Nanoparticles as an exotic antibacterial, antifungal, and antiviral agents

Globally, concerns regarding the COVID-19 pandemic its prevention have become important. Because of COVID-19 and other microbial diseases, enhance research work has emerged revealing new antimicrobial and antiviral materials and techniques. Tremendous growth in nanotechnology has opened up the door to fabricating numerous nanomaterials. These nanomaterials are employed as antimicrobial and antiviral agents for various applications with 99.99% effectiveness compared with conventional techniques. Nanoparticles possess unique physicochemical characteristics for multiple applications. This chapter details the use of nanoparticles for antifungal, antimicrobial, and antiviral applications. It describes various kinds of nanoparticles, such as nanometals, metal oxides, polymeric nanomaterials, and carbon-based nanomaterials. © 2023 Elsevier Inc. All rights reserved.

Bifunctional Au@Pt/Au nanoparticles as electrochemiluminescence signaling probes for SARS-CoV-2 detection.

A novel immunosensor based on electrochemiluminescence resonance energy transfer (ECL-RET) for the sensitive determination of N protein of the SARS-CoV-2 coronavirus is described. For this purpose, bifunctional core@shell nanoparticles composed of a Pt-coated Au core and finally decorated with small Au inlays (Au@Pt/Au NPs) have been synthesized to act as ECL acceptor, using [Ru (bpy)3]2+ as ECL donor. These nanoparticles are efficient signaling probes in the immunosensor developed. The proposed ECL-RET immunosensor has a wide linear response to the concentration of N protein of the SARS-CoV-2 coronavirus with a detection limit of 1.27 pg/mL. Moreover, it has a high stability and shows no response to other proteins related to different virus. The immunosensor has achieved the quantification of N protein of the SARS-CoV-2 coronavirus in saliva samples. Results are consistent with those provided by a commercial colorimetric ELISA kit. Therefore, the developed immunosensor provides a feasible and reliable tool for early and effective detection of the virus to protect the population.

Coating of favipiravir (FVP) on silver nanoparticles: First principle study

Silver nanoparticles, thanks to their antiviral and antibacterial properties, have great potential in a variety of applications, such as drug-delivery carriers. The coating properties of silver nanoparticles (size range of 1.6 nm) with a well-known drug, Favipirair, were investigated in this study using quantum mechanical and classical atomistic molecular dynamics simulation in order to use as the drug delivery to treat COVID-19 disease. The drug molecule's optimized structure, frequencies, charge distribution, and electrostatic potential maps were simulated using density functional theory (DFT) at the B3LYP/6–311++g(d,p) level of theory. The coating of AgNP with each of these drugs was then studied using molecular dynamics simulation. The interaction affinity obtained from MD results agrees with the DFT results on drug adsorption on the Ag(1 1 1) slab. © 2023

A simple cost-effective microfluidic platform for rapid synthesis of diverse metal nanoparticles: A novel approach towards fighting SARS-CoV-2.

The latest addition to the family of Coronaviruses, SARS-CoV-2, unleashed its wrath across the globe. The outbreak has been so rapid and widespread that even the most developed countries are still struggling with ways to contain the spread of the virus. The virus began spreading from Wuhan in China in December 2019 and has currently affected more than200 countries worldwide. Nanotechnology has huge potential for killing viruses as severe as HIV, herpes, human papilloma virus, and viruses of the respiratory tract, both inside as well as outside the host. Metal-nanoparticles can be employed for biosensing methodology of viruses/bacteria, along with the development of novel drugs and vaccines for COVID-19 and future pandemics. It is thus required for the nanoparticles to be synthesized quickly along with precise control over their size distribution. In this study, we propose a simple microfluidic-reactor-platform for in-situ metal-nanoparticle synthesis to be used against the pandemic for the development of preventive, diagnostic, and antiviral drug therapies. The device has been fabricated using a customized standard photolithography process using a simple and cost-effective setup. The confirmation on standard silver and gold metal nanoparticle formation in the microfluidic reactor platform was analysed using optical fiber spectrophotometer. This novel microfluidic platform provides the advantage of in-situ synthesis, flow parameter control and reduced agglomeration of nanoparticles over the bulk synthesis due to segregation of nucleation and growth stages inside a microchannel. The results are highly reproducible and hence scaling up of the nanoparticle production is possible without involving complex instrumentation.

