C60-based Multivalent Glycoporphyrins Inhibit SARS-CoV-2 Specific Interaction with the DC-SIGN Transmembrane Receptor

Since WHO has declared the COVID-19 outbreak a global pandemic, nearly seven million deaths have been reported. This efficient spread of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is facilitated by the ability of the spike glycoprotein to bind multiple cell membrane receptors. Although ACE2 is identified as the main receptor for SARS-CoV-2, other receptors could play a role in viral entry. Among others, C-type lectins such as DC-SIGN are identified as efficient trans-receptor for SARS-CoV-2 infection, so the use of glycomimetics to inhibit the infection through the DC-SIGN blockade is an encouraging approach. In this regard, multivalent nanostructures based on glycosylated [60]fullerenes linked to a central porphyrin scaffold have been designed and tested against DC-SIGN-mediated SARS-CoV-2 infection. First results show an outstanding inhibition of the trans-infection up to 90%. In addition, a deeper understanding of nanostructure-receptor binding is achieved through microscopy techniques, high-resolution NMR experiments, Quartz Crystal Microbalance experiments, and molecular dynamic simulations.

Water-Soluble Fullerene Monoderivatives for Biomedical Applications

Monoderivatives of fullerenes functionalized with hydrophilic groups make them water soluble, while preserving the hydrophobic fullerene cage. This class of molecules have intriguing biomedical applications, including drug delivery, photodynamic therapy (PDT), antiviral and antimicrobial activity and reactive oxygen species (ROS)-scavenging abilities. In this Concept we discuss the synthesis and biomedical applications of water-soluble fullerene monoderivatives and their biological behavior based on their structures.

Glycofullerene-AuNPs as multivalent ligands of DC-SIGN and bacterial lectin FimH: tuning nanoparticle size and ligand density

Glycoclusters have been extensively investigated for their inhibition of multivalent carbohydrate-protein interactions, which is often the first step for bacterial and viral pathogens to selectively bind their host cells. Glycoclusters may thus prevent infections by blocking the microbe attachment onto the host cell surface. The potency of multivalent carbohydrate-protein interactions is largely derived from the spatial arrangement of the ligand and the nature and flexibility of the linker. The size of the glycocluster may also have a dramatic impact on the multivalent effect. The main objective of this study is to provide a systematic comparison of gold nanoparticles of three representative sizes and ligand densities at their surface. Therefore, AuNPs with diameters of 20, 60, and 100 nm were coupled either to a monomeric D-mannoside or a decameric glycofullerene. Lectin DC-SIGN and lectin FimH were selected as representative models of viral and bacterial infections, respectively. We also report the synthesis of a hetero-cluster built from 20 nm AuNPs and a mannose-derived glycofullerene and monomeric fucosides. All final glycoAuNPs were evaluated as ligands of DC-SIGN- and FimH using the GlycoDiag LectProfile technology. This investigation revealed that the 20 nm AuNPs bearing glycofullerenes with short linker are the most potent binders of both DC-SIGN and FimH. Moreover, the hetero-glycoAuNPs showed an enhanced selectivity and inhibitory ability towards DC-SIGN. Hemagglutination inhibition assays using uropathogenic E. coli corroborated the in vitro assays. Overall, these results showed smaller glycofullerene-AuNPs (20 nm) exhibited the best potential as anti-adhesive materials for a variety of bacterial and viral pathogens.

The Emergence of Carbon Nanomaterials as Effective Nano-Avenues to Fight against COVID-19

COVID-19 (Coronavirus Disease 2019), a viral respiratory ailment that was first identified in Wuhan, China, in 2019, and then expanded globally, was caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The severity of the illness necessitated quick action to cease the virus's spread. The best practices to avert the infection include early detection, the use of protective clothing, the consumption of antiviral medicines, and finally the immunization of the patients through vaccination. The family of carbon nanomaterials, which includes graphene, fullerene, carbon nanotube (CNT), and carbon dot (CD), has a great deal of potential to effectively contribute to each of the main trails in the battle against the coronavirus. Consequently, the recent advances in the application of carbon nanomaterials for containing and combating the SARS-CoV-2 virus are discussed herein, along with their associated challenges and futuristic applicability.

