Nanobiotechnology-driven innovations for tackling antimicrobial resistance

 Corresponding author: Oluwaseyi Ajibola Fagbemi; Email: Copyright © 2025 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0. Nanobiotechnology-driven innovations for tackling antimicrobial resistance Oluwaseyi Ajibola Fagbemi 1, *, Matthew Essuah 2, Darlignton Chukwuma Ugwu 3, Adeola Badrat Ajibola 4, Sarah Oluwaseun Julius 5, Ikemefuna Nnamdi Onyeyili 6 and Damilola Samuel Ojo-omoniyi 7 1 Department of Human Anatomy, College of Medicine, Federal University Lokoja, Kogi State, Nigeria. 2 Department of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Ghana. 3 Department of Health Emergency Preparedness and Response, Nigeria Centre for Disease Control and Prevention. 4 Department of Animal Nutrition and Biotechnology, Ladoke Akintola University of Technology, Oyo, Nigeria. 5 Department of Microbiology, University of Ibadan, Nigeria. 6 Department of treatment care and support, AIDS Healthcare Foundation Lokoja, Nigeria. 7 Department of Pharmaceutical Chemistry, University of Ibadan, Nigeria. World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 Publication history: Received on 14 December 2024; revised on 07 February 2025; accepted on 10 February 2025 Article DOI: https://doi.org/10.30574/wjbphs.2025.21.2.0093 Abstract Antimicrobial resistance (AMR) is an escalating global health crisis, challenging the efficacy of conventional antibiotics and necessitating novel approaches to infection management. This review explores the transformative role of nanobiotechnology in addressing AMR by leveraging the unique properties of nanomaterials for diagnostics, therapeutics, and vaccine development. Nanoparticles exhibit diverse mechanisms of action, including biofilm penetration, targeted drug delivery, and reactive oxygen species (ROS) generation, providing a multi-faceted approach to combating resistant pathogens. Innovations such as metallic nanoparticles, nanozymes, and lipid-based nanocarriers demonstrate significant potential in disrupting resistance mechanisms, enhancing the efficacy of existing antimicrobials, and reducing the likelihood of resistance development. Additionally, this review examines the integration of advanced methodologies like CRISPR-based gene editing and artificial intelligence (AI) to optimize nanoparticle design and function. Emerging applications in resource-limited settings highlight the scalability and accessibility of nanobiotechnological solutions, addressing healthcare disparities in regions disproportionately affected by AMR. However, challenges such as nanoparticle toxicity, environmental impact, and regulatory barriers underscore the need for interdisciplinary collaboration to ensure the safe and ethical deployment of these technologies. By synthesizing current advancements and addressing the barriers to clinical translation, this review underscores the transformative potential of nanobiotechnology in revolutionizing AMR management and safeguarding global health. Continued innovation and multidisciplinary cooperation will be critical to harnessing the full potential of nanobiotechnology in the fight against resistant infections. Keywords: Nanobiotechnology; Antimicrobial resistance; Nanoparticles; Drug delivery; CRISPR; nanozymes; Biofilm disruption; Metagenomics; Vaccine development 1. Introduction Antimicrobial resistance (AMR) represents a formidable challenge to global public health, characterized by the diminishing efficacy of standard treatments against a spectrum of infections. It is one of the gravest threats to global public health, with far-reaching implications for human health, animal well-being, and economic stability. The World Health Organization (WHO) has identified AMR as one of the top ten threats to global health, and has repeatedly emphasized the urgency of addressing this issue, warning that AMR could reverse decades of progress in medicine and usher in a "post-antibiotic era" where minor infections and routine surgeries become life-threatening. The emergence World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 301 of multidrug-resistant pathogens, fueled by the misuse and overuse of antibiotics in clinical and agricultural settings, has compounded the crisis. According to Chakraborty et al. [1], global estimates attribute 4.95 million deaths annually to drug-resistant bacterial infections, with 1.27 million directly caused by AMR. This growing threat demands innovative and interdisciplinary solutions that extend beyond traditional antimicrobial strategies. Efforts to develop new antibiotics have been hindered by scientific, economic, and logistical challenges. The pipeline for novel antimicrobials has dwindled, with only a few agents reaching late-stage clinical trials in recent decades. Furthermore, the adaptability of pathogens, often through genetic mutations and horizontal gene transfer, allows them to rapidly circumvent even newly developed drugs. This dynamic is exacerbated by the ability of certain bacteria, such as Staphylococcus aureus and Klebsiella pneumoniae, to form biofilms that act as protective barriers, rendering them resistant to conventional treatments [2]. In this context, nanobiotechnology has emerged as a transformative frontier with the potential to overcome these limitations. By leveraging the unique physicochemical properties of nanoparticles, such as their high surface area-tovolume ratio and tunable functionalities, researchers have developed innovative approaches for combating AMR. Nanoparticles offer multiple mechanisms of action, including direct microbial destruction via oxidative stress, disruption of bacterial membranes, and enhanced delivery of existing antibiotics to infection sites. These properties make them particularly effective against biofilm-associated infections and intracellular pathogens, which are notoriously difficult to treat using standard antibiotics [3]. This interdisciplinary field leverages the unique physicochemical properties of nanoscale materials to develop novel therapeutic and diagnostic tools. Nanoparticles, due to their high surface area-to-volume ratio and tunable surface functionalities, can interact with microbial cells in ways that circumvent traditional resistance mechanisms. For instance, metallic nanoparticles such as silver and gold have demonstrated intrinsic antimicrobial properties, including the ability to disrupt bacterial cell membranes and generate reactive oxygen species, leading to cell death. Additionally, nanocarriers can enhance the delivery and efficacy of existing antibiotics by facilitating targeted delivery, improving solubility, and enabling controlled release. These advancements suggest that nanobiotechnology could play a pivotal role in developing next-generation antimicrobials capable of overcoming the challenges posed by resistant pathogens. Figure 1 Recent advancements in nanobiotechnology (nanobiotics) in tackling AMR. Reproduced from Ref [1] with permission Recent advancements in nanotechnology have also paved the way for novel applications in diagnostics, therapeutics, and vaccine development (See Figure 1). Metallic nanoparticles, such as silver (AgNPs) and zinc oxide (ZnO), have World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 302 demonstrated broad-spectrum antimicrobial activity, while liposome-based nanocarriers have shown promise in delivering drugs with improved efficacy and reduced toxicity. Additionally, the development of nanozymes—catalytic nanoparticles that mimic natural enzymes—offers exciting opportunities for biofilm disruption and reactive oxygen species generation to combat resistant pathogens [4]. Despite these promising developments, the field of nanobiotechnology faces several challenges that must be addressed before its full potential can be realized. These include concerns over nanoparticle toxicity, environmental impact, scalability, and regulatory approval. Furthermore, the translation of nanobiotechnology from laboratory settings to clinical applications requires robust preclinical and clinical studies to establish safety, efficacy, and cost-effectiveness. As highlighted by Chakraborty et al. [1], interdisciplinary collaboration and public engagement are essential to overcoming these barriers and ensuring the successful integration of nanobiotechnology into global healthcare systems. This review aims to provide a comprehensive analysis of nanobiotechnology’s role in combating AMR, exploring its mechanisms of action, recent advancements, and potential applications. It will also critically evaluate the challenges and limitations associated with this field and propose strategies for addressing these obstacles. By synthesizing insights from current research, this paper seeks to underscore the transformative potential of nanobiotechnology in addressing one of the most pressing public health challenges of our time. As the global health community grapples with the escalating threat of AMR, nanobiotechnology offers a beacon of hope. Its innovative approaches have the potential to circumvent existing resistance mechanisms and restore the efficacy of antimicrobial therapies. However, realizing this potential requires addressing existing challenges through rigorous research and collaboration across disciplines [5]. The subsequent sections of this review will delve deeper into the specific applications, benefits, and obstacles associated with nanobiotechnology in the context of AMR, providing a roadmap for future research and development in this promising field. 2. Nanobiotechnology Solutions for AMR Figure 2 A Schematic diagram illustrating Nanoparticle Mechanisms in Combating AMR. Reproduced from Ref [7] with permission The field of nanobiotechnology has gained significant attention for its potential to revolutionize antimicrobial resistance (AMR) management. Unlike traditional antibiotics, which often fail against resistant pathogens due to biofilm formation, genetic mutations, or efflux pump mechanisms, nanobiotechnology offers a versatile platform to combat these challenges [1,6]. Nanoparticles possess unique physicochemical properties, including high surface area-to-volume ratios, tunable functionalities, and the ability to interact with bacterial systems at a molecular level. These features World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 303 enable nanoparticles to disrupt biofilms, enhance drug delivery, and target resistant pathogens through mechanisms that reduce the likelihood of further resistance development. According to Chakraborty et al. [1], the multifunctionality of nanomaterials allows for applications beyond direct antimicrobial action, including use as drug carriers and diagnostic tools. For example, metallic nanoparticles such as silver and zinc oxide have demonstrated inherent bactericidal properties, while polymeric nanocarriers improve drug stability and reduce toxicity. This section delves into the various nanobiotechnology-based approaches to combat AMR, focusing on nanoparticle-mediated drug delivery, metallic nanoparticles, and emerging technologies like nanozymes (see Figure 2). 