A Novel Vision of Reinforcing Nanofibrous Masks with Metal Nanoparticles: Antiviral Mechanisms Investigation.

Prevention of spreading viral respiratory disease, especially in case of a pandemic such as coronavirus disease of 2019 (COVID-19), has been proved impossible without considering obligatory face mask-wearing protocols for both healthy and contaminated populations. The widespread application of face masks for long hours and almost everywhere increases the risks of bacterial growth in the warm and humid environment inside the mask. On the other hand, in the absence of antiviral agents on the surface of the mask, the virus may have a chance to stay alive and be carried to different places or even put the wearers at risk of contamination when touching or disposing the masks. In this article, the antiviral activity and mechanism of action of some of the potent metal and metal oxide nanoparticles in the role of promising virucidal agents have been reviewed, and incorporation of them in an electrospun nanofibrous structure has been considered an applicable method for the fabrication of innovative respiratory protecting materials with upgraded safety levels.

Covalent organic frameworks and metal-organic frameworks against pathogenic viruses and antibiotic-resistant bacteria: Diagnostic and therapeutic applications

Antimicrobial resistance and antiviral infections statistics show that the number of global cases has been exponentially increasing;thus there is an unmet need for developing alternatives rather than to continue conventional strategies such as antibiotic administration, since they failed to show promise especially during the past few decades. Among different porous materials, metal-organic frameworks (MOFs) are a class of porous coordination polymers broadly explored in nano- and biomedicine due to their desirable properties, including excellent surface area, structural variability, the richness of their crystal structures/architectures, allowing for engineering synergies between metal nodes, functional linkers, encapsulated substrates or nanoparticles, heterogeneous catalysis, ion exchange, controlled and targeted drug delivery, energetics, etc. MOF-based sensing platforms have shown suitable potentials for specific viral detection. Covalent organic frameworks (COFs) are porous crystalline organic materials with two- or three-dimensional structures, which can be employed for reducing the interaction between the spike protein of SARS-CoV-2 and angiotensin-converting enzyme 2 (ACE2) in addition to other inhibitory effects. These frameworks can be applied for encapsulating antibiotics or antiviral agents against pathogens;they have been also studied for photodynamic inactivation of pathogenic bacteria. Herein, the most recent advancements pertaining to the applications of these frameworks for specific detection and inhibition of pathogenic viruses and antibiotic-resistant bacteria are cogitated, focusing on important challenges and perspectives. This review also provides expert recommendations on the future development and utility of these frameworks to manage antimicrobial resistance and infectious diseases more efficiently. © 2023 Elsevier Ltd

Antibacterial, Anti-Biofilm and Pro-Migratory Effects of Double Layered Hydrogels Packaged with Lactoferrin-DsiRNA-Silver Nanoparticles for Chronic Wound Therapy.

Antimicrobial resistance and biofilm formation in diabetic foot infections worsened during the COVID-19 pandemic, resulting in more severe infections and increased amputations. Therefore, this study aimed to develop a dressing that could effectively aid in the wound healing process and prevent bacterial infections by exerting both antibacterial and anti-biofilm effects. Silver nanoparticles (AgNPs) and lactoferrin (LTF) have been investigated as alternative antimicrobial and anti-biofilm agents, respectively, while dicer-substrate short interfering RNA (DsiRNA) has also been studied for its wound healing effect in diabetic wounds. In this study, AgNPs were complexed with LTF and DsiRNA via simple complexation before packaging in gelatin hydrogels. The formed hydrogels exhibited 1668% maximum swellability, with a 46.67 ± 10.33 µm average pore size. The hydrogels demonstrated positive antibacterial and anti-biofilm effects toward the selected Gram-positive and Gram-negative bacteria. The hydrogel containing AgLTF at 125 µg/mL was also non-cytotoxic on HaCaT cells for up to 72 h of incubation. The hydrogels containing DsiRNA and LTF demonstrated superior pro-migratory effects compared to the control group. In conclusion, the AgLTF-DsiRNA-loaded hydrogel possessed antibacterial, anti-biofilm, and pro-migratory activities. These findings provide a further understanding and knowledge on forming multipronged AgNPs consisting of DsiRNA and LTF for chronic wound therapy.

