Biodegradable Nanocomposite Antimicrobials for the Eradication of Multidrug-Resistant Bacterial Biofilms without Accumulated Resistance

A New Class of Polyion Complex Vesicles (PIC-somes) to Improve Antimicrobial Activity of Tobramycin in Pseudomonas Aeruginosa Biofilms

Pseudomonas aeruginosa (PA) is a major healthcare concern due to its tolerance to antibiotics when enclosed in biofilms. Tobramycin (Tob), an effective cationic aminoglycoside antibiotic against planktonic PA, loses potency within PA biofilms due to hindered diffusion caused by interactions with anionic biofilm components. Loading Tob into nano-carriers can enhance its biofilm efficacy by shielding its charge. Polyion complex vesicles (PIC-somes) are promising nano-carriers for charged drugs, allowing higher drug loadings than liposomes and polymersomes. In this study, a new class of nano-sized PIC-somes, formed by Tob-diblock copolymer complexation is presented. This approach replaces conventional linear PEG with brush-like poly[ethylene glycol (methyl ether methacrylate)] (PEGMA) in the shell-forming block, distinguishing it from past methods. Tob paired with a block copolymer containing hydrophilic PEGMA induces micelle formation (PIC-micelles), while incorporating hydrophobic pyridyldisulfide ethyl methacrylate (PDSMA) monomer into PEGMA chains reduces shell hydrophilicity, leads to the formation of vesicles (PIC-somes). PDSMA unit incorporation enables unprecedented dynamic disulfide bond-based shell cross-linking, significantly enhancing stability under saline conditions. Neither PIC-somes nor PIC-micelles show any relevant cytotoxicity on A549, Calu-3, and dTHP-1 cells. Tob's antimicrobial efficacy against planktonic PA remains unaffected after encapsulation into PIC-somes and PIC-micelles, but its potency within PA biofilms significantly increases.

Polymeric Nanoparticles for Drug Delivery

The recent emergence of nanomedicine has revolutionized the therapeutic landscape and necessitated the creation of more sophisticated drug delivery systems. Polymeric nanoparticles sit at the forefront of numerous promising drug delivery designs, due to their unmatched control over physiochemical properties such as size, shape, architecture, charge, and surface functionality. Furthermore, polymeric nanoparticles have the ability to navigate various biological barriers to precisely target specific sites within the body, encapsulate a diverse range of therapeutic cargo and efficiently release this cargo in response to internal and external stimuli. However, despite these remarkable advantages, the presence of polymeric nanoparticles in wider clinical application is minimal. This review will provide a comprehensive understanding of polymeric nanoparticles as drug delivery vehicles. The biological barriers affecting drug delivery will be outlined first, followed by a comprehensive description of the various nanoparticle designs and preparation methods, beginning with the polymers on which they are based. The review will meticulously explore the current performance of polymeric nanoparticles against a myriad of diseases including cancer, viral and bacterial infections, before finally evaluating the advantages and crucial challenges that will determine their wider clinical potential in the decades to come.

Acer tegmentosum extract-mediated silver nanoparticles loaded chitosan/alginic acid scaffolds enhance healing of E. coli-infected wounds

This work developed Acer tegmentosum extract-mediated silver nanoparticles (AgNPs) loaded chitosan (CS)/alginic acid (AL) scaffolds (CS/AL-AgNPs) to enhance the healing of E. coli-infected wounds. The SEM-EDS and XRD results revealed the successful formation of the CS/AL-AgNPs. FTIR analysis evidenced that the anionic group of AL (-COO-) and cationic amine groups of CS (-NH3+) were ionically crosslinked to form scaffold (CS/AL). The CS/AL-AgNPs exhibited significant antimicrobial activity against both Gram-positive (G+) and Gram-negative (G-) bacterial pathogens, while being non-toxic to red blood cells (RBCs), the hen's egg chorioallantoic membrane (HET-CAM), and a non-cancerous cell line (NIH3T3). Treatment with CS/AL-AgNPs significantly accelerated the healing of E. coli-infected wounds by regulating the collagen deposition and blood parameters as evidenced by in vivo experiments. Overall, these findings suggest that CS/AL-AgNPs are promising for the treatment of infected wounds.

Nature-Derived Gelatin-Based Antifungal Nanotherapeutics for combatting Candida albicans Biofilms

Infections caused by fungi are emerging global health challenges that are exacerbated by the formation of fungal biofilms. Further challenges arise from environmental contamination with antifungal agents, which promotes environmental acquisition of antifungal resistance. We report the generation of an efficient, sustainable, all-natural antifungal nanotherapeutic based on the integration of an antimicrobial natural essential oil into a gelatin-based nanoemulsion platform. Carvacrol-loaded gelatin nanoemulsions penetrated Candida albicans biofilms, resulting in death of C. albicans cells in biofilms, and displayed selective biofilm elimination without harmful effects on fibroblast cells in a fungal biofilm-mammalian fibroblast co-culture model. Furthermore, the nanoemulsions degraded in the presence of physiologically relevant biomolecules, reducing the potential for environmental pollution and ecotoxicity. Overall, the sustainability, and efficacy of the described gelatin nanoemulsion formulation provides an environmentally friendly strategy for treating biofilm-associated fungal infections, including those caused by drug-resistant fungi.

Bioinspired silver nanoparticle-based nanocomposites for effective control of plant pathogens: A review

Plant pathogens, including bacteria, fungi, and viruses, pose significant challenges to the farming community due to their extensive diversity, the rapidly evolving phenomenon of multi-drug resistance (MDR), and the limited availability of effective control measures. Amid mounting global pressure, particularly from the World Health Organization, to limit the use of antibiotics in agriculture and livestock management, there is increasing consideration of engineered nanomaterials (ENMs) as promising alternatives for antimicrobial applications. Studies focusing on the application of ENMs in the fight against MDR pathogens are receiving increasing attention, driven by significant losses in agriculture and critical knowledge gaps in this crucial field. In this review, we explore the potential contributions of silver nanoparticles (AgNPs) and their nanocomposites in combating plant diseases, within the emerging interdisciplinary arena of nano-phytopathology. AgNPs and their nanocomposites are increasingly acknowledged as promising countermeasures against plant pathogens, owing to their unique physicochemical characteristics and inherent antimicrobial properties. This review explores recent advancements in engineered nanocomposites, highlights their diverse mechanisms for pathogen control, and draws attention to their potential in antibacterial, antifungal, and antiviral applications. In the discussion, we briefly address three crucial dimensions of combating plant pathogens: green synthesis approaches, toxicity-environmental concerns, and factors influencing antimicrobial efficacy. Finally, we outline recent advancements, existing challenges, and prospects in scholarly research to facilitate the integration of nanotechnology across interdisciplinary fields for more effective treatment and prevention of plant diseases.

