating not only induces localized hyperthermia and reactive oxygen species (ROS) generation but also initiates Fenton-like and laccase-mimicking reactions and depletes glutathione (GSH) within the diabetes infection microenvironment. The cascade amplification therapeutic effects of phototherapy and biocatalytic therapy confer the engineered implants with robust cyclic antibacterial properties. Furthermore, in vivo, assessment demonstrated that the multi-functional bio-HJzyme can effectively eradicate infectious pathogens located on the implant and peri-implant tissues and promote the regeneration of diabetic infectious skin. Collectively, this study provides a revolutionary approach for constructing multi-functional implants with cascade amplification therapeutic capabilities for intractable diabetic IAIs.

Functional hydrogel empowering 3D printing titanium alloys

Titanium alloys are widely used in the manufacture of orthopedic prosthesis given their excellent mechanical properties and biocompatibility. However, the primary drawbacks of traditional titanium alloy prosthesis are their much higher elastic modulus than cancellous bone and poor interfacial adhesion, which lead to poor osseointegration. 3D-printed porous titanium alloys can partly address these issues, but their bio-inertness still requires modifications to adapt to different physiological and pathological microenvironments. Hydrogels composed of three-dimensional networks of hydrophilic polymers can effectively simulate the extracellular matrix of natural bone and are capable of loading bioactive molecules such as proteins, peptides, growths factors, polysaccharides, or nucleotides for localized release within the human body, by directly participating in biological processes. Combining 3D-printed porous titanium alloys with hydrogels to construct a bioactive composite system that regulates cellular adhesion, proliferation, migration, and differentiation in the local microenvironment is of great significance for enhancing the bioactivity of the prosthesis surface. In this review, we focus on three aspects of the bioactive composite system: (Ⅰ) strategies for constructing bioactive interfaces with hydrogels, and (Ⅱ) how bioactive composite systems regulate the microenvironment under different physiological and pathological conditions to enhance the osteointegration and bone regeneration capability of prostheses. Considering the current research status in this field, innovations in orthopedic prosthesis can be achieved through material optimization, personalized customization, and the development of multifunctional composite systems. These advancements provide essential references for the clinical translation of osseointegration and bone regeneration in various physiological and pathological microenvironments.

Diacetylene-bridged covalent organic framework as crystalline graphdiyne analogue for photocatalytic hydrogen evolution

Graphdiyne (GDY) alone as a photocatalyst is unsatisfactory because of its low crystallinity, limited regulation of the band gap, weak photogenerated charge separation, etc., and heterojunctioning with other materials is necessary to activate the photocatalytic activity of GDY. Through elaborate design, a diacetylene-rich linker (S2) was prepared and employed to construct a crystalline and structurally well-defined GDY-like covalent organic framework (COF, namely S2-TP COF) which merges the merits of both COF and GDY to boost the photocatalytic hydrogen evolution reaction (HER). By theoretical prediction on the donor-acceptor (D-A) pair, two other monoacetylene-bridged COFs (S1-TP COF and S3-TP COF) were prepared for comparison. Exhibiting enhanced separation and suppressed recombination of photogenerated excitons, Pt-photodeposited S2-TP COF showed a higher HER rate (10.16 mmol g-1 h-1) than the other two non-GDY-like COFs (3.71 and 1.13 mmol g-1 h-1). A joint experimental-theoretical study suggests that the appropriate D-A structure for photogenerated charge separation and diacetylene motif as the adsorption site are the key reasons for the boosted HER. This work opens a new avenue for the rational design of COFs as GDY mimics for photocatalytic application.

Visualizing Hydrogen Peroxide Diffusion in Soils with Precipitation-Based Fluorescent Probe

Hydrogen peroxide (H2O2)-based advanced oxidation technology has emerged as a cost-effective and green solution for tackling soil pollution. Given the highly heterogeneous nature of soil, the effectiveness of H2O2 remediation is significantly influenced by its diffusion distance in soils. However, the dynamics of H2O2 diffusion and its effective range remain largely unexplored, primarily due to the lack of analytical methods for mapping H2O2 in soils. This study introduces a precipitation-based fluorescent probe (PFP) method for in situ, high-resolution (micrometer scale) mapping of H2O2 diffusion in soils. Using the PFP method, we visualized real-time H2O2 diffusion in various types of soils, revealing distinct diffusion patterns with rates ranging from 0.011 to >0.56 mm min-1. The observed differences in diffusion rates are associated with soil permeability. Additionally, soils exhibited a wide range of diffusion distances, from 0.22 to >11 mm in 20 min. Soil's reactivity for H2O2 decomposition, a previously overlooked factor, is critical in determining the diffusion distance of H2O2. We further demonstrate that the efficacy of H2O2 diffusion in soils is a pivotal factor in controlling pollutant degradation and soil remediation efficiency. These findings enhance our understanding of reagent diffusion processes in soil remediation, informing the optimization of more efficient soil remediation strategies.