Current Trends and Prospects for Application of Green Synthesized Metal Nanoparticles in Cancer and COVID-19 Therapies.

Cancer and COVID-19 have been deemed as world health concerns due to the millions of lives that they have claimed over the years. Extensive efforts have been made to develop sophisticated, site-specific, and safe strategies that can effectively diagnose, prevent, manage, and treat these diseases. These strategies involve the implementation of metal nanoparticles and metal oxides such as gold, silver, iron oxide, titanium oxide, zinc oxide, and copper oxide, formulated through nanotechnology as alternative anticancer or antiviral therapeutics or drug delivery systems. This review provides a perspective on metal nanoparticles and their potential application in cancer and COVID-19 treatments. The data of published studies were critically analysed to expose the potential therapeutic relevance of green synthesized metal nanoparticles in cancer and COVID-19. Although various research reports highlight the great potential of metal and metal oxide nanoparticles as alternative nanotherapeutics, issues of nanotoxicity, complex methods of preparation, biodegradability, and clearance are lingering challenges for the successful clinical application of the NPs. Thus, future innovations include fabricating metal nanoparticles with eco-friendly materials, tailor making them with optimal therapeutics for specific disease targeting, and in vitro and in vivo evaluation of safety, therapeutic efficiency, pharmacokinetics, and biodistribution.

A portable, low-cost and high-throughput electrochemical impedance spectroscopy device for point-of-care biomarker detection

This paper presents a portable, fast and accurate electrochemical impedance spectroscopy (EIS) device with 8-well interdigitated electrode chips for biomarker detection. The design adopts low crest factor multisine signal synthesis at low frequencies (<1 kHz) and single-tone signals at high frequencies (>1 kHz), which significantly increases measurement speed without sacrificing accuracy. In addition, the low excitation amplitude of 10 mV preserves impedance linearity and protects the biosamples. The system achieved an average magnitude accuracy error of 0.30% in the frequency range of interest and it requires only 0.46 s to scan 28 frequency points from 10 Hz to 1 MHz. Experiments were conducted to test the capability to detect antibodies against SARS-CoV-2. Gold nanoparticles bound with protein G (GNP-G) were employed as the conjugated secondary antibody probe to detect anti-SARS-CoV-2 IgG in serum. A highly statistical significance (p = 7×10−6) could be found in the impedance data at 10 kHz. The impedance magnitude alteration caused by the GNP-G of the positive and negative groups were 27.2%±13.6% and 4.1%±1.7%, respectively. The results imply that the proposed system enables rapid COVID-19 antibody biomarker detection. Moreover, the EIS system and GNPs have the potential to be modified to detect other biomarkers. © 2022 The Author(s)

A comparative performance of antibacterial effectiveness of copper and silver coated textiles

During current COVID-19 crises, the antimicrobial textiles primarily those utilized in hospital by doctors and paramedical staff have become increasingly important. Thus, there is an unmet requirement to develop antimicrobial textiles for infection control and hygiene practices. Metallic nanoparticles exhibit great effectiveness towards resistant microbial species making them a potential solution to the increasing antibiotic resistance. Due to this, nanoparticles particularly copper and silver have become most prevalent forms of antibacterial finishing agents for the development of antimicrobial textiles. This review is mainly focused on the significance of copper and silver nanoparticles for the development of antimicrobial textiles. The comparative analysis of the antibacterial effectiveness of copper and silver nanoparticles as well as the possible physical and chemical interactions responsible for their antibacterial action are explained. The negative impact of pathogenic microbes on textiles and possible interactions of antimicrobial agents with microbes have also been highlighted. The significance of nanotechnology for the development of antimicrobial textiles and their applications in medical textiles domain have also been discussed. Various green synthesis and chemical methods used for the synthesis of Ag and Cu nanoparticles and their application on textile substrates to impart antimicrobial functionality have also been discussed. The various qualitative and quantitative standard testing protocols utilised for the antimicrobial characterization of textiles have also discussed in this review. The developed Cu and Ag coated textiles could be effectively applied in the field of hospital textiles for the preparation of antibacterial scrub suits, surgical gowns, panel covers, protective clothing, bedding textiles, coveralls, wound dressings, table covers, curtains, and chair covers etc. © The Author(s) 2022.