Single atom nanozymes for bacterial infection therapy

Bacterial infection-related diseases continue to pose a significant challenge to global human health. Antibiotic therapy, as a conventional therapeutic strategy, has been extensively employed in clinical settings to treat bacterial infections. However, the effectiveness of these conventional strategies is often impeded by the antimicrobial resistance of bacteria. Consequently, the development of alternative antibacterial agents has emerged as a promising approach to addressing this issue. In recent years, single-atom nanozymes (SAzymes), a novel class of nanocatalytic medicines, have garnered increasing attention due to their numerous advantages, including uniformly dispersed metal active sites, tunable coordination structures, and maximal metal atomic utilization efficiency. To date, a variety of SAzymes have been developed and widely applied in antibacterial therapy. In this minireview, we provide an overview of the latest advances in the synthesis and antibacterial application of different metal-based SAzymes. Furthermore, we discuss the future challenges and opportunities of utilizing SAzymes for bacterial infection treatment. It is our hope that this minireview will contribute to the development of the next generation of SAzyme-based antibacterial agents.

Antimicrobial-loaded biodegradable nanoemulsions for efficient clearance of intracellular pathogens in bacterial peritonitis

Intracellular pathogenic bacteria use immune cells as hosts for bacterial replication and reinfection, leading to challenging systemic infections including peritonitis. The spread of multidrug-resistant (MDR) bacteria and the added barrier presented by host cell internalization limit the efficacy of standard antibiotic therapies for treating intracellular infections. We present a non-antibiotic strategy to treat intracellular infections. Antimicrobial phytochemicals were stabilized and delivered by polymer-stabilized biodegradable nanoemulsions (BNEs). BNEs were fabricated using different phytochemicals, with eugenol-loaded BNEs (E-BNEs) affording the best combination of antimicrobial efficacy, macrophage accumulation, and biocompatibility. The positively-charged polymer groups of the E-BNEs bind to the cell surface of macrophages, facilitating the entry of eugenol that then kills the intracellular bacteria without harming the host cells. Confocal imaging and flow cytometry confirmed that this entry occurred mainly via cholesterol-dependent membrane fusion. As eugenol co-localized and interacted with intracellular bacteria, antibacterial efficacy was maintained. E-BNEs reversed the immunosuppressive effects of MRSA on macrophages. Notably, E-BNEs did not elicit resistance selection after multiple exposures of MRSA to sub-therapeutic doses. The E-BNEs were highly effective against a murine model of MRSA-induced peritonitis with better bacterial clearance (99 % bacteria reduction) compared to clinically-employed treatment with vancomycin. Overall, these findings demonstrate the potential of E-BNEs in treating peritonitis and other refractory intracellular infections.

The Phytochemical Tactics for Battling Antibiotic Resistance in Microbes: Secondary Metabolites and Nano Antibiotics Methods

One of the most serious threats to human health is antibiotic resistance, which has left the world without effective antibiotics. While continuous research and inventions for new antibiotics are going on, especially those with new modes of action, it is unlikely that this alone would be sufficient to win the battle. Furthermore, it is also important to investigate additional approaches. One such strategy for improving the efficacy of existing antibiotics is the discovery of adjuvants. This review has collected data from various studies on the current crisis and approaches for combating multi-drug resistance in microbial pathogens using phytochemicals. In addition, the nano antibiotic approaches, are discussed, highlighting the high potentials of essential oils, alkaloids, phenolic compounds, and nano antibiotics in combating antibiotic resistance.

Biodegradable nanoemulsion-based bioorthogonal nanocatalysts for intracellular generation of anticancer therapeutics

Bioorthogonal catalysis mediated by transition metal catalysts (TMCs) provides controlled in situ activation of prodrugs through chemical reactions that do not interfere with cellular bioprocesses. The direct use of 'naked' TMCs in biological environments can have issues of solubility, deactivation, and toxicity. Here, we demonstrate the design and application of a biodegradable nanoemulsion-based scaffold stabilized by a cationic polymer that encapsulates a palladium-based TMC, generating bioorthogonal nanocatalyst "polyzymes". These nanocatalysts enhance the stability and catalytic activity of the TMCs while maintaining excellent mammalian cell biocompatibility. The therapeutic potential of these nanocatalysts was demonstrated through efficient activation of a non-toxic prodrug into an active chemotherapeutic drug, leading to efficient killing of cancer cells.

Synergistic Treatment of Multidrug-Resistant Bacterial Biofilms Using Silver Nanoclusters Incorporated into Biodegradable Nanoemulsions

Multidrug resistance (MDR) in bacteria is a critical global health challenge that is exacerbated by the ability of bacteria to form biofilms. We report a combination therapy for biofilm infections that integrates silver nanoclusters (AgNCs) into polymeric biodegradable nanoemulsions (BNEs) incorporating eugenol. These Ag-BNEs demonstrated synergistic antimicrobial activity between the AgNCs and the BNEs. Microscopy studies demonstrated that Ag-BNEs penetrated the dense biofilm matrix and effectively disrupted the bacterial membrane. The Ag-BNE vehicle also resulted in more effective silver delivery into the biofilm than AgNCs alone. This combinacional system featured disruptionof biofilms by BNEs and enhanced delivery of AgNCs for synergy to provide highly efficient killing of MDR biofilms.

Integration of Antimicrobials and Delivery Systems: Synergistic Antibiofilm Activity with Biodegradable Nanoemulsions Incorporating Pseudopyronine Analogs

Multi-drug-resistant (MDR) bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), pose a significant challenge in healthcare settings. Small molecule antimicrobials (SMAs) such as α-pyrones have shown promise as alternative treatments for MDR infections. However, the hydrophobic nature of many SMAs limits their solubility and efficacy in complex biological environments. In this study, we encapsulated pseudopyronine analogs (PAs) in biodegradable polymer nanoemulsions (BNEs) for efficient eradication of biofilms. We evaluated a series of PAs with varied alkyl chain lengths and examined their antimicrobial activity against Gram-positive pathogens (S. aureus, MRSA, and B. subtilis). The selected PA with the most potent antibiofilm activity was incorporated into BNEs for enhanced solubility and penetration into the EPS matrix (PA-BNEs). The antimicrobial efficacy of PA-BNEs was assessed against biofilms of Gram-positive strains. The BNEs facilitated the solubilization and effective delivery of the PA deep into the biofilm matrix, addressing the limitations of hydrophobic SMAs. Our findings demonstrated that the PA2 exhibited synergistic antibiofilm activity when it was loaded into nanoemulsions. This study presents a promising platform for addressing MDR infections by combining pseudopyronine analogs with antimicrobial biodegradable nanoemulsions, overcoming challenges associated with treating biofilm infections.