2.1. Nanoparticle-Based Drug Delivery Systems Nanoparticle-based drug delivery systems have emerged as a transformative approach in combating antimicrobial resistance (AMR). By harnessing the unique properties of nanoparticles, researchers have developed advanced drug delivery platforms capable of overcoming the limitations of conventional antibiotic therapies [7]. These systems enhance the efficacy of antimicrobial agents through targeted delivery, controlled release, and improved solubility, while also addressing key challenges like biofilm penetration and intracellular infections. Nanocarriers offer distinct advantages over conventional antibiotics, especially when dealing with resistant pathogens. They enable targeted delivery, minimize off-target effects, and enhance the therapeutic index of antibiotics. This is achieved through encapsulation, functionalization, or conjugation of antibiotics with nanomaterials, which improves their efficacy while reducing toxicity. To illustrate these advantages, Table 1 provides a comparison of nanocarrierbased antibiotic delivery systems and their traditional counterparts in terms of their mechanisms and results. Table 1 Comparative Efficacy of Nanocarriers and Traditional Antibiotics Antibiotic/Nanocarr ier Pathogen Resistance Overcome Delivery Mechanism Results Liposomal Vancomycin Methicillin-Resistant Staphylococcus aureus (MRSA) Methicillin resistance Encapsulation of vancomycin in liposomes Minimum inhibitory concentration (MIC) reduced by 50% compared to free vancomycin. [7] Cephradine-Loaded Silver and Gold Nanoparticles Escherichia coli and Staphylococcus aureus Betalactam resistance Antibiotic conjugation with metal nanoparticles Enhanced antibacterial effect with lower MIC compared to cephradine alone. [6] Ampicillin-Conjugated Gold Nanoparticles Pseudomonas aeruginosa, Enterobacter aerogenes, and Methicillin-Resistant Staphylococcus aureus (MRSA) Multidrug resistance Functionalization of gold nanoparticles with ampicillin Effective bactericidal activity against multiple antibioticresistant strains. [5] Silver Nanoparticles Combined with Amoxicillin, Penicillin, or Gentamicin Various bacterial strains Multiple antibiotic resistances Synergistic combination of silver nanoparticles with antibiotics Improved activity of antibiotics, reducing the MIC required for bacterial inhibition. [5] Lipid NanoparticleEncapsulated Antibiotics Various bacterial strains General antibiotic resistance Encapsulation of antibiotics in lipidbased nanoparticles Reduced collateral damage to gut microbiota and enhanced delivery to target sites. [5] 2.1.1. Mechanisms: Targeted Delivery, Controlled Release, and Enhanced Solubility Nanoparticles offer unparalleled advantages in drug delivery by enabling the precise targeting of resistant pathogens, thereby minimizing off-target effects and enhancing therapeutic outcomes. Targeted delivery mechanisms rely on surface modifications of nanoparticles with ligands, such as antibodies, peptides, or small molecules, that specifically bind to receptors on bacterial cells. According to Nazli et al. [8], these modifications facilitate the selective delivery of antibiotics to infection sites, bypassing systemic circulation and reducing the risk of toxicity. For instance, nanoparticles functionalized with mannose have been shown to bind effectively to Escherichia coli via lectin receptors, achieving higher localized drug concentrations compared to non-targeted systems. Controlled release is another critical World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 304 mechanism enabled by nanoparticle-based systems. Polymeric nanoparticles, such as those made from poly(lactic-coglycolic acid) (PLGA), are designed to release encapsulated drugs in a sustained manner, maintaining therapeutic concentrations over extended periods. Zou et al. [2] highlighted that controlled-release nanoparticles could reduce dosing frequency and improve patient compliance, particularly for chronic infections. In one study by Hua et al [9], ciprofloxacin-loaded PLGA nanoparticles demonstrated a prolonged drug release profile, maintaining antimicrobial activity against Pseudomonas aeruginosa for up to 72 hours [9]. Enhanced solubility of hydrophobic antibiotics is a significant advantage offered by nanoparticle-based systems. Many potent antimicrobial agents suffer from poor aqueous solubility, limiting their bioavailability and therapeutic efficacy. Liposomes, which are lipid bilayer vesicles, encapsulate hydrophobic drugs within their lipid phase, dramatically improving solubility. Himanshu et al. [3] reported that amphotericin B-loaded liposomes effectively treated fungal infections, overcoming the solubility challenges associated with free amphotericin B. 2.1.2. Applications: Case Studies of Nanoparticles Delivering Antibiotics to Resistant Pathogens The application of nanoparticle-based drug delivery systems has shown tremendous potential in treating infections caused by multidrug-resistant (MDR) bacteria. A notable example is the use of silver nanoparticles (AgNPs) as drug carriers. AgNPs not only exhibit intrinsic antimicrobial properties but also enhance the delivery of conventional antibiotics. Chakraborty et al. [1] demonstrated that amoxicillin-loaded AgNPs exhibited synergistic activity against Staphylococcus aureus, significantly reducing bacterial growth compared to amoxicillin alone. Liposomes have also been extensively studied as nanocarriers for antibiotic delivery. Zou et al. [2] described the efficacy of vancomycin-loaded liposomes in targeting Methicillin-resistant Staphylococcus aureus (MRSA) biofilms. The liposomal formulation improved drug penetration into the biofilm matrix, resulting in a 90% reduction in bacterial viability. This finding underscores the potential of liposomes to overcome the protective barriers that hinder conventional antibiotic therapies. Polymeric nanoparticles, particularly those based on PLGA and chitosan, have gained attention for their versatility and biocompatibility. Himanshu et al. [3] highlighted a study where chitosan nanoparticles loaded with gentamicin exhibited enhanced antimicrobial activity against Klebsiella pneumoniae biofilms. The nanoparticles facilitated sustained drug release and improved penetration into biofilm-embedded bacterial cells, achieving superior therapeutic outcomes compared to free gentamicin. Biofilm Penetration: Overcoming Biofilm Barriers with Nanosystems Biofilms are structured communities of bacteria encased in an extracellular polymeric substance (EPS) matrix, which serves as a protective barrier against antibiotics and immune responses. Overcoming biofilm-related resistance is one of the most significant challenges in AMR management, and nanoparticle-based systems offer promising solutions. The small size of nanoparticles allows them to penetrate the dense EPS matrix, delivering antimicrobial agents directly to the embedded bacteria [10-12]. According to Olatunji et al. [4], metallic nanoparticles, such as zinc oxide and gold nanoparticles, exhibit biofilmdisrupting properties by generating reactive oxygen species (ROS) that degrade the EPS matrix. In one study, zinc oxide nanoparticles demonstrated the ability to penetrate Pseudomonas aeruginosa biofilms, reducing bacterial viability by over 80%. These findings highlight the potential of metallic nanoparticles to address biofilm-associated infections that are resistant to conventional therapies. Nanoparticle-mediated drug delivery also enhances the efficacy of existing antibiotics against biofilms. Zou et al. (2023) reported that ciprofloxacin-loaded polymeric nanoparticles effectively disrupted Staphylococcus epidermidis biofilms, achieving complete eradication within 48 hours. This result underscores the synergistic potential of combining nanotechnology with traditional antibiotics. Furthermore, nanozymes, which mimic natural enzymatic activity, have been shown to degrade biofilm matrices through catalytic mechanisms. Chakraborty et al. [1] described the use of cerium oxide nanozymes to disrupt biofilms formed by Enterococcus faecalis, demonstrating their potential as a novel anti-biofilm strategy. 2.2. Metallic Nanoparticles with Intrinsic Antimicrobial Properties Metallic nanoparticles (MNPs) have emerged as a pivotal innovation in the fight against antimicrobial resistance (AMR), offering potent, multifaceted mechanisms of action against resistant pathogens. Unlike traditional antibiotics that target specific cellular processes, metallic nanoparticles leverage their nanoscale dimensions and surface functionalities to disrupt bacterial systems in diverse ways [13]. These nanoparticles—comprising silver (Ag), gold (Au), zinc oxide (ZnO), and others—exhibit inherent antimicrobial properties that make them particularly effective against multidrug-resistant World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 305 bacteria, including biofilm-associated pathogens. By targeting bacterial membranes, inducing oxidative stress, and releasing toxic ions, metallic nanoparticles circumvent many of the mechanisms that confer resistance to conventional antibiotics [13,14]. To provide a comprehensive understanding, Table 2 summarizes the primary mechanisms of action of various nanoparticles and their efficacy against specific resistant pathogens. Table 2 Mechanisms of Action of Nanoparticles Against Resistant Pathogens Nanoparticle Type Mechanism of Action Targeted Pathogen Literature Reference Efficacy Data Silver Nanoparticles (AgNPs) Induction of oxidative stress through reactive oxygen species (ROS) generation, leading to DNA/RNA damage and disruption of membrane integrity. Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa Antibacterial properties of nanoparticles [14] Demonstrated significant bactericidal activity at low concentrations. Gold Nanoparticles (AuNPs) Disruption of bacterial cell membranes and interference with protein synthesis. Salmonella typhimurium, Enterococcus faecalis Antibiotic properties of nanoparticles [14] Showed enhanced antibacterial effects when functionalized with antibiotics. Zinc Oxide Nanoparticles (ZnO NPs) Generation of ROS causing oxidative stress, leading to lipid peroxidation and membrane damage. Staphylococcus aureus, Escherichia coli Antibiotic properties of nanoparticles [14] Exhibited strong antibacterial activity with minimal cytotoxicity. Copper Nanoparticles (CuNPs) Release of copper ions disrupting enzymatic processes and inducing oxidative stress. Listeria monocytogenes, Salmonella enterica Antibiotic properties of nanoparticles [14] Effective at low concentrations against various pathogens. Graphene Oxide (GO) Nanosheets Physical disruption of cell membranes and extraction of phospholipids, leading to cell lysis. Escherichia coli, Staphylococcus aureus Antibiotic properties of nanoparticles [14] Achieved high antibacterial efficiency through membrane disruption. Carbon Nanotubes (CNTs) Penetration and disruption of bacterial cell walls, leading to leakage of intracellular contents. Bacillus subtilis, Klebsiella pneumoniae Antibiotic properties of nanoparticles [14] Demonstrated potent antibacterial activity with potential for functionalization. Mesoporous Silica Nanoparticles (MSNs) with Silver Sustained release of silver ions causing prolonged antimicrobial effects. Mycobacterium tuberculosis Mesoporous silica nanoparticles containing silver as novel antimycobacterial agents against Mycobacterium tuberculosis [13] Showed significant reduction in bacterial viability in vitro. 2.2.1. Mechanisms: Membrane Disruption, Oxidative Stress, and Ion Release The antimicrobial activity of metallic nanoparticles is largely attributed to their ability to disrupt bacterial membranes, induce oxidative stress, and release antimicrobial ions. Membrane disruption is a primary mode of action, wherein nanoparticles interact with the bacterial cell membrane, leading to structural damage and leakage of intracellular contents. This interaction is facilitated by the electrostatic attraction between the positively charged nanoparticles and the negatively charged bacterial membranes, as demonstrated by Modi et al. [15]. In one study, silver nanoparticles World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 306 disrupted the membrane integrity of Escherichia coli and Staphylococcus aureus, resulting in significant bacterial death within hours of exposure. Oxidative stress induction is another critical mechanism by which metallic nanoparticles exert their antimicrobial effects. These nanoparticles catalyze the production of reactive oxygen species (ROS), such as hydrogen peroxide, hydroxyl radicals, and superoxide anions. ROS generation leads to oxidative damage of cellular components, including proteins, lipids, and DNA, ultimately causing cell death. Olatunji et al. [4] reported that zinc oxide nanoparticles exhibited superior ROS generation capabilities, effectively killing Pseudomonas aeruginosa and Klebsiella pneumoniae biofilm-associated bacteria. Ion release further amplifies the antimicrobial properties of metallic nanoparticles. Upon interaction with bacterial cells or exposure to specific physiological conditions, these nanoparticles release metal ions that interfere with critical cellular functions. Silver ions (Ag⁺), for example, are known to bind to thiol groups in proteins and enzymes, disrupting metabolic pathways and DNA replication. This multi-targeted approach reduces the likelihood of resistance development, as bacteria would need to undergo multiple simultaneous mutations to counteract these effects. According to Zou et al. [2], ion release from gold nanoparticles was instrumental in eradicating methicillin-resistant Staphylococcus aureus (MRSA) in vitro. 2.2.2. Examples: Silver, Gold, and Zinc Oxide Nanoparticles in Combating Resistant Bacteria Silver nanoparticles (AgNPs) are among the most extensively studied metallic nanoparticles for their antimicrobial properties. Their efficacy against a wide range of resistant bacteria, including MRSA and Escherichia coli, has been welldocumented [16]. Himanshu et al. [3] highlighted a study where AgNPs reduced MRSA biofilm formation by over 80% within 24 hours. This was achieved through a combination of membrane disruption, ROS generation, and Ag⁺ ion release, which collectively led to bacterial eradication. Moreover, silver nanoparticles have been incorporated into wound dressings and coatings for medical devices, where they provide long-lasting antimicrobial protection. Gold nanoparticles (AuNPs) are another versatile class of metallic nanoparticles with significant potential in combating AMR. While less inherently toxic than silver, AuNPs can be functionalized with antibiotics or other therapeutic agents to enhance their antimicrobial activity. Wang et al. [17] reported that gold nanoparticles functionalized with vancomycin demonstrated enhanced activity against vancomycin-resistant Enterococci (VRE), achieving up to a 90% reduction in bacterial viability. The ability to tailor the surface chemistry of AuNPs allows for targeted delivery and synergistic effects, making them an attractive option for resistant infections. Zinc oxide nanoparticles (ZnO NPs) are particularly effective against biofilm-associated infections. Their high ROS generation capacity and ability to penetrate biofilms have made them a focus of recent research. Chakraborty et al. (2022) described a study in which ZnO NPs eradicated Pseudomonas aeruginosa biofilms by inducing oxidative stress and disrupting the EPS matrix. This dual-action mechanism resulted in complete biofilm clearance within 48 hours, demonstrating the potential of ZnO NPs to address one of the most challenging aspects of AMR. 2.2.3. Synergistic Applications: Combining Metallic Nanoparticles with Existing Antibiotics One of the most promising aspects of metallic nanoparticles is their ability to work synergistically with existing antibiotics, enhancing their efficacy and overcoming resistance mechanisms. This synergism is achieved through multiple pathways, including improved drug delivery, enhanced penetration into biofilms, and complementary modes of action. Zou et al. [2] reported that combining silver nanoparticles with ciprofloxacin significantly reduced the minimum inhibitory concentration (MIC) of the antibiotic against Klebsiella pneumoniae. The nanoparticles disrupted the bacterial membrane, allowing higher intracellular concentrations of ciprofloxacin, which then inhibited DNA replication. Gold nanoparticles have also been shown to enhance the activity of antibiotics. In one study by Hagbani et al [18], vancomycin-functionalized gold nanoparticles exhibited superior efficacy against vancomycin-resistant Staphylococcus aureus (VRSA) compared to vancomycin alone. This effect was attributed to the ability of the gold nanoparticles to bypass resistance mechanisms, such as efflux pumps, that would otherwise reduce the drug’s efficacy. Zinc oxide nanoparticles have demonstrated synergistic effects when combined with tetracycline. Abdelghafar et al. [19] highlighted a study where ZnO NPs enhanced the penetration of tetracycline into E. coli biofilms, achieving a 70% reduction in biofilm mass. This combination therapy not only improved antibiotic efficacy but also reduced the likelihood of resistance development by targeting bacteria through multiple pathways. World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 307 2.3. Nanozymes and Novel Catalytic Nanomaterials Nanozymes, a groundbreaking class of nanomaterials with enzyme-like catalytic properties, have garnered significant attention for their potential to combat antimicrobial resistance (AMR). These synthetic enzyme mimetics are engineered to perform catalytic functions analogous to natural enzymes, such as oxidases, peroxidases, and catalases [20]. Unlike biological enzymes, nanozymes are structurally robust, exhibit remarkable stability under diverse environmental conditions, and can be precisely tailored for specific applications. Their ability to degrade biofilms and generate reactive oxygen species (ROS) positions them as a powerful tool in addressing multidrug-resistant bacterial infections, particularly those involving biofilm-associated pathogens [21,22]. The role of nanotechnology in addressing antimicrobial resistance (AMR) extends beyond therapeutic delivery to advanced diagnostics. Innovative diagnostic platforms utilizing nanomaterials have proven transformative in identifying resistant pathogens and tailoring treatment strategies. These advancements are particularly critical in early detection and management of AMR. Table 3 provides an overview of key nanotechnology-driven diagnostic innovations, their mechanisms, and their contributions to AMR detection. Table 3 Advances in Nanotechnology-Based Diagnostics for Antimicrobial Resistance Diagnostic Technology Nanotechnology Utilized Target Pathogen(s) Detection Method Advantages Rapid Sepsis Test Magnetic nanoparticles Various bacterial pathogens Pathogen identification and antibiotic susceptibility testing Reduces diagnosis time to 13 hours, enabling quicker targeted treatment Automated Optical System for Antimicrobial Susceptibility Testing (AST) Optical nanomaterials Staphylococcus aureus Deep learning analysis of bacterial growth Provides early AST results, minimizing incubation time and eliminating human errors Nanomechanical Sensor for AntibioticMucopeptide Binding Cantilever arrays Staphylococcus aureus Detection of vancomycin binding to bacterial cell wall precursors Offers label-free detection with high sensitivity at clinically relevant concentrations Nanoscale Devices for Real-Time Monitoring Various nanomaterials Multiple bacterial species Real-time monitoring of bacterial populations Allows early detection of resistance development Nanotechnology-Based Detection Platforms Various nanomaterials Multiple pathogens Rapid and sensitive pathogen identification Enhances diagnostic speed and sensitivity 2.3.1. Nanozymes as Enzyme Mimetics for Biofilm Degradation and ROS Generation Nanozymes are nanomaterials that mimic enzymatic activities by catalyzing biochemical reactions, effectively breaking down biofilm matrices and targeting bacterial systems. Their catalytic activity stems from their nanoscale architecture, which provides a high surface area-to-volume ratio and facilitates interactions with bacterial systems at the molecular level. According to Chakraborty et al. [1], nanozymes are particularly effective in generating ROS, such as hydroxyl radicals and superoxide ions, which are highly reactive and capable of damaging bacterial membranes, proteins, and nucleic acids. This catalytic ROS generation disrupts bacterial homeostasis and ultimately leads to cell death. Biofilms represent one of the most challenging aspects of AMR. These structured communities of bacteria, encased in an extracellular polymeric substance (EPS) matrix, act as a physical and biochemical barrier, protecting bacterial cells from antibiotics and the host immune system. Nanozymes have demonstrated the ability to degrade these biofilm matrices through catalytic mechanisms. For instance, cerium oxide nanoparticles (CeO₂ nanozymes) exhibit peroxidaselike activity, breaking down hydrogen peroxide into ROS that attack the EPS matrix. Himanshu et al. [3] highlighted that these nanozymes effectively penetrated biofilms formed by Pseudomonas aeruginosa and Staphylococcus aureus, achieving significant reductions in biofilm biomass and bacterial viability. World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 308 Nanozymes also outperform natural enzymes in terms of stability and resilience. While natural enzymes are often susceptible to denaturation under extreme pH, temperature, or salinity conditions, nanozymes maintain their catalytic functionality across a wide range of environmental conditions [23]. This robustness makes them particularly suited for treating infections in diverse physiological and environmental contexts. 