Multivalent glycosystems for human lectins

Human lectins are involved in a wide variety of biological processes, both physiological and pathological, which have attracted the interest of the scientific community working in the glycoscience field. Multivalent glycosystems have been employed as useful tools to understand carbohydrate-lectin binding processes as well as for biomedical applications. The review shows the different scaffolds designed for a multivalent presentation of sugars and their corresponding binding studies to lectins and in some cases, their biological activities. We summarise this research by organizing based on lectin types to highlight the progression in this active field. The paper provides an overall picture of how these contributions have furnished relevant information on this topic to help in understanding and participate in these carbohydrate-lectin interactions.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2017-2018

This review is the tenth update of the original article published in 1999 on the application of matrix-assisted laser desorption/ionization mass spectrometry (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2018. Also included are papers that describe methods appropriate to glycan and glycoprotein analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, new methods, matrices, derivatization, MALDI imaging, fragmentation and the use of arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Most of the applications are presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. The reported work shows increasing use of combined new techniques such as ion mobility and highlights the impact that MALDI imaging is having across a range of diciplines. MALDI is still an ideal technique for carbohydrate analysis and advancements in the technique and the range of applications continue steady progress.

Carbon-based glyco-nanoplatforms: towards the next generation of glycan-based multivalent probes

Cell surface carbohydrates mediate a wide range of carbohydrate-protein interactions key to healthy and disease mechanisms. Many of such interactions are multivalent in nature and in order to study these processes at a molecular level, many glycan-presenting platforms have been developed over the years. Among those, carbon nanoforms such as graphene and their derivatives, carbon nanotubes, carbon dots and fullerenes, have become very attractive as biocompatible platforms that can mimic the multivalent presentation of biologically relevant glycosides. The most recent examples of carbon-based nanoplatforms and their applications developed over the last few years to study carbohydrate-mediate interactions in the context of cancer, bacterial and viral infections, among others, are highlighted in this review.

Progress in Antiviral Fullerene Research

Unlike traditional small molecule drugs, fullerene is an all-carbon nanomolecule with a spherical cage structure. Fullerene exhibits high levels of antiviral activity, inhibiting virus replication in vitro and in vivo. In this review, we systematically summarize the latest research regarding the different types of fullerenes investigated in antiviral studies. We discuss the unique structural advantage of fullerenes, present diverse modification strategies based on the addition of various functional groups, assess the effect of structural differences on antiviral activity, and describe the possible antiviral mechanism. Finally, we discuss the prospective development of fullerenes as antiviral drugs.

Topological and Multivalent Effects in Glycofullerene Oligomers as EBOLA Virus Inhibitors

The synthesis of new biocompatible antiviral materials to fight against the development of multidrug resistance is being widely explored. Due to their unique globular structure and excellent properties, [60]fullerene-based antivirals are very promising bioconjugates. In this work, fullerene derivatives with different topologies and number of glycofullerene units were synthesized by using a SPAAC copper free strategy. This procedure allowed the synthesis of compounds 1–3, containing from 20 to 40 mannose units, in a very efficient manner and in short reaction times under MW irradiation. The glycoderivatives were studied in an infection assay by a pseudotyped viral particle with Ebola virus GP1. The results obtained show that these glycofullerene oligomers are efficient inhibitors of EBOV infection with IC₅₀s in the nanomolar range. In particular, compound 3, with four glycofullerene moieties, presents an outstanding relative inhibitory potency (RIP). We propose that this high RIP value stems from the appropriate topological features that efficiently interact with DC-SIGN.

