Antiviral Activity of Tannic Acid Modified Silver Nanoparticles: Potential to Activate Immune Response in Herpes Genitalis

Advances in engineered nanosystems: immunomodulatory interactions for therapeutic applications

Advances in nanotechnology have led to significant progress in the design and fabrication of nanoparticles (NPs) with improved therapeutic properties. NPs have been explored for modulating the immune system, serving as carriers for drug delivery or vaccine adjuvants, or acting as therapeutics themselves against a wide range of deadly diseases. The combination of NPs with immune system-targeting moieties has facilitated the development of improved targeted immune therapies. Targeted delivery of therapeutic agents using NPs specifically to the disease-affected cells, distinguishing them from other host cells, offers the major advantage of concentrating the therapeutic effect and reducing systemic side effects. Furthermore, the properties of NPs, including size, shape, surface charge, and surface modifications, influence their interactions with the targeted biological components. This review aims to provide insights into these diverse emerging and innovative approaches that are being developed and utilized for modulating the immune system using NPs. We reviewed various types of NPs composed of different materials and their specific application for modulating the immune system. Furthermore, we focused on the mechanistic effects of these therapeutic NPs on primary immune components, including T cells, B cells, macrophages, dendritic cells, and complement systems. Additionally, a recent overview of clinically approved immunomodulatory nanomedicines and potential future perspectives, offering new paradigms of this field, is also highlighted.

Tannin-albumin particles as stable carriers of medicines

Background: The effectiveness of a drug is dependent on its accumulation at the site of therapeutic action, as well as its time in circulation. The aim of the research was the creation of stable albumin/tannin (punicalagin, punicalin) particles, which might serve for the delivery of medicines. Methods: Numerous chromatographic and analytical methods, docking analyses and in vivo testing were applied and used. Results: Stable tannin-albumin/medicine particles with a diameter of ∼100 nm were obtained. The results of in vivo experiments proved that tannin-albumin particles are more stable than albumin particles. Conclusion: Based on the experiments and docking analyses, these stable particles can carry an extended number of medicines, with diverse chemical structures.

Preparation and characterization of ι-carrageenan nanocomposite hydrogels with dual anti-HPV and anti-bacterial activities

Sexually transmitted diseases (STDs) are usually caused by co-infections of bacteria and viruses. However, there is a lack of products that possess both antibacterial and antiviral activities without using chemical drugs. Here, we developed a carrageenan silver nanoparticle composite hydrogel (IC-AgNPs-Gel) based on the antiviral activity of iota carrageenan (IC) and the antibacterial effect of silver nanoparticles (AgNPs) to prevent STDs. IC-AgNPs-Gel showed excellent biocompatibility, hemostasis, antibacterial and antiviral effects. IC-AgNPs-Gel not only effectively prevented S. aureus, E. coli, P. aeruginosa, and C. albicans without using antibiotics, but also significantly inhibited human papilloma virus (HPV)-16 and HPV-6 without using chemotherapy drugs. Moreover, IC-AgNPs-Gel showed the effects of accelerating infected wound healing and reducing inflammation in a rat wound model infected with S. aureus. Therefore, the multifunctional hydrogel shows great potential application prospect in preventing STDs.

Antiviral functionalization of cellulose using tannic acid and tannin-rich extracts

Due to seasonally appearing viruses and several outbreaks and present pandemic, we are surrounded by viruses in our everyday life. In order to reduce viral transmission, functionalized surfaces that inactivate viruses are in large demand. Here the endeavor was to functionalize cellulose-based materials with tannic acid (TA) and tannin-rich extracts by using different binding polymers to prevent viral infectivity of both non-enveloped coxsackievirus B3 (CVB3) and enveloped human coronavirus OC43 (HCoV-OC43). Direct antiviral efficacy of TA and spruce bark extract in solution was measured: EC50 for CVB3 was 0.12 and 8.41 μg/ml and for HCoV-OC43, 78.16 and 95.49 μg/ml, respectively. TA also led to an excellent 5.8- to 7-log reduction of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus infectivity. TA functionalized materials reduced infectivity already after 5-min treatment at room temperature. All the tested methods to bind TA showed efficacy on paperboard with 0.1 to 1% (w/v) TA concentrations against CVB3 whereas material hydrophobicity decreased activities. Specific signatures for TA and HCoV-OC43 were discovered by Raman spectroscopy and showed clear co-localization on the material. qPCR study suggested efficient binding of CVB3 to the TA functionalized cellulose whereas HCoV-OC43 was flushed out from the surfaces more readily. In conclusion, the produced TA-materials showed efficient and broadly acting antiviral efficacy. Additionally, the co-localization of TA and HCoV-OC43 and strong binding of CVB3 to the functionalized cellulose demonstrates an interaction with the surfaces. The produced antiviral surfaces thus show promise for future use to increase biosafety and biosecurity by reducing pathogen persistence.

A Reappraisal of the Antiviral Properties of and Immune Regulation through Dietary Phytochemicals

In the present era of the COVID-19 pandemic, viral infections remain a major cause of morbidity and mortality worldwide. In this day and age, viral infections are rampant and spreading rapidly. Among the most aggressive viral infections are ebola, AIDS (acquired immunodeficiency syndrome), influenza, and SARS (severe acute respiratory syndrome). Even though there are few treatment options for viral diseases, most of the antiviral therapies are ineffective owing to frequent mutations, the development of more aggressive strains, drug resistance, and possible side effects. Traditionally, herbal remedies have been used by healers, including for dietary and medicinal purposes. Many clinical and scientific studies have demonstrated the therapeutic potential of plant-derived natural compounds. Because of unsafe practices like blood transfusions and organ transplants from infected patients, medical supply contamination. Our antiviral therapies cannot achieve sterile immunity, and we have yet to find a cure for these pernicious infections. Herbs have been shown to improve therapeutic efficacy against a wide variety of viral diseases because of their high concentration of immunomodulatory phytochemicals (both immunoinhibitory and anti-inflammatory). Combined with biotechnology, this folk medicine system can lead to the development of novel antiviral drugs and therapies. In this Review, we will summarize some selected bioactive compounds with probable mechanisms of their antiviral actions, focusing on the immunological axis of these compounds.

Study of the Fe3O4@ZIF-8@Sor Composite Modified by Tannic Acid for the Treatment of Sorafenib-Resistant Hepatocellular Carcinoma

Chemotherapeutic agents fail in clinical chemotherapy in the absence of targeting and acquired resistance. We, therefore, synthesized Fe3O4@ZIF-8@Sor@TA nanocomposite drugs based on the drug delivery properties of nanomaterials. ZIF-8 is a nanomaterial with a porous structure that can load anticancer drugs. The nanodrug used the paramagnetic property of Fe3O4 to deliver sorafenib (Sor) precisely to the tumor site, then used the pH responsiveness of ZIF-8 to slowly release Sor in the tumor microenvironment, and finally used tannic acid (TA) to inhibit P-glycoprotein to suppress the Sor resistance. The results of material characterization presented that the prepared material was structurally stable and was able to achieve a cumulative drug release of 38.2% at pH 5.0 for 72 h. The good biocompatibility of the composite was demonstrated by in vitro and in vivo experiments, which could improve antitumor activity and reduce Sor resistance through magnetic targeting TA. In conclusion, the Fe3O4@ZIF-8@Sor@TA material prepared in this study demonstrated high antitumor activity in hepatocellular carcinoma treatment, promising to reduce drug resistance and providing a novel research approach for cancer treatment.

The shape-dependent inhibitory effect of rhein/silver nanocomposites on porcine reproductive and respiratory syndrome virus

Traditional Chinese medicines (TCMs)/nanopreparations as viral antagonists exhibited a structure-function correlation, i.e., the differences in surface area/volume ratio caused by the variations in shape and size could result in different biochemical properties and biological activities, suggesting an important impact of morphology and structure on the antiviral activity of TCM-based nanoparticles. However, few studies paid attention to this aspect. Here, the effect of TCM-based nanoparticles with different morphologies on their antiviral activity was explored by synthesizing rhein/silver nanocomposites (Rhe@AgNPs) with spherical (S-Rhe/Ag) and linear (L-Rhe/Ag) morphologies, using rhein (an active TCM ingredient) as a reducing agent and taking its self-assembly advantage. Using porcine reproductive and respiratory syndrome virus (PRRSV) as a model virus, the inhibitory effects of S-Rhe/Ag and L-Rhe/Ag on PRRSV were compared. Results showed that the product morphology could be regulated by varying pH values, and both S- and L-Rhe/Ag exhibited good dispersion and stability, but with a smaller size for L-Rhe/Ag. Antiviral experiments revealed that Rhe@AgNPs could effectively inhibit PRRSV infection, but the antiviral effect was morphology-dependent. Compared with L-Rhe/Ag, S-Rhe/Ag could more effectively inactivate PRRSV in vitro and antagonize its adsorption, invasion, replication, and release stages. Mechanistic studies indicated that Rhe@AgNPs could reduce the production of reactive oxygen species (ROS) induced by PRRSV infection, and S-Rhe/Ag also had stronger ROS inhibitory effect. This work confirmed the inhibitory effect of Rhe@AgNPs with different morphologies on PRRSV and provided useful information for treating PRRSV infection with metal nanoparticles synthesized from TCM ingredients.

Current Overview of Metal Nanoparticles' Synthesis, Characterization, and Biomedical Applications, with a Focus on Silver and Gold Nanoparticles

Metal nanoparticles (NPs) have garnered considerable attention, due to their unique physicochemical properties, that render them promising candidates for various applications in medicine and industry. This article offers a comprehensive overview of the most recent advancements in the manufacturing, characterization, and biomedical utilization of metal NPs, with a primary focus on silver and gold NPs. Their potential as effective anticancer, anti-inflammatory, and antimicrobial agents, drug delivery systems, and imaging agents in the diagnosis and treatment of a variety of disorders is reviewed. Moreover, their translation to therapeutic settings, and the issue of their inclusion in clinical trials, are assessed in light of over 30 clinical investigations that concentrate on administering either silver or gold NPs in conditions ranging from nosocomial infections to different types of cancers. This paper aims not only to examine the biocompatibility of nanomaterials but also to emphasize potential challenges that may limit their safe integration into healthcare practices. More than 100 nanomedicines are currently on the market, which justifies ongoing study into the use of nanomaterials in medicine. Overall, the present review aims to highlight the potential of silver and gold NPs as innovative and effective therapeutics in the field of biomedicine, citing some of their most relevant current applications.

Epigallocatechin Gallate-Modified Silver Nanoparticles Show Antiviral Activity against Herpes Simplex Type 1 and 2

(1) Background: Epigallocatechin gallate (EGCG) has been recognized as a flavonoid showing antiviral activity against various types of DNA and RNA viruses. In this work, we tested if EGCG-modified silver nanoparticles (EGCG-AgNPs) can become novel microbicides with additional adjuvant properties to treat herpes infections. (2) Methods: The anti-HSV and cytotoxic activities of EGCG-AgNPs were tested in human HaCaT and VK-2-E6/E7 keratinocytes. HSV-1/2 titers and immune responses after treatment with EGCG-AgNPs were tested in murine models of intranasal HSV-1 infection and genital HSV-2 infection. (3) Results: EGCG-AgNPs inhibited attachment and entry of HSV-1 and HSV-2 in human HaCaT and VK-2-E6/E7 keratinocytes much better than EGCG at the same concentration. Infected mice treated intranasally (HSV-1) or intravaginally (HSV-2) with EGCG-AgNPs showed lower virus titers in comparison to treatment with EGCG alone. After EGCG-AgNPs treatment, mucosal tissues showed a significant infiltration in dendritic cells and monocytes in comparison to NaCl-treated group, followed by significantly better infiltration of CD8+ T cells, NK cells and increased expression of IFN-α, IFN-γ, CXCL9 and CXCL10. (4) Conclusions: Our findings show that EGCG-AgNPs can become an effective novel antiviral microbicide with adjuvant properties to be applied upon the mucosal tissues.

Nanocarrier-based drug delivery system in herpes simplex virus treatment

Herpes simplex virus (HSV) is a highly contagious DNA virus that affects the majority of people worldwide. HSV establishes a latent infection in the ganglia, where it can reactivate, leading to recurrent disease. Currently, there are many experimental vaccines against HSV, but none have been used to treat herpes infections. At the same time, the therapeutic effect of existing anti-HSV drugs is limited. Nanocarriers, which deliver drugs to specific targets, have been used in different diseases, including viral infections. Nanocarriers could be designed to encapsulate drugs and directly target infected cells. This review will describe in detail the use of nanocarriers for targeted therapy of HSV infection.

Silver Nanoparticles: Review of Antiviral Properties, Mechanism of Action and Applications

New antiviral drugs and new preventive antiviral strategies are a target of intense scientific interest. Thanks to their peculiar properties, nanomaterials play an important role in this field, and, in particular, among metallic materials, silver nanoparticles were demonstrated to be effective against a wide range of viruses, in addition to having a strong antibacterial effect. Although the mechanism of antiviral action is not completely clarified, silver nanoparticles can directly act on viruses, and on their first steps of interaction with the host cell, depending on several factors, such as size, shape, functionalization and concentration. This review provides an overview of the antiviral properties of silver nanoparticles, along with their demonstrated mechanisms of action and factors mainly influencing their properties. In addition, the fields of potential application are analyzed, demonstrating the versatility of silver nanoparticles, which can be involved in several devices and applications, including biomedical applications, considering both human and animal health, environmental applications, such as air filtration and water treatment, and for food and textile industry purposes. For each application, the study level of the device is indicated, if it is either a laboratory study or a commercial product.

Advanced Plasmonic Nanoparticle-Based Techniques for the Prevention, Detection, and Treatment of Current COVID-19

Coronavirus is an ongoing global pandemic caused by severe acute respiratory syndrome coronavirus 2. Coronavirus disease 2019 known as COVID-19 is the worst pandemic since World War II. The outbreak of COVID-19 had a significant repercussion on the health, economy, politics, and environment, making coronavirus-related issues more complicated and becoming one of the most challenging pandemics of the last century with deadly outcomes and a high rate of the reproduction number. There are thousands of different types - or variants - of COVID circulating across the world. Viruses mutate all the time; it emphasizes the critical need for the designing of efficient vaccines to prevent virus infection, early and fast diagnosis, and effective antiviral and protective therapeutics. In this regard, the use of nanotechnology offers new opportunities for the development of novel strategies in terms of prevention, diagnosis, and treatment of COVID-19. This review presents an outline of the platforms developed using plasmonic nanoparticles in the detection, treatment, and prevention of SARS-CoV-2. We select the best strategies in each of these approaches. The properties of metallic plasmon NPs and their relevance in the development of novel point-of-care diagnosis approaches for COVID-19 are highlighted. Also, we discuss the current challenges and the future perspectives looking towards the clinical translation and the commercial aspects of nanotechnology and plasmonic NP-based diagnostic tools and therapy to fight COVID-19 pandemic. The article could be of significance for researchers dedicated to developing suitable plasmonic detection tools and therapy approaches for COVID-19 viruses and future pandemics.

Inhibition of White Spot Syndrome Virus (WSSV) in Pacific White Shrimp (Litopenaeus vannamei) Using Polyamine-Modified Carbon Quantum Dots

White spot syndrome virus (WSSV), an enveloped double-stranded DNA virus, is the causative agent of white spot syndrome (WSS), which has been linked to cultured shrimp mass mortality in many countries. Therefore, the development of anti-WSSV agents is among the top priorities of the aquaculture sector. Here, we describe the preparation of polyamine-modified carbon quantum dots (polyamine CQDs) for the treatment of WSSV. Moreover, in vivo experiments were conducted in shrimp to confirm the anti-WSSV effect of the proposed CQD-based strategy.

Biocidal Activity of Tannic Acid-Prepared Silver Nanoparticles towards Pathogens Isolated from Patients with Exacerbations of Chronic Rhinosinusitis

The microbiome's significance in chronic rhinosinusitis (CRS) is unclear. Antimicrobials are recommended in acute exacerbations of the disease (AECRS). Increasing rates of antibiotic resistance have stimulated research on alternative therapeutic options, including silver nanoparticles (AgNPs). However, there are concerns regarding the safety of silver administration. The aim of this study was to assess the biological activity of tannic acid-prepared AgNPs (TA-AgNPs) towards sinonasal pathogens and nasal epithelial cells (HNEpC). The minimal inhibitory concentration (MIC) for pathogens isolated from patients with AECRS was approximated using the well diffusion method. The cytotoxicity of TA-AgNPswas evaluated using an MTT assay and trypan blue exclusion. A total of 48 clinical isolates and 4 reference strains were included in the study (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Klebsiellaoxytoca, Acinetobacter baumannii, Serratia marcescens, Enterobacter cloacae). The results of the studies revealed that the MIC values differed between isolates, even within the same species. All the isolates were sensitive to TA-AgNPs in concentrations non-toxic to human cells during 24 h exposition. However, 48 h exposure to TA-AgNPs increased toxicity to HNEpC, narrowing their therapeutic window and enabling 19% of pathogens to resist the TA-AgNPs' biocidal action. It was concluded that TA-AgNPs are non-toxic for the investigated eukaryotic cells after short-term exposure and effective against most pathogens isolated from patients with AECRS, but sensitivity testing may be necessary before application.

Insights into Antiviral Properties and Molecular Mechanisms of Non-Flavonoid Polyphenols against Human Herpesviruses

Herpesviruses are one of the most contagious DNA viruses that threaten human health, causing severe diseases, including, but not limited to, certain types of cancer and neurological complications. The overuse and misuse of anti-herpesvirus drugs are key factors leading to drug resistance. Therefore, targeting human herpesviruses with natural products is an attractive form of therapy, as it might improve treatment efficacy in therapy-resistant herpesviruses. Plant polyphenols are major players in the health arena as they possess diverse bioactivities. Hence, in this article, we comprehensively summarize the recent advances that have been attained in employing plant non-flavonoid polyphenols, such as phenolic acids, tannins and their derivatives, stilbenes and their derivatives, lignans, neolignans, xanthones, anthraquinones and their derivatives, curcuminoids, coumarins, furanocoumarins, and other polyphenols (phloroglucinol) as promising anti-herpesvirus drugs against various types of herpesvirus such as alpha-herpesviruses (herpes simplex virus type 1 and 2 and varicella-zoster virus), beta-herpesviruses (human cytomegalovirus), and gamma-herpesviruses (Epstein-Barr virus and Kaposi sarcoma-associated herpesvirus). The molecular mechanisms of non-flavonoid polyphenols against the reviewed herpesviruses are also documented.

Functionalized Noble Metal Nanoparticles for the Treatment of Herpesvirus Infection

Neuroinfections caused by herpesviruses, mainly by HHV-1, represent a significant problem for modern medicine due to the small number of therapeutic substances available in the pharmaceutical sector. Furthermore, HHV-1 infection has been linked to neurodegenerative processes such as Alzheimer’s disease, which justifies the search for new effective therapies. The development of nanotechnology opens up new possibilities for the treatment of neuroinflammation. Gold and silver nanoparticles are gaining popularity, and the number of clinical trials involving metallic nanoparticles is constantly increasing. This paper reviews the research on gold and silver nanoparticles and their potential use in the treatment of herpesvirus neuroinfection.

Anti-HSV Activity of Metallic Nanoparticles Functionalized with Sulfonates vs. Polyphenols

Metallic nanoparticles exhibit broad-spectrum activity against bacteria, fungi, and viruses. The antiviral activity of nanoparticles results from the multivalent interactions of nanoparticles with viral surface components, which result from the nanometer size of the material and the presence of functional compounds adsorbed on the nanomaterial surface. A critical step in the virus infection process is docking and entry of the virus into the host cell. This stage of the infection can be influenced by functional nanomaterials that exhibit high affinity to the virus surface and hence can disrupt the infection process. The affinity of the virus to the nanomaterial surface can be tuned by the specific surface functionalization of the nanomaterial. The main purpose of this work was to determine the influence of the ligand type present on nanomaterial on the antiviral properties against herpes simplex virus type 1 and 2. We investigated the metallic nanoparticles (gold and silver) with different sizes (5 nm and 30 nm), coated either with polyphenol (tannic acid) or sulfonates (ligands with terminated sulfonate groups). We found that the antiviral activity of nano-conjugates depends significantly on the ligand type present on the nanoparticle surface.

Highly Stable Core-Shell Nanocolloids: Synergy between Nano-Silver and Natural Polymers to Prevent Biofilm Formation

Active investment in research time in the development and study of novel unconventional antimicrobials is trending for several reasons. First, it is one of the ways which might help to fight antimicrobial resistance and bacterial contamination due to uncontrolled biofilm growth. Second, minimizing harmful environmental outcomes due to the overuse of toxic chemicals is one of the highest priorities nowadays. We propose the application of two common natural compounds, chitosan and tannic acid, for the creation of a highly crosslinked polymer blend with not only intrinsic antimicrobial properties but also reducing and stabilizing powers. Thus, the fast and green synthesis of fine spherically shaped Ag nanoparticles and further study of the composition and properties of the colloids took place. A positively charged core-shell nanocomposition, with an average size in terms of the metal core of 17 ± 4 nm, was developed. Nanoantimicrobials were characterized by several spectroscopic (UV-vis and FTIR) and microscopic (transmission and scanning electron microscopies) techniques. The use of AgNPs as a core and an organic polymer blend as a shell potentially enable a synergistic long-lasting antipathogen effect. The antibiofilm potential was studied against the food-borne pathogens Salmonella enterica and Listeria monocytogenes. The antibiofilm protocol efficiency was evaluated by performing crystal violet assay and optical density measurements, direct visualization by confocal laser scanning microscopy and morphological studies by SEM. It was found that the complex nanocomposite has the ability to prevent the growth of biofilm. Further investigation for the potential application of this stable composition in food packaging will be carried out.

Lactoferrin-Conjugated Nanoparticles as New Antivirals

Lactoferrin is an iron-binding glycoprotein with multiple functions in the body. Its activity against a broad spectrum of both DNA and RNA viruses as well as the ability to modulate immune responses have made it of interest in the pharmaceutical and food industries. The mechanisms of its antiviral activity include direct binding to the viruses or its receptors or the upregulation of antiviral responses by the immune system. Recently, much effort has been devoted to the use of nanotechnology in the development of new antivirals. In this review, we focus on describing the antiviral mechanisms of lactoferrin and the possible use of nanotechnology to construct safe and effective new antiviral drugs.

Pharmacological effects and mechanisms of tannic acid

In recent years, increasing attention has been paid to the pharmacological efficacy of tannins. Tannic acid (TA), the simplest hydrolysable tannin that has been approved by the FDA as a safe food additive, is one of the most important components of these traditional medicines. Studies have shown that TA displays a wide range of pharmacological activities, such as anti-inflammatory, neuroprotective, antitumor, cardioprotective, and anti-pathogenic effects. Here, we summarize the known pharmacological effects and associated mechanisms of TA. We focus on the effect and mechanism of TA in various animal models of inflammatory disease and organ, brain, and cardiovascular injury. Moreover, we discuss the possible molecular targets and signaling pathways of TA, in addition to the pharmacological effects of TA-based nanoparticles and TA in combination with chemotherapeutic drugs.

Synthesis of silver nanoparticles using Eucommia ulmoides extract and their potential biological function in cosmetics

Silver nanoparticles (AgNPs) synthesized from plant extracts have recently emerged as a rapidly growing field with numerous applications in pharmaceutical and clinical contexts. The purpose of this research is to come up with a novel method for the biosynthesis of silver nanoparticles that use Eucommia ulmoides leaf extract as a reducing agent. The synthesis of AgNPs was confirmed using UV-vis spectroscopy, and the properties of AgNPs were characterized using Transmission Electron Microscope, Fourier Infrared Spectrometer, X-ray diffraction, Thermogravimetric Analysis, and Zeta potential. The results showed that the AgNPs exhibited a characteristic absorption peak at 430 nm, their diameter ranged from 4 nm to 52 nm, and C, O, and Cl elements, which might represent flavonoids and phenolic components absorbed on the surface of AgNPs. The zeta potential of AgNPs was found to be −30.5 mV, which indicates repulsion among AgNPs and they have good dispersion stability. AgNPs have been found to suppress the tyrosinase activity both in mushroom tyrosinase and A375 cells, as well as diminish ROS formation in HaCat cells. According to this study, AgNPs is a novel material that can enhance skin health by preventing melanin development.

Metal and metal oxide-based antiviral nanoparticles: Properties, mechanisms of action, and applications

Certain types of metal-based nanoparticles are effective antiviral agents when used in their original form ("bare") or after their surfaces have been functionalized ("modified"), including those comprised of metals (e.g., silver) and metal oxides (e.g., zinc oxide, titanium dioxide, or iron dioxide). These nanoparticles can be prepared with different sizes, morphologies, surface chemistries, and charges, which leads to different antiviral activities. They can be used as aqueous dispersions or incorporated into composite materials, such as coatings or packaging materials. In this review, we provide an overview of the design, preparation, and characterization of metal-based nanoparticles. We then discuss their potential mechanisms of action against various kinds of viruses. Finally, the applications of some of the most common metal and metal oxide nanoparticles are discussed, including those fabricated from silver, zinc oxide, iron oxide, and titanium dioxide. In general, the major antiviral mechanisms of metal and metal oxide nanoparticles have been observed to be 1) attachment of nanoparticles to surface moieties of viral particles like spike glycoproteins, that disrupt viral attachment and uncoating in host cells; 2) generation of reactive oxygen species (ROS) that denature viral macromolecules such as nucleic acids, capsid proteins, and/or lipid envelopes; and 3) inactivation of viral glycoproteins by the disruption of the disulfide bonds of viral proteins. Several physicochemical properties of metal and metal oxide nanoparticles including size, shape, zeta potential, stability in physiological conditions, surface modification, and porosity can all impact the antiviral efficacy of the nanoparticles.

Updates in immunocompatibility of biomaterials: applications for regenerative medicine

INTRODUCTION

Biomaterials, either metallic, ceramic, or polymeric, can be used in medicine as a part of the implants, dialysis membranes, bone scaffolds, or components of artificial organs. Polymeric biomaterials cover a vast range of biomedical applications. The biocompatibility and immunocompatibility of polymeric materials are of fundamental importance for their possible therapeutic uses, as the immune system can intervene in the materials' performance. Therefore, based on application, different routes can be utilized for immunoregulation.

AREAS COVERED

As different biomaterials can be modulated by different strategies, this study aims to summarize and evaluate the available methods for the immunocompatibility enhancement of more common polymeric biomaterials based on their nature. Different strategies such as surface modification, physical characterization, and drug incorporation are investigated for the immunomodulation of nanoparticles, hydrogels, sponges, and nanofibers.

EXPERT OPINION

Recently, strategies for triggering appropriate immune responses by functional biomaterials have been highlighted. As most strategies correspond to the physical and surface properties of biomaterials, specific modulation can be conducted for each biomaterial system. Besides, different applications require different modulations of the immune system. In the future, the selection of novel materials and immune regulators can play a role in tuning the immune system for regenerative medicine.

Tannic Acid Coating Augments Glioblastoma Cellular Uptake of Magnetic Nanoparticles with Antioxidant Effects

Coating of nanoparticles with gallates renders them antioxidant and enhances cellular internalization. In this study, (amino)silica magnetic particles modified with tannic acid (TA) and optionally with chitosan (CS) were developed, and their physicochemical properties and antioxidant activity were evaluated. The results demonstrated that the TA-modified aminosilica-coated particles, as well as the silica-coated particles with a double TA layer, exhibited high antioxidant activity, whereas the silica-coated particles with no or only a single TA layer were well-internalized by LN-229 cells. In addition, a magnet placed under the culture plates greatly increased the cellular uptake of all TA-coated magnetic nanoparticles. The coating thus had a considerable impact on nanoparticle–cell interactions and particle internalization. The TA-coated magnetic nanoparticles have great potential as intracellular carriers with preserved antioxidant activity.

The Emerging Roles of Silver Nanoparticles to Target Viral Life Cycle and Detect Viral Pathogens

Along the line of recent vaccine advancements, new antiviral therapeutics are compelling to combat viral infection-related public health crises. Several properties of silver nanoparticles (AgNPs) such as low level of cytotoxicity, ease of tunability of the AgNPs in the ultra-small nanoscale size and shape through different convenient bottom-up chemistry approaches, high penetration of the composite with drug formulations into host cells has made AgNPs, a promising candidate for developing antivirals. In this review, we have highlighted the recent advancements in the AgNPs based nano-formulations to target cellular mechanisms of viral propagation, immune modulation of the host, and the ability to synergistically enhance the activity of existing antiviral drugs. On the other hand, we have discussed the recent advancements on AgNPs based detection of viral pathogens from clinical samples using inherent physicochemical properties. This article will provide an overview of our current knowledge on AgNPs based formulations that has promising potential for developing a counteractive strategy against emerging and existing viruses.

Antiviral activity of algae biosynthesized silver and gold nanoparticles against Herps Simplex (HSV-1) virus in vitro using cell-line culture technique

As therapeutic antiviral agents, biological nanoparticles can fight the drug-resistant types of viruses helping the antiviral drug development. In this study, two blue-green algal strains; Oscillatoria sp. and Spirulina platensis were used, mediated by green Ag₂O|AgO-NPs and Au-NPs, respectively. For NPs characterization, the UV/Vis spectroscopy were used where their formation and crystallinity were proven with λ_max values for silver and gold NPs of 432 and 552 nm, respectively. The transmission electron microscope (TEM) X-ray diffraction showed a spherical-shaped Ag₂O|AgO-NPs (size; 14.42 to 48.97) while Au-NPs appeared with octahedral, pentagonal and triangular structures (size; 15.60-77.13 nm). The reducing, capping, and stabilization activities of algal polysaccharides and proteins were indicated via FTIR spectroscopy. Both Ag₂O|AgO-NPs and Au-NPs were investigated against Herpes Simplex virus (HSV-1) that has been indicated by its reduction activity of cytopathic effect (CPE). Cytotoxicity was evaluated on Vero cells and measured by MTT assay. Results showed a 90% reduction in CPE of HSV-1 applying Ag₂O|AgO-NPs, and Au-NPs at 31.25 μL., with a high reduction rate (49.23%) with Ag₂O|AgO-NPs than that of Au-NPs (42.75%). Current results proved the efficiency of green nanotechnology application with both Ag₂O|AgO-NPs, and Au-NPs as reducing and inhibitory agents for the HSV-1 replication.

Recent advances on therapeutic potentials of gold and silver nanobiomaterials for human viral diseases

Viral diseases are prominent among the widely spread infections threatening human well-being. Real-life clinical successes of the few available therapeutics are challenged by pathogenic resistance and suboptimal delivery to target sites. Nanotechnology has aided the design of functionalised and non-functionalised Au and Ag nanobiomaterials through physical, chemical and biological (green synthesis) methods with improved antiviral efficacy and delivery. In this review, innovative designs as well as interesting antiviral activities of the nanotechnology-inclined biomaterials of Au and Ag, reported in the last 5 years were critically overviewed against several viral diseases affecting man. These include influenza, respiratory syncytial, adenovirus, severe acute respiratory syndromes (SARS), rotavirus, norovirus, measles, chikungunya, HIV, herpes simplex virus, dengue, polio, enterovirus and rift valley fever virus. Notably identified among the nanotechnologically designed promising antiviral agents include AuNP-M2e peptide vaccine, AgNP of cinnamon bark extract and AgNP of oseltamivir for influenza, PVP coated AgNP for RSV, PVP-AgNPs for SARS-CoV-2, AuNRs of a peptide pregnancy-induce d hypertension and AuNP nanocarriers of antigen for MERS-CoV and SARS-CoV respectively. Others are AgNPs of collagen and Bacillus subtilis for rotavirus, AgNPs labelled Ag30-SiO 2 for murine norovirus in water, AuNPs of Allium sativum and AgNPs of ribavirin for measles, AgNPs of Citrus limetta and Andrographis Paniculata for Chikungunya, AuNPs of efavirenz and stavudine, and AgNPs-curcumin for HIV, NPAuG3-S8 for HSV, AgNPs of Moringa oleifera and Bruguiera cylindrica for dengue while AgNPs of polyethyleneimine and siRNA analogues displayed potency against enterovirus. The highlighted candidates are recommended for further translational studies towards antiviral therapeutic designs.

Antiviral Activities of High Energy E-Beam Induced Copper Nanoparticles against H1N1 Influenza Virus

The pandemic outbreak of COVID-19 in the year of 2020 that drastically changed everyone's life has raised the urgent and intense need for the development of more efficacious antiviral material. This study was designed to develop copper nanoparticles (Cu NPs) as an antiviral agent and to validate the antiviral activities of developed copper NP. The Cu NPs were synthesized using a high energy electron beam, and the characteristic morphologies and antiviral activities of Cu NPs were evaluated. We found that Cu NPs are of spherical shape and uniformly distributed, with a diameter of around 100 nm, as opposed to the irregular shape of commercially available copper microparticles (Cu MPs). An X-ray diffraction analysis showed the presence of Cu and no copper oxide II and I in the Cu NPs. A virus inactivation assay revealed no visible viral DNA after 10- and 30-min treatment of H1N1 virus with the Cu NPs. The infectivity of the Cu NPs-treated H1N1 virus significantly decreased compared with that of the Cu MPs-treated H1N1 virus. The viability of A549 bronchial and Madin-Darby Canine Kidney (MDCK) cells infected with Cu NPs-treated H1N1 was significantly higher than those infected with Cu MPs-treated H1N1 virus. We also found cells infected with Cu NPs-treated H1N1 virus exhibited a markedly decreased presence of virus nucleoprotein (NuP), an influenza virus-specific structural protein, compared with cells infected with Cu MPs-treated H1N1 virus. Taken together, our study shows that Cu NPs are a more effective and efficacious antiviral agent compared with Cu MPs and offer promising opportunities for the prevention of devastatingly infectious diseases.

Lactoferrin-Functionalized Noble Metal Nanoparticles as New Antivirals for HSV-2 Infection

(1) Background: Lactoferrin has been recognized as a potent inhibitor of human herpetic viruses, such as herpes simplex type 1 (HSV-1) and 2 (HSV-2). In this work, we tested if silver and gold nanoparticles modified with lactoferrin (LF-Ag/AuNPs) can become novel microbicides with additional adjuvant properties to treat genital herpes infection. (2) Methods: The antiviral and cytotoxic activities of LF-Ag/AuNPs were tested in human skin HaCaT and vaginal VK-2-E6/E7 keratinocytes. Viral titers and immune responses after treatment with LF-Ag/AuNPs were tested in murine vaginal HSV-2 infection. (3) Results: LF-Ag/AuNPs inhibited attachment and entry of HSV-2 in human keratinocytes much better than lactoferrin. Furthermore, pretreatment with LF-AgNPs led to protection from infection. Infected mice treated intravaginally with LF-Ag/AuNPs showed lower virus titers in the vaginal tissues and spinal cords in comparison to treatment with lactoferrin. Following treatment, vaginal tissues showed a significant increase in CD8+/granzyme B + T cells, NK cells and dendritic cells in comparison to NaCl-treated group. LF-Ag/AuNPs-treated animals also showed significantly better expression of IFN-γ, CXCL9, CXCL10, and IL-1β in the vaginal tissues. (4) Conclusions: Our findings show that LF-Ag/AuNPs could become effective novel antiviral microbicides with immune-stimulant properties to be applied upon the mucosal tissues.

AgNPs reduce reproductive capability of female mouse for their toxic effects on mouse early embryo development

Silver nanoparticles (AgNPs) are widely applied in the field of personal protection for their powerful toxic effects on cells, and recently, a new type of vaginal gel with AgNPs is used to protect the female reproductive tract from microbes and viruses. However, a high risk of AgNPs to the fetus and the underlying mechanism of AgNPs to interfere in embryo development still remain unclear. Thus, this study investigated the impact of two drugs of vaginal gel with AgNPs on reproductive capability of the female mouse by animal experiment. Then, kinetics of AgNPs affecting embryo development was investigated by in vitro embryos culturing, and cell membrane potential (CMP) of zygotes was analyzed by DiBAC4(3) staining. Results indicated that one of the drugs of vaginal gel certainly injured embryo development in spite of no apparent histological change found in ovaries and uteruses of drug-treated mice. In vitro embryo culturing discovered that the toxic effect of AgNPs on embryo development presented particle sizes and dose dependent, and AgNP treatment could rapidly trigger depolarization of the cell membrane of zygotes. Moreover, AgNPs changed the gene expression pattern of Oct-4 and Cdx2 in blastocysts. All these findings suggest that AgNPs can interfere with normal cellular status including cell membrane potential, which has not been noticed in previous studies on the impact of AgNPs on mammalian embryos. Thus, findings of this study alarm us the risk of applying vaginal gel with AgNPs in individual caring and protection of the female reproductive system.

Masks for COVID-19

Sustainable solutions on fabricating and using a face mask to block the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread during this coronavirus pandemic of 2019 (COVID-19) are required as society is directed by the World Health Organization (WHO) toward wearing it, resulting in an increasingly huge demand with over 4 000 000 000 masks used per day globally. Herein, various new mask technologies and advanced materials are reviewed to deal with critical shortages, cross-infection, and secondary transmission risk of masks. A number of countries have used cloth masks and 3D-printed masks as substitutes, whose filtration efficiencies can be improved by using nanofibers or mixing other polymers into them. Since 2020, researchers continue to improve the performance of masks by adding various functionalities, for example using metal nanoparticles and herbal extracts to inactivate pathogens, using graphene to make masks photothermal and superhydrophobic, and using triboelectric nanogenerator (TENG) to prolong mask lifetime. The recent advances in material technology have led to the development of antimicrobial coatings, which are introduced in this review. When incorporated into masks, these advanced materials and technologies can aid in the prevention of secondary transmission of the virus.

Synthesis approach-dependent antiviral properties of silver nanoparticles and nanocomposites

Numerous viral infections are common among humans, and some can lead to death. Even though conventional antiviral agents are beneficial in eliminating viral infections, they may lead to side effects or physiological toxicity. Silver nanoparticles and nanocomposites have been demonstrated to possess inhibitory properties against several pathogenic microbes, including archaea, bacteria, fungi, algae, and viruses. Its pronounced antimicrobial activity against various microbe-mediated diseases potentiates its use in combating viral infections. Notably, the appropriated selection of the synthesis method to fabricate silver nanoparticles is a major factor for consideration as it directly impacts antiviral efficacy, level of toxicity, scalability, and environmental sustainability. Thus, this article presents and discusses various synthesis approaches to produce silver nanoparticles and nanocomposites, providing technological insights into selecting approaches to generate antiviral silver-based nanoparticles. The antiviral mechanism of various formulations of silver nanoparticles and the evaluation of its propensity to combat specific viral infections as a potential antiviral agent are also discussed.

Tannic Acid Exhibits Adjuvant Activity by Enhancing Humoral and Cell-Mediated Immunity Against BSA as a Protein Antigen

BACKGROUND

Immunization or vaccination is the process of inducing artificial immunity against an antigen taking advantage of the mechanisms of immunological memory. Current vaccines include substances known as adjuvants, which tend to improve the immunogenicity of the antigen, reduce the antigen quantity employed, and boost the immune response in weak responders. Unfortunately, only a few vaccine adjuvants are approved for human use.

OBJECTIVE

Thus, the objective of this study was to investigate the effect of Tannic acid on humoral and cell-mediated immunity against bovine serum albumin (BSA) as a protein antigen in Wistar rats.

METHOD

In order to establish the Tannic acid concentration to test it as an adjuvant, the lethal dose 50 and maximum non-toxic dose were calculated through cytotoxicity and hemolytic assays with J774 A.1 cell line and rat erythrocytes by resazurin reduction method and UV/vis spectrophotometry. Thirty Wistar rats were divided into 5 groups that included two controls without antigen and three treatment groups of adjuvants plus BSA as a protein antigen. The rats were immunized in a 30-day scheme. Blood samples were collected for humoral immunity analysis by means of immunoglobulin quantification, isotyping and antigen-antibody precipitation inhibition analysis. Rat peritoneal macrophages and splenocytes were isolated for cell-mediated immunity analysis by means of nitric oxide quantification from adjuvant stimulated peritoneal macrophages and lymphocytes proliferation assay.

RESULTS

Tannic acid was capable of increasing the immunogenicity of the antigen; besides, it was able to stimulate cell-mediated immunity by means of increased lymphocyte proliferation. Moreover, Tannic acid improved the humoral response by means of increased specific antibodies titers. These activities may be attributed to pattern recognition receptors stimulation.

CONCLUSION

Tannic acid was considered biocompatible when tested in vivo because the concentration tested did not show cytotoxicity or hemolytic effect, and there was no detrimental effect observed on the animals' health. These results show Tannic acid as a promising candidate for vaccine adjuvant.

Nanomedicines for the topical treatment of vulvovaginal infections: Addressing the challenges of antimicrobial resistance

Recent years have, surprisingly, witnessed an increase in incidence of sexually transmitted infections (STIs). At the same time, antimicrobial therapy came under the threat of ever rising antimicrobial resistance (AMR), resulting in STIs with extremely limited therapy options. In this review, we addressed the challenges of treating vaginal infections in an era of AMR. We focused on published work regarding nanomedicine destined for localized treatment of vaginal infections. Localized therapy offers numerous advantages such as assuring high drug concentration at the infection site, limiting systemic drug exposure that can lead to faster development of AMR reduction in the systemic side effects and potentially safe therapy in pregnancy. We provided a state-of-the-art overview of nanoformulations proposed to topically treat STIs, emphasizing the challenges and advantages of each type of nanocarriers, as well as issues of potential toxicity.

Antiviral Properties of Polyphenols from Plants

Polyphenols are active substances against various types of viral infections. Researchers have characterized methods of how to isolate polyphenols without losing their potential to formulate pharmaceutical products. Researchers have also described mechanisms against common viral infections (i.e., influenza, herpes, hepatitis, rotavirus, coronavirus). Particular compounds have been discussed together with the plants in the biomass in which they occur. Quercetin, gallic acid and epigallocatechin are exemplary compounds that inhibit the growth cycle of viruses. Special attention has been paid to identify plants and polyphenols that can be efficient against coronavirus infections. It has been proven that polyphenols present in the diet and in pharmaceuticals protect us from viral infections and, in case of infection, support the healing process by various mechanisms, i.e., they block the entry into the host cells, inhibit the multiplication of the virus, seal blood vessels and protect against superinfection.

Polyphenols affect the humoral response in cancer, infectious and allergic diseases and autoimmunity by modulating the activity of TH1 and TH2 cells

Polyphenols are a wide class of natural substances, pleiotropic molecules capable of modulating several processes, involved in the humoral and cellular immune response. The activation, differentiation of B cells, and production of antibodies to protein antigens by plasma cells depend on T helper (T_H) CD4⁺ cells and secreted cytokines. Cancer, infectious, allergic, and autoimmune diseases are characterized by an imbalance of T_H1/T_H2 immunity and abnormal activation of the humoral response. Accordingly, polyphenols modulate the T_H1/T_H2 ratio, the secretion of multiple cytokines, the levels of antibodies, and therefore could contribute to recovering the state of health in these diseases. In this review, we summarize the current knowledge on the effects of polyphenols in modulating the humoral response in cancer, infectious and allergic diseases and in autoimmunity by affecting the activity of T_H1 and T_H2 cells.

Polymeric Materials as Potential Inhibitors Against SARS-CoV-2

Recently discovered SARS-CoV-2 caused a pandemic that triggered researchers worldwide to focus their research on all aspects of this new peril to humanity. However, in the absence of specific therapeutic intervention, some preventive strategies and supportive treatment minimize the viral transmission as studied by some factors such as basic reproduction number, case fatality rate, and incubation period in the epidemiology of viral diseases. This review briefly discusses coronaviruses' life cycle of SARS-CoV-2 in a human host cell and preventive strategies at some selected source of infection. The antiviral activities of synthetic and natural polymers such as chitosan, hydrophobically modified chitosan, galactosylated chitosan, amine-based dendrimers, cyclodextrin, carrageenans, polyethyleneimine, nanoparticles are highlighted in this article. Mechanism of virus inhibition, detection and diagnosis are also presented. It also suggests that polymeric materials and nanoparticles can be effective as potential inhibitors and immunization against coronaviruses which would further develop new technologies in the field of polymer and nanoscience.

AgNPs reduce reproductive capability of female mouse for their toxic effects on mouse early embryo development

Silver nanoparticles (AgNPs) are widely applied in the field of personal protection for their powerful toxic effects on cells, and recently, a new type of vaginal gel with AgNPs is used to protect the female reproductive tract from microbes and viruses. However, a high risk of AgNPs to the fetus and the underlying mechanism of AgNPs to interfere in embryo development still remain unclear. Thus, this study investigated the impact of two drugs of vaginal gel with AgNPs on reproductive capability of the female mouse by animal experiment. Then, kinetics of AgNPs affecting embryo development was investigated by in vitro embryos culturing, and cell membrane potential (CMP) of zygotes was analyzed by DiBAC4(3) staining. Results indicated that one of the drugs of vaginal gel certainly injured embryo development in spite of no apparent histological change found in ovaries and uteruses of drug-treated mice. In vitro embryo culturing discovered that the toxic effect of AgNPs on embryo development presented particle sizes and dose dependent, and AgNP treatment could rapidly trigger depolarization of the cell membrane of zygotes. Moreover, AgNPs changed the gene expression pattern of Oct-4 and Cdx2 in blastocysts. All these findings suggest that AgNPs can interfere with normal cellular status including cell membrane potential, which has not been noticed in previous studies on the impact of AgNPs on mammalian embryos. Thus, findings of this study alarm us the risk of applying vaginal gel with AgNPs in individual caring and protection of the female reproductive system.

Silver Nanoparticles Biosynthesis, Characterization, Antimicrobial Activities, Applications, Cytotoxicity and Safety Issues: An Updated Review

Rapid advances in nanotechnology have led to its emergence as a tool for the development of green synthesized noble metal nanoparticles, especially silver nanoparticles (AgNPs), for applications in diverse fields such as human health, the environment and industry. The importance of AgNPs is because of their unique physicochemical and antimicrobial properties, with a myriad of activities that are applicable in various fields, including the pharmaceutical industry. Countries with high biodiversity require the collection and transformation of information about biological assets into processes, associations, methods and tools that must be combined with the sustainable utilization of biological diversity. Therefore, this review paper discusses the applicable studies of the biosynthesis of AgNPs and their antimicrobial activities towards microorganisms in different areas viz. medicine and agriculture. The confirmed antiviral properties of AgNPs promote their applicability for SARS-CoV-2 treatment, based on assimilating the virus’ activities with those of similar viruses via in vivo studies. In this review, an insight into the cytotoxicity and safety issues of AgNPs, along with their future prospects, is also provided.

Metal Nanoparticles: a Promising Treatment for Viral and Arboviral Infections

Globally, viral diseases continue to pose a significant threat to public health. Recent outbreaks, such as influenza, coronavirus, Ebola, and dengue, have emphasized the urgent need for new antiviral therapeutics. Considerable efforts have focused on developing metal nanoparticles for the treatment of several pathogenic viruses. As a result of these efforts, metal nanoparticles are demonstrating promising antiviral activity against pathogenic surrogates and clinical isolates. This review summarizes the application of metal nanoparticles for the treatment of viral infections. It provides information on synthesis methods, size-related properties, nano-bio-interaction, and immunological effects of metal nanoparticles. This article also addresses critical criteria and considerations for developing clinically translatable nanosized metal particles to treat viral diseases.

Silver, copper and copper oxide nanoparticles in the fight against human viruses: progress and perspectives

The rapid development of nanomedicine has created a high demand for silver, copper and copper oxide nanoparticles. Due to their high reactivity and potent antimicrobial activity, silver and copper-based nanomaterials have been playing an important role in the search for new alternatives for the treatment of several issues of concern, such as pathologies caused by bacteria and viruses. Viral diseases are a significant and constant threat to public health. The most recent example is the pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this context, the object of the present review is to highlight recent progress in the biomedical uses of these metal nanoparticles for the treatment and prevention of human viral infections. We discuss the antiviral activity of AgNPs and Cu-based NPs, including their actions against SARS-CoV-2. We also discuss the toxicity, biodistribution and excretion of AgNPs and CuNPs, along with their uses in medical devices or on inert surfaces to avoid viral dissemination by fomites. The challenges and limitations of the biomedical use of these nanoparticles are presented.

Preclinical autophagy modulatory nanomedicines: big challenges, slow advances

INTRODUCTION

Autophagy is a critical housekeeping pathway to remove toxic protein aggregates, damaged organelles, providing cells with bioenergetic substrates needed to survive under adverse conditions. Since altered autophagy is associated with diverse diseases, its pharmacological modulation is considered of therapeutic interest. Nanomedicines may reduce the toxicity and improve the activity of toxic autophagy modulatory drugs (amd).

AREAS COVERED

The status of the most relevant anti-tumor, anti-inflammatory, and anti-infectious treatments mediated by autophagy modulatory nanomedicines (amN) published in the last 5 years is discussed.

EXPERT OPINION

Antitumor and anti-inflammatory treatments may be improved by administering amN for selective, massive, and targeted delivery of amd to diseased tissues. The use of amN as antimicrobial agent remains almost underexploited. Assessing the effect of amN on the complex autophagy machinery operating under different basal diseases, however, is not a trivial task. Besides structural reproducibility, nanomedicines must grant higher efficiency, and lower adverse effects than conventional medication. Simplicity of design, carefully chosen (scalable) preparation techniques, and rigorous monitoring of preclinical efficacy and nanotoxicity will improve the chances of clinical success. Currently, available data are not sufficient to envisage a fast-succeeding translation. Application of quality by design criteria would help to reach such milestones.

Green synthesized plant-based silver nanoparticles: therapeutic prospective for anticancer and antiviral activity

Nanotechnology holds an emerging domain of medical science as it can be utilized virtually in all areas. Phyto-constituents are valuable and encouraging candidates for synthesizing green silver nanoparticles (AgNPs) which possess great potentials toward chronic diseases. This review gives an overview of the Green approach of AgNPs synthesis and its characterization. The present review further explores the potentials of Phyto-based AgNPs toward anticancer and antiviral activity including its probable mechanism of action. Green synthesized AgNPs prepared by numerous medicinal plants extract are critically reviewed for cancer and viral infection. Thus, this article mainly highlights green synthesized Phyto-based AgNPs with their potential applications for cancer and viral infection including mechanism of action and therapeutic future prospective in a single window.

Preparation of cellulose-based wipes treated with antimicrobial and antiviral silver nanoparticles as novel effective high-performance coronavirus fighter

Coronaviruses (CoV) are a large family of viruses that cause illness ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS-CoV). We succeeded in preparing disinfectant cellulose-based wipes treated with antimicrobial and antiviral silver nanoparticles to be used for prevention of contamination and transmission of several pathogenic viruses and microbes to human in critical areas such as hospitals and healthcare centers especially coronavirus. In this work, the antimicrobial and antiviral activities of silver nanoparticles (AgNPs) prepared with four different techniques were investigated for the utilization as a disinfectant for cellulose-based wipes. These four methods are namely; 1) trisodium citrate with cotton yarn as a reducing agent, 2) preparing AgNP's using aqueous solution of PVA in the presence of glucose, 3) trisodium citrate with cotton fabric as a reducing agent, and 4) photochemical reaction of polyacrylic acid and silver nitrate solution. Polyester/viscose blended spunlace nonwoven fabrics as cellulose based fabrics were treated with the prepared silver nanoparticles to be used as surfaces disinfection wipes. The properties of the nonwoven fabrics were examined including thickness, tensile strength in dry and wet conditions in both machine direction (MD) and cross-machine direction (CMD), bursting strength, air permeability, water permeability and surface wettability. Characterization of the AgNPs was carried out in terms of UV-VIS spectroscopy, TEM, SEM, and Zeta potential analysis. The assessment of AgNPs active solutions for antimicrobial and antiviral activities was evaluated. The results obtained from the analyses of the AgNPs samples prepared with different techniques showed good uniformity and stability of the particles, as well uniform coating of the AgNPs on the fibers. Additionally, there is a significant effect of the AgNPs preparation method on their disinfectant performance that proved its effectiveness against coronavirus (MERS-CoV), S. aureus and B. subtilis as Gram-positive bacteria, E. coli and P. mirabilis as Gram-negative bacteria, A. niger and C. albicans fungi.

Advanced Material Against Human (Including Covid-19) and Plant Viruses: Nanoparticles As a Feasible Strategy

The SARS-CoV-2 virus outbreak revealed that these nano-pathogens have the ability to rapidly change lives. Undoubtedly, SARS-CoV-2 as well as other viruses can cause important global impacts, affecting public health, as well as, socioeconomic development. But viruses are not only a public health concern, they are also a problem in agriculture. The current treatments are often ineffective, are prone to develop resistance, or cause considerable adverse side effects. The use of nanotechnology has played an important role to combat viral diseases. In this review three main aspects are in focus: first, the potential use of nanoparticles as carriers for drug delivery. Second, its use for treatments of some human viral diseases, and third, its application as antivirals in plants. With these three themes, the aim is to give to readers an overview of the progress in this promising area of biotechnology during the 2017-2020 period, and to provide a glance at how tangible is the effectiveness of nanotechnology against viruses. Future prospects are also discussed. It is hoped that this review can be a contribution to general knowledge for both specialized and non-specialized readers, allowing a better knowledge of this interesting topic.

Recent Advances in Nanosystems and Strategies for Vaginal Delivery of Antimicrobials

Vaginal infections such as bacterial vaginosis (BV), chlamydia, gonorrhea, genital herpes, candidiasis, and trichomoniasis affect millions of women each year. They are caused by an overgrowth of microorganisms, generally sexually transmitted, which in turn can be favored by alterations in the vaginal flora. Conventional treatments of these infections consist in systemic or local antimicrobial therapies. However, in the attempt to reduce adverse effects and to contrast microbial resistance and infection recurrences, many efforts have been devoted to the development of vaginal systems for the local delivery of antimicrobials. Several topical dosage forms such as aerosols, lotions, suppositories, tablets, gels, and creams have been proposed, although they are sometimes ineffective due to their poor penetration and rapid removal from the vaginal canal. For these reasons, the development of innovative drug delivery systems, able to remain in situ and release active agents for a prolonged period, is becoming more and more important. Among all, nanosystems such as liposomes, nanoparticles (NPs), and micelles with tunable surface properties, but also thermogelling nanocomposites, could be exploited to improve local drug delivery, biodistribution, retention, and uptake in vulvovaginal tissues. The aim of this review is to provide a survey of the variety of nanoplatforms developed for the vaginal delivery of antimicrobial agents. A concise summary of the most common vaginal infections and of the conventional therapies is also provided.

A proposed insight into the anti-viral potential of metallic nanoparticles against novel coronavirus disease-19 (COVID-19)

BACKGROUND

Over the last ten months since December 2019, the world has faced infectious emerging novel coronavirus disease-2019 (COVID-19) outbreaks that had a massive global impact affecting over 185 countries.

MAIN BODY

Emerging novel COVID-19 is a global health emergency on a pandemic scale that represents a terror to human health through its ability to escape anti-viral measures. Such viral infections impose a great socioeconomic burden, besides global health challenges. This imposes a pressing need for the development of anti-viral therapeutic agents and diagnostic tools that demonstrate multifunctional, target-specific, and non-toxic properties. Nanotheranostics is regarded as a promising approach for the management of different viral infections. Nanotheranostics facilitates targeted drug-delivery of anti-viral therapeutics as well as contributing to the development of diagnostic systems. Multifunctional metallic nanoparticles (NPs) have emerged as innovative theranostic agents that enable sustainable treatment and effective diagnosis. Here we have reviewed current advances in the use of theranostic metallic NPs to fight against COVID-19, and discussed the application as well as limitations associated with nanotechnology-based theranostic approaches.

CONCLUSION

This review verified the potential use of some metal-based NPs as anti-viral nanotheranostic agents. Metal-based NPs could act as carriers that enable the sustainable and targeted delivery of active anti-viral molecules, or as diagnostic agents that allow rapid and sensitive diagnosis of viral infections.