2.3.2. Nanozymes Targeting Multidrug-Resistant Gram-Negative Bacteria Gram-negative bacteria, characterized by their complex outer membrane and intrinsic resistance mechanisms, pose a significant challenge in AMR management. Nanozymes have demonstrated remarkable efficacy in targeting these pathogens. According to Zou et al. [2], iron oxide nanozymes (Fe₃O₄) have shown peroxidase-like activity that enhances the penetration of antibiotics into the protective layers of Gram-negative bacteria, such as Escherichia coli and Klebsiella pneumoniae. These nanozymes generate ROS in situ, degrading the outer membrane and facilitating the entry of antimicrobial agents. Gold-based nanozymes (AuNZs) have also emerged as potent tools in combating Gram-negative bacteria. Their catalytic activity, combined with their biocompatibility, makes them ideal candidates for treating multidrug-resistant infections. Ma et al. [24] described the use of AuNZs functionalized with antimicrobial peptides to target Acinetobacter baumannii. The nanozymes not only generated ROS but also disrupted bacterial membranes, achieving complete eradication of the pathogen in in vitro models. Another promising example is manganese oxide nanozymes (MnO₂), which exhibit dual catalytic activities as oxidases and catalases. These nanozymes have been shown to degrade EPS matrices and generate ROS, effectively combating biofilms formed by Pseudomonas aeruginosa. Chakraborty et al. [1] reported that MnO₂ nanozymes reduced biofilm mass by over 75% within 48 hours, demonstrating their potential as a novel therapeutic strategy for biofilm-associated infections. The multifunctionality of nanozymes extends to their ability to act synergistically with existing antibiotics. Zou et al. [3] highlighted a study where cerium oxide nanozymes were combined with ciprofloxacin to treat biofilm-associated infections caused by Staphylococcus epidermidis. The nanozymes degraded the biofilm matrix, allowing ciprofloxacin to penetrate deeper into the biofilm and achieve higher bacterial eradication rates. 2.4. Vaccines and Immunotherapeutics The escalating threat of antimicrobial resistance (AMR) necessitates innovative strategies beyond traditional antibiotic development. Nanobiotechnology offers promising avenues, particularly in enhancing vaccine efficacy and developing novel immunotherapeutics. By leveraging nanoscale materials, researchers aim to potentiate immune responses against resistant pathogens, thereby reducing reliance on antibiotics and mitigating the spread of resistance [25,26]. 2.4.1. Nano-Based Adjuvants: Enhancing Immune Responses Against Resistant Pathogens Adjuvants are critical components of vaccines, designed to enhance the body's immune response to an antigen. Traditional adjuvants, such as aluminum salts, have limitations, including suboptimal induction of cellular immunity and potential side effects. Nanotechnology introduces a new generation of adjuvants with improved efficacy and safety profiles [27,28]. Nanoparticle-based adjuvants can be engineered to possess unique physicochemical properties that modulate the immune system more effectively. For instance, clay nanoparticles, or nanoclays, have demonstrated strong adjuvant activity, leading to immune responses significantly more potent than those elicited by conventional adjuvants like alum. Studies have shown that layered double hydroxides and hectorite nanoparticles can enhance both humoral and cellular immunity, making them promising candidates for vaccine formulations against resistant pathogens [29-31]. Furthermore, the size, shape, and surface charge of nanoparticles can be tailored to optimize antigen delivery and presentation. Nanoparticles can protect antigens from degradation, facilitate targeted delivery to antigen-presenting cells, and promote sustained antigen release, leading to prolonged immune stimulation. This precision in design allows for the induction of specific immune responses, such as Th1 or Th2 pathways, which are crucial in combating different types of infections, including those caused by resistant bacteria [32]. In addition to synthetic nanoparticles, natural nanomaterials are being explored as adjuvants. Saponin-based nanoparticles, such as Matrix-M, have been utilized in various vaccine candidates, including the Novavax COVID-19 vaccine. Matrix-M is composed of nanoparticles derived from saponins extracted from the Quillaja saponaria tree, World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 315 microorganisms may adapt over time, leading to reduced susceptibility. Continuous monitoring and judicious use of nanobiotechnologies are essential to mitigate this risk [73]. 4.1. Toxicity: Adverse Effects of Metallic NPs on Human Cells and the Environment Nanoparticles (NPs), particularly metallic ones such as silver, gold, and zinc oxide, have emerged as powerful tools in combating antimicrobial resistance (AMR). However, their therapeutic promise is tempered by significant concerns about toxicity and environmental impact. While metallic NPs possess unique physicochemical properties that enhance their antimicrobial efficacy, these same properties may pose risks to human health and ecological systems [75]. Metallic NPs can generate reactive oxygen species (ROS) through surface interactions, leading to oxidative stress, inflammation, and cytotoxicity in human cells. According to Hajipour et al. [74], ROS production by metallic NPs such as silver nanoparticles (AgNPs) can result in DNA damage, protein denaturation, and lipid peroxidation, all of which contribute to cell death. Zou et al. [2] also reported that the small size of NPs facilitates their penetration into cellular membranes, potentially disrupting mitochondrial function and triggering apoptosis. Furthermore, prolonged exposure to metallic NPs may accumulate in vital organs such as the liver, kidneys, and brain, raising concerns about chronic toxicity and carcinogenicity [73]. The environmental implications of NP usage are equally concerning. Nanoparticles can persist in ecosystems, interacting with soil and water systems and potentially disrupting microbial communities critical for ecological balance. Chakraborty et al. [1] noted that AgNPs released into aquatic environments exhibit toxicity toward non-target organisms, including algae, fish, and amphibians, by altering their metabolic and reproductive functions. The persistence of metallic NPs in the environment underscores the need for sustainable design and disposal strategies to mitigate their ecological impact [74]. 4.2. Cost and Scalability: Economic Challenges in Large-Scale Nanoparticle Production The transition of nanoparticle technologies from laboratory settings to large-scale production faces significant economic challenges. The synthesis of high-quality, uniform NPs with consistent properties requires sophisticated equipment, stringent control of reaction conditions, and often expensive raw materials. According to Allahverdiyev et al. [72], the scalability of NP production is hindered by the cost of precursors such as noble metals and the energyintensive nature of many synthesis techniques. Zou et al. [2] emphasized that batch-to-batch variability in NP properties such as size, shape, and surface charge remains a significant obstacle in scaling up production. This variability can affect the reproducibility of therapeutic outcomes and necessitate additional quality control measures, further inflating costs. Additionally, advanced techniques like functionalizing NPs with targeting ligands or stimuli-responsive coatings demand specialized reagents and expertise, limiting their accessibility in resource-constrained settings [74]. Economic analyses suggest that the high costs associated with NP production may deter their adoption, particularly in lowand middle-income countries where the burden of AMR is often highest. Efforts to develop cost-effective synthesis methods, such as green chemistry approaches using plant extracts or microbial systems, are ongoing and may help bridge this gap [73]. However, these methods require further optimization to meet clinical-grade production standards. 4.3. Regulatory Hurdles: Lack of Standardized Guidelines for Nanomedicine Approval The regulatory landscape for nanomedicines remains poorly defined, posing a major barrier to their clinical translation. Traditional frameworks for evaluating drug safety and efficacy are often inadequate for nanotechnologies, which exhibit complex pharmacokinetics, biodistribution patterns, and interactions with biological systems. Hajipour et al. [74] highlighted that the lack of standardized testing protocols for nanomedicines complicates their approval process, as conventional methods may not accurately capture NP-specific risks such as aggregation, protein corona formation, or immune activation. From the findings of Chakraborty et al. [1], regulatory agencies like the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) require comprehensive preclinical and clinical data for nanoparticle-based therapeutics, including their pharmacokinetics, toxicity profiles, and environmental impact. However, the absence of universal guidelines for these evaluations often leads to inconsistencies and delays in the approval process. Moreover, the interdisciplinary nature of nanomedicine development—spanning chemistry, biology, and engineering— necessitates collaboration among diverse stakeholders, including researchers, manufacturers, and regulatory bodies. Allahverdiyev et al. [72] argued that establishing clear regulatory pathways and fostering dialogue among these stakeholders are essential for streamlining the approval process. Efforts to address these challenges include initiatives World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 316 such as the International Organization for Standardization (ISO) and the Organisation for Economic Co-operation and Development (OECD), which are working to develop harmonized guidelines for nanotechnology assessment. 