A microchamber-free and enzyme-free digital assay based on ultrabright fluorescent microspheres

Digital analysis is an effective single-molecule detection method and has attracted extensive attention in the field of bioassays. However, most digital assays require microchambers for signal compartmentalization. Herein, we developed a microchamber-free and enzyme-free digital assay by labeling paramagnetic beads directly with ultrabright fluorescent microspheres. In this assay, a DNA sandwich analysis was firstly performed on the bead to label a fluorescent microsphere. Then, the beads were loaded on the glass slide to form a monolayer film for signal readout. The whole analysis process does not require the participation of enzymes and the preparation of microchambers, which greatly simplifies the experimental steps and saves the costs. Furthermore, by introducing non-enzymatic hybridization chain reaction (HCR) and biotinylated DNA-conjugated gold nanoparticles (Au NPs-Bio), the capture efficiency and analytical sensitivity were improved. As a proof of concept, single-stranded DNA (ssDNA) of SARS-CoV-2 fragment was chosen as a model, and a detection limit of 1.5 fM was achieved. Spiked and recovery experiments on human serum and saliva samples validated the good performance of the proposed digital assay in real biological samples. The proposed assay provides a facile way of signal generation and readout for digital analysis. © 2023 Elsevier B.V.

In vitro antiviral effect of silver nanoparticles against SARS-CoV-2

Introduction: COVID-19 is an acute respiratory tract disease caused by the emerging coronavirus SARS-CoV-2. Although several options for che-moprophylaxis are under development, effective treatment for COVID-19 is not yet available. Objective(s): To investigate the antiviral properties of synthesized silver na-noparticles (AgNPs) against SARS-CoV-2 using in vitro models. Material(s) and Method(s): This work synthesized AgNPs using an electrochemical method and characterized them using physico-chemical techniques (ICP-OES, ultraviolet-visible spectroscopy, and transmission electron microscopy). AgNPs with diameter sizes ranging between 2.6 to 30 nm and an average size of 6.2 nm were obtained by the electrochemical method. The cytotoxic effect and the antiviral activity of prepared AgNPs against SARS-CoV-2 were evaluated in vitro using Vero E6 cells. Cell viability was evaluated by MTT assay in the presence of serial dilutions of AgNPs. The antiviral effect of AgNPs was evaluated before and after the infection of Vero E6 cells by plaque assay. Result(s): Cytotoxic effect was observed at concentrations above 0.07 ppm. AgNPs exhibit a significant reduction of SARS-CoV-2 viral titer after a pre-post treatment strategy with inhibition of 96.5%, 64.13%, and 74.72% at 0.03, 0.017, and 0.008 ppm, respectively. Conclusion(s): Our results suggest that AgNPs could reduce SARS-CoV-2 replication with a low cytotoxic effect. Still, additional in vitro and in vivo studies are required to define its potential therapeutic application in humans. Copyright © 2023 Universidad de Antioquia.