Nanoscience and quantum science-led biocidal and antiviral strategies

The severe acute respiratory syndrome coronavirus (SARS-CoV-2) caused the COVID-19 pandemic. According to the World Health Organization, this pandemic continues to be a serious threat to public health due to the worldwide spread of variants and their higher rate of transmissibility. A range of measures are necessary to slow the pandemic and save lives, which include constant evaluation and the careful adjustment of public-health responses augmented by medical treatments, vaccines and protective gear. It is hypothesized that nanostructured particulates underpinned by nanoscience and quantum science yield high-performing antiviral strategies, which can be applied in preventive, diagnostic, and therapeutic applications such as face masks, respirators, COVID test kits, vaccines, and drugs. This review is aimed at providing comprehensive and cohesive perspectives on various nanostructures that are suited to intensifying and amplifying the effectiveness of antiviral strategies. Growing scientific literature over the past eighteen months indicates that quantum dots, iron oxide, silicon oxide, polymeric and metallic nanoparticles have been employed in COVID-19 diagnostic assays, vaccines, and personal protective equipment (PPE). Quantum dots have displayed their suitability as more sensitive imaging probes in diagnostics and prognostics, and as controlled drug-release carriers that target the virus. Nanoscience and quantum science have assisted the design of advanced vaccine delivery since nanostructured materials are suited for antigen delivery, as mimics of viral structures and as adjuvants. Furthermore, the quantum science- and nanoscience-supported tailored functionalization of nanostructured materials offers insight and pathways to deal with future pandemics. This review seeks to illustrate several examples, and to explain the underpinning quantum science and nanoscience phenomena, which include wave functions, electrostatic interactions, van der Waals forces, thermal and electrodynamic fluctuations, dispersion forces, local field-enhancement effects, and the generation of reactive oxygen species (ROS). This review discusses how nanostructured materials are helpful in the detection, prevention, and treatment of the SARS-CoV-2 infection, other known viral infection diseases, and future pandemics.

Carbohydrate-Based Macromolecular Biomaterials

Carbohydrates are the most abundant and one of the most important biomacromolecules in Nature. Except for energy-related compounds, carbohydrates can be roughly divided into two categories: Carbohydrates as matter and carbohydrates as information. As matter, carbohydrates are abundantly present in the extracellular matrix of animals and cell walls of various plants, bacteria, fungi, etc., serving as scaffolds. Some commonly found polysaccharides are featured as biocompatible materials with controllable rigidity and functionality, forming polymeric biomaterials which are widely used in drug delivery, tissue engineering, etc. As information, carbohydrates are usually referred to the glycans from glycoproteins, glycolipids, and proteoglycans, which bind to proteins or other carbohydrates, thereby meditating the cell-cell and cell-matrix interactions. These glycans could be simplified as synthetic glycopolymers, glycolipids, and glycoproteins, which could be afforded through polymerization, multistep synthesis, or a semisynthetic strategy. The information role of carbohydrates can be demonstrated not only as targeting reagents but also as immune antigens and adjuvants. The latter are also included in this review as they are always in a macromolecular formulation. In this review, we intend to provide a relatively comprehensive summary of carbohydrate-based macromolecular biomaterials since 2010 while emphasizing the fundamental understanding to guide the rational design of biomaterials. Carbohydrate-based macromolecules on the basis of their resources and chemical structures will be discussed, including naturally occurring polysaccharides, naturally derived synthetic polysaccharides, glycopolymers/glycodendrimers, supramolecular glycopolymers, and synthetic glycolipids/glycoproteins. Multiscale structure-function relationships in several major application areas, including delivery systems, tissue engineering, and immunology, will be detailed. We hope this review will provide valuable information for the development of carbohydrate-based macromolecular biomaterials and build a bridge between the carbohydrates as matter and the carbohydrates as information to promote new biomaterial design in the near future.

Recent advances in multivalent carbon nanoform-based glycoconjugates

Multivalent carbohydrate-mediated interactions are fundamental to many biological processes, including disease mechanisms. To study these significant glycan-mediated interactions at a molecular level, carbon nanoforms such as fullerenes, carbon nanotubes, or graphene and their derivatives have been identified as promising biocompatible scaffolds that can mimic the multivalent presentation of biologically relevant glycans. In this minireview, we will summarize the most relevant examples of the last few years in the context of their applications.

An Ultra-Long-Lived Triplet Excited State in Water at Room Temperature: Insights on the Molecular Design of Tridecafullerenes

Suitably engineered molecular systems exhibiting triplet excited states with very long lifetimes are important for high-end applications in nonlinear optics, photocatalysis, or biomedicine. We report the finding of an ultra-long-lived triplet state with a mean lifetime of 93 ms in an aqueous phase at room temperature, measured for a globular tridecafullerene with a highly compact glycodendrimeric structure. A series of three tridecafullerenes bearing different glycodendrons and spacers to the C60 units have been synthesized and characterized. UV/Vis spectra and DLS experiments confirm their aggregation in water. Steady-state and time-resolved fluorescence experiments suggest a different degree of inner solvation of the multifullerenes depending on their molecular design. Efficient quenching of the triplet states by O2 but not by waterborne azide anions has been observed. Molecular modelling reveals dissimilar access of the aqueous phase to the internal structure of the tridecafullerenes, differently shielded by the glycodendrimeric shell.