5. Emerging Trends and Future Directions The escalating threat of antimicrobial resistance (AMR) has galvanized the scientific community to explore innovative solutions beyond traditional antibiotics. Nanobiotechnology has emerged as a promising frontier in this endeavor, offering novel strategies to combat resistant pathogens. Recent advancements have focused on the development of nanoparticles (NPs) with intrinsic antimicrobial properties, such as metal-based NPs, which exhibit unique mechanisms of action that reduce the likelihood of resistance development [73]. Additionally, the integration of nanomaterials with existing antibiotics has shown synergistic effects, enhancing efficacy against multidrug-resistant bacteria [72]. Researchers are also investigating the potential of two-dimensional (2D) nanomaterials, such as graphene oxide and molybdenum disulfide, which possess high surface area and unique electronic properties conducive to antimicrobial applications [1]. These materials have demonstrated the ability to disrupt bacterial membranes and inhibit biofilm formation, addressing critical challenges in AMR management. Furthermore, the design of stimuli-responsive nanocarriers capable of targeted drug delivery and controlled release is being explored to minimize off-target effects and enhance therapeutic outcomes [74]. Despite these promising developments, challenges remain in translating nanobiotechnologies from the laboratory to clinical settings. Concerns regarding the toxicity, biocompatibility, and environmental impact of nanomaterials necessitate comprehensive studies to ensure safety and efficacy [73]. Moreover, the lack of standardized regulatory frameworks for nanomedicine approval poses significant hurdles to commercialization [74]. Future research is poised to address these challenges by focusing on the development of biodegradable and environmentally friendly nanomaterials, as well as establishing standardized guidelines for their evaluation and approval. The convergence of nanotechnology with other disciplines, such as synthetic biology and artificial intelligence, holds the potential to revolutionize the development of next-generation antimicrobials and diagnostic tools, offering a multifaceted approach to tackling the global AMR crisis. 5.1. Biodegradable and Eco-Friendly Nanoparticles The rapid advancements in nanotechnology have significantly enhanced the capabilities of nanomaterials in combating antimicrobial resistance (AMR). However, concerns over toxicity and environmental impact have led researchers to prioritize the development of biodegradable and eco-friendly nanoparticles (NPs). These innovations aim to maintain therapeutic efficacy while minimizing adverse effects on human health and the environment [76]. Biodegradable nanoparticles are engineered to break down into non-toxic components within biological systems, reducing the risks associated with prolonged retention and accumulation. Materials such as poly(lactic-co-glycolic acid) (PLGA), chitosan, and polypeptides are frequently employed due to their excellent biocompatibility and established safety profiles. According to Allahverdiyev et al. [72], PLGA-based NPs have demonstrated promising results in delivering antimicrobial agents, as they degrade into lactic and glycolic acids that are naturally metabolized by the body. Moreover, researchers like Zou et al. [2] have explored lipid-based nanoparticles, such as liposomes, for their ability to encapsulate hydrophobic drugs while offering controlled release properties. These carriers not only enhance drug stability but also degrade safely within physiological environments, ensuring minimal long-term toxicity. The environmental implications of NP use have driven the adoption of green synthesis methods, which utilize plant extracts, microorganisms, or biopolymers as reducing and stabilizing agents. This approach eliminates the need for hazardous chemicals typically used in conventional synthesis processes. Santhosh et al. [77] highlighted the potential of silver and gold NPs synthesized using plant-derived polyphenols, which exhibit robust antimicrobial properties while being eco-friendly. In addition to green synthesis, researchers have emphasized the use of naturally occurring materials such as silk fibroin and alginate for NP production. These materials are biodegradable, renewable, and possess inherent biocompatibility. Himanshu et al. [3] reported that alginate-based NPs have shown efficacy in targeting biofilms and delivering antimicrobial agents while decomposing into harmless byproducts. 5.1.1. Enhancing Biocompatibility Through Surface Modifications Surface modifications play a critical role in improving the biocompatibility of NPs. Functionalizing NPs with polyethylene glycol (PEG), polysaccharides, or proteins can reduce immunogenicity and enhance circulation time. Huh and Kwon [73] emphasized that PEGylation prevents the recognition of NPs by the mononuclear phagocyte system, World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 317 thereby increasing their therapeutic window. Similarly, Zou et al. [2] noted that decorating NPs with ligands such as folic acid or antibodies allows for selective targeting of bacterial cells, minimizing off-target effects on healthy tissues. 5.1.2. Applications and Future Directions Biodegradable and eco-friendly NPs are being integrated into various biomedical applications, including drug delivery, wound healing, and diagnostic tools. For instance, PLGA NPs loaded with antibiotics have been successfully used to treat chronic wound infections, reducing both bacterial load and inflammation [72]. Additionally, alginate-based NPs have shown potential in addressing multidrug-resistant tuberculosis by targeting mycobacteria within pulmonary tissues [3]. The future of NP research lies in further optimizing their design for enhanced safety and performance. Advances in stimuli-responsive NPs, which degrade under specific conditions such as pH or temperature changes, offer additional control over drug release. Furthermore, integrating artificial intelligence (AI) into NP design could enable the prediction and customization of biodegradation pathways, ensuring minimal environmental impact. 5.2. CRISPR and Gene-Editing Nanocarriers The convergence of CRISPR-Cas gene-editing technology with nanocarrier systems represents a promising frontier in the battle against antimicrobial resistance (AMR). CRISPR-Cas systems offer unparalleled precision in targeting and modifying genetic material, enabling the selective disruption of antibiotic resistance genes in pathogenic bacteria. However, the clinical application of CRISPR-based therapies is often hindered by challenges in delivering these molecular tools into bacterial cells. Nanocarriers have emerged as effective vehicles to facilitate the transport of CRISPR components across bacterial membranes, enhancing the efficacy of these gene-editing strategies. 5.2.1. Nanocarrier Systems for CRISPR Delivery Nanocarriers, including liposomes, polymeric nanoparticles, and gold nanoparticles, have been extensively explored for delivering CRISPR-Cas systems. These nanocarriers protect CRISPR components from degradation, improve cellular uptake, and can be engineered to target specific bacterial species. For instance, liposomal nanocarriers have been utilized to encapsulate CRISPR-Cas9 plasmids, facilitating their delivery into multidrug-resistant Escherichia coli strains and resulting in the successful disruption of resistance genes [78]. Similarly, polymer-based nanoparticles have been employed to deliver CRISPR-Cas systems into Staphylococcus aureus, leading to the elimination of antibiotic resistance genes and restoration of antibiotic susceptibility [79]. 5.2.2. Mechanisms of Action The primary mechanism by which CRISPR-Cas systems combat AMR involves the targeted cleavage of resistance genes within bacterial genomes or plasmids. This precise targeting is facilitated by guide RNAs that direct the Cas nuclease to specific DNA sequences associated with resistance. Upon delivery by nanocarriers, the CRISPR-Cas system induces double-stranded breaks in these resistance genes, leading to their inactivation. This approach not only eradicates existing resistance traits but also reduces the likelihood of resistance dissemination through horizontal gene transfer [80]. 5.2.3. Recent Advances and Research Findings Recent studies have demonstrated the potential of CRISPR-Cas-loaded nanocarriers in reversing antibiotic resistance. For example, a study by Bikard et al. [81] utilized phagemid particles to deliver CRISPR-Cas9 constructs targeting antibiotic resistance genes in Staphylococcus aureus, resulting in a significant reduction of resistant bacterial populations. Similarly, Yosef et al. [82] engineered bacteriophages to deliver CRISPR-Cas3 systems into Escherichia coli, effectively sensitizing the bacteria to antibiotics. These findings underscore the therapeutic potential of combining CRISPR technology with nanocarrier delivery systems to address AMR. 5.2.4. Challenges and Future Directions Despite the promising results, several challenges impede the widespread application of CRISPR-based nanotherapies. These include potential off-target effects, immune responses against the CRISPR components or nanocarriers, and difficulties in delivering the therapeutic agents to specific sites of infection. Future research is directed towards enhancing the specificity and efficiency of CRISPR delivery, developing biocompatible and non-immunogenic nanocarriers, and establishing standardized protocols for evaluating the safety and efficacy of these novel therapeutics. World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 318 5.3. Artificial Intelligence (AI) in Nanoparticle Design The integration of artificial intelligence (AI) into nanoparticle design heralds a transformative approach to combating antimicrobial resistance (AMR). AI-driven methodologies enable the precise optimization of nanoparticle properties, enhancing their therapeutic efficacy while minimizing unintended effects [83]. By leveraging vast datasets, machine learning (ML) algorithms, and predictive models, AI facilitates the rational design of nanoparticles tailored to target resistant pathogens effectively. 