Low-cost voltammetric sensor based on reduced graphene oxide anchored on platinum nanoparticles for robust determination of Favipiravir in real samples

This research describes a simple, sensitive, and disposable modified glassy carbon electrode constructed using platinum nanoparticles anchored on reduced graphene oxide nanocomposite as a conductive modifier (Pt@rGO/GCE) to detect an anti-coronavirus drug, Favipiravir (FAV). The as-synthesized nanocomposite was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), and atomic force microscopy (AFM). Under optimized conditions, the square wave voltammetry (SWV) method was used to determine trace amounts of FAV in real samples. The proposed electrode demonstrated a wide linear concentration range of 3.16 to 100.0 μM with a low detection limit (LOD) of 2.46 μM. Moreover, the developed electrode showed outstanding selectivity in the presence of several interferences with high repeatability and reproducibility. Finally, the developed electrode was applied to detect FAV in human plasma and pharmaceutical samples. © 2022 Elsevier B.V.

Recent development of antiviral nano-coatings for COVID-19 management-a review

Global pandemic COVID-19 has affected almost the entire world population in every aspect of life in terms of health, environment, and economy. According to WHO, the main source of transmission of this deadly virus (SARS-CoV-2) is proven to be through the aerosol coming from the infected person's cough, sneeze, or exhalation. These aerosols are likely to settle down on the exposed surfaces and such infected surfaces are known to be potential source of contamination. The spread of the viral infections can be controlled in a great extent with the development of anti-viral nano-coating materials for various surfaces. Thus, development of such anti-viral nano-coating materials becomes increasingly popular amongst the researchers due to their extensive applications on surfaces, such as, glass, cotton, plastic and many more. In this short review, we will describe a summary of the popular metals and metal oxide nanomaterials commonly explored as antiviral coatings to control the spread of various viral disease along with the corresponding working principle and effectivity of such coatings.

Amino-terminated hyperbranched polymer functionalized graphene oxide with in situ trapped silver nanoparticles for high-performance antibacterial nonwoven fabric

Antibacterial fabric with high thermal stability and mechanical strength is important for personalized protection, especially under the background of coronavirus pandemic (COVID-19). This paper presents a facile approach toward high-efficient antibacterial polypropylene spunbonded nonwoven fabrics (SNFs), which are decorated by a composite of graphene oxide embedded with silver nanoparticles (AgNPs/GO) through dip-coating and in situ reduction effect of pre-introduced amino-terminated hyperbranched polymer (HBP-NH2). Typically, HBP-NH2 was grafted onto the GO nanosheets, then silver ions were trapped and self-reduced by the HBP-NH2 to generate silver nanoparticles decorated GO. The produced AgNPs are uniformly dispersed on the GO with a size of 13 nm. As an antibacterial coating, the Ag/GO composite could tightly wrap the SNFs fibers through the dip-padding method, capable of enhancing the thermal stability and mechanical property of SNFs. The treated SNFs exhibited excellent antibacterial activities (~99.9%) against both Echerisia coli and Staphylococcus aureus, promising important potential for biomedical and personal protection applications. © 2022 Wiley Periodicals LLC.

Copper Nanoparticle Synthesis on Plasma Treated Poly(lactic) Acid Nonwoven Fabrics

The demand for antibacterial fabric surfaces is increasing day by day. With the covid-19 pandemic situation, there is attention to antibacterial and antiviral nonwoven fabrics which can be used towards the development of personal protective wear. To reduce the environmental pollution caused by disposable and non-biodegradable polymer-made personal protective wear can be replaced by biodegradable polymers like poly(lactic) acid (PLA), which is quite similar to polypropylene, but biodegradable. In this study, the non-thermal plasma treatment method is used to increase the surface reactivity of the PLA nonwoven polymer surface. On the activated nonwoven surface copper nanoparticles are in-situ synthesized by chemical treatments. After 30 minutes of plasma treatment, better copper nanoparticle distribution and higher yield were achieved. Fourier transformed infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were used to characterize the treated PLA nonwoven fabric surfaces. © 2022 IEEE.

Metal nanoparticles-assisted early diagnosis of diseases

Early diagnosis is essential for effective illness treatment, but traditional diagnostic approaches inevitably have major downsides. Recent advancements in nanoparticle-based biosensors have created new opportunities for accelerating diagnosis. High surface area, exceptional sensitivity, high specificity, and optical characteristics of metal and metal oxide nanoparticles have made it possible to detect a variety of health conditions and diseases immediately, including cancer, viral infection, biomarkers, and in-vivo imaging. Metal nanoparticles may be produced in a variety of ways, enabling the creation of innovative tools for chemical and biological sensing targets. The utilization of various metal nano-formulations, metal oxide nanoplatforms, and their composites in the early identification of illnesses is reported and summarized in this review. Additionally, the challenging corners in the use of metal oxide-based nano-scale diagnostic technologies in clinical applications are highlighted. The current work is believed to serve as a roadmap for in-depth research on inorganic nanomedicine, both in-vitro and in-vivo diagnosis of diseases and illnesses, especially pandemic infections like COVID-19.

Printed Capacitive Immunoassay for Detecting SARS-CoV-2 Viral Particles

The key to fight against a global pandemic such as COVID-19 is to have low-cost, reliable and fast response diagnostic tools. Electronic biosensors are preferred because of their ease of integration into current centralized health care networks and integration with modern point-of-care testing (POCT) devices. Printed electronic sensors provide a sensitive and reliable diagnostic platform to aid in controlling transmissible diseases. In this work, we demonstrate a fully printed capacitive biosensor. The sensor uses coplanar electrodes, coupled with capture antibodies immobilized on microporous Polyvinylidene-fluoride (PVDF) film to detect the SARS-CoV-2 spike protein in spiked buffer solutions. Antibody immobilization on PVDF surface is confirmed with confocal fluorescent imaging microscopy. Gold nanoparticle (GNP) tagged detection antibodies are also introduced to provide increased sensitivity. The gold nanoparticles provide a reflectance layer which leads to increased capacitance. This increased capacitance can be measured directly and has demonstrated the ability to screen for spiked samples with statistical significance. This fully printed capacitive immunoassay has the potential to be used as a transmissible disease screening and vaccine efficacy assessment tool for resource-limited areas. IEEE

Handheld, Low-Cost, Aptamer-Based Sensing Device for Rapid SARS-CoV-2 RNA Detection Using Novelly Synthesized Gold Nanoparticles.

The development of a cost-efficient device to rapidly detect pandemic viruses is paramount. Hence, an innovative and scalable synthesis of metal nanoparticles followed by its usage for rapid detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been reported in this work. The simple synthesis of metal nanoparticles utilizing tin as a solid-state reusable reducing agent is used for the SARS-CoV-2 ribonucleic acid (RNA) detection. Moreover, the solid-state reduction process occurs faster and leads to the enhanced formation of silver and gold nanoparticles (AuNPs) with voltage. By adding tin as a solid-state reducing agent with the precursor, the nanoparticles are formed within 30 s. This synthesis method can be easily scaled up for a commercially viable process to obtain different-sized metal nanoparticles. This is the first disclosure of the usage of tin as a reusable solid-state reducing agent for metal nanoparticle synthesis. An electronic device, consisting of AuNPs functionalized with a deoxyribonucleic acid (DNA)-based aptamer, can detect SARS-CoV-2 RNA in less than 5 min. With an increase in SARS-CoV-2 variants, such as Delta and Omicron, the detection device could be used for identifying the nucleic acids of the COVID-19 variants by modifying the aptamer sequence. The reported work overcomes the drawbacks of complex instrumentation, trained labor, and increased turnaround time.

Development of a nano-bioplatform for SARS-CoV-2 specific antigens detection

Lateral Flow Immunoassay (LFIA) has been employed for the development of rapid, low-cost, and relatively simple devices for Covid-19 diagnosis. The proposed approach reports the use of the antibody labeled by Gold nanoparticles for the simultaneous detection of Nucleocapsid protein and Spike protein. A comparison with the results obtained by conventional analytical methods (PCR) has been considered in a significant number of nasopharyngeal swabs;48 and 26 samples from positive and negative individuals respectively. This research provides the basis for the development of a more efficient antigenic test for SARS-Co V-2 detection as a low-cost and quick pre-screening tool. © 2022 IEEE.