Secured Nanosynthesis-Deposition Aerosol Process for Composite Thin Films Incorporating Highly Dispersed Nanoparticles

Application of nanocomposites in daily life requires not only small nanoparticles (NPs) well dispersed in a matrix, but also a manufacturing process that is mindful of the operator and the environment. Avoiding any exposure to NPs is one such way, and direct liquid reaction-injection (DLRI) aims to fulfill this need. DLRI is based on the controlled in situ synthesis of NPs from the decomposition of suitable organometallic precursors in conditions that are compatible with a pulsed injection mode of an aerosol into a downstream process. Coupled with low-pressure plasma, DLRI produces nanocomposite with homogeneously well-dispersed small nanoparticles that in the particular case of ZnO-DLC nanocomposite exhibit unique properties. DLRI favorably compares with the direct liquid injection of ex situ formed NPs. The exothermic hydrolysis reaction of the organometallic precursor at the droplet-gas interface leads to the injection of small and highly dispersed NPs and, consequently, the deposition of fine and controlled distribution in the nanocomposite. The scope of DLRI nanosynthesis has been extended to several metal oxides such as zinc, tin, tungsten, and copper to generalize the concept. Hence, DLRI is an attractive method to synthesize, inject, and deposit nanoparticles and meets the prevention and atom economy requirements of green chemistry.

The role of nanocomposites against biofilm infections in humans

The use of nanomaterials in several fields of science has undergone a revolution in the last few decades. It has been reported by the National Institutes of Health (NIH) that 65% and 80% of infections are accountable for at least 65% of human bacterial infections. One of their important applications in healthcare is the use of nanoparticles (NPs) to eradicate free-floating bacteria and those that form biofilms. A nanocomposite (NC) is a multiphase stable fabric with one or three dimensions that are much smaller than 100 nm, or systems with nanoscale repeat distances between the unique phases that make up the material. Using NC materials to get rid of germs is a more sophisticated and effective technique to destroy bacterial biofilms. These biofilms are refractory to standard antibiotics, mainly to chronic infections and non-healing wounds. Materials like graphene and chitosan can be utilized to make several forms of NCs, in addition to different metal oxides. The ability of NCs to address the issue of bacterial resistance is its main advantage over antibiotics. This review highlights the synthesis, characterization, and mechanism through which NCs disrupt Gram-positive and Gram-negative bacterial biofilms, and their relative benefits and drawbacks. There is an urgent need to develop materials like NCs with a larger spectrum of action due to the rising prevalence of human bacterial diseases that are multidrug-resistant and form biofilms.

Guanidinium-Decorated Nanostructure for Precision Sonodynamic-Catalytic Therapy of MRSA-Infected Osteomyelitis

Osteomyelitis caused by methicillin-resistant Staphylococcus aureus (MRSA) biofilm infection is difficult to eradicate and can even be life-threatening. Given that the infection is persistent and deep-seated in the bone tissue, controlled and efficient treatment of osteomyelitis remains challenging. Herein, an activatable nanostructure (Au/TNT@PG) is presented for synergistic sonodynamic-catalytic therapy of MRSA-infected osteomyelitis. The Au/TNT@PG backbone is obtained by conjugating a guanidinium-rich polymer (PG), a component that penetrates the biofilm matrix, onto ultrasound (US)-absorbing gold-doped titanate nanotubes (Au/TNTs). Under deep-penetrating US irradiation, the nanocomposite generates ¹ O₂ for sonodynamic therapy and catalyzes the decomposition of endogenous H₂ O₂ into toxic •OH in the acidic infection microenvironment for catalytic therapy, leading to bacterial cell death. Its robust antibacterial effectiveness is attributable to its bacteria-capturing ability, the biofilm penetrability of positively charged guanidinium, and the subsequent synergistic effect of sonodynamic-catalytic action of Au/TNT. Such a remotely controlled approach potentiates the polarization of macrophages to M2-type while suppressing the M1-type, leading to topical inflammation resolution and enhanced osteoblast proliferation and differentiation to inhibit bone loss. Therefore, this study provides a generic nanotherapeutic approach for efficient sonodynamic-catalytic therapy with respect to osteomyelitis.

Enzyme-triggered smart antimicrobial drug release systems against bacterial infections

The rapid emergence and spread of drug-resistant bacteria, as one of the most pressing public health threats, are declining our arsenal of available antimicrobial drugs. Advanced antimicrobial drug delivery systems that can achieve precise and controlled release of antimicrobial agents in the microenvironment of bacterial infections will retard the development of antimicrobial resistance. A variety of extracellular enzymes are secreted by bacteria to destroy physical integrity of tissue during their invasion of host body, which can be utilized as stimuli to trigger "on-demand" release of antimicrobials. In the past decade, such bacterial enzyme responsive drug release systems have been intensively studied but few review has been released. Herein, we systematically summarize the recent progress of smart antimicrobial drug delivery systems triggered by bacteria secreted enzymes such as lipase, hyaluronidase, protease and antibiotic degrading enzymes. The perspectives and existing key issues of this field will also be discussed to fuel the innovative research and translational application in the future.