5.3.1. Optimizing Nanoparticle Properties AI algorithms play a crucial role in identifying optimal nanoparticle attributes such as size, shape, surface charge, and functionalization to maximize antimicrobial efficacy. According to Zou et al. [2], the physicochemical properties of nanoparticles directly influence their interactions with bacterial membranes, penetration efficiency, and biofilm disruption capabilities. AI models analyze complex datasets derived from experimental studies to predict the most effective combinations of these properties for specific pathogens. For example, Godoy-Gallardo et al. [84] reported the use of AI to optimize the design of silver nanoparticles (AgNPs) for enhanced antimicrobial activity against multidrug-resistant Escherichia coli. Their model identified a narrow size range (10–20 nm) as ideal for maximizing membrane disruption while minimizing cytotoxicity to human cells. Similarly, Huh and Kwon [73] demonstrated how AI-driven simulations could predict the optimal surface functionalization of nanoparticles with ligands to enhance targeting specificity. 5.3.2. Accelerating Drug Discovery and Development AI has significantly accelerated the discovery of nanocarriers for delivering antimicrobial agents. From the findings of Chakraborty et al. [1], AI models were utilized to predict the stability and drug-loading capacity of lipid-based nanoparticles, enabling the rapid identification of formulations suitable for encapsulating antibiotics. By simulating the interactions between nanoparticles and bacterial biofilms, AI algorithms have also facilitated the design of particles capable of penetrating these protective layers, a critical challenge in AMR management. 5.3.3. Enhancing Targeting Efficiency The ability of AI to process large-scale genomic and proteomic data allows for the identification of biomarkers specific to resistant bacterial strains. These biomarkers serve as targets for nanoparticles engineered to deliver antimicrobial agents with high precision. Kretzmann et al. [85] utilized machine learning to analyze bacterial gene expression data, identifying molecular pathways uniquely upregulated in biofilm-forming Pseudomonas aeruginosa. Based on these findings, AI-guided nanoparticle design incorporated ligands targeting these pathways, achieving improved therapeutic outcomes. 5.3.4. AI-Powered Predictive Models Predictive modeling is another area where AI is revolutionizing nanoparticle research. By training ML models on experimental and theoretical datasets, researchers can predict nanoparticle performance in diverse biological environments. For instance, a study by Singh et al. [86] applied deep learning to predict the cytotoxicity of nanoparticles based on their composition and surface chemistry, providing critical insights for designing safer nanomaterials. Similarly, Rahman et al. [4] highlighted the use of AI in modeling nanoparticle behavior under physiological conditions to ensure their stability and efficacy. 5.3.5. Challenges and Future Directions Despite its transformative potential, the application of AI in nanoparticle design faces several challenges. Data scarcity, especially for novel nanoparticle formulations, limits the robustness of predictive models. Additionally, the interdisciplinary nature of AI-driven nanotechnology necessitates collaboration between computational scientists, material engineers, and biologists, which can be logistically complex [87,88]. Future directions include the development of open-access databases for nanoparticle properties and biological interactions, enabling more comprehensive training of AI models. The integration of AI with high-throughput screening platforms and automated synthesis technologies could further enhance the efficiency of nanoparticle development. Moreover, advancements in explainable AI will provide greater transparency in model predictions, fostering trust and adoption in clinical and regulatory settings [88]. World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 319 5.4. Nanotechnology in Resource-Limited Settings The application of nanotechnology in resource-limited settings offers transformative potential for addressing the challenges of diagnostics and therapeutics in developing countries. the burden of infectious diseases exacerbated by antimicrobial resistance (AMR) disproportionately affecting lowand middle-income regions, cost-effective and portable nanosolutions are emerging as critical tools to bridge healthcare gaps. These technologies leverage the unique properties of nanomaterials to deliver affordable, efficient, and scalable solutions that are accessible even in infrastructure-constrained environments [89]. 5.4.1. Cost-Effective Nanodiagnostics One of the key applications of nanotechnology in resource-limited settings lies in the development of affordable diagnostic tools. Traditional diagnostic methods often require expensive reagents, sophisticated equipment, and skilled personnel, making them inaccessible in many developing regions. Nanotechnology circumvents these limitations by enabling the creation of portable, point-of-care diagnostic platforms. For example, nanomaterial-based biosensors, such as gold nanoparticles (AuNPs) and quantum dots, have been employed to develop rapid diagnostic kits for bacterial infections. According to Geng et al. [90], AuNPs conjugated with specific antibodies can detect pathogen-specific antigens in patient samples, yielding results within minutes. Similarly, Hajipour et al. [74] highlighted the use of zinc oxide nanoparticles in colorimetric assays for detecting AMR genes, providing a low-cost and efficient alternative to polymerase chain reaction (PCR)-based methods. Furthermore, paper-based microfluidic devices incorporating nanomaterials have gained attention for their affordability and ease of use. A study by Yetisen et al. [91] demonstrated that these devices could detect pathogens like Mycobacterium tuberculosis using minimal sample volumes, making them ideal for field diagnostics in underserved areas. 5.4.2. Portable Nanotherapeutics Nanotechnology is also transforming the delivery of therapeutics in resource-limited settings by offering portable and efficient drug delivery systems. Liposomal formulations and polymeric nanoparticles provide cost-effective carriers for antibiotics and other drugs, enhancing their stability, bioavailability, and targeted delivery. Zou et al. [2] noted that nanoparticle-based drug formulations can reduce the required dosage and frequency of administration, lowering treatment costs while minimizing side effects. This is particularly valuable for diseases requiring long-term treatment, such as multidrug-resistant tuberculosis (MDR-TB). For instance, Kennedy et al. [92] highlighted the development of silver nanoparticle-based coatings for medical devices, which reduce the incidence of device-associated infections and decrease dependence on systemic antibiotics. 5.4.3. Decentralized Manufacturing and Scalability Nanotechnology also facilitates decentralized production, enabling local manufacturing in resource-limited settings. Green synthesis methods using plant extracts or microbial systems offer an eco-friendly and cost-effective approach to nanoparticle production. According to Huh and Kwon [73], these methods reduce reliance on expensive raw materials and centralized facilities, making them particularly suited for low-resource environments. 5.4.4. Overcoming Barriers to Implementation While nanotechnology holds significant promise, its implementation in resource-limited settings faces challenges, including regulatory hurdles, affordability, and public acceptance. Addressing these barriers requires collaboration among governments, researchers, and industry stakeholders. Organizations like the World Health Organization (WHO) and the Bill & Melinda Gates Foundation have initiated programs to promote the adoption of nanotechnology-based solutions in developing countries, focusing on affordability and accessibility [93]. 5.4.5. Success Case Studies and Future Directions Several success stories illustrate the potential of nanotechnology in addressing healthcare challenges in resourcelimited settings. A notable example is the use of gold nanoparticle-based rapid diagnostic tests for malaria, which have been deployed in sub-Saharan Africa with significant success. These tests, as reported by Yetisen et al. [91], have reduced the need for expensive microscopy-based diagnostics and improved disease management in remote areas. Similarly, liposomal formulations of amphotericin B have been utilized for the treatment of leishmaniasis in India, demonstrating the effectiveness of nanotechnology in tackling neglected tropical diseases. The future of nanotechnology in resource-limited settings lies in the development of integrated platforms that combine diagnostics and therapeutics. Point-of-care diagnostic systems that can simultaneously detect pathogens and administer targeted therapy are being explored to reduce the time between diagnosis and treatment. Additionally, World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 320 efforts to create sustainable and biodegradable nanomaterials will ensure that these solutions are not only cost-effective but also environmentally friendly. 5.5. Metagenomics: Studying Microbial Communities to Find New Antimicrobial Compounds The rise of antimicrobial resistance (AMR) has necessitated innovative approaches for discovering new antimicrobial compounds. Metagenomics, the study of genetic material recovered directly from environmental samples, has emerged as a transformative tool in this endeavor. Unlike traditional culture-dependent methods that can analyze only a small fraction of microbial diversity, metagenomics allows researchers to explore the genetic blueprints of entire microbial communities, unlocking access to previously unculturable organisms [94]. This comprehensive approach not only aids in the identification of novel antibiotics but also provides insights into resistance mechanisms and microbial ecology. 5.5.1. Unlocking Microbial Diversity Natural environments such as soil, oceans, and the human microbiome harbor an immense reservoir of microbial diversity, much of which remains unexplored. According to Chakraborty et al. [1], only about 1% of microbial species are culturable using standard laboratory techniques, leaving vast genetic resources untapped. Metagenomics circumvents this limitation by directly sequencing and analyzing microbial DNA from environmental samples, enabling the discovery of new antimicrobial compounds produced by rare or previously unidentified microorganisms. For example, Thompson et al. [95] employed metagenomics to discover teixobactin, a novel antibiotic derived from unculturable soil bacteria. This compound exhibits potent activity against Gram-positive pathogens, including Staphylococcus aureus and Mycobacterium tuberculosis, and represents a significant breakthrough in antibiotic discovery. Similarly, metagenomic studies of marine environments have revealed unique biosynthetic gene clusters encoding antimicrobial peptides and secondary metabolites, expanding the arsenal of therapeutic agents available for combating AMR [74]. Metagenomics is pivotal in uncovering antimicrobial resistance genes (ARGs) directly from environmental, clinical, or agricultural samples without the need for culturing microbes [95]. This technology employs high-throughput sequencing to analyze the genetic material of entire microbial communities. For instance, researchers can sequence DNA from hospital wastewater to identify novel ARGs that may not be detectable using traditional methods. According to Sukhum et al. [96], shotgun metagenomics was used to reveal over one thousand previously uncharacterized resistance genes in urban water systems, highlighting hidden reservoirs of resistance. Moreover, tools like ARGem and ResFinder have been instrumental in annotating ARGs across diverse environments [97]. These findings provide critical insights into the spread of AMR, aiding policymakers and healthcare practitioners in designing better intervention strategies. 5.5.2. Tracking Resistance Gene Mobility Horizontal gene transfer (HGT) is a major driver of AMR spread, and metagenomics excels in tracking this process. Using sequencing data, scientists can identify mobile genetic elements such as plasmids, transposons, and integrons that carry resistance genes across microbial populations. For example, a study by Ding et al. [98] utilized metagenomic assemblies to map the transfer of plasmid-borne resistance genes between bacteria in agricultural soils and nearby water bodies. This highlights how resistance genes move from anthropogenic sources to natural ecosystems. Advanced tools like HAM-ART facilitate the reconstruction of these mobile elements, linking them to their host organisms. Understanding gene mobility is crucial for developing containment strategies, particularly in high-risk environments like hospitals or intensive farming systems. 5.5.3. Analyzing Resistance Mechanisms Beyond discovering new antibiotics, metagenomics provides a powerful platform for studying resistance mechanisms at a community level. By analyzing the resistome—the collection of all antibiotic resistance genes within a microbial community—researchers can identify patterns of resistance and understand how these genes are transferred among bacteria. Torres‐Cortés et al. [99] demonstrated that metagenomic sequencing of soil samples revealed a diverse array of resistance genes, including those conferring resistance to synthetic antibiotics not previously encountered in the environment. Such findings underscore the importance of monitoring environmental reservoirs of resistance genes to predict and mitigate the spread of AMR. Metagenomics also serves as a powerful platform for discovering new antibiotics from previously unculturable microorganisms. By analyzing microbial genomes, researchers can identify biosynthetic gene clusters (BGCs) responsible for producing novel antimicrobial compounds. In a landmark study, Asante et al. [100] used metagenomic World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 321 data from soil samples to discover a new class of antibiotics called malacidins, which showed efficacy against multi-drug resistant pathogens. Functional metagenomics, where environmental DNA is cloned and expressed in lab strains, has further expanded this potential. The discovery of such compounds not only addresses current AMR challenges but also replenishes the dwindling pipeline of effective antibiotics. 5.5.4. Functional Metagenomics Functional metagenomics, which involves the cloning and expression of environmental DNA in surrogate hosts, adds another dimension to antibiotic discovery. This technique enables the identification of novel bioactive compounds based on their functional activity rather than sequence similarity. For instance, Santos-Pereira et al. [101] utilized functional metagenomics to identify a new class of lipopeptides with antimicrobial properties from microbial communities inhabiting extreme environments such as hot springs. These compounds demonstrated activity against multidrug-resistant pathogens, highlighting the potential of functional metagenomics in uncovering therapeutic leads. 5.5.5. Insights into Microbial Interactions Metagenomics also sheds light on the intricate interactions within microbial communities, which often influence the production of antimicrobial compounds. Intermicrobial competition, signaling, and cooperation can drive the synthesis of secondary metabolites with antibiotic properties. According to Yetisen et al. [91], studying microbial interactions through metagenomics has led to the discovery of quorum-sensing inhibitors and biofilm-disrupting agents that target resistant bacterial populations. 5.5.6. Challenges and Future Directions Despite its promise, metagenomics faces several challenges. The complexity of environmental samples and the sheer volume of sequencing data necessitate advanced bioinformatics tools for analysis and interpretation. Additionally, the functional expression of metagenomic libraries remains limited by host compatibility issues and the difficulty of replicating native microbial conditions. Future directions in metagenomics include the integration of AI and machine learning algorithms to streamline data analysis and predict the activity of novel gene clusters. Advances in single-cell genomics and high-throughput functional assays will further enhance the utility of metagenomics in antibiotic discovery. Collaborative efforts to build open-access databases of metagenomic data, such as the Earth Microbiome Project, will provide invaluable resources for researchers worldwide. 6. Regulatory and Ethical Considerations The rapid advancement of nanobiotechnology, particularly its applications in combating antimicrobial resistance (AMR), has sparked both enthusiasm and caution. While these innovations promise groundbreaking solutions to global health challenges, they also raise critical regulatory and ethical considerations. Addressing issues related to safety, efficacy, and public trust is essential to ensure the responsible development and deployment of nanobiotechnological solutions. 6.1. Ensuring Safety and Efficacy The safety and efficacy of nanomaterials remain central concerns in their regulatory assessment. Unlike conventional therapeutics, nanoparticles exhibit unique physicochemical properties such as high surface-to-volume ratios, which can result in unforeseen interactions with biological systems. Hajipour et al. [74] highlighted that nanoparticles can generate reactive oxygen species (ROS), potentially causing oxidative stress, DNA damage, and inflammatory responses in human cells. Additionally, long-term exposure to nanoparticles may lead to their accumulation in vital organs, raising concerns about chronic toxicity. To address these challenges, regulatory frameworks must adapt to the distinct characteristics of nanomaterials. The U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have called for comprehensive preclinical studies evaluating nanoparticle biodistribution, pharmacokinetics, and toxicology. However, Chakraborty et al. [1] noted that existing testing paradigms often fail to capture nanoparticle-specific risks, necessitating the development of novel methodologies. Advances in computational modeling and in vitro assays are aiding in the predictive assessment of nanoparticle safety. AI-driven models, as discussed by Padhiary et al. [102], are being used to simulate nanoparticle behavior in biological environments, providing insights into potential risks and facilitating the design of safer materials. World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 322 6.2. Ethical Implications The ethical implications of nanobiotechnology extend beyond safety to encompass issues of equity, accessibility, and environmental impact. As these technologies are developed, ensuring equitable access remains a significant challenge. Zou et al. [2] emphasized that high costs associated with nanoparticle production could limit their availability in lowand middle-income countries, exacerbating global health disparities. Environmental considerations are equally pressing. The potential for nanoparticles to persist in ecosystems and interact with non-target organisms raises concerns about their long-term ecological impact. Studies have shown that silver nanoparticles, widely used for their antimicrobial properties, can disrupt aquatic ecosystems by affecting microbial communities critical for nutrient cycling [73]. Public engagement and transparency are essential to addressing these ethical concerns. Tawiah et al. [103] argued that fostering dialogue among stakeholders, including scientists, policymakers, and the public, can build trust and ensure that the benefits of nanobiotechnology are equitably distributed. 6.3. Regulatory Challenges One of the most significant regulatory challenges in nanobiotechnology is the lack of standardized guidelines for evaluating nanomaterials. Traditional metrics for assessing drug safety and efficacy are often inadequate for nanoparticles, given their unique properties. Olatunji et al. [4] noted that the absence of universal standards leads to inconsistencies in regulatory decisions across regions, delaying the approval and commercialization of nanotechnologies. Efforts are underway to address these challenges. The Organisation for Economic Co-operation and Development (OECD) has established working groups to develop harmonized guidelines for nanomaterial evaluation. Similarly, the International Organization for Standardization (ISO) is collaborating with regulatory agencies to create robust testing protocols that account for the complexities of nanobiotechnology. 6.4. Building Public Trust Public perception of nanobiotechnology plays a pivotal role in its adoption and success. Historical examples of public resistance to emerging technologies, such as genetically modified organisms (GMOs), underscore the importance of transparent communication and education. Chakraborty et al. [1] emphasized that addressing public concerns about nanoparticle safety and environmental impact through proactive engagement can foster trust. Initiatives such as citizen science projects and open-access databases are being used to involve the public in nanobiotechnology research. By demystifying the science behind nanoparticles and highlighting their potential benefits, these efforts can mitigate fears and build societal support for their use. 7. Conclusion Nanobiotechnology stands at the forefront of innovative strategies to combat antimicrobial resistance (AMR), offering unparalleled potential to revolutionize the management of this escalating global health crisis. The advancements in nanomaterials, ranging from metal-based nanoparticles to functionalized nanocarriers, have demonstrated remarkable efficacy in addressing key challenges such as biofilm penetration, site-specific drug delivery, and resistance to conventional antibiotics. By leveraging the unique physicochemical properties of nanoscale materials, researchers have opened new avenues for targeted therapies, efficient diagnostics, and enhanced antimicrobial efficacy. These developments underscore the transformative impact of nanobiotechnology in redefining the landscape of AMR management. Despite its promise, the path to fully realizing the potential of nanobiotechnology is fraught with challenges that demand a multidisciplinary approach. The complexity of nanoparticle interactions within biological systems necessitates collaborative efforts from materials scientists, microbiologists, clinicians, and regulatory experts. Addressing issues such as nanoparticle toxicity, environmental impact, scalability, and regulatory compliance requires concerted research initiatives that integrate expertise across these domains. Such collaborations are essential not only for overcoming technical and logistical barriers but also for ensuring the clinical translation of nanobiotechnology into accessible, effective, and safe solutions for AMR. The urgency of leveraging nanobiotechnology in the global fight against AMR cannot be overstated. AMR poses a profound threat to public health, with the potential to render current antibiotic therapies obsolete, disrupt healthcare systems, and incur catastrophic economic consequences. Nanobiotechnology offers a unique opportunity to stem this tide by enabling the development of next-generation antimicrobials, improving diagnostic precision, and enhancing the effectiveness of existing treatments. However, realizing this potential requires immediate action to bridge the gap World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 323 between laboratory research and real-world applications. Governments, funding agencies, and private sector stakeholders must prioritize investments in nanobiotechnology to accelerate its deployment as a critical tool in combating AMR. Looking forward, innovative strategies are imperative to sustain and expand the impact of nanobiotechnology. Emphasis should be placed on the development of biodegradable and environmentally friendly nanomaterials to mitigate ecological concerns. Integrating artificial intelligence and machine learning into the design and optimization of nanoparticles can enhance their efficacy and safety profiles. Furthermore, global collaborative networks must be established to share resources, data, and expertise, fostering a unified approach to tackling AMR. Initiatives aimed at educating the public and building trust in nanobiotechnological solutions are equally crucial, ensuring societal acceptance and widespread adoption. In essence, nanobiotechnology offers a beacon of hope in the relentless battle against AMR. By harnessing its transformative potential through multidisciplinary collaboration and innovative thinking, the global scientific community can turn the tide against this pressing challenge. With sustained efforts and a shared commitment to innovation, nanobiotechnology has the capacity to safeguard public health and reshape the future of antimicrobial therapeutics Compliance with ethical standards Acknowledgments The authors wish to acknowledge the collaborative effort of all contributing scholars and colleagues who jointly authored and edited this review paper. This work was conducted entirely through the intellectual and academic contributions of the authoring team, without external funding or assistance from any individual, institution, or organization. Disclosure of conflict of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. References [1] Chakraborty, N., Jha, D., Roy, I., Kumar, P., Gaurav, S. S., Marimuthu, K., ... & Gautam, H. K. (2022). Nanobiotics against antimicrobial resistance: harnessing the power of nanoscale materials and technologies. Journal of nanobiotechnology, 20(1), 375. [2] Zou, W., McAdorey, A., Yan, H., & Chen, W. (2023). Nanomedicine to overcome antimicrobial resistance: Challenges and prospects. Nanomedicine, 18(5), 471-484. [3] Himanshu, Mukherjee, R., Vidic, J., Leal, E., da Costa, A. C., Prudencio, C. R., ... & Pandey, R. P. (2023). Nanobiotics and the One Health Approach: Boosting the Fight against Antimicrobial Resistance at the Nanoscale. Biomolecules, 13(8), 1182. [4] Olatunji, A. O., Varghese, N., Lakkimsetti, M., Rahman, M. M., Abosaoda, M. K., Ahmad, W., ... & Nosheen, S. (2024). Combating Antimicrobial Resistance with Nanotechnology: Developing New Antimicrobial Agents and Coatings. Nanotechnology Perceptions, 20(5), 734–761. [5] Olatunji, A. O., Olaboye, J. A., Maha, C. C., Kolawole, T. O., & Abdul, S. (2024). Next-Generation strategies to combat antimicrobial resistance: Integrating genomics, CRISPR, and novel therapeutics for effective treatment. Engineering Science & Technology Journal, 5(7), 2284-2303. [6] Khan, A., Jabeen, H., Ahmad, T., Rehman, N. U., Khan, S. S., Shareef, H., ... & Al-Harrasi, A. (2022). Comparative efficacy of cephradine-loaded silver and gold nanoparticles against resistant human pathogens. Artificial Cells, Nanomedicine, and Biotechnology, 50(1), 312-321. [7] Balderrama-González, A. S., Piñón-Castillo, H. A., Ramírez-Valdespino, C. A., Landeros-Martínez, L. L., OrrantiaBorunda, E., & Esparza-Ponce, H. E. (2021). Antimicrobial resistance and inorganic nanoparticles. International journal of molecular sciences, 22(23), 12890. [8] Nazli, A., He, D. L., Liao, D., Khan, M. Z. I., Huang, C., & He, Y. (2022). Strategies and progresses for enhancing targeted antibiotic delivery. Advanced drug delivery reviews, 189, 114502. World Journal of Biology Pharmacy and Health Sciences, 2025, 21(02), 300-328 324 [9] Hua, X., Tan, S., Bandara, H. M. H. N., Fu, Y., Liu, S., & Smyth, H. D. (2014). Externally controlled triggered-release of drug from PLGA micro and nanoparticles. PLoS One, 9(12), e114271. [10] Shree, P., Singh, C. K., Sodhi, K. K., Surya, J. N., & Singh, D. K. (2023). Biofilms: Understanding the structure and contribution towards bacterial resistance in antibiotics. Medicine in Microecology, 16, 100084. [11] Ragupathi, H., Pushparaj, M. M., Gopi, S. M., Govindarajan, D. K., & Kandaswamy, K. (2024). Biofilm matrix: a multifaceted layer of biomolecules and a defensive barrier against antimicrobials. Archives of Microbiology, 206(11), 432. [12] Shaikh, S., Nazam, N., Rizvi, S. M. D., Ahmad, K., Baig, M. H., Lee, E. J., & Choi, I. (2019). Mechanistic insights into the antimicrobial actions of metallic nanoparticles and their implications for multidrug resistance. International journal of molecular sciences, 20(10), 2468. [13] Montalvo-Quirós, S., Gómez-Graña, S., Vallet-Regí, M., Prados-Rosales, R. C., González, B., & Luque-Garcia, J. L. (2021). Mesoporous silica nanoparticles containing silver as novel antimycobacterial agents against Mycobacterium tuberculosis. Colloids and Surfaces B: Biointerfaces, 197, 111405. [14] Wikipedia contributors. (2024, December 2). Antibiotic properties of nanoparticles. In Wikipedia, The Free Encyclopedia. Retrieved 17:44, January 20, 2025, from https://en.wikipedia.org/w/index.php?title=Antibiotic_properties_of_nanoparticles&oldid=1260699397 [15] Modi, S. K., Gaur, S., Sengupta, M., & Singh, M. S. (2023). Mechanistic insights into nanoparticle surface-bacterial membrane interactions in overcoming antibiotic resistance. Frontiers in Microbiology, 14, 1135579. [16] Fortaleza, J. A. G., Ong, C. J. N., & De Jesus, R. (2024). Efficacy and clinical potential of phage therapy in treating methicillin-resistant Staphylococcus aureus (MRSA) infections: A review. European Journal of Microbiology and Immunology, 14(1), 13-25. [17] Wang, S. G., Chen, Y. C., & Chen, Y. C. (2018). Antibacterial gold nanoparticle-based photothermal killing of vancomycin-resistant bacteria. Nanomedicine, 13(12), 1405-1416. [18] Hagbani, T. A., Yadav, H., Moin, A., Lila, A. S. A., Mehmood, K., Alshammari, F., ... & Abdallah, M. H. (2022). Enhancement of vancomycin potential against pathogenic bacterial strains via gold nano-formulations: a nanoantibiotic approach. Materials, 15(3), 1108. [19] Abdelghafar, A., Yousef, N., & Askoura, M. (2022). Zinc oxide nanoparticles reduce biofilm formation, synergize antibiotics action and attenuate Staphylococcus aureus virulence in host; an important message to clinicians. BMC microbiology, 22(1), 244. [20] Huang, R., Hu, Q., Ko, C. N., Tang, F. K., Xuan, S., Wong, H. M., ... & Leung, K. C. F. (2024). Nano-based theranostic approaches for infection control: current status and perspectives. Materials Chemistry Frontiers, 8(1), 9-40. [21] Alfei, S., Schito, G. C., Schito, A. M., & Zuccari, G. (2024). Reactive oxygen species (ROS)-mediated antibacterial oxidative therapies: available methods to generate ROS and a novel option proposal. International Journal of Molecular Sciences, 25(13), 7182. [22] Hetta, H. F., Ramadan, Y. N., Al-Harbi, A. I., A. Ahmed, E., Battah, B., Abd Ellah, N. H., ... & Donadu, M. G. (2023). Nanotechnology as a promising approach to combat multidrug resistant bacteria: a comprehensive review and future perspectives. Biomedicines, 11(2), 413. [23] Meng, Y., Li, W., Pan, X., & Gadd, G. M. (2020). Applications of nanozymes in the environment. Environmental Science: Nano, 7(5), 1305-1318. [24] Ma, T., Huang, K., & Cheng, N. (2023). Recent advances in nanozyme-mediated strategies for pathogen detection and control. International Journal of Molecular Sciences, 24(17), 13342. [25] Li, Y., Li, S., Jiang, Z., Tan, K., Meng, Y., Zhang, D., & Ma, X. (2023). Targeting lymph node delivery with nanovaccines for cancer immunotherapy: recent advances and future directions. Journal of Nanobiotechnology, 21(1), 212. [26] Mainini, F., De Santis, F., Fucà, G., Di Nicola, M., Rivoltini, L., & Eccles, M. (2021). Nanobiotechnology and immunotherapy: Two powerful and cooperative allies against cancer. Cancers, 13(15), 3765. [27] Gupta, A., & Chaphalkar, S. R. (2015). Vaccine adjuvants: the current necessity of life. Shiraz E-Medical Journal, 16(7). [28] Di Pasquale, A., Preiss, S., Tavares Da Silva, F., & Garçon, N. (2015). Vaccine adjuvants: from 1920 to 2015 and beyond. Vaccines, 3(2), 320-343.