Spin polarization induced by atomic strain of MBene promotes the ·O2- production for groundwater disinfection

Superbugs in groundwater are posing severe health risks through waterborne pathways. An emerging approach for green disinfection lies at photocatalysis, which levers the locally generated superoxide radical (·O2-) for neutralization. However, the spin-forbidden feature of O2 hinders the photocatalytic generation of active ·O2-, and thus greatly limited the disinfection efficiency, especially for real groundwater with a low dissolved oxygen (DO) concentration. Herein, we report a class of strained Mo4/3B2-xTz MBene (MB) with enhanced adsorption/activation of molecular O2 for photocatalytic disinfection, and find the strain induced spin polarization of In2S3/Mo4/3B2-xTz (IS/MB) can facilitate the spin-orbit hybridization of Mo sites and O2 to overcome the spin-forbidden of O2, which results in a 16.59-fold increase in ·O2- photocatalytic production in low DO condition (2.46 mg L-1). In particular, we demonstrate an In2S3/Mo4/3B2-xTz (50 mg)-based continuous-flow-disinfection system stably operates over 62 h and collects 37.2 L bacteria-free groundwater, which represents state-of-the-art photodisinfection materials for groundwater disinfection. Most importantly, the disinfection capacity of the continuous-flow-disinfection system is 25 times higher than that of commercial sodium hypochlorite (NaOCl), suggesting the practical potential for groundwater purification.

A Microenvironment-Responsive Graphdiyne-Iron Nanozyme Hydrogel with Antibacterial and Anti-Inflammatory Effect for Periodontitis Treatment

Periodontitis is a chronic inflammatory disease caused by dental plaque, which leads to tooth loosening and shifting or even tooth loss. Current treatments, including mechanical debridement and antibiotics, often fail to eradicate recalcitrant biofilms and mitigate excessive inflammation. Moreover, these interventions can disrupt the oral microbiome, potentially compromising long-term treatment outcomes. To address these limitations, an injectable nanoenzyme hydrogel composed of a dopamine (DA)-modified hyaluronic acid (HA) scaffold and a graphdiyne-iron (GDY-Fe) complex, named GDY-Fe@HA-DA, exhibits excellent tissue adhesion, self-healing, antibacterial properties, and biocompatibility. Under near-infrared laser irradiation, GDY-Fe@HA-DA effectively eradicates a variety of pathogens, including Escherichia coli, Staphylococcus aureus, and Porphyromonas gingivalis, through a synergistic combination of chemodynamical and photothermal therapies. The hydrogel's efficacy is further validated in both bacterial-infected skin wounds and rat periodontitis models. It effectively alleviates the inflammatory environment and promotes wound healing and periodontal tissue recovery. This findings highlight the potential of GDY-Fe@HA-DA as a promising therapeutic material for periodontitis and other tissue injuries.

Electrospun nanofibrous membranes meet antibacterial nanomaterials: From preparation strategies to biomedical applications

Electrospun nanofibrous membranes (eNFMs) have been extensively developed for bio-applications due to their structural and compositional similarity to the natural extracellular matrix. However, the emergence of antibiotic resistance in bacterial infections significantly impedes the further development and applications of eNFMs. The development of antibacterial nanomaterials substantially nourishes the engineering design of antibacterial eNFMs for combating bacterial infections without relying on antibiotics. Herein, a comprehensive review of diverse fabrication techniques for incorporating antibacterial nanomaterials into eNFMs is presented, encompassing an exhaustive introduction to various nanomaterials and their bactericidal mechanisms. Furthermore, the latest achievements and breakthroughs in the application of these antibacterial eNFMs in tissue regenerative therapy, mainly focusing on skin, bone, periodontal and tendon tissues regeneration and repair, are systematically summarized and discussed. In particular, for the treatment of skin infection wounds, we highlight the antibiotic-free antibacterial therapy strategies of antibacterial eNFMs, including (i) single model therapies such as metal ion therapy, chemodynamic therapy, photothermal therapy, and photodynamic therapy; and (ii) multi-model therapies involving arbitrary combinations of these single models. Additionally, the limitations, challenges and future opportunities of antibacterial eNFMs in biomedical applications are also discussed. We anticipate that this comprehensive review will provide novel insights for the design and utilization of antibacterial eNFMs in future research.

Polydopamine-based surface coating fabrication on titanium implant by combining a photothermal agent and TiO2 nanosheets for efficient photothermal antibacterial therapy and promoted osteogenic activity

Developing titanium-based dental implants with both excellent antibacterial properties and good osseointegration is crucial for the success of the implant operation and the long-term durability of the implant. In this study, a polydopamine-based coating was created by attaching TiO2 nanosheets-cyanine composites onto the titanium surface, enabling the integration of effective photothermal antibacterial therapy with osseointegration. The exceptional dual-photothermal conversion abilities of polydopamine and cyanine in the coating resulted in outstanding photothermal antibacterial and antibiofilm therapy against four types of bacteria. Furthermore, TiO2 nanosheets promoted the adhesion, proliferation and early osteogenic differentiation of osteoblasts. In an infected dental implant model in rats, the developed coating exhibited potent antibacterial activity and remarkable osteogenic differentiation in the bone, leading to increased bone formation around the implants. This innovative approach, combining photothermal therapy with osteogenic two-dimensional nanomaterials, presents a novel method for surface functionalization of implants to achieve effective antibacterial and osseointegration capabilities.