Multivalent Tryptophan- and Tyrosine-Containing [60]Fullerene Hexa-Adducts as Dual HIV and Enterovirus A71 Entry Inhibitors

Unprecedented 3D hexa‐adducts of [60]fullerene peripherally decorated with twelve tryptophan (Trp) or tyrosine (Tyr) residues have been synthesized. Studies on the antiviral activity of these novel compounds against HIV and EV71 reveal that they are much more potent against HIV and equally active against EV71 than the previously described dendrimer prototypes AL‐385 and AL‐463, which possess the same number of Trp/Tyr residues on the periphery but attached to a smaller and more flexible pentaerythritol core. These results demonstrate the relevance of the globular 3D presentation of the peripheral groups (Trp/Tyr) as well as the length of the spacer connecting them to the central core to interact with the viral envelopes, particularly in the case of HIV, and support the hypothesis that [60]fullerene can be an alternative and attractive biocompatible carbon‐based scaffold for this type of highly symmetrical dendrimers. In addition, the functionalized fullerenes here described, which display twelve peripheral negatively charged indole moieties on their globular surface, define a new and versatile class of compounds with a promising potential in biomedical applications.

Synthesis of Glycodendrimers with Antiviral and Antibacterial Activity

Glycodendrimers are an important class of synthetic macromolecules that can be used to mimic many structural and functional features of cell-surface glycoconjugates. Their carbohydrate moieties perform key important functions in bacterial and viral infections, often regulated by carbohydrate-protein interactions. Several studies have shown that the molecular structure, valency and spatial organisation of carbohydrate epitopes in glycoconjugates are key factors in the specificity and avidity of carbohydrate-protein interactions. Choosing the right glycodendrimers almost always helps to interfere with such interactions and blocks bacterial or viral adhesion and entry into host cells as an effective strategy to inhibit bacterial or viral infections. Herein, the state of the art in the design and synthesis of glycodendrimers employed for the development of anti-adhesion therapy against bacterial and viral infections is described.

Glycodendritic structures as DC-SIGN binders to inhibit viral infections

DC-SIGN, a lectin discovered two decades ago, plays a relevant role in innate immunity. Since its discovery, it has turned out to be a target for developing antiviral drugs based on carbohydrates due to its participation in the infection process of several pathogens. A plethora of carbohydrate multivalent systems using different scaffolds have been described to achieve this goal. Our group has made significant contributions to this field, which are revised herein.

Nanotechnology-based approaches for emerging and re-emerging viruses: Special emphasis on COVID-19

In recent decades, the major concern of emerging and re-emerging viral diseases has become an increasingly important area of public health concern, and it is of significance to anticipate future pandemic that would inevitably threaten human lives. The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a newly emerged virus that causes mild to severe pneumonia. Coronavirus disease (COVID-19) became a very much concerned issue worldwide after its super-spread across the globe and emerging viral diseases have not got specific and reliable diagnostic and treatments. As the COVID-19 pandemic brings about a massive life-loss across the globe, there is an unmet need to discover a promising and typically effective diagnosis and treatment to prevent super-spreading and mortality from being decreased or even eliminated. This study was carried out to overview nanotechnology-based diagnostic and treatment approaches for emerging and re-emerging viruses with the current treatment of the disease and shed light on nanotechnology's remarkable potential to provide more effective treatment and prevention to a special focus on recently emerged coronavirus.

Multivalent cationic dendrofullerenes for gene transfer: synthesis and DNA complexation

Non-viral nucleic acid vectors able to display high transfection efficiencies with low toxicity and overcoming the multiple biological barriers are needed to further develop the clinical applications of gene therapy. The synthesis of hexakis-adducts of [60]fullerene endowed with 12, 24 and 36 positive ammonium groups and a tridecafullerene appended with 120 positive charges has been performed. The delivery of a plasmid containing the green fluorescent protein (EGFP) gene into HEK293 (Human Embryonic Kidney) cells resulting in effective gene expression has demonstrated the efficacy of these compounds to form polyplexes with DNA. Particularly, giant tridecafullerene macromolecules have shown higher efficiency in the complexation and transfection of DNA. Thus, they can be considered as promising non-viral vectors for transfection purposes.

Recent Advancