One-step cascade method via glucose oxidase-copper ion complex for detecting glucose using a portable device

In this study, a one-step cascade fluorescence method was developed for the detection of glucose in honey, based on the glucose oxidase-copper ion complexes (GOx@Cu2+). These complexes exhibit dual enzymatic activities-glucose oxidase and peroxidase-like activities-which enable them to catalyze a cascade reaction. This reaction involves the oxidation of glucose and o-phenylenediamine (OPD), leading to the formation of 2,3-diaminophenazine (oxOPD), a compound with fluorescent properties. The proposed method overcomes the challenges of pH mismatch between enzymes and streamlines the testing process, eliminating the need for nanomaterial preparation and reducing the detection time to just 20 min. The feasibility of the method was validated by analyzing three honey samples, achieving recoveries between 96.4 % and 106 %, with relative standard deviations of less than 1.9 %. The selectivity and accuracy of the method were verified by capillary electrophoresis in three honey samples. Moreover, a self-designed portable device was introduced to enable on-site glucose detection.

Bacterial clustering biomaterials as anti-infective therapies

In Nature, bacterial clustering by host-released peptides or nucleic acids is an evolutionarily conserved immune defense strategy employed to prevent adhesion of pathogenic microbes, which is prerequisite for most infections. Synthetic anti-adhesion strategies present as non-lethal means of targeting bacteria and may potentially be used to avoid resistance against antimicrobial therapies. From bacteria-agglutinating biomolecules discovered in nature to synthetic designs involving peptides, cationic polymers and nanoparticles, the modes of actions appear broad and unconsolidated. Herein, we present a critical review and update of the state-of-the-art in synthetic bacteria-clustering designs with proposition of a more streamlined nomenclature and classification. Overall, this review aims to consolidate the conceptual framework in the field of bacterial clustering and highlight its potentials as an avenue for discovering novel antibacterial biomaterials.

Design and function of boronic acid-based polyamidoamine dendrimer probes for bacteria recognition

Selective bacterial recognition and early diagnosis are urgently required to address the growing problem of antimicrobial resistance and are crucial for achieving sustainable development goals (SDGs). Saccharide recognition is a promising solution because bacterial surfaces are composed of specific polysaccharides. In this study, we summarize our investigations into the use of boronic acid analogs for bacterial recognition, which shows potential for broad applications in various bacterial detection methods using nanoprobes. Methods were developed for the convenient, sensitive, and selective recognition of bacteria using spherical poly(amidoamine) dendrimers functionalized with boronic acids. We evaluated various measurement protocols (turbidity and fluorescence), interactions with bacterial surfaces (electrostatic and hydrophobic), recognition targets, and the further development of ditopic and benzoxaborole-based probes. As these methods require less than ten min, boronic acid-based recognition could serve as a powerful tool for rapid and simple clinical applications in the future. We believe that our study makes a significant contribution to the field, as the findings can be effectively applied to other studies involving boronic acid compounds or targeting bacterial surface saccharides.

Micro-nano robots for treatment of eye diseases

In recent years, micro-nano robots have found extensive applications in the field of medicine. Among these, micro-nano robots demonstrate significant potential for the treatment of eye diseases. Micro-nano robots can penetrate eye tissue barriers to directly target the posterior segment of the eye for precise drug delivery, enabling non-invasive or minimally invasive treatment. This review explores the primary fabrication methods and propulsion mechanisms of various micro-nano robots, and their applications in treating various eye conditions, offering inspiration and guidance for advancing the use of micro-nanorobots in ophthalmic therapies.

Magnetic Prussian blue nanoparticles to enhance dual-readout lateral flow immunoassay for Salmonella typhimurium detection

BACKGROUND

Traditional immunochromatographic assay (ICA) test strips typically utilize colloidal gold nanoparticles as colorimetric signal reporters, but they often suffer from compromised sensitivity and quantitative accuracy, making them inadequate for the stringent demands of trace-level screening. In addition, the heterogeneous nature of food matrices, such as dairy products, meat, and ready-to-eat fruits and vegetables, complicates the accuracy and reliability of ICA for detecting foodborne pathogens. Therefore, enhancing the detection accuracy of ICA is critical to meet the stringent requirements for pathogen detection in complex food samples.

RESULTS

Here, we synthesized a novel Prussian blue-coated Fe3O4 nanoparticle (Fe3O4@PB) via a simple in-situ growth method. The synthesized Fe3O4@PB nanoparticles demonstrate a high magnetization strength and excellent photothermal conversion efficiency, enabling their application as efficient probes in ICA. Leveraging these properties, we developed a dual-readout ICA incorporating both colorimetric and photothermal modalities for the sensitive detection of Salmonella typhimurium in milk and lettuce samples. The detection limit (LOD) for Fe3O4@PB-ICA reached 2.5 × 103 CFU/mL in colorimetric formats and 1.04 × 103 CFU/mL in photothermal formats, representing approximately 4-fold and 10-fold improvements compared to AuNP-ICA (LOD = 1 × 104 CFU/mL). Furthermore, the average recovery rates ranged from 89.1 % to 111.9 %, while the coefficients of variation below 13.7 %, demonstrating excellent accuracy and precision.

SIGNIFICANCE

The proposed Fe3O4@PB serves as effective probe for purifying and enriching target analytes, significantly improving the accuracy and sensitivity of colorimetric and photothermal immunochromatographic analysis applications. By leveraging the magnetic and photothermal capabilities of Fe3O4@PB, the developed Fe3O4@PB-ICA represents a promising rapid diagnostic platform for the sensitive detection of foodborne pathogens and other analytes.

Effect of carbon nanodots on the cellular redox reaction and immune system

Carbon nanodots are ultra-small carbonaceous nanostructures with excellent photoluminescence and cytocompatibility properties, making them suitable for developing excellent bioimaging probes. They exhibit dual properties, generating and scavenging reactive oxygen species, and are used as photosensitizers to produce reactive oxygen species under light and as photothermal agents that transform light energy into heat. This makes it possible to use them in photothermal and photodynamic therapies to treat cancer. They may enter the body by various means, including inhalation, ingestion, or intravenous injection. Once inside, they travel through the bloodstream, infiltrating tissues where they come into contact with the immune system, similar to infectious agents. These nanodots are identified by several receptors on the surface of innate immune cells, such as monocytes and macrophages, which attempt to engulf these nanodots. This interaction can induce a pro-inflammatory (M1) or anti-inflammatory (M2) response, modulating immune activity. This review explores the immuno-toxic potential of carbon nanodots, focusing on their ability to modulate redox balance by catalase, glutathione peroxidase, and superoxide dismutase, which are examples of antioxidant enzymes. Although carbon nanodots have demonstrated a wide range of applications, their effect on the cellular immune system remains largely unexplored. In this study, we primarily addressed the sophisticated impacts of carbon nanodots on the immune system and their diverse processes, such as the many cellular redox reactions implicated in antibacterial and antiviral treatment, wound healing, drug administration, and tumor therapy. As a result, we outline the benefits and difficulties of carbon nanodots in the biomedical domain and discuss their potential in the future development of clinical medicine.

Phytochemical-Loaded Thermo-responsive Liposome for Synergistic Treatment of Methicillin-Resistant Staphylococcus aureus Infection

The ever-increasing emergence and prevalence of multidrug-resistant bacteria accelerate the desire for the development of new antibacterial strategies. Although antibacterial phytochemicals are a promising approach for long-term treatment of resistant bacteria, their low antibacterial activity and poor solubility hinder their practical applications. Here, the natural antibacterial compound sanguinarine (SG) together with gallic acid-ferrous coordination nanoparticles (GA-Fe(II) NPs) was encapsulated in a near-infrared (NIR)-activated thermo-responsive liposome. By virtue of the photothermal effect of GA-Fe(II) NPs, the nanoplatform released SG on demand upon NIR irradiation. Additionally, the heat can boost the Fenton reaction triggered by GA-Fe(II) NPs to generate hydroxyl radicals and perform sterilization. By coupling with photothermal therapy, chemodynamic therapy, and SG-based pharmacotherapy, the platform showed enhanced antibacterial efficiency and an antibiofilm effect toward methicillin-resistant Staphylococcus aureus and reduced the risk of developing new bacterial resistance. This antibacterial system displayed excellent antibacterial activity in a methicillin-resistant S. aureus-caused skin abscess, demonstrating its potential clinical application. Moreover, transcription analysis clarified that the platform achieved a synergistic antibacterial effect by attacking the cell membrane, inducing energy metabolism disorder, inhibiting nucleic acid synthesis, etc. The developed NIR-controlled phytochemical-loaded platform offers new possibilities for killing antibiotic-resistant bacteria and avoiding bacterial resistance, making it contributory in the fields of anti-infective therapy and precision medicine.

Versatile nanomaterials used in combatting biofilm infections

Microbial infections are a pressing global health issue, exacerbated by the rise of antibiotic-resistant bacteria due to widespread antibiotic overuse. This resistance diminishes the effectiveness of current treatments, intensifying the need for new antimicrobial agents and innovative drug delivery strategies. Nanotechnology presents promising solutions, leveraging the unique properties of nanomaterials such as tunable optical and electronic characteristics, nanoscale size, and high surface-to-volume ratios. These features enhance their effectiveness as innovative antimicrobial agents and versatile drug delivery systems. This minireview classifies antimicrobial nanomaterials into four categories based on their mechanisms of action: thermal generation, reactive oxygen species generation, gas generation, and nanocarrier systems such as liposomes, polymersomes, and metal-organic frameworks. Uniquely, this review integrates a comparative analysis of these mechanisms, highlighting their relative advantages, limitations, and applications across diverse microbial targets. Additionally, it identifies emerging trends in the field, providing a forward-looking perspective on how recent advancements in nanotechnology can be leveraged to address unmet clinical needs. Finally, this article discusses future directions and emerging opportunities in antimicrobial nanotechnology.

Photothermal-Photocatalytic Ternary Heterostructure for Solar Light-Driven Highly Efficient Degradation of Antimicrobial Agents and Inactivation of Superbugs

A significant proportion of antimicrobial agents, such as different antibiotics discharged into the environment via human and animal waste, poses significant problems for ecological balance and human health. Moreover, widespread overuse and misuse of antibiotics have led to antibiotic-resistant bacteria (superbugs), which is one of the biggest global health problems in the 21st century. Since the utilization of solar energy, which is an abundant and natural resource for the photocatalytic system, we report the design of a photothermal-photocatalytic dual-functional light absorber-based ternary heterostructure using plasmonic gold nanoparticle (AuNP)-anchored WO3 nanoplatelet (WO3 NPL)-decorated reduced graphene oxide (r-GO) (AuNP/WO3 NPL/r-GO), which exhibits strong absorption between 400 and 900 nm regions and has the capability for the sunlight-driven 100% degradation of doxycycline antibiotics. Herein, we show that due to the excellent photothermal performance of AuNP and r-GO in the heterostructure, the local temperature increased under 785 NIR nm light irradiation, which boosted the photocatalytic degradation reaction kinetics for doxycycline antibiotics via enhancing the transfer of "hot carriers" and the formation of reactive oxygen species (ROS). Furthermore, experimental data indicate that by integrating photothermal-photocatalytic materials, sunlight can be used for 100% doxycycline antibiotic degradation after 80 min of light irradiation. Moreover, we demonstrate that the ternary heterostructure can be used for sunlight-based 100% inactivation of carbapenem-resistant Enterobacteriaceae Escherichia coli (CRE E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) superbugs by just exposing them to light for 60 min. This study sheds light on the construction of photothermally assisted photocatalytic ternary heterostructures for high-efficiency sunlight-driven degradation of antibiotics and superbugs.

2D/2D Co3O4/BiOCl nanocomposite with enhanced antibacterial activity under full spectrum: Synergism of mesoporous structure, photothermal effect and photocatalytic reactive oxygen species

The overuse of antibiotics has caused the emergence of drug-resistant bacteria and even superbugs, which makes it imperative to develop promising antibiotic-free alternatives. Herein, a multimodal antibacterial nanoplatform of two dimensional/two dimensional (2D/2D) mesoporous Co3O4/BiOCl nanocomposite is constructed, which possesses the effect of "kill three birds with one stone": (1) the use of mesoporous Co3O4 can enlarge the surface area of the nanocomposite and promote the adsorption of bacteria; (2) Co3O4 displays remarkable full-spectrum absorption and photo-induced self-heating effect, which can raise the temperature of Co3O4/BiOCl and help to kill bacteria; (3) the p-type Co3O4 and n-type BiOCl form a p-n heterojunction, which promotes the separation of photoelectrons and holes, thus producing more reactive oxygen species (ROS) for killing bacteria. The synergism of mesoporous structure, photothermal effect and photocatalytic ROS makes the developed Co3O4/BiOCl a promising antibacterial material, which shows outstanding antibacterial activity with an inhibition rate of nearly 100 % against Escherichia coli (E. coli) within 8 min. This work provides inspiration for designing multimodal synergistic nanoplatform for antibacterial applications.

Shape and Size Dependent Antimicrobial and Anti-biofilm Properties of Functionalized MoS2

Bacterial resistance, accelerated by the misuse of antibiotics, remains a critical concern for public health, promoting an ongoing exploration for cost-effective and safe antibacterial agents. Recently, there has been significant focus on various nanomaterials for the development of alternative antibiotics. Among these, molybdenum disulfide (MoS2) has gained attention due to its unique chemical, physical, and electronic properties, as well as its semiconducting nature, biocompatibility, and colloidal stability, positioning it as a promising candidate for biomedical research. The impact of the shape and size of MoS2 nanomaterials on the antibacterial activity remains largely unexplored. In this study, we investigated the effect of the shape and size of MoS2 nanomaterials, such as quantum dots, nanoflowers, and nanosheets, on antimicrobial and anti-biofilm activity. As we had established earlier, functionalization with positively charged thiol ligands can enhance colloidal stability, biocompatibility, and antibacterial efficacy; we functionalized all targeted nanomaterials. Our results revealed that functionalized MoS2 quantum dots (F-MQDs) exhibited superior activity compared to functionalized MoS2 nanoflowers (F-MNFs) and functionalized MoS2 nanosheets (F-MNSs) against Staphylococcus aureus (SA), both drug-resistant (methicillin) and nonresistant strains. We observed very low minimum inhibitory concentration (MIC, 30 ng/mL) for F-MQDs. The observed trend in antibacterial efficacy was as follows: F-MQDs > F-MNFs ≥ F-MNSs. We explored the relevant mechanism related to the antibacterial activity where the balance between membrane depolarization and internalization plays the determining role. Furthermore, F-MQDs show enhanced anti-biofilm activity compared to F-MNFs and F-MNSs against mature MRSA biofilms. Due to the superior antibacterial and anti-biofilm activity of F-MQDs, we extended their application to wound healing. This study will help us to develop other appropriate surface modified nanomaterials for antibacterial and anti-biofilm activity for further applications such as antibacterial coatings, water disinfection, and wound healing.

Mechanochemical synthesis of novel metronidazole cocrystal: Structure characterization and pharmaceutical properties study

A new cocrystalline form of metronidazole (MET) with propyl gallate (PRO), referred to as MET-PRO, has been successfully synthesized and characterized. Structural characterization reveals that MET and PRO are present in a 1:1 ratio within the cocrystal lattice, with one water molecule equivalent incorporated into the structure. This arrangement facilitates the formation of MET-PRO heterodimers and multiple stable units, collectively constructing a three-dimensional supramolecular network. The solubility and permeability of the current cocrystal, along with the parent drug MET, are evaluated under physiological pH conditions. Experimental findings reveal that MET within the cocrystal exhibits a 1.54-2.37 folds increase in solubility and approximately a threefold improvement in permeability compared to its standalone form. Intriguingly, these concurrent enhancements in the physicochemical properties of MET lead to augmented antibacterial activity in vitro, evidenced by a reduction in minimum inhibitory concentration. Even more intriguingly, the enhanced physicochemical properties observed in vitro for the current cocrystal translate into tangible pharmacokinetic benefits in vivo, characterized by prolonged half-life and enhanced bioavailability. Consequently, this research not only introduces a fresh crystal structure for antibacterial medication but also presents approach for optimizing drug properties across in vitro and in vivo settings, while concurrently bolstering the antibacterial effectiveness of MET through pharmaceutical cocrystallization techniques.

How nanomaterials act against bacterial structures? a narrative review focusing on nanoparticle molecular mechanisms

OBJECTIVE

In recent years, significant progress has been made in the field of nanotechnology for the treatment and prevention of biofilm formation and Multidrug-resistant bacteria (MDR). MDR bacteria challenges is hazardous when microorganisms induce the formation of biofilms, which amplify resistance to antibiotics and promote the development of multidrug-resistant conditions. The unique physicochemical properties of certain nanomaterials make nanotechnology a promising option for combating MDR infections. Several studies have introduced nanomaterials with different antibacterial mechanisms that can effectively destroy MDR bacteria and their biofilms. This study reviews the research results, focusing on the various nanoparticle mechanisms that target bacterial structures.

METHOD

To accomplish this study, we conducted investigations to gather articles and relevant studies from validated medical databases such as Scopus, PubMed, Google Scholar, and Web of Science. The selected publications from 2007 to 2023. In this review, we provide a brief overview of nanoparticles, their mechanisms, and how they function against the structure of bacteria. Furthermore, we discuss the recent advancements in using certain nanoparticles to combat infection-induced biofilms and complications caused by multidrug resistance.

FINDING

Our findings demonstrate that various nanoparticles have the potential to effectively overcome bacterial infectious diseases by targeting biofilms and antibiotic-resistant strains. Additionally, the development of a new drug delivery approach based on nanosystems shows promise in overcoming antibiotic resistance and biofilms.

Progress and challenges in bacterial infection theranostics based on functional metal nanoparticles

The rapid proliferation and infection of bacteria, especially multidrug-resistant bacteria, have become a great threat to global public health. Focusing on the emergence of "super drug-resistant bacteria" caused by the abuse of antibiotics and the insufficient and delayed early diagnosis of bacterial diseases, it is of great research significance to develop new technologies and methods for early targeted detection and treatment of bacterial infection. The exceptional effects of metal nanoparticles based on their unique physical and chemical properties make such systems ideal for the detection and treatment of bacterial infection both in vitro and in vivo. Metal nanoparticles also have admirable clinical application prospects due to their broad antibacterial spectrum, various antibacterial mechanisms and excellent biocompatibility. Herein, we summarized the research progress concerning the mechanism of metal nanoparticles in terms of antibacterial activity together with the detection of bacterial. Representative achievements are selected to illustrate the proof-of-concept in vitro and in vivo applications. Based on these observations, we also give a brief discussion on the current problems and perspective outlook of metal nanoparticles in the diagnosis and treatment of bacterial infection.

Black Phosphorus Nanosheets-Based Hydrogel for Efficient Bacterial Inhibition and Accelerating Wound Healing

With the swift evolution of multidrug-resistant bacteria resulting from the intense and inappropriate use of antibiotics, there is a pressing need for innovative solutions. In this study, a thermosensitive hydrogel was developed for efficient bacterial inhibition and promotion of wound healing. The antibacterial chitosan (CS) thermosensitive hydrogel, cross-linked with two-dimensional photothermal nanomaterial black phosphorus (BP) nanosheets through electrostatic interactions, effectively encapsulates and sustains the release of angiogenic drug deferoxamine mesylate (DFO). This facilitates the acceleration of re-epithelialization and neovascularization by enhancing cell migration and proliferation. Following near-infrared (NIR) treatment, this hydrogel demonstrates rapid eradication of the most common multidrug-resistant bacteria encountered in clinical settings, achieved through physical disruption of bacterial membranes and photothermal therapies. Noteworthy is the significant upregulation of IL-19 expression via STAT3 signaling pathways by the BP/CS-DFO hydrogel in a full-thickness wound model. This results in the polarization of the anti-inflammatory M2 macrophage phenotype, altering the microenvironment to a pro-healing state and enhancing extracellular matrix deposition and blood vessel formation. In conclusion, the BP/CS-DFO hydrogel shows immense promise as a potential clinical candidate for wound healing and antimicrobial therapy. Its innovative design and multifunctional capabilities position it as a valuable asset in combating antibiotic resistance and enhancing efficiency in wound healing.

Sunlight-Driven Photothermally Boosted Photocatalytic Eradication of Superbugs Using a Plasmonic Gold Nanoparticle-Decorated WO3 Nanowire-Based Heterojunction

Superbug infections are currently one of the biggest global health problems in our society. Herein, we report the design of a plasmonic gold nanoparticle (GNP)-decorated WO3 nanowire-based heterojunction for the proficient usage of sunlight-based renewable energy to inactivate 100% superbugs via photothermally boosted photocatalytic action. Additionally, a synergistic photothermal and photocatalytic approach has been used for sunlight-driven complete eradication of carbapenem-resistant Enterobacteriaceae Escherichia coli (CRE E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) superbugs. Interestingly, photocatalytic activity of methylene blue (MB) dye degradation in the presence of 670 nm near-infrared light shows that photothermally boosted photocatalytic performance is much superior to that of only a photocatalytic or photothermal process. The observed higher photocatalytic performance for the heterojunction is because the plasmonic GNP enhanced the absorption capability at 670 nm and increased the temperature of the photocatalyst surface, which reduces the activation energy of the degradation reaction. Similarly, sunlight-driven photocatalytic experiments show 100% degradation of MB after 60 min of sunlight irradiation. Moreover, sunlight-based photocatalytic inactivation of MRSA and CRE E. coli experiments show 100% inactivation after 60 min of light irradiation.

Polydopamine Nanocarriers with Cascade-Activated Nitric Oxide Release Combined Photothermal Activity for the Therapy of Drug-Resistant Bacterial Infections

Antibiotic abuse leads to increased bacterial resistance, and the surviving planktonic bacteria aggregate and secrete extracellular polymers to form biofilms. Conventional antibacterial agents find it difficult to penetrate the biofilm, remove the bacteria wrapped in it, and produce an excellent therapeutic effect. In this study, a dual pH- and NIR-responsive nanocomposite (A-Ca@PDA) was developed to remove drug-resistant bacteria through a cascade of catalytic nitric oxide (NO) release and photothermal clearance. NO can melt in the outer package of the biofilm, facilitating the nanocomposites to have better permeability. Thermal therapy further inhibits the growth of planktonic bacteria. The locally generated high temperature and the burst release of NO together aggravate the biofilm collapse and bacterial death after NIR irradiation. The nanocomposites achieved a remarkable photothermal conversion efficiency of 47.5%, thereby exhibiting significant advancements in energy conversion. The nanocomposites exhibited remarkable efficacy in inhibiting multidrug-resistant (MDR) Escherichia coli and MDR Staphylococcus aureus, thus achieving an inhibition rate of >90%. Moreover, these nanocomposites significantly improved the wound-healing process in the MDR S. aureus-infected mice. Thus, this novel nanocomposite offers a novel strategy to combat drug-resistant bacterial infections.

Iron-doped nanozymes with spontaneous peroxidase-mimic activity as a promising antibacterial therapy for bacterial keratitis

The development of non-antibiotic pharmaceuticals with biocompatible and efficient antibacterial properties is of great significance for the treatment of bacterial keratitis. In this study, we have developed antibacterial iron-doped nanozymes (Fe3+-doped nanozymes, FNEs) with distinguished capacity to fight against bacterial infections. The iron-doped nanozymes are composed of Fe3+ doped zeolitic imidazolate framework-8 (Fe/ZIF-8) and polyethylene imide (PEI), which were functionally coated on the surface of Fe/ZIF-8 and imparted the FNEs with improved water dispersibility and biocompatibility. FNEs possess a significant spontaneous peroxidase-mimic activity without the need for external stimulation, thus elevating cellular reactive oxygen species level by catalyzing local H2O2 at the infection site and resulting in bacteria damaged to death. FNEs eliminated 100% of Staphylococcus aureus within 6 h, and significantly relieved inflammation and bacterial infection levels in mice bacterial keratitis, exhibiting higher bioavailability and a superior therapeutic effect compared to conventional antibiotic eye drops. In addition, the FNEs would not generate drug resistance, suggesting that FNEs have great potential in overcoming infectious diseases caused by antimicrobial resistant bacteria.

Photothermal Hydrogel Composites Featuring G4-Carbon Nanomaterial Networks for Staphylococcus aureus Inhibition

Microbial infections represent a significant health risk, often leading to severe complications and, in some cases, even fatalities. As a result, there is an urgent need to explore innovative drug delivery systems and alternative therapeutic techniques. The photothermal therapy has emerged as a promising antibacterial approach and is the focus of this study. Herein, we report the successful synthesis of two distinct supramolecular composite hydrogels by incorporating graphene oxide (GO) and single-walled carbon nanotubes (SWNTs) into guanosine quadruplex (G4) based hydrogels containing covalently bound β-cyclodextrin (β-CD). The G4 matrix was synthesized through a two-step process, establishing a robust network between G4 and β-CDs, followed by the encapsulation of either GO or SWNTs. Comprehensive characterization of these composite hydrogels were conducted using analytical techniques, including circular dichroism, Raman spectroscopy, rheological investigations, X-ray diffraction, and scanning electron microscopy. A notable discovery from the conducted research is the differential photothermal responses exhibited by the hydrogels when exposed to near-infrared laser irradiation. Specifically, SWNT-based hydrogels demonstrated superior photothermal performance, achieving a remarkable temperature increase of up to 52 °C, in contrast to GO-based hydrogels, which reached a maximum of 34 °C. These composite hydrogels showed good cytotoxicity evaluation results and displayed synergistic antibacterial activity against Staphylococcus aureus, positioning them as promising candidates for antibacterial photothermic platforms, particularly in the context of wound treatment. This study offers a valuable contribution to the development of advanced and combined therapeutic strategies for combating microbial infections and highlights the potential of carbon nanomaterial-enhanced supramolecular hydrogels in photothermal therapy applications.

Disruption of Communication: Recent Advances in Antibiofilm Materials with Anti-Quorum Sensing Properties

Biofilm contamination presents a significant threat to public health, the food industry, and aquatic/marine-related applications. In recent decades, although various methods have emerged to combat biofilm contamination, the intricate and persistent nature of biofilms makes complete eradication challenging. Therefore, innovative alternative solutions are imperative for addressing biofilm formation. Instead of solely focusing on the eradication of mature biofilms, strategically advantageous measures involve the delay or prevention of biofilm formation on surfaces. Quorum sensing, a communication system enabling bacteria to coordinate their behavior based on population density, plays a pivotal role in biofilm formation for numerous microbial species. Materials possessing antibiofilm properties that target quorum sensing have gained considerable attention for their potential to prevent biofilm formation. This Review consolidates recent research progress on the utilization of materials with antiquorum sensing properties for combating biofilm formation. These materials can be categorized into three distinct types: (i) antibiofilm nanomaterials, (ii) antibiofilm surfaces, and (iii) antibiofilm hydrogels with antiquorum sensing capabilities. Finally, the Review concludes with a brief discussion of current challenges and outlines potential avenues for future research.

Emerging Issues and Initial Insights into Bacterial Biofilms: From Orthopedic Infection to Metabolomics

Bacterial biofilms, enigmatic communities of microorganisms enclosed in an extracellular matrix, still represent an open challenge in many clinical contexts, including orthopedics, where biofilm-associated bone and joint infections remain the main cause of implant failure. This study explores the scenario of biofilm infections, with a focus on those related to orthopedic implants, highlighting recently emerged substantial aspects of the pathogenesis and their potential repercussions on the clinic, as well as the progress and gaps that still exist in the diagnostics and management of these infections. The classic mechanisms through which biofilms form and the more recently proposed new ones are depicted. The ways in which bacteria hide, become impenetrable to antibiotics, and evade the immune defenses, creating reservoirs of bacteria difficult to detect and reach, are delineated, such as bacterial dormancy within biofilms, entry into host cells, and penetration into bone canaliculi. New findings on biofilm formation with host components are presented. The article also delves into the emerging and critical concept of immunometabolism, a key function of immune cells that biofilm interferes with. The growing potential of biofilm metabolomics in the diagnosis and therapy of biofilm infections is highlighted, referring to the latest research.

An Overview of Polymeric Nanoplatforms to Deliver Veterinary Antimicrobials

There is an urgent need to find new solutions for the global dilemma of increasing antibiotic resistance in humans and animals. Modifying the performance of existing antibiotics using the nanocarrier drug delivery system (DDS) is a good option considering economic costs, labor costs, and time investment compared to the development of new antibiotics. Numerous studies on nanomedicine carriers that can be used for humans are available in the literature, but relatively few studies have been reported specifically for veterinary pharmaceutical products. Polymer-based nano-DDS are becoming a research hotspot in the pharmaceutical industry owing to their advantages, such as stability and modifiability. This review presents current research progress on polymer-based nanodelivery systems for veterinary antimicrobial drugs, focusing on the role of polymeric materials in enhancing drug performance. The use of polymer-based nanoformulations improves treatment compliance in livestock and companion animals, thereby reducing the workload of managers. Although promising advances have been made, many obstacles remain to be addressed before nanoformulations can be used in a clinical setting. Some crucial issues currently facing this field, including toxicity, quality control, and mass production, are discussed in this review. With the continuous optimization of nanotechnology, polymer-based DDS has shown its potential in reducing antibiotic resistance to veterinary medicines.

A pomegranate seed-structured nanozyme-based colorimetric immunoassay for highly sensitive and specific biosensing of Staphylococcus aureus

Staphylococcus aureus (S. aureus) infections are a serious threat to human health. The development of rapid and sensitive detection methods for pathogenic bacteria is crucial for accurate drug administration. In this research, by combining the advantages of enzyme-linked immunosorbent assay (ELISA), we synthesized nanozymes with high catalytic performance, namely pomegranate seed-structured bimetallic gold-platinum nanomaterials (Ps-PtAu NPs), which can catalyze a colorless TMB substrate into oxidized TMB (oxTMB) with blue color to achieve colorimetric analysis of S. aureus. Under the optimal conditions, the proposed biosensor could quantitatively detect S. aureus at levels ranging from 1.0 × 101 to 1.0 × 106 CFU mL-1 with a limit of detection (LOD) of 3.9 CFU mL-1. Then, an integrated color picker APP on a smartphone enables on-site point-of-care testing (POCT) of S. aureus with LOD as low as 1 CFU mL-1. Meanwhile, the proposed biosensor is successfully applied to the detection of S. aureus in clinical samples with high sensitivity and specificity.

Functional fluorescent nanomaterials for the detection, diagnosis and control of bacterial infection and biofilm formation: Insight towards mechanistic aspects and advanced applications

Infectious diseases resulting from the high pathogenic potential of several bacteria possesses a major threat to human health and safety. Traditional methods used for screening of these microorganisms face major issues with respect to detection time, selectivity and specificity which may delay treatment for critically ill patients past the optimal time. Thus, a convincing and essential need exists to upgrade the existing methodologies for the fast detection of bacteria. In this context, increasing number of newly emerging nanomaterials (NMs) have been discovered for their effective use and applications in the area of diagnosis in bacterial infections. Recently, functional fluorescent nanomaterials (FNMs) are extensively explored in the field of biomedical research, particularly in developing new diagnostic tools, nanosensors, specific imaging modalities and targeted drug delivery systems for bacterial infection. It is interesting to note that organic fluorophores and fluorescent proteins have played vital role for imaging and sensing technologies for long, however, off lately fluorescent nanomaterials are increasingly replacing these due to the latter's unprecedented fluorescence brightness, stability in the biological environment, high quantum yield along with high sensitivity due to enhanced surface property etc. Again, taking advantage of their photo-excitation property, these can also be used for either photothermal and photodynamic therapy to eradicate bacterial infection and biofilm formation. Here, in this review, we have paid particular attention on summarizing literature reports on FNMs which includes studies detailing fluorescence-based bacterial detection methodologies, antibacterial and antibiofilm applications of the same. It is expected that the present review will attract the attention of the researchers working in this field to develop new engineered FNMs for the comprehensive diagnosis and treatment of bacterial infection and biofilm formation.

Nanomaterials-Enabled Physicochemical Antibacterial Therapeutics: Toward the Antibiotic-Free Disinfections

Bacterial infection continues to be an increasing global health problem with the most widely accepted treatment paradigms restricted to antibiotics. However, the overuse and misuse of antibiotics have triggered multidrug resistance of bacteria, frustrating therapeutic outcomes, and leading to higher mortality rates. Even worse, the tendency of bacteria to form biofilms on living and nonliving surfaces further increases the difficulty in confronting bacteria because the extracellular matrix can act as a robust barrier to prevent the penetration of antibiotics and resist environmental damage. As a result, the inability to eliminate bacteria and biofilms often leads to persistent infection, implant failure, and device damage. Therefore, it is of paramount importance to develop alternative antimicrobial agents while avoiding the generation of bacterial resistance to prevent the large-scale growth of bacterial resistance. In recent years, nano-antibacterial materials have played a vital role in the antibacterial field because of their excellent physical and chemical properties. This review focuses on new physicochemical antibacterial strategies and versatile antibacterial nanomaterials, especially the mechanism and types of 2D antibacterial nanomaterials. In addition, this advanced review provides guidance on the development direction of antibiotic-free disinfections in the antibacterial field in the future.

In situ Tracking of Exoenzyme Activity Using Droplet Luminescence Concentrators for Ratiometric Detection of Bacteria

We demonstrate a novel, rapid, and cost-effective biosensing paradigm that is based on an in situ visualization of bacterial exoenzyme activity using biphasic Janus emulsion droplets. Sensitization of the droplets toward dominant extracellular enzymes of bacterial pathogens is realized via selective functionalization of one hemisphere of Janus droplets with enzyme-cleavable surfactants. Surfactant cleavage results in an interfacial tension increase at the respective droplet interface, which readily transduces into a microscopically detectable change of the internal droplet morphologies. A macroscopic fluorescence read-out of such morphological transitions is obtained via ratiometrically recording the angle-dependent anisotropic emission signatures of perylene-containing droplets from two different angles. The optical read-out method facilitates detection of marginal morphological responses of polydisperse droplet samples that can be easily produced in any environment. The performance of Janus droplets as powerful optical transducers and signal amplifiers is highlighted by rapid (<4 h) and cost-effective antibody and DNA-free identification of three major foodborne pathogens, with detection thresholds of below 10 CFU mL-1 for Salmonella and <102 to 103 CFU mL-1 for Listeria and Escherichia coli.

CRISPR-based Biosensors for Human Health: A Novel Strategy to Detect Emerging Infectious Diseases

Infectious diseases (such as sepsis, influenza, and malaria), caused by various pathogenic bacteria and viruses, are widespread across the world. Early and rapid detection of disease-related pathogens is necessary to reduce their spread in the world and prevent their potential global pandemics. The clustered regularly interspaced short palindromic repeats (CRISPR) technology, as the next-generation molecular diagnosis technique, holds immense promise in the detection of infectious diseases because of its remarkable advantages, including supreme flexibility, sensitivity, and specificity. While numerous CRISPR-based biosensors have been developed for application in environmental monitoring, food safety, and point-of-care diagnosis, there remains a critical need to summarize and explore their potential in human health. This review aims to address this gap by focusing on the latest advancements in CRISPR-based biosensors for infectious disease detection. We provide an overview of the current status, pre-amplification methods, the unique feature of each CRISPR system, and the design of CRISPR-based biosensing strategies to detect disease-associated nucleic acids. Last but not least, the review analyzes the current challenges and provides future perspectives, which will contribute to developing more effective CRISPR-based biosensors for human health.

Recent advance on nanoparticles or nanomaterials with anti-multidrug resistant bacteria and anti-bacterial biofilm properties: A systematic review

Objective

With the wide spread of Multidrug-resistant bacteria (MDR) due to the transfer and acquisition of antibiotic resistance genes and the formation of microbial biofilm, various researchers around the world are looking for a solution to overcome these resistances. One potential strategy and the best candidate to overcome these infections is using an effective nanomaterial with antibacterial properties against them.

Methods

and analysis: In this study, we overview nanomaterials with anti-MDR bacteria and anti-biofilm properties. Hence, we systematically explored biomedical databases (Web of Sciences, Google Scholar, PubMed, and Scopus) to categorize related studies about nanomaterial with anti-MDR bacteria and anti-biofilm activities from 2007 to December 2022.

Results

In total, forty-one studies were investigated to find antibacterial and anti-biofilm information about the nanomaterial during 2007-2022. According to the collected documents, nineteen types of nanomaterial showed putative antibacterial effects such as Cu, Ag, Au, Au/Pt, TiO2, Al2O3, ZnO, Se, CuO, Cu/Ni, Cu/Zn, Fe3O4, Au/Fe3O4, Au/Ag, Au/Pt, Graphene O, and CuS. In addition, seven types of them considered as anti-biofilm agents such as Ag, ZnO, Au/Ag, Graphene O, Cu, Fe3O4, and Au/Ag.

Conclusion

According to the studies, each of nanomaterial has been designed with different methods and their effects against standard strains, clinical strains, MDR strains, and bacterial biofilms have been investigated in-vitro and in-vivo conditions. In addition, nanomaterials have different destructive mechanism on bacterial structures. Various nanoparticles (NP) introduced as the best candidate to designing new drug and medical equipment preventing infectious disease outbreaks by overcome antibiotic resistance and bacterial biofilm.

A modular phage vector platform for targeted photodynamic therapy of Gram-negative bacterial pathogens

Growing antibiotic resistance has encouraged the revival of phage-inspired antimicrobial approaches. On the other hand, photodynamic therapy (PDT) is considered a very promising research domain for the protection against infectious diseases. Yet, very few efforts have been made to combine the advantages of both approaches in a modular, retargetable platform. Here, we foster the M13 bacteriophage as a multifunctional scaffold, enabling the selective photodynamic killing of bacteria. We took advantage of the well-defined molecular biology of M13 to functionalize its capsid with hundreds of photo-activable Rose Bengal sensitizers and contemporarily target this light-triggerable nanobot to specific bacterial species by phage display of peptide targeting moieties fused to the minor coat protein pIII of the phage. Upon light irradiation of the specimen, the targeted killing of diverse Gram(-) pathogens occurred at subnanomolar concentrations of the phage vector. Our findings contribute to the development of antimicrobials based on targeted and triggerable phage-based nanobiotherapeutics.

Ag+-Adsorbing Semiconducting Polymer Nanosponge for Smart Local Treatment of Wound Infection

Nanoplatform combined with photothermal therapy (PTT) and silver nanoparticles have been widely used to combat bacterial infections. However, the development of environmentally benign antibacterial nanoplatforms with controllable and long-term antibacterial activity is still challenging. Herein, we synthesized an Ag+-adsorbing organic semiconducting polymeric nanosponge (PDPP3T NPe@Ag+) to realize Ag+ enhanced photothermal anti-infective therapy. Furthermore, the PDPP3T NPe@Ag+ sponge can also spatiotemporally release silver ions in a pH/NIR light-responsive manner for controllable and long-term antimicrobial therapy. Owing to good biocompatibility and controlled release of silver ions, PDPP3T NPe@Ag+ can effectively kill bacteria in vitro and promote wound healing in vivo. We expect that this antimicrobial platform could be utilized as a robust antibacterial agent for infective therapy.

Impact of silver substitution on the structural, magnetic, optical, and antibacterial properties of cobalt ferrite

Silver-doped Cobalt Ferrite nanoparticles AgxCo1-xFe2O4 with concentrations (x = 0, 0.05, 0.1, 0.15) have been prepared using a hydrothermal technique. The XRD pattern confirms the formation of the spinel phase of CoFe2O4 and the presence of Ag ions in the spinel structure. The spinel phase AgxCo1-xFe2O4 nanoparticles are confirmed by FTIR analysis by the major bands formed at 874 and 651 cm-1, which represent the tetrahedral and octahedral sites. The analysis of optical properties reveals an increase in band gap energy with increasing concentration of the dopant. The energy band gap values depicted for prepared nanoparticles with concentrations x = 0, 0.05, 0.1, 0.15 are 3.58 eV, 3.08 eV, 2.93 eV, and 2.84 eV respectively. Replacement of the Co2+ ion with the nonmagnetic Ag2+ ion causes a change in saturation magnetization, with Ms values of 48.36, 29.06, 40.69, and 45.85 emu/g being recorded. The CoFe2O4 and Ag2+ CoFe2O4 nanoparticles were found to be effective against the Acinetobacter Lwoffii and Moraxella species, with a high inhibition zone value of x = 0.15 and 8 × 8 cm against bacteria. It is suggested that, by the above results, the synthesized material is suitable for memory storage devices and antibacterial activity.

Nano-Biotechnology for Bacteria Identification and Potent Anti-bacterial Properties: A Review of Current State of the Art

Sepsis is a critical disease caused by the abrupt increase of bacteria in human blood, which subsequently causes a cytokine storm. Early identification of bacteria is critical to treating a patient with proper antibiotics to avoid sepsis. However, conventional culture-based identification takes a long time. Polymerase chain reaction (PCR) is not so successful because of the complexity and similarity in the genome sequence of some bacterial species, making it difficult to design primers and thus less suitable for rapid bacterial identification. To address these issues, several new technologies have been developed. Recent advances in nanotechnology have shown great potential for fast and accurate bacterial identification. The most promising strategy in nanotechnology involves the use of nanoparticles, which has led to the advancement of highly specific and sensitive biosensors capable of detecting and identifying bacteria even at low concentrations in very little time. The primary drawback of conventional antibiotics is the potential for antimicrobial resistance, which can lead to the development of superbacteria, making them difficult to treat. The incorporation of diverse nanomaterials and designs of nanomaterials has been utilized to kill bacteria efficiently. Nanomaterials with distinct physicochemical properties, such as optical and magnetic properties, including plasmonic and magnetic nanoparticles, have been extensively studied for their potential to efficiently kill bacteria. In this review, we are emphasizing the recent advances in nano-biotechnologies for bacterial identification and anti-bacterial properties. The basic principles of new technologies, as well as their future challenges, have been discussed.

Recent advances and perspectives of functionalized carbon dots in bacteria sensing

Bacterial infectious diseases are severe threats to human health and increase substantial financial burdens. Nanomaterials have shown great potential in timely and accurate bacterial identification, detection, and monitoring to improve the cure rate and reduce mortality. Recently, carbon dots have been evidenced to be ideal candidates for bacterial identification and detection due to their superior physicochemical properties and biocompatibility. This review outlines the detailed recognition elements and recognition strategies with functionalized carbon dots (FCDs) for bacterial identification and detection. The advantages and limitations of different kinds of FCDs-based sensors will be critically discussed. Meanwhile, the ongoing challenges and perspectives of FCDs-based sensors for bacteria sensing are put forward.

Detection and discrimination of pathogenic bacteria with nanomaterials-based optical biosensors: A review

Pathogenic bacteria can pose a great threat to food safety and human health. It is therefore imperative to develop a rapid, portable, and sensitive determination and discrimination method for pathogenic bacteria. Over the past few years, various nanomaterials (NMs) have been employed as desirable nanoprobes because they possess extraordinary properties that can be used for optical signal enabled detection and identification of bacteria. By means of modification, NMs can, depending on different mechanisms, sense targets directly or indirectly, which then provides an essential support for the detection and differentiation of pathogenic bacteria. In this review, recent application of NMs-based optical biosensors for food safety bacterial detection and discrimination is performed, mainly in but not limited to noble metal NMs, fluorescent NMs, and point-of-care testing (POCT). This review also focuses on future trends in bacterial detection and discrimination, and machine learning in performing intelligent rapid detection and multiple accurate identification of bacteria.

Near-Infrared Copper Sulfide Hollow Nanostructures with Enhanced Photothermal and Photocatalytic Performance for Effective Bacterial Sterilization

The development of nonantibiotic strategies to combat bacterial infection is highly needed, owing to the widespread infectious disease and bacterial resistance becoming a significant health threat to the world's population. In recent years, photoactivated antibacterial therapies including photocatalytic and photothermal therapies have attracted increasing attention due to their high efficiency and low side effect. Herein, we introduce a copper sulfide (Cu_2-xS) hollow nanostructure-based near-infrared antibacterial platform with synergy photothermal and photocatalytic properties for effective bacterial sterilization. Compared to traditional Cu_2-xS nanoparticles, this unique hollow Cu_2-xS nanostructure can generate multiple scattered light, which is conducive to light collection. Moreover, its thin shell can shorten the transmission distance of carrier, thus reducing the charge recombination that usually causes the greatest energy loss. As a result, such a Cu_2-xS hollow nanostructure enables enhanced photothermal and photocatalytic bacterial killing activities against both Escherichia coli and Staphylococcus aureus, showing promise for antibiotic-free infection treatment and other bacterial sterilization applications.

Advanced Nitric Oxide Generating Nanomedicine for Therapeutic Applications

Nitric oxide (NO), a gaseous transmitter extensively present in the human body, regulates vascular relaxation, immune response, inflammation, neurotransmission, and other crucial functions. Nitrite donors have been used clinically to treat angina, heart failure, pulmonary hypertension, and erectile dysfunction. Based on NO's vast biological functions, it further can treat tumors, bacteria/biofilms and other infections, wound healing, eye diseases, and osteoporosis. However, delivering NO is challenging due to uncontrolled blood circulation release and a half-life of under five seconds. With advanced biotechnology and the development of nanomedicine, NO donors packaged with multifunctional nanocarriers by physically embedding or chemically conjugating have been reported to show improved therapeutic efficacy and reduced side effects. Herein, we review and discuss recent applications of NO nanomedicines, their therapeutic mechanisms, and the challenges of NO nanomedicines for future scientific studies and clinical applications. As NO enables the inhibition of the replication of DNA and RNA in infectious microbes, including COVID-19 coronaviruses and malaria parasites, we highlight the potential of NO nanomedicines for antipandemic efforts. This review aims to provide deep insights and practical hints into design strategies and applications of NO nanomedicines.

An achromatic colorimetric nanosensor for sensitive multiple pathogen detection by coupling plasmonic nanoparticles with magnetic separation

Rapid screening of multiple pathogens will greatly improve the efficiency of pandemic prevention and control. Colorimetric methods exhibit the advantages of convenience, portability, low cost, time efficiency, and free of sophisticated instruments, yet usually have difficulties in simultaneous detection and suffer from monotonous color changes with low visual resolution and sensitivity. Hence, coupled three kinds of plasmonic nanoparticles (NPs) with magnetic separation, we developed an achromatic colorimetric nanosensor with highly enhanced visual resolution for simultaneous detection of SARS-CoV-2, Staphylococcus aureus, and Salmonella typhimurium. The achromatic nanosensor was composed of SARS-CoV-2-targeting red gold NPs, S. aureus-targeting yellow silver NPs and S. typhimurium-targeting blue silver triangle NPs mixed as black color. In the detection, three corresponding magnetic probes were added into the above mixture. In the presence of a target pathogen, it would be recognized and combined with corresponding colored reporters and magnetic probes to form sandwich complexes, which were removed by magnetic separation, and the sensor changed from black to a chromatic color (the color of the reporters remained in supernatant). Consequently, different target pathogen induced different color. For example, SARS-CoV-2, S. aureus, and S. typhimurium respectively produced green, purple, and orange. While coexistence of S. aureus and S. typhimurium produced red, and coexistence of S. aureus and SARS-CoV-2 produced blue, etc. Therefore, by observing the color change or measuring the absorption spectra, multiple pathogen detection was achieved conveniently. Compared with most colorimetric sensors, this achromatic nanosensor involved rich color change, thus significantly enhancing visual resolution and inspection sensitivity. Therefore, this sensor opened a promising avenue for efficient monitoring and early warning of food safety and quality.

Second Near-Infrared Plasmonic Nanomaterials for Photoacoustic Imaging and Photothermal Therapy

Photoacoustic imaging (PAI) and imaging-guided photothermal therapy (PTT) in the second near-infrared window (NIR-II, 1000-1700 nm) have received increasing attention owing to their advantages of greater penetration depth and higher signal-to-noise ratio. Plasmonic nanomaterials with tunable optical properties and strong light absorption provide an alternative to dye molecules, showing great prospects for phototheranostic applications. In this review, the research progress in principally modulating the optical properties of plasmonic nanomaterials, especially affecting parameters such as size, morphology, and surface chemical modification, is introduced. The commonly used plasmonic nanomaterials in the NIR-II window, including noble metals, semiconductors, and heterostructures, are then summarized. In addition, the biomedical applications of these NIR-II plasmonic nanomaterials for PAI and PTT in phototheranostics are highlighted. Finally, the perspectives and challenges for advancing plasmonic nanomaterials for practical use and clinical translation are discussed.

Carbon monoxide therapy: a promising strategy for cancer

Cancer is one of the acute life-threatening diseases endangering the whole of humanity. The treatment modalities for cancer are various. However, in most cases, a single treatment choice provides multiple side effects, poor targeting, and ineffective treatment. In recent years, the physiological regulatory function of carbon monoxide (CO) in the cancer process has been reported gradually, and CO-related nano-drugs have been explored. It shows better application prospects in cancer treatment and provides new ideas for treatment. The present review introduces the pathophysiological role of CO. The recent advances in cancer therapy, such as CO-mediated gas therapy, combined application of CO chemotherapy, photodynamic therapy (PDT), photothermal therapy (PTT), and immunotherapy, are described. Current challenges and future developments in CO-based treatment are also discussed. This review provides comprehensive information on recent advances in CO therapy and also some valuable guidance for promoting the progress of gas therapy nanomedicine.

Emerging nanoparticle designs against bacterial infections

The rise of antibiotic resistance has caused the prevention and treatment of bacterial infections to be less effective. Therefore, researchers turn to nanomedicine for novel and effective antibacterial therapeutics. The effort resulted in the first-generation antibacterial nanoparticles featuring the ability to improve drug tolerability, circulation half-life, and efficacy. Toward developing the next-generation antibacterial nanoparticles, researchers have integrated design elements that emphasize physical, broad-spectrum, biomimetic, and antivirulence mechanisms. This review highlights four emerging antibacterial nanoparticle designs: inorganic antibacterial nanoparticles, responsive antibacterial nanocarriers, virulence nanoscavengers, and antivirulence nanovaccines. Examples in each design category are selected and reviewed, and their structure-function relationships are discussed. These emerging designs open the door to nontraditional antibacterial nanomedicines that rely on mechano-bactericidal, function-driven, nature-inspired, or virulence-targeting mechanisms to overcome antibiotic resistance for more effective antibacterial therapy. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.

WO3 Nanowire-Attached Reduced Graphene Oxide-Based 1D-2D Heterostructures for Near-Infrared Light-Driven Synergistic Photocatalytic and Photothermal Inactivation of Multidrug-Resistant Superbugs

The rapid emergence of superbugs which are resistant to existing antibiotics is becoming a huge global threat to public health, which demands the discovery of next-generation antibacterial agents for combating superbugs. Herein, we report the design of a two-dimensional (2D) reduced graphene oxide (r-GO) and one-dimensional (1D) WO₃ nanowire-based photothermal-photocatalytic heterostructure for combating multiantibiotic-resistant Salmonella DT104, carbapenem-resistant Enterobacteriaceae Escherichia coli, and methicillin-resistant Staphylococcus aureus superbugs. In the presence of near-infrared (NIR) light, due to the generation of electrons and holes, the WO₃-based heterostructure generates reactive oxygen species by photocatalytic reaction from water and oxygen, which kills superbugs. To enhance the photocatalytic superbug killing efficiency, r-GO has been used for suppressing the recombination of the photoinduced electron-hole pairs. Reported data show that NIR light-driven synergistic photocatalytic-photothermal processes can be used for 100% degradation of methylene blue using a heterostructure-based catalyst, and the photodegradation rate for the heterostructure is much better than the literature data for different types of WO₃/GO-based nanocomposites. Experimentally, time-dependent antibacterial efficiency data reveals that the heterostructure can destroy 100% superbugs within 30 min of light exposure via a synergistic photothermal and photocatalytic mechanism, whereas the WO₃ nanowire can kill around 35% superbugs only via photocatalytic action only and r-GO can kill 25% superbugs via photothermal action even after 30 min of exposure to light. Systematic time-dependent microscopy and spectroscopy studies reveal that the excellent antisuperbug activities for heterostructures are due to membrane damage, ATP, and DNA/RNA breakage. For possible real-life applications, sun light-based superbug inactivation shows 100% inactivation possible within 250 min of light exposure using 12 mg/mL heterostructures. The reported sun light-driven killing of superbugs provides a simple and versatile platform to combat drug-resistant superbugs.

Silent Raman imaging of highly effective anti-bacterial activity synchronous with biofilm breakage using poly(4-cyanostyrene)@silver@polylysine nanocomposites

Biofilms are known to be a great challenge for their anti-bacterial activity as they obstruct drug action for deeper and more thorough bacteria-killing effects. Therefore, developing highly effective antibacterial agents to destroy biofilms and eradicate bacteria is of great significance. Herein, a new type of nanocomposites (denoted as poly(4-cyanostyrene)@silver@polylysine) is proposed, in which polylysine (PLL) could rapidly capture the biofilms and exhibit excellent antibacterial efficacy together with decorated silver (Ag) nanoparticles (NPs) through the charge effect and Ag⁺ release. Notably, nearly 100% antibacterial rates against Gram-positive bacterium (Staphylococcus aureus, S. aureus) and Gram-negative bacterium (Escherichia coli, E. coli) were achieved. More importantly, poly(4-cyanostyrene) with biological silent Raman imaging capacity is able to illustrate the relationship between antibacterial efficiency and biofilm breakage. In short, such novel nanocomposites can improve the bioavailability of each component and display tremendous potential in antibacterial applications.

Targeted photothermal release of antibiotics by a graphene nanoribbon-based supramolecular glycomaterial

Here, we report the simple construction of a supramolecular glycomaterial for the targeted delivery of antibiotics to P. aeruginosa in a photothermally-controlled manner. A galactose-pyrene conjugate (Gal-pyr) was developed to self-assemble with graphene nanoribbon-based nanowires via π-π stacking to produce a supramolecular glycomaterial, which exhibits a 1250-fold enhanced binding avidity toward a galactose-selective lectin when compared to Gal-pyr. The as-prepared glycomaterial when loaded with an antibiotic that acts as an inhibitor of the bacterial folic acid biosynthetic pathway eradicated P. aeruginosa-derived biofilms under near-infrared light irradiation due to the strong photothermal effect of the nanowires accelerating antibiotic release.

Functional insights to the development of bioactive material for combating bacterial infections

The emergence of antibiotic-resistant "superbugs" poses a serious threat to human health. Nanomaterials and cationic polymers have shown unprecedented advantages as effective antimicrobial therapies due to their flexibility and ability to interact with biological macromolecules. They can incorporate a variety of antimicrobial substances, achieving multifunctional effects without easily developing drug resistance. Herein, this article discusses recent advances in cationic polymers and nano-antibacterial materials, including material options, fabrication techniques, structural characteristics, and activity performance, with a focus on their fundamental active elements.

Natural resources for sustainable synthesis of nanomaterials with anticancer applications: A move toward green nanomedicine

Today, researchers have focused on the application of environmentally-benign and sustainable micro- and nanosystems for drug delivery and cancer therapy. Compared to conventional chemotherapeutics, advanced micro- and nanosystems designed by applying abundant, natural, and renewable feedstocks have shown biodegradability, biocompatibility, and low toxicity advantages. However, important aspects of toxicological assessments, clinical translational studies, and suitable functionalization/modification still need to be addressed. Herein, the benefits and challenges of green nanomedicine in cancer nanotherapy and targeted drug delivery are cogitated using nanomaterials designed by exploiting natural and renewable resources. The application of nanomaterials accessed from renewable natural resources, comprising metallic nanomaterials, carbon-based nanomaterials, metal-organic frameworks, natural-derived nanomaterials, etc. for targeted anticancer drug delivery and cancer nanotherapy are deliberated, with emphasis on important limitations/challenges and future perspectives.

Targeting Proinflammatory Molecules Using Multifunctional MnO Nanoparticles to Inhibit Breast Cancer Recurrence and Metastasis

Photothermal therapy (PTT) is an effective treatment modality that is highly selective for tumor suppression and is a hopeful alternative to traditional cancer therapy. However, PTT-induced inflammatory responses may result in undesirable side effects including increased risks of tumor recurrence and metastasis. Here we developed multifunctional MnO nanoparticles as scavengers of proinflammatory molecules to alleviate the PTT-induced inflammatory response. The MnO nanoparticles improve the PTT therapy by (1) binding and scavenging proinflammatory molecules to inhibit the proinflammatory molecule-induced Toll-like receptors (TLR) activation and nuclear factor kappa B (NF-κB) signaling; (2) inhibiting activated macrophage-induced macrophage recruitment; and (3) inhibiting tumor cell migration and invasion. In vivo experimental results showed that further treatment with MnO nanoparticles after laser therapy not only inhibited the PTT-induced inflammatory response and primary tumor recurrence but also significantly reduced tumor metastasis due to the scavenging activity. These findings suggest that MnO nanoparticles hold the potential for mitigating the therapy-induced severe inflammatory response and inhibiting tumor recurrence and metastasis.

Research progress of stimulus-responsive antibacterial materials for bone infection

Infection is one of the most serious complications harmful to human health, which brings a huge burden to human health. Bone infection is one of the most common and serious complications of fracture and orthopaedic surgery. Antibacterial treatment is the premise of bone defect healing. Among all the antibacterial strategies, irritant antibacterial materials have unique advantages and the ability of targeted therapy. In this review, we focus on the research progress of irritating materials, the development of antibacterial materials and their advantages and disadvantages potential applications in bone infection.