Biomimetic Scaffolds Regulating the Iron Homeostasis for Remolding Infected Osteogenic Microenvironment

The treatment of infected bone defects (IBDs) needs simultaneous elimination of infection and acceleration of bone regeneration. One mechanism that hinders the regeneration of IBDs is the iron competition between pathogens and host cells, leading to an iron deficient microenvironment that impairs the innate immune responses. In this work, an in situ modification strategy is proposed for printing iron-active multifunctional scaffolds with iron homeostasis regulation ability for treating IBDs. As a proof-of-concept, ultralong hydroxyapatite (HA) nanowires are modified through in situ growth of a layer of iron gallate (FeGA) followed by incorporation in the poly(lactic-co-glycolic acid) (PLGA) matrix to print biomimetic PLGA based composite scaffolds containing FeGA modified HA nanowires (FeGA-HA@PLGA). The photothermal effect of FeGA endows the scaffolds with excellent antibacterial activity. The released iron ions from the FeGA-HA@PLGA help restore the iron homeostasis microenvironment, thereby promoting anti-inflammatory, angiogenesis and osteogenic differentiation. The transcriptomic analysis shows that FeGA-HA@PLGA scaffolds exert anti-inflammatory and pro-osteogenic differentiation by activating NF-κB, MAPK and PI3K-AKT signaling pathways. Animal experiments confirm the excellent bone repair performance of FeGA-HA@PLGA scaffolds for IBDs, suggesting the promising prospect of iron homeostasis regulation therapy in future clinical applications.

A Shape-Restorable hierarchical polymer membrane composite system for enhanced antibacterial and antiadhesive efficiency

Intelligent shape memory polymer can be potentially used in manufacturing implantable devices that enables a benign variation of implant dimensions with the external stimuli, thus effectively lowering insertion forces and evading associated risks. However, in surgical implantation, biomaterials-associated infection has imposed a huge burden to healthcare system that urgently requires an efficacious replacement of antibiotic usages. Preventing the initial attachment and harvesting a biocidal function upon native surfaces may be deemed as a preferable strategy to tackle the issues of bacterial infection. Herein, a functionalized polylactic acid (PLA) composite membrane assembled with graphene (GE, a widely used photothermal agent) was fabricated through a blending process and then polydimethylsiloxane utilized as binders to pack hydrophobic SiO2 tightly onto polymer surface (denoted as PLA-GE/SiO2). Such an active platform exhibited a moderate shape-memory performance upon near-infrared (NIR) light stimulation, which was feasible for programmed deformation and shape recovery. Particularly stirring was that PLA-GE/SiO2 exerted a pronounced bacteria-killing effect under NIR illumination, 99.9 % of E. coli and 99.8 % of S. aureus were effectively eradicated in a lean period of 5 min. Furthermore, the obtained composite membrane manifested excellent antiadhesive properties, resulting in a bacteria-repelling efficacy of up to 99 % for both E. coli and S. aureus species. These findings demonstrated the potential value of PLA-GE/SiO2 as a shape-restorable platform in "kill&repel" integration strategy, further expanding its applications for clinical anti-infective treatment.

Exploration of bone metabolism status in the distal femur of mice at different growth stages

The mouse femur, particularly the distal femur, is commonly utilized in orthopedic research. Despite its significance, little is known about the key events involved in the postnatal development of the distal femur. Therefore, investigating the development process of the mouse distal femur is of great importance. In this study, distal femurs of CD-1 mice aged 1, 2, 4, 6, and 8 weeks were examined. We found that the width and height of the distal femur continued to increase till the 4th week, followed with stabilization. Notably, the width to height ratio remained relatively consistent with age. Micro computed tomography analysis demonstrated gradual increases in bone volume/tissue volume, trabecular number, and trabecular thickness from 1 to 6 weeks, alongside a gradual decrease in trabecular separation. Histological analysis further indicated the appearance of the secondary ossification center at approximately 2 weeks, with ossification mostly completed by 4 weeks, leading to the formation of a prototype epiphyseal plate. Subsequently, the epiphyseal plate gradually narrowed at 6 and 8 weeks. Moreover, the thickness and maturity of the bone cortex surrounding the epiphyseal plate increased over time, reaching peak cortical bone density at 8 weeks. In conclusion, to enhance model stability and operational ease, we recommend constructing conventional mouse models of the distal femur between 4 and 8 weeks old.

The Antibacterial Activities and Effects of Baicalin on Ampicillin Resistance of MRSA and Stenotrophomonas maltophilia

The development of novel antibacterial agents from plant sources is emerging as a successful strategy to combat antibiotic resistance in pathogens. In this study, we systemically investigated the antibacterial activity and underlying mechanisms of baicalin against methicillin-resistant Staphylococcus aureus (MRSA) and Stenotrophomonas maltophilia. Our results showed that baicalin effectively restrained bacterial proliferation, compromised the integrity of cellular membranes, increased membrane permeability, and triggered oxidative stress within bacteria. Transcriptome profiling revealed that baicalin disrupted numerous biological pathways related to antibiotic resistance, biofilm formation, cellular membrane permeability, bacterial virulence, and so on. Furthermore, baicalin demonstrated a synergistic antibacterial effect when combined with ampicillin against both MRSA and S. maltophilia. In conclusion, baicalin proves to be a potent antibacterial agent with significant potential for addressing the challenge of antibiotic resistance in pathogens.

Facile Surface Modification with Croconaine-Functionalized Polymer on Polypropylene for Antifouling and NIR-Light-Mediated Photothermal Sterilization

Biomedical-device-associated infection (BAI) is undoubtedly a major concern and a serious challenge in modern medicine. Therefore, the development of biomedical materials that are capable of resisting or killing bacteria is of great importance. In this work, a croconaine-functionalized polymer with antifouling and near-infrared (NIR) photothermal bactericidal properties was prepared and facilely modified on polypropylene (PP) to combat medical device infections. Croconaine dye is elaborately modified as a "living" initiator, termed CR-4EBiB, for preparing amphiphilic block polymers by atom transfer radical polymerization (ATRP). In the formed polymer coating, the hydrophobic block can strongly adhere to the surface of the PP substrate, whereas the hydrophilic block is located on the outer layer by solvent-induced resistance to bacterial adhesion. Under the irradiation of an NIR laser (808 nm), the croconaine dye in the coating achieved maximum conversion of light to heat to effectively kill E. coli, S. aureus, and methicillin-resistant Staphylococcus aureus (MRSA). This work provides a facile and promising strategy for the development of implantable antibacterial biomedical materials.

Inhibition of PLA2G4A attenuated valproic acid- induced lysosomal membrane permeabilization and restored impaired autophagic flux: Implications for hepatotoxicity

Valproic acid (VPA) has broad efficacy against several seizures but causes liver injury limiting its prolonged clinical use. Some studies have demonstrated that VPA-induced hepatotoxicity is characterized by microvesicular hepatic steatosis. However, novel detailed mechanisms to explain VPA-induced hepatic steatosis and experimentally rigorously validated protective agents are still lacking. In this study, 8-week-old C57BL/6J mice were gavaged with VPA (500 mg/kg/d) for 4 weeks to establish an in vivo model of VPA-induced chronic liver injury. Quantitative proteomic and non-targeted lipidomic analyses were performed to explore the underlying mechanisms of VPA-induced hepatotoxicity. As a result, VPA-induced hepatotoxicity is associated with impaired autophagic flux, which is attributed to lysosomal dysfunction. Further studies revealed that VPA-induced lysosomal membrane permeabilization (LMP), allows soluble lysosomal enzymes to leak into the cytosol, which subsequently led to impaired lysosomal acidification. A lower abundance of glycerophospholipids and an increased abundance of lysophospholipids in liver tissues of mice in the VPA group strongly indicated that VPA-induced LMP may be mediated by the activation of phospholipase PLA2G4A. Metformin (Met) acted as a potential protective agent attenuating VPA-induced liver dysfunction and excessive lipid accumulation. Molecular docking and cellular thermal shift assays demonstrated that Met inhibited the activity of PLA2G4A by directly binding to it, thereby ameliorating VPA-induced LMP and autophagic flux impairment. In conclusion, this study highlights the therapeutic potential of targeting PLA2G4A-mediated lysosomal dysfunction in VPA-induced hepatotoxicity.

Artificial Phages with Biocatalytic Spikes for Synergistically Eradicating Antibiotic-Resistant Biofilms

Antibiotic-resistant pathogens have become a global public health crisis, especially biofilm-induced refractory infections. Efficient, safe, and biofilm microenvironment (BME)-adaptive therapeutic strategies are urgently demanded to combat antibiotic-resistant biofilms. Here, inspired by the fascinating biological structures and functions of phages, the de novo design of a spiky Ir@Co3O4 particle is proposed to serve as an artificial phage for synergistically eradicating antibiotic-resistant Staphylococcus aureus biofilms. Benefiting from the abundant nanospikes and highly active Ir sites, the synthesized artificial phage can simultaneously achieve efficient biofilm accumulation, extracellular polymeric substance (EPS) penetration, and superior BME-adaptive reactive oxygen species (ROS) generation, thus facilitating the in situ ROS delivery and enhancing the biofilm eradication. Moreover, metabolomics found that the artificial phage obstructs the bacterial attachment to EPS, disrupts the maintenance of the BME, and fosters the dispersion and eradication of biofilms by down-regulating the associated genes for the biosynthesis and preservation of both intra- and extracellular environments. The in vivo results demonstrate that the artificial phage can treat the biofilm-induced recalcitrant infected wounds equivalent to vancomycin. It is suggested that the design of this spiky artificial phage with synergistic "penetrate and eradicate" capability to treat antibiotic-resistant biofilms offers a new pathway for bionic and nonantibiotic disinfection.

Emerging trends and future challenges of advanced 2D nanomaterials for combating bacterial resistance

The number of multi-drug-resistant bacteria has increased over the last few decades, which has caused a detrimental impact on public health worldwide. In resolving antibiotic resistance development among different bacterial communities, new antimicrobial agents and nanoparticle-based strategies need to be designed foreseeing the slow discovery of new functioning antibiotics. Advanced research studies have revealed the significant disinfection potential of two-dimensional nanomaterials (2D NMs) to be severed as effective antibacterial agents due to their unique physicochemical properties. This review covers the current research progress of 2D NMs-based antibacterial strategies based on an inclusive explanation of 2D NMs' impact as antibacterial agents, including a detailed introduction to each possible well-known antibacterial mechanism. The impact of the physicochemical properties of 2D NMs on their antibacterial activities has been deliberated while explaining the toxic effects of 2D NMs and discussing their biomedical significance, dysbiosis, and cellular nanotoxicity. Adding to the challenges, we also discussed the major issues regarding the current quality and availability of nanotoxicity data. However, smart advancements are required to fabricate biocompatible 2D antibacterial NMs and exploit their potential to combat bacterial resistance clinically.

Promoting Proton Donation through Hydrogen Bond Breaking on Carbon Nitride for Enhanced H2O2 Photosynthesis

Photocatalytic H2O2 production has attracted much attention as an alternative way to the industrial anthraquinone oxidation process but is limited by the weak interaction between the catalysts and reactants as well as inefficient proton transfer. Herein, we report on a hydrogen-bond-broken strategy in carbon nitride for the enhancement of H2O2 photosynthesis without any sacrificial agent. The H2O2 photosynthesis is promoted by the hydrogen bond formation between the exposed N atoms on hydrogen-bond-broken carbon nitride and H2O molecules, which enhances proton-coupled electron transfer and therefore the photocatalytic activity. The exposed N atoms serve as proton buffering sites for the proton transfer from H2O molecules to carbon nitride. The H2O2 photosynthesis is also enhanced through the enhanced adsorption and reduction of O2 gas toward H2O2 on hydrogen-bond-broken carbon nitride because of the formation of nitrogen vacancies (NVs) and cyano groups after the intralayer hydrogen bond breaking on carbon nitride. A high light-to-chemical conversion efficiency (LCCE) value of 3.85% is achieved. O2 and H2O molecules are found to undergo a one-step two-electron reduction pathway by photogenerated hot electrons and a four-electron oxidation process to produce O2 gas, respectively. Density functional theory (DFT) calculations validate the O2 adsorption and reaction pathways. This study elucidates the significance of the hydrogen bond formation between the catalyst and reactants, which greatly increases the proton tunneling dynamics.

A Biomimetic Multifunctional Scaffold for Infectious Vertical Bone Augmentation

The regenerative treatment of infectious vertical bone defects remains difficult and challenging today. Current clinical treatments are limited in their ability to control bacteria and infection, which is unfavorable for new bone formation and calls for a new type of material with excellent osteogenic and antibacterial properties. Here a multifunctional scaffold is synthesized that mimics natural bone nanostructures by incorporating silver nanowires into a hierarchical, intrafibrillar mineralized collagen matrix (IMC/AgNWs), to achieve the therapeutic goals of inhibiting bacterial activity and promoting infectious alveolar bone augmentation in rats and beagle dogs. An appropriate concentration of 0.5 mg mL-1 AgNWs is selected to balance biocompatibility and antibacterial properties. The achieved IMC/AgNWs exhibit a broad spectrum of antimicrobial properties against Gram-negative Porphyromonas gingivalis and Gram-positive Streptococcus mutans. When the IMC/AgNWs are cocultured with periodontal ligament stem cells, it possesses excellent osteoinductive activities under both non-inflammatory and inflammatory conditions. By constructing a rat mandibular infected periodontal defect model, the IMC/AgNWs achieve a near-complete healing through the canonical BMP/Smad signaling. Moreover, the IMC/AgNWs enhance vertical bone height and osseointegration in peri-implantitis in beagle dogs, indicating the clinical translational potential of IMC/AgNWs for infectious vertical bone augmentation.

Comparison of developmental toxicity of graphene oxide and graphdiyne to zebrafish larvae

Graphdiyne (GDY) is a new member of family of carbon-based 2D nanomaterials (NMs), but the environmental toxicity is less investigated compared with other 2D NMs, such as graphene oxide (GO). In this study, we compared with developmental toxicity of GO and GDY to zebrafish larvae. It was shown that exposure of zebrafish embryos from 5 h post fertilization to GO and GDY for up to 5 days decreased hatching rate and induced morphological deformity. Behavioral tests indicated that GO and GDY treatment led to hyperactivity of larvae. However, blood flow velocity was not significantly affected by GO or GDY. RNA-sequencing data revealed that both types of NMs altered gene expression profiles as well as gene ontology terms and KEGG pathways related with metabolism. We further confirmed that the NMs altered the expression of genes related with lipid droplets and autophagy, which may be account for the delayed development of zebrafish larvae. At the same mass concentrations, GO induced comparable or even larger toxic effects compared with GDY, indicating that GDY might be more biocompatible compared with GO. These results may provide novel understanding about the environmental toxicity of GO and GDY in vivo.

TiO2/SiO2 spiral crimped Janus fibers engineered for stretchable ceramic membranes with high-temperature resistance

The tensile brittleness of ceramic nanofibrous materials makes them unable to withstand the relatively large fracture strain, greatly limiting their applications in extreme environments such as high or ultra-low temperatures. Herein, highly stretchable and elastic ceramic nanofibrous membranes composed of titanium dioxide/silicon dioxide (TiO2/SiO2) bicomponent spiral crimped Janus fibers were designed and synthesized via conjugate electrospinning combined with calcination treatment. Owing to the opposite charges attached, the two fibers assembled side by side to form a Janus structure. Interestingly, radial shrinkage differences existed on the two sides of the TiO2/SiO2 composite nanofibers, constructing a helical crimp structure along the fiber axis. The special configuration effectively improves the stretchability of TiO2/SiO2 ceramic nanofibrous membranes, with up to 70.59% elongation at break, excellent resilience at 20% tensile strain and plastic deformation of only 3.48% after 100 cycles. Additionally, the relatively fluffy ceramic membranes constructed from spiral crimped Janus fibers delivered a lower thermal conductivity of 0.0317 W m-1 K-1, attributed to the increased internal still air content. This work not only reveals the attractive tensile mechanism of ceramic membranes arising from the highly curly nanofibers, but also proposes an effective strategy to make the ceramic materials withstand the complex dynamic strain in extreme temperature environments (from -196 °C to 1300 °C).

Nano-Based Approaches in Surface Modifications of Dental Implants: A Literature Review

Rehabilitation of fully or partially edentulous patients with dental implants represents one of the most frequently used surgical procedures. The work of Branemark, who observed that a piece of titanium embedded in rabbit bone became firmly attached and difficult to remove, introduced the concept of osseointegration and revolutionized modern dentistry. Since then, an ever-growing need for improved implant materials towards enhanced material-tissue integration has emerged. There is a strong belief that nanoscale materials will produce a superior generation of implants with high efficiency, low cost, and high volume. The aim of this review is to explore the contribution of nanomaterials in implantology. A variety of nanomaterials have been proposed as potential candidates for implant surface customization. They can have inherent antibacterial properties, provide enhanced conditions for osseointegration, or act as reservoirs for biomolecules and drugs. Titania nanotubes alone or in combination with biological agents or drugs are used for enhanced tissue integration in dental implants. Regarding immunomodulation and in order to avoid implant rejection, titania nanotubes, graphene, and biopolymers have successfully been utilized, sometimes loaded with anti-inflammatory agents and extracellular vesicles. Peri-implantitis prevention can be achieved through the inherent antibacterial properties of metal nanoparticles and chitosan or hybrid coatings bearing antibiotic substances. For improved corrosion resistance various materials have been explored. However, even though these modifications have shown promising results, future research is necessary to assess their clinical behavior in humans and proceed to widespread commercialization.

One-step hydrothermal synthesis of CeVO4/bentonite nanocomposite as a dual-functional photocatalytic adsorbent for the removal of methylene blue from aqueous solutions

Cerium vanadate/modified bentonite (CeVO4/mbt) nanocomposite with different composition percentages was synthesized through a simple one-step hydrothermal method at 180 ℃, and then its photocatalytic activity was evaluated by decolorizing methylene blue (MB) in an aqueous solution under light exposure. In order to increase the surface area as an important parameter in photocatalytic processes, bentonite was modified by ball mill method. The structural and optical properties of the synthesized composites were determined by XRD, FT-IR, DRS, FESEM, EDS, and BET measurements. XRD and EDS results confirmed the successful synthesis of pure CeVO4. FESEM images and EDS mapping showed a proper distribution of rice-like CeVO4 nanoparticles on bentonite. The removal efficiency of MB with only 0.1 g of CeVO4/mbt nanocomposite in 15 min was about 99%, which is significant compared to neat bentonite and pure CeVO4 with efficiency of 30% and 57%. The mentioned nanocomposite followed the first-order kinetics, had a reaction rate constant equal to 0.1483 min-1, and showed acceptable stability in five consecutive cycles.

Ilmenite-Grafted Graphene Oxide as an Antimicrobial Coating for Fruit Peels

Postharvest loss is a significant global challenge that needs to be urgently addressed to sustain food systems. This study describes a simple microwave-assisted green synthesis method in developing a nanohybrid material combining natural ilmenite (FeTiO3) and graphene oxide (GO) as a promising antimicrobial fruit peel coating to reduce postharvest loss. The natural ilmenite was calcined in an inert environment and was mixed with GO in a microwave reactor to obtain the nanohybrid. The nanohybrid was then incorporated into an alginate biopolymer to form the fruit coating. Microscopic images revealed successful grafting of FeTiO3 nanoparticles onto the GO sheets. Spectroscopic measurements of Raman, X-ray photoemission, and infrared provided insights into the interactions between the two matrices. The optical band gap calculated from Tauc's relation using UV-vis data showed a significant reduction in the band gap of the hybrid compared to that of natural ilmenite. The antimicrobial activity was assessed using Escherichia coli, which showed a substantial decrease in colony counts. Bananas coated with the nanohybrid showed a doubling in the shelf life compared with uncoated fruits. Consistent with this, the electronic nose (E-nose) measurements and freshness indicator tests revealed less deterioration of the physicochemical properties of the coated bananas. Overall, the results show promising applications for the ilmenite-grafted GO nanohybrid as a food coating capable of minimizing food spoilage due to microbial activity.

Investigation on the Osteogenic and Antibacterial Properties of Silicon Nitride-Coated Titanium Dental Implants

The silicon nitride (Si3N4) coating exhibits promising potential in oral applications due to its excellent osteogenic and antibacterial properties. However, a comprehensive investigation of Si3N4 coatings in the context of dental implants is still lacking, especially regarding their corrosion resistance and in vivo performance. In this study, Si3N4 coatings were prepared on a titanium surface using the nonequilibrium magnetron sputtering method. A systematic comparison among the titanium group (Ti), Si3N4 coating group (Si3N4-Ti), and sandblasted and acid-etched-treated titanium group (SLA-Ti) has been conducted in vitro and in vivo. The results showed that the Si3N4-Ti group had the best corrosion resistance and antibacterial properties, which were mainly attributed to the dense structure and chemical activity of Si-O and Si-N bonds on the surface. Furthermore, the Si3N4-Ti group exhibited superior cellular responses in vitro and new bone regeneration and osseointegration in vivo, respectively. In this sense, silicon nitride coating shows promising prospects in the field of dental implantology.

Photochemical Strategies toward Precision Targeting against Multidrug-Resistant Bacterial Infections

Infectious diseases pose a serious threat and a substantial economic burden on global human and public health security, especially with the frequent emergence of multidrug-resistant (MDR) bacteria in clinical settings. In response to this urgent need, various photobased anti-infectious therapies have been reported lately. This Review explores and discusses several photochemical targeted antibacterial therapeutic strategies for addressing bacterial infections regardless of their antibiotic susceptibility. In contrast to conventional photobased therapies, these approaches facilitate precise targeting of pathogenic bacteria and/or infectious microenvironments, effectively minimizing toxicity to mammalian cells and surrounding healthy tissues. The highlighted therapies include photodynamic therapy, photocatalytic therapy, photothermal therapy, endogenous pigments-based photobleaching therapy, and polyphenols-based photo-oxidation therapy. This comprehensive exploration aims to offer updated information to facilitate the development of effective, convenient, safe, and alternative strategies to counter the growing threat of MDR bacteria in the future.

Innovative Biomaterials for Bone Tumor Treatment and Regeneration: Tackling Postoperative Challenges and Charting the Path Forward

Surgical resection of bone tumors is the primary approach employed in the treatment of bone cancer. Simultaneously, perioperative interventions, particularly postoperative adjuvant anticancer strategies, play a crucial role in achieving satisfactory therapeutic outcomes. However, the occurrence of postoperative bone tumor recurrence, metastasis, extensive bone defects, and infection are significant risks that can result in unfavorable prognoses or even treatment failure. In recent years, there has been significant progress in the development of biomaterials, leading to the emergence of new treatment options for bone tumor therapy and bone regeneration. This progress report aims to comprehensively analyze the strategic development of unique therapeutic biomaterials with inherent healing properties and bioactive capabilities for bone tissue regeneration. These composite biomaterials, classified into metallic, inorganic non-metallic, and organic types, are thoroughly investigated for their responses to external stimuli such as light or magnetic fields, internal interventions including chemotherapy or catalytic therapy, and combination therapy, as well as their role in bone regeneration. Additionally, an overview of self-healing materials for osteogenesis is provided and their potential applications in combating osteosarcoma and promoting bone formation are explored. Furthermore, the safety concerns of integrated materials and current limitations are addressed, while also discussing the challenges and future prospects.

Ultrasound-augmented enzyodynamic-Ca2+ overload synergetic tumor nanotherapy

The excessive intracellular Ca2+ can induce oxidative stress, mitochondrial damage and cell apoptosis, which has been extensively explored for tumor therapy. However, the low Ca2+ accumulation originated from Ca2+-based nanosystems substantially weakens the therapeutic effect. Herein, a functional plant polyphenol-appended enzyodynamic nanozyme system CaFe2O4@BSA-curcumin (abbreviation as CFO-CUR) has been rationally designed and engineered to achieve magnified Ca2+ accumulation process, deleterious reactive oxygen species (ROS) production, as well as mitochondrial dysfunction through enzyodynamic-Ca2+ overload synergistic effect. The exogenous Ca2+ released by CaFe2O4 nanozymes under the weakly acidic tumor microenvironment and Ca2+ efflux inhibition by curcumin boost mitochondria-dominant antineoplastic efficiency. The presence of Fe components with multivalent characteristic depletes endogenous glutathione and outputs the incremental ROS due to the oxidase-, peroxidase-, glutathione peroxidase-mimicking activities. The ROS burst-triggered regulation of Ca2+ channels and pumps strengthens the intracellular Ca2+ accumulation. Especially, the exogenous ultrasound stimulation further amplifies mitochondrial damage. Both in vitro and in vivo experimental results affirm the ultrasound-augmented enzyodynamic-Ca2+ overload synergetic tumor inhibition outcomes. This study highlights the role of ultrasound coupled with functional nanozyme in the homeostasis imbalance and function disorder of mitochondria for highly efficient tumor treatment.

Ultrasound-driven radical chain reaction and immunoregulation of piezoelectric-based hybrid coating for treating implant infection

The poor efficiency of US-responsive coatings on implants restricts their practical application. Immunotherapy that stimulates immune cells to enhance their antibacterial activity is expected to synergize with sonodynamic therapy for treating implant infection effectively and safely. Herein, US-responsive hybrid coatings composed of the oxygen-deficient BaTiO3 nanorod arrays and l-arginine (BaTiO3-x/LA) are designed and prepared on titanium implants for sonocatalytic therapy-cooperated immunotherapy to treat Methicillin-resistant Staphylococcus aureus (MRSA) infection. BaTiO3-x/LA can generate more oxidizing reactive oxygen species (ROS, hydroxyl radical (·OH)) and reactive nitrogen species (RNS, peroxynitrite anion (ONOO-)). The construction of nanorod arrays and oxygen defects balances the piezoelectric properties and sonocatalytic capability during US treatment. The generated piezoelectric electric field provides a sufficient driving force to separate electrons and holes, and the oxygen defects attenuate the electron-hole recombination efficiency, consequently increasing the yield of ROS during the US treatment. Moreover, nitric oxide (NO) released by l-arginine reacts with the superoxide radical (·O2-) to produce ONOO-. Since, this radical chain reaction improves the oxidizing ability between bacteria and radicals, the cell membrane (argB, secA2) and DNA (dnaBGXN) are destroyed. The bacterial self-repair mechanism indirectly accelerates bacterial death based on the transcriptome analysis. In addition to participating in the radical chain reaction, NO positively affects macrophage M1 polarization to yield potent phagocytosis to MRSA. As a result, without introducing an extra sonosensitizer, BaTiO3-x/LA exhibits excellent antibacterial activity against MRSA after the US treatment for 15 min. Furthermore, BaTiO3-x/LA facilitates macrophage M2 polarization after implantation and improves osteogenic differentiation. The combined effects of sonodynamic therapy and immunoregulation lead to an effective and safe treatment method for implant-associated infections.

Black Titania Janus Mesoporous Nanomotor for Enhanced Tumor Penetration and Near-Infrared Light-Triggered Photodynamic Therapy

Thanks to their excellent photoelectric characteristics to generate cytotoxic reactive oxygen species (ROS) under the light-activation process, TiO2 nanomaterials have shown significant potential in photodynamic therapy (PDT) for solid tumors. Nevertheless, the limited penetration depth of TiO2-based photosensitizers and excitation sources (UV/visible light) for PDT remains a formidable challenge when confronted with complex tumor microenvironments (TMEs). Here, we present a H2O2-driven black TiO2 mesoporous nanomotor with near-infrared (NIR) light absorption capability and autonomous navigation ability, which effectively enhances solid tumor penetration in NIR light-triggered PDT. The nanomotor was rationally designed and fabricated based on the Janus mesoporous nanostructure, which consists of a NIR light-responsive black TiO2 nanosphere and an enzyme-modified periodic mesoporous organosilica (PMO) nanorod that wraps around the TiO2 nanosphere. The overexpressed H2O2 can drive the nanomotor in the TME under catalysis of catalase in the PMO domain. By precisely controlling the ratio of TiO2 and PMO compartments in the Janus nanostructure, TiO2&PMO nanomotors can achieve optimal self-propulsive directionality and velocity, enhancing cellular uptake and facilitating deep tumor penetration. Additionally, by the decomposition of endogenous H2O2 within solid tumors, these nanomotors can continuously supply oxygen to enable highly efficient ROS production under the NIR photocatalysis of black TiO2, leading to intensified PDT effects and effective tumor inhibition.

Bioinspired Photoelectronic Synergy Coating with Antifogging and Antibacterial Properties

Optically transparent glass with antifogging and antibacterial properties is in high demand for endoscopes, goggles, and medical display equipment. However, many of the previously reported coatings have limitations in terms of long-term antifogging and efficient antibacterial properties, environmental friendliness, and versatility. In this study, inspired by catfish and sphagnum moss, a novel photoelectronic synergy antifogging and antibacterial coating was prepared by cross-linking polyethylenimine-modified titanium dioxide (PEI-TiO2), polyvinylpyrrolidone (PVP), and poly(acrylic acid) (PAA). The as-prepared coating could remain fog-free under hot steam for more than 40 min. The experimental results indicate that the long-term antifogging properties are due to the water absorption and spreading characteristics. Moreover, the organic-inorganic hybrid of PEI and TiO2 was first applied to enhance the antibacterial performance. The Staphylococcus aureus and the Escherichia coli growth inhibition rates of the as-prepared coating reached 97 and 96% respectively. A photoelectronic synergy antifogging and antibacterial mechanism based on the positive electrical and photocatalytic properties of PEI-TiO2 was proposed. This investigation provides insight into designing multifunctional bioinspired surface materials to realize antifogging and antibacterial that can be applied to medicine and daily lives.

Properties, Synthesis and Emerging Applications of Graphdiyne: A Journey Through Recent Advancements

Graphdiyne (GDY) is a new variant of nano-carbon material with excellent chemical, physical and electronic properties. It has attracted wide attention from researchers and industrialists for its extensive role in the fields of optics, electronics, bio-medics and energy. The unique arrangement of sp-sp2 carbon atoms, linear acetylenic linkages, uniform pores and highly conjugated structure offer numerous potentials for further exploration of GDY materials. However, since the material is at its infancy, not much understanding is available regarding its properties, growth mechanism and future applications. Therefore, in this review, readers are guided through a brief discussion on GDY's properties, different synthesis procedures with a special focus on surface functionalization and a list of applications for GDY. The review also critically analyses the advantages and disadvantages of each synthesis route and emphasizes the future scope of the material.

Nanomedomics

Nanomaterials have attractive physicochemical properties. A variety of nanomaterials such as inorganic, lipid, polymers, and protein nanoparticles have been widely developed for nanomedicine via chemical conjugation or physical encapsulation of bioactive molecules. Superior to traditional drugs, nanomedicines offer high biocompatibility, good water solubility, long blood circulation times, and tumor-targeting properties. Capitalizing on this, several nanoformulations have already been clinically approved and many others are currently being studied in clinical trials. Despite their undoubtful success, the molecular mechanism of action of the vast majority of nanomedicines remains poorly understood. To tackle this limitation, herein, this review critically discusses the strategy of applying multiomics analysis to study the mechanism of action of nanomedicines, named nanomedomics, including advantages, applications, and future directions. A comprehensive understanding of the molecular mechanism could provide valuable insight and therefore foster the development and clinical translation of nanomedicines.