Therapeutic Intervention for Various Hospital Setting Strains of Biofilm Forming Candida auris with Multiple Drug Resistance Mutations Using Nanomaterial Ag-Silicalite-1 Zeolite

Candida auris (C. auris), an emerging multidrug-resistant microorganism, with limited therapeutical options, is one of the leading causes of nosocomial infections. The current study includes 19 C. auris strains collected from King Fahd Hospital of the University and King Fahad Specialist Hospital in Dammam, identified by 18S rRNA gene and ITS region sequencing. Drug-resistance-associated mutations in ERG11, TAC1B and FUR1 genes were screened to gain insight into the pattern of drug resistance. Molecular identification was successfully achieved using 18S rRNA gene and ITS region and 5 drug-resistance-associated missense variants identified in the ERG11 (F132Y and K143R) and TAC1B (H608Y, P611S and A640V) genes of C. auris strains, grouped into 3 clades. The prophylactic and therapeutic application of hydrothermally synthesized Ag-silicalite-1 (Si/Ag ratio 25) nanomaterial was tested against the 3 clades of clinical C. auris strains. 4wt%Ag/TiZSM-5 prepared using conventional impregnation technique was used for comparative study, and nano formulations were characterized using different techniques. The antibiofilm activity of nanomaterials was tested by cell kill assay, scanning electron microscopy (SEM) and light microscopy. Across all the clades of C. auris strains, 4 wt%Ag/TiZSM-5 and Ag-silicalite-1 demonstrated a significant (p = 1.1102 × 10^-16) inhibitory effect on the biofilm's survival rate: the lowest inhibition value was (10%) with Ag-silicalite-1 at 24 and 48 h incubation. A profound change in morphogenesis in addition to the reduction in the number of C.auris cells was shown by SEM and light microscopy. The presence of a high surface area and the uniform dispersion of nanosized Ag species displays enhanced anti-Candida activity, and therefore it has great potential against the emerging multidrug-resistant C. auris.

Self-Propelling Nanomotors Integrated with Biofilm Microenvironment-Activated NO Release to Accelerate Healing of Bacteria-Infected Diabetic Wounds

Diabetic foot ulcer (DFU) treatment is challenged by persistent bacterial infection and hyperglycemia-caused vascular dysplasia. Herein, self-propelled nanomotors are designed to achieve biofilm microenvironment (BME)-activated multistage release of NO for effective sterilization and subsequent angiogenesis promotion. CaO₂ nanoparticles (NPs) are capped with PDA layers, followed by complexation with Fe²⁺ and surface grafting of cysteine-NO to obtain Janus Ca@PDA_Fe -CNO NPs. In response to low pH in BME, the decomposition of CaO₂ cores generates O₂ from one side of Janus NPs to propel biofilm penetration, and the released H₂ O₂ and Fe²⁺ produce •OH through Fenton reaction. The concurrent glutathione-triggered release of NO can be converted into reactive nitrogen species, which exhibit significantly higher bactericidal efficacy than those with only generation of •OH or NO. The slow release of NO for an extended time period promotes endothelial cell proliferation and migration. On Staphylococcus aureus-infected skin wounds of diabetic mice, NP treatment eliminates bacterial infections and significantly elevates blood vessel densities, leading to full wound recovery and regeneration of arranged collagen fibers and skin accessories. Thus, the self-propelling and multistage release of NO provide a feasible strategy to combat biofilm infection without using any antibiotics and accelerate angiogenesis and wound healing for DFU treatment.

Supramolecular Adhesive Materials with Antimicrobial Activity for Emerging Biomedical Applications

Traditional adhesives or glues such as cyanoacrylates, fibrin glue, polyethylene glycol, and their derivatives have been widely used in biomedical fields. However, they still suffer from numerous limitations, including the mechanical mismatch with biological tissues, weak adhesion on wet surfaces, biological incompatibility, and incapability of integrating desired multifunction. In addition to adaptive mechanical and adhesion properties, adhesive biomaterials should be able to integrate multiple functions such as stimuli-responsiveness, control-releasing of small or macromolecular therapeutic molecules, hosting of various cells, and programmable degradation to fulfill the requirements in the specific biological systems. Therefore, rational molecular engineering and structural designs are required to facilitate the development of functional adhesive materials. This review summarizes and analyzes the current supramolecular design strategies of representative adhesive materials, serving as a general guide for researchers seeking to develop novel adhesive materials for biomedical applications.

Addressing a future pandemic: how can non-biological complex drugs prepare us for antimicrobial resistance threats?

Loss of effective antibiotics through antimicrobial resistance (AMR) is one of the greatest threats to human health. By 2050, the annual death rate resulting from AMR infections is predicted to have climbed from 1.27 million per annum in 2019, up to 10 million per annum. It is therefore imperative to preserve the effectiveness of both existing and future antibiotics, such that they continue to save lives. One way to conserve the use of existing antibiotics and build further contingency against resistant strains is to develop alternatives. Non-biological complex drugs (NBCDs) are an emerging class of therapeutics that show multi-mechanistic antimicrobial activity and hold great promise as next generation antimicrobial agents. We critically outline the focal advancements for each key material class, including antimicrobial polymer materials, carbon nanomaterials, and inorganic nanomaterials, and highlight the potential for the development of antimicrobial resistance against each class. Finally, we outline remaining challenges for their clinical translation, including the need for specific regulatory pathways to be established in order to allow for more efficient clinical approval and adoption of these new technologies.

Enhanced antibacterial activity of surface re-engineered lysozyme against Gram-negative bacteria without accumulated resistance

In this study, we show a way to improve the antibacterial activity of lysozyme by incorporating guanidino functional groups onto its surface (Lyz-Gua), which could treat pathogenic bacteria without accumulated resistance and shows advantages over commercial antibiotics.

Antibacterial metal nanoclusters

Combating bacterial infections is one of the most important applications of nanomedicine. In the past two decades, significant efforts have been committed to tune physicochemical properties of nanomaterials for the development of various novel nanoantibiotics. Among which, metal nanoclusters (NCs) with well-defined ultrasmall size and adjustable surface chemistry are emerging as the next-generation high performance nanoantibiotics. Metal NCs can penetrate bacterial cell envelope more easily than conventional nanomaterials due to their ultrasmall size. Meanwhile, the abundant active sites of the metal NCs help to catalyze the bacterial intracellular biochemical processes, resulting in enhanced antibacterial properties. In this review, we discuss the recent developments in metal NCs as a new generation of antimicrobial agents. Based on a brief introduction to the characteristics of metal NCs, we highlight the general working mechanisms by which metal NCs combating the bacterial infections. We also emphasize central roles of core size, element composition, oxidation state, and surface chemistry of metal NCs in their antimicrobial efficacy. Finally, we present a perspective on the remaining challenges and future developments of metal NCs for antibacterial therapeutics.

Dual antimicrobial-loaded biodegradable nanoemulsions for synergistic treatment of wound biofilms

Wound biofilm infections caused by multidrug-resistant (MDR) bacteria constitute a major threat to public health; acquired resistance combined with resistance associated with the biofilm phenotype makes combatting these infections challenging. Biodegradable polymeric nanoemulsions that encapsulate two hydrophobic antimicrobial agents (eugenol and triclosan) (TE-BNEs) as a strategy to combat chronic wound infections are reported here. The cationic nanoemulsions efficiently penetrate and accumulate in biofilms, synergistically eradicating MDR bacterial biofilms, including persister cells. Notably, the nanoemulsion platform displays excellent biocompatibility and delays emergence of resistance to triclosan. The TE-BNEs are active in an in vivo murine model of mature MDR wound biofilm infections, with 99% bacterial elimination. The efficacy of this system coupled with prevention of emergence of bacterial resistance highlight the potential of this combination platform to treat MDR wound biofilm infections.

Acid-Responsive Nanoporphyrin Evolution for Near-Infrared Fluorescence-Guided Photo-Ablation of Biofilm

Combating biofilm infections remains a challenge due to the shield and acidic conditions. Herein, an acid-responsive nanoporphyrin (PN3-NP) based on the self-assembly of a water-soluble porphyrin derivative (PN3) is constructed. Additional kinetic control sites formed by the conjugation of the spermine molecules to a porphyrin macrocycle make PN3 self-assemble into stable nanoparticles (PN3-NP) in the physiological environment. Noteworthily, near-infrared (NIR) fluorescence monitoring and synergistic photodynamic therapy (PDT) and photothermal therapy (PTT) effects of PN3-NP can be triggered by the acidity in biofilms, accompanied by intelligent transformation into dot-like nanospheres. Thus, damage to normal tissue is effectively avoided and accurate diagnosis and treatment of biofilms is achieved successfully. The good results of fluorescence imaging-guided photo-ablation of antibiotic-resistant strains methicillin-resistant Staphylococcus aureus (MRSA) biofilms verify that PN3-NP is a promising alternative to antibiotics. Meanwhile, this strategy also opens new horizons to engineer smart nano-photosensitizer for accurate diagnosis and treatment of biofilms.

NIR-regulated dual-functional silica nanoplatform for infected-wound therapy via synergistic sterilization and anti-oxidation

Nature-derived bioactive components and photothermal synergistic therapy bring potential strategies for fighting bacterial infection and accelerating would healing by virtue of their excellent therapeutic efficiencies and ignorable side effects, where photothermal property not only acts as sterilization energy but also as a doorkeeper to control the natural component release. Herein, by integrating the excellent antibacterial property of cinnamaldehyde (CA) and the outstanding photothermal performance of copper sulfide nanoparticles (CuS NPs), a multifunctional nanoplatform of SiO₂ @CA@CuS nanospheres (NSs) is constructed with silica nanosphere (SiO₂ NSs) as carrier. SiO₂ @CA@CuS NSs exhibit photothermal property, bacterial absorption capacity, extraordinary antibacterial activity and antioxidant property. Mechanism characteriazation and antibacterial experiment indicate that positive charged SiO₂ @CA@CuS can adhere to the negative charged surface of bacteria, and quickly kill bacteria through the synergistic action of the released CA and heat produced under near infrared light (NIR) irradiation at 980 nm. The sterilization efficiencies for Escherichia coli (E. coli) and S. aureus reach 99.86% and 99.84%, respectively. Furthermore, NIR-regulated SiO₂ @CA@CuS perform great biocompatibility, as well as effective effects for accelerating S. aureus-infected wound healing at a low photothermal temperature (45 °C) relying on synergistic sterilization and anti-oxidation.

Nanomaterials: The New Antimicrobial Magic Bullet

Bacterial infections are a significant cause of mortality and morbidity worldwide, despite decades of use of numerous existing antibiotics and constant efforts by researchers to discover new antibiotics. The emergence of infections associated with antibiotic-resistant bacterial strains, has amplified the pressure to develop additional bactericidal therapies or new unorthodox approaches that can deal with antimicrobial resistance. Nanomaterial-based strategies, particularly those that do not rely on conventional small-molecule antibiotics, offer promise in part due to their ability to dodge existing mechanisms used by drug-resistant bacteria. Therefore, the use of nanomaterial-based formulations has attracted attention in the field of antibiotic therapy. In this Review, we highlight novel and emerging nanomaterial-based formulations along with details about the mechanisms by which nanoparticles can target bacterial infections and antimicrobial resistance. A detailed discussion about types and the activities of nanoparticles is presented, along with how they can be used as either delivery systems or as inherent antimicrobials, or a combination of both. Lastly, we highlight some toxicological concerns for the use of nanoparticles in antibiotic therapies.

Nanomaterials Aiming to Tackle Antibiotic-Resistant Bacteria

The global health of humans is seriously affected by the dramatic increases in the resistance patterns of antimicrobials against virulent bacteria. From the statements released by the Centers for Disease Control and Prevention about the world entering a post-antibiotic era, and forecasts about human mortality due to bacterial infection being increased compared to cancer, the current body of literature indicates that emerging tools such as nanoparticles can be used against lethal infections caused by bacteria. Furthermore, a different concept of nanomaterial-based methods can cope with the hindrance faced by common antimicrobials, such as resistance to antibiotics. The current review focuses on different approaches to inhibiting bacterial infection using nanoparticles and aiding in the fabrication of antimicrobial nanotherapeutics by emphasizing the functionality of nanomaterial surface design and fabrication for antimicrobial cargo.

Multiplexed Identification of Bacterial Biofilm Infections Based on Machine-Learning-Aided Lanthanide Encoding

Pathogenic biofilms are up to 1000-fold more drug-resistant than planktonic pathogens and cause about 80% of all chronic infections worldwide. The lack of prompt and reliable biofilm identification methods seriously prohibits the diagnosis and treatment of biofilm infections. Here, we developed a machine-learning-aided cocktail assay for prompt and reliable biofilm detection. Lanthanide nanoparticles with different emissions, surface charges, and hydrophilicity are formulated into the cocktail kits. The lanthanide nanoparticles in the cocktail kits can offer competitive interactions with the biofilm and further maximize the charge and hydrophilicity differences between biofilms. The physicochemical heterogeneities of biofilms were transformed into luminescence intensity at different wavelengths by the cocktail kits. The luminescence signals were used as learning data to train the random forest algorithm, and the algorithm could identify the unknown biofilms within minutes after training. Electrostatic attractions and hydrophobic-hydrophobic interactions were demonstrated to dominate the binding of the cocktail kits to the biofilms. By rationally designing the charge and hydrophilicity of the cocktail kit, unknown biofilms of pathogenic clinical isolates were identified with an overall accuracy of over 80% based on the random forest algorithm. Moreover, the antibiotic-loaded cocktail nanoprobes efficiently eradicated biofilms since the nanoprobes could penetrate deep into the biofilms. This work can serve as a reliable technique for the diagnosis of biofilm infections and it can also provide instructions for the design of multiplex assays for detecting biochemical compounds beyond biofilms.

Polymers as advanced antibacterial and antibiofilm agents for direct and combination therapies

The growing prevalence of antimicrobial drug resistance in pathogenic bacteria is a critical threat to global health. Conventional antibiotics still play a crucial role in treating bacterial infections, but the emergence and spread of antibiotic-resistant micro-organisms are rapidly eroding their usefulness. Cationic polymers, which target bacterial membranes, are thought to be the last frontier in antibacterial development. This class of molecules possesses several advantages including a low propensity for emergence of resistance and rapid bactericidal effect. This review surveys the structure-activity of advanced antimicrobial cationic polymers, including poly(α-amino acids), β-peptides, polycarbonates, star polymers and main-chain cationic polymers, with low toxicity and high selectivity to potentially become useful for real applications. Their uses as potentiating adjuvants to overcome bacterial membrane-related resistance mechanisms and as antibiofilm agents are also covered. The review is intended to provide valuable information for design and development of cationic polymers as antimicrobial and antibiofilm agents for translational applications.

A biofilm microenvironment-responsive one-for-all bactericidal nanoplatform for photothermal-augmented multimodal synergistic therapy of pathogenic bacterial biofilm infection

We rationally construct a biofilm microenvironment-responsive bactericidal nanoplatform (ZnPMp) consisting of ZnO core, a Fe3+-doped polydopamine coating and methylene blue (MB) payload for combined CT/CDT/PTT/PDT multi-mode antibacterial therapy.

Chain-folding regulated self-assembly, outstanding bactericidal activity and biofilm eradication by biomimetic amphiphilic polymers

Chain-folding regulated hierarchical self-assembly of cationic host defense peptide mimicking amphiphilic polyurethanes exhibit excellent antibacterial activity and biofilm killing.

A Degradable, Broad-Spectrum and Resistance-Resistant Antimicrobial Oligoguanidine as Disinfecting and Therapeutic Agent in Aquaculture

The threat of antibiotic resistance to community healthcare and global economy has raised extensive concern, and the over-use of antibiotics in animal husbandry plays a significant role in the occurrence...

A Biofilm Microenvironment-Activated Single-Atom Iron Nanozyme with NIR-Controllable Nanocatalytic Activities for Synergetic Bacteria-Infected Wound Therapy

Biofilm microenvironment (BME)-activated antimicrobial agents display great potential for improved biofilm-related infection therapy because of their superior specificities and sensitivities, effective eliminations, and minimal side effects. Herein, BME-activated Fe-doped polydiaminopyridine nanofusiform-mediated single-atom nanozyme (FePN SAzyme) is presented for photothermal/chemodynamic synergetic bacteria-infected wound therapy. The photothermal therapy (PTT) function of SAzyme can be specifically initiated by the high level of H₂ O₂ and further accelerated through mild acid within the inflammatory environment through "two-step rocket launching-like" process. Additionally, the enhanced chemodynamic therapy (CDT) for the FePN SAzyme can also be endowed by producing hydroxyl radicals through reacting with H₂ O₂ and consuming glutathione (GSH) of the BME, thereby contributing to more efficient synergistic therapeutic effect. Meanwhile, FePN SAzyme could catalyze biofilm-overexpressed H₂ O₂ decomposing into O₂ and overcome the hypoxia of biofilm, which significantly enhances the susceptibility of biofilm and increases the synergistic efficacy. Most importantly, the synergistic therapy of bacterial-induced infection diseases can be switched on by the internal and external stimuli simultaneously, resulting in minimal nonspecific damage to healthy tissue. These remarkable characteristics of FePN SAzyme not only develop an innovative strategy for the BME-activated combination therapy but also open a new avenue to explore other nanozyme-involved nanoplatforms for bacterial biofilm infections.

Phosphonate/quaternary ammonium copolymers as high-efficiency antibacterial coating for metallic substrates

Designing a coating material with efficient bactericidal property to cope with bacterial associated infections is highly desirable for metallic implants and devices. Here, we report phosphonate/quaternary ammonium copolymers, p(DEMMP-co-TMAEMA), as the new type of metal anchorable high-efficiency antibacterial coating. Seven p(DEMMP-co-TMAEMA) polymers with varied cationic components were precisely prepared via random radical polymerization. Copolymers were constructed on titanium alloy (TC4) substrates based on strong covalent bonding between the phosphonate group and metallic substrates through a one-step process as evidenced by XPS and water contact angle tests. A robust relationship between the composition of the copolymers and the bactericidal ability endowed to TC4 substrates was established. Results showed that the copolymer, with the pDEMMP content even as low as 6.3%, was able to anchor onto TC4 substrates. With the increase of cationic pTMAEMA content from 4.0 to 93.7% in the coating copolymer, the bactericidal ability endowed to the TC4 substrates was steadily increased from 39.4 to 98.8% for S. aureus and from 70.0 to 99.4% for E. coli after 8 h's of contacting. All p(DEMMP-co-TMAEMA) coating on TC4 substrates showed limited cytotoxicity to C2C12 cells. Notably, the phosphonate/quaternary amine copolymers can be easily constructed on diverse biomedical metals such as titanium (Ti), stainless steel (SS), and Ni/Cr alloys with significantly increased antibacterial performance, demonstrating the potency of the copolymer as the general high-efficiency antibacterial coating for diverse bio-metals.

Biodegradable Poly(lactic acid) Stabilized Nanoemulsions for the Treatment of Multidrug-Resistant Bacterial Biofilms

Biofilm infections caused by multidrug-resistant (MDR) bacteria are an urgent global health threat. Incorporation of natural essential oils into biodegradable oil-in-water cross-linked polymeric nanoemulsions (X-NEs) provides effective eradication of MDR bacterial biofilms. The X-NE platform combines the degradability of functionalized poly(lactic acid) polymers with the antimicrobial activity of carvacrol (from oregano oil). These X-NEs exhibited effective penetration and killing of biofilms formed by pathogenic bacteria. Biofilm-fibroblast coculture models demonstrate that X-NEs selectively eliminate bacteria without harming mammalian cells, making them promising candidates for antibiofilm therapeutics.

Macromolecular Nanotherapeutics and Antibiotic Adjuvants to Tackle Bacterial and Fungal Infections

The escalating rise in the population of multidrug-resistant (MDR) pathogens coupled with their biofilm forming ability has struck the global health as nightmare. Alongwith the threat of aforementioned menace, the sluggish development of new antibiotics and the continuous deterioration of the antibiotic pipeline has stimulated the scientific community toward the search of smart and innovative alternatives. In near future, membrane targeting antimicrobial polymers, inspired from antimicrobial peptides, can stand out significantly to combat against the MDR superbugs. Many of these amphiphilic polymers can form nanoaggregates through self-assembly with superior and selective antimicrobial efficacy. Additionally, these macromolecular nanoaggregrates can be utilized to engineer smart antibiotic-delivery system for on-demand drug-release, exploiting the infection site's micoenvironment. This strategy substantially increases the local concentration of antibiotics and reduces the associated off-target toxicity. Furthermore, amphiphilc macromolecules can be utilized to rejuvinate obsolete antibiotics to tackle the drug-resistant infections. This review article highlights the recent developments in macromolecular architecture to design numerous nanostructures with broad-spectrum antimicrobial activity, their application in fabricating smart drug delivery systems and their efficacy as antibiotic adjuvants to circumvent antimicrobial resistance. Finally, the current challenges and future prospects are briefly discussed for further exploration and their practical application in clinical settings.

Current progress and prospects of organic nanoparticles against bacterial biofilm

Biofilm plays a vital role in the pathogenicity and resistance of bacteria, and is an important problem to be settled urgently in the treatment of bacterial diseases. Exploring effective strategies to control bacterial biofilm has become a hot research topic. Compared to other measures, organic nanomaterials have shown greater prospects in overcoming the problems of bacterial biofilms due to their unique properties. In order to explore more effective organic nanomaterials against biofilms, we used relevant keywords to search for related published publications on the Web of Science . On the basis of these searched publications, this review firstly summarized the properties, formulation, harmness, and treatment challenges of biofilm. Secondly, the current progress of organic nanomaterials against bacterial biofilm and its possible anti-biofilm mechanisms (e.g., reducing the adhesion of biofilms, enhancing the permeability of antimicrobial agents, maintaining drug stability, fighting against biofilm using specific actions) was analyzed. Thirdly, the influences on the anti-biofilm efficacy of organic nanomaterials were discussed from nanoparticles and biofilm characteristics. Finally, the challenges and prospects of organic nanoparticles against biofilm were concluded. This review may help researchers to realize the progress and challenges of nanoparticles against biofilm and thus help to design more efficient organic nanomaterial to fight against biofilms.

Chitosan modified ultra-thin hollow nanoparticles for photosensitizer loading and enhancing photodynamic antibacterial activities

Antibacterial photodynamic therapy (PDT) has attracted extremely attention due to not inducing bacteria to generate resistance. However, the poor utilization and low reactive oxygen species (ROS) field of photosensitizers hinder their further application for antibacterial. Here, we designed ultra-thin hollow silica nanoparticles (UHSN), followed by pore-engineering including covalent anchoring of chitosan (UHSN@CS) for enhanced loading and photodynamic property of photosensitizer. The UHSN@CS exhibit high loading efficiency (80.6%, pH = 6.0) and controllable pH-responsive release for Ce6. Additionally, UHSN@CS can enhance the ROS yield of photosensitizers and effectively adhere to S. aureus, thus enormously enhancing antibacterial performance toward bacteria. Moreover, UHSN@CS-Ce6 can obliterate mature S. aureus biofilm and cause an 81% decrease in the biomass, showing a better therapeutic effect than Ce6 (59.2%) under laser irradiation. In vivo results confirm that UHSN@CS-Ce6 is effective to promote infectious wound regeneration. As photodynamic-based nanoplatforms, UHSN@CS-Ce6 are potential antibacterial agents for skin infection therapy.

Photoenhanced Dual-Functional Nanomedicine for Promoting Wound Healing: Shifting Focus from Bacteria Eradication to Host Microenvironment Modulation

Pathogenic bacterial infection has become a serious medical threat to global public health. Once the skin has serious defects, bacterial invasion and the following chain reactions will be a thorny clinical conundrum, which takes a long time to heal. Although various strategies have been used to eradicate bacteria, the treatment which can simultaneously disinfect and regulate the infection-related host responses is rarely reported. Herein, inspired by the host microenvironment, a photoenhanced dual-functional nanomedicine is constructed (Hemin@Phmg-TA-MSN) for localized bacterial ablation and host microenvironment modulation. The "NIR-triggered local microthermal therapy" and positively charged surface endow the nanomedicine with excellent bacterial capture and killing activities. Meanwhile, the nanomedicine exhibits broad-spectrum reactive oxygen species (ROS) scavenging activity via the synergistic effect of hemin and tannic acid with photoenhanced electron and hydrogen transfers. Furthermore, the in vivo experiments demonstrate that the dual-functional nanomedicine not only presents robust bacterial eradication capability, but also triggers the oxidative stress and inflammatory microenvironment regulation. The work not only shows a facile and effective way for infected wound management but also provides a new horizon for designing novel and efficient anti-infection therapy shifting focus from bacteria treatment to host microenvironment modulation.

Approaches for the inhibition and elimination of microbial biofilms using macromolecular agents

Biofilms are complex three-dimensional structures formed at interfaces by the vast majority of bacteria and fungi. These robust communities have an important detrimental impact on a wide range of industries and other facets of our daily lives, yet their removal is challenging owing to the high tolerance of biofilms towards conventional antimicrobial agents. This key issue has driven an urgent search for new innovative antibiofilm materials. Amongst these emerging approaches are highly promising materials that employ aqueous-soluble macromolecules, including peptides, proteins, synthetic polymers, and nanomaterials thereof, which exhibit a range of functionalities that can inhibit biofilm formation or detach and destroy organisms residing within established biofilms. In this Review, we outline the progress made in inhibiting and removing biofilms using macromolecular approaches, including a spotlight on cutting-edge materials that respond to environmental stimuli for "on-demand" antibiofilm activity, as well as synergistic multi-action antibiofilm materials. We also highlight materials that imitate and harness naturally derived species to achieve new and improved biomimetic and biohybrid antibiofilm materials. Finally, we share some speculative insights into possible future directions for this exciting and highly significant field of research.

Isoflavonoid-Antibiotic Thin Films Fabricated by MAPLE with Improved Resistance to Microbial Colonization

Staphylococcus aureus (Gram-positive) and Pseudomonas aeruginosa (Gram-negative) bacteria represent major infectious threats in the hospital environment due to their wide distribution, opportunistic behavior, and increasing antibiotic resistance. This study reports on the deposition of polyvinylpyrrolidone/antibiotic/isoflavonoid thin films by the matrix-assisted pulsed laser evaporation (MAPLE) method as anti-adhesion barrier coatings, on biomedical surfaces for improved resistance to microbial colonization. The thin films were characterized by Fourier transform infrared spectroscopy, infrared microscopy, and scanning electron microscopy. In vitro biological assay tests were performed to evaluate the influence of the thin films on the development of biofilms formed by Gram-positive and Gram-negative bacterial strains. In vitro biocompatibility tests were assessed on human endothelial cells examined for up to five days of incubation, via qualitative and quantitative methods. The results of this study revealed that the laser-fabricated coatings are biocompatible and resistant to microbial colonization and biofilm formation, making them successful candidates for biomedical devices and contact surfaces that would otherwise be amenable to contact transmission.

Nanotherapeutics using all-natural materials. Effective treatment of wound biofilm infections using crosslinked nanoemulsions

Bacterial wound infections are a threat to public health. Although antibiotics currently provide front-line treatments for bacterial infections, the development of drug resistance coupled with the defenses provided through biofilm formation render these infections difficult, if not impossible, to cure. Antimicrobials from natural resources provide unique antimicrobial mechanisms and are generally recognized as safe and sustainable. Herein, an all-natural antimicrobial platform is reported. It is active against bacterial biofilms and accelerates healing of wound biofilm infections in vivo. This antimicrobial platform uses gelatin stabilized by photocrosslinking using riboflavin (vitamin B2) as a photocatalyst, and carvacrol (the primary constituent of oregano oil) as the active antimicrobial. The engineered nanoemulsions demonstrate broad-spectrum antimicrobial activity towards drug-resistant bacterial biofilms and significantly expedite wound healing in an in vivo murine wound biofilm model. The antimicrobial activity, wound healing promotion, and biosafety of these nanoemulsions provide a readily translatable and sustainable strategy for managing wound infections.

Design of nanoengineered antibacterial polymers for biomedical applications

Pathogenic bacteria have become global threats to public health. Since the advent of antibiotics about 100 years ago, their use has been embraced with great enthusiasm because of their effective treatment of bacterial infections. However, the evolution of pathogenic bacteria with resistance to conventional antibiotics has resulted in an urgent need for the development of a new generation of antibiotics. The use of antimicrobial polymers offers the promise of enhancing the efficacy of antimicrobial agents. Of the various antibacterial polymers that effectively eradicate pathogenic bacteria, those that are nanoengineered have garnered significant research interest in their design and biomedical applications. Because of their high surface area and high reactivity, these polymers show greater antibacterial activity than conventional antibacterial agents, by inhibiting the growth or destroying the cell membrane of pathogenic bacteria. This review summarizes several strategies for designing nanoengineered antibacterial polymers, explores the factors that affect their antibacterial properties, and examines key features of their design. It then comments briefly on the future prospects for nanoengineered antibacterial polymers. This review thus provides a feasible guide to developing nanoengineered antibacterial polymers by presenting both broad and in-depth bench research, and it offers suggestions for their potential in biomedical applications.

Protein-stabilized silver nanoparticles encapsulating gentamycin for the therapy of bacterial biofilm infections

Aim: An antibiotic-conjugated protein-stabilized nanoparticle hybrid system was developed to combat the challenges faced during the treatment of drug-resistant bacterial biofilm-associated infections. Materials & methods: Biocompatible silver nanoparticles were synthesized using intracellular protein and gentamycin was attached. The resulting nanohybrid was characterized and its antibacterial efficiency was assessed against Gram-positive, Gram-negative and drug-resistant bacteria. Results: Spectroscopic and electron microscopic analysis revealed that the nanoparticles were spherical with a diameter of 2-6 nm. Red-shifting of the surface plasmon peak and an increase in hydrodynamic diameter confirmed attachment of gentamycin. The nanohybrid exhibited antibacterial efficiency against a range of bacteria with the ability to inhibit and disrupt bacterial biofilm. Conclusion: A unique nanohybrid was designed that has potential to be used to control drug-resistant bacterial infections in the future.

From bulk to nano-delivery of essential phytochemicals: recent progress and strategies for antibacterial resistance

Bacterial biofilms caused by antibiotic resistance are a severe cause of infection threatening human health nowadays. The primary causes of this emerging threat are poor penetration of conventional antibiotics and the growing number of varied strains of resistant bacteria. Recently, bulk phytochemical oils have been widely explored for their potential as antibacterial agents. However, due to their poor solubility, low stability, and highly volatile properties, essential oils are not effective for in vitro and in vivo antibacterial applications and require further preparation. In this review, we discuss the recent progress and strategies to overcome the drawbacks of bulk phytochemical oils using nano-delivery, as well as the current challenges and future outlook of these nano-delivery systems against bacterial resistance.

PAMAM dendrimers with dual-conjugated vancomycin and Ag-nanoparticles do not induce bacterial resistance and kill vancomycin-resistant Staphylococci

The effective life-time of new antimicrobials until the appearance of the first resistant strains is steadily decreasing, which discourages incentives for commercialization required for clinical translation and application. Therefore, development of new antimicrobials should not only focus on better and better killing of antimicrobial-resistant strains, but as a paradigm shift on developing antimicrobials that prevent induction of resistance. Heterofunctionalized, poly-(amido-amine) (PAMAM) dendrimers with amide-conjugated vancomycin (Van) and incorporated Ag nanoparticles (AgNP) showed a 6-7 log reduction in colony-forming-units of a vancomycin-resistant Staphylococcus aureus strain in vitro, while not inducing resistance in a vancomycin-susceptible strain. Healing of a superficial wound in mice infected with the vancomycin-resistant S. aureus was significantly faster and more effective by irrigation with low-dose, dual-conjugated Van-PAMAM-AgNP dendrimer suspension than by irrigation with vancomycin in solution or a PAMAM-AgNP dendrimer suspension. Herewith, dual-conjugation of vancomycin together with AgNPs in heterofunctionalized PAMAM dendrimers fulfills the need for new, prolonged life-time antimicrobials killing resistant pathogens without inducing resistance in susceptible strains. Important for clinical translation, this better use of antibiotics can be achieved with currently approved and clinically applied antibiotics, provided suitable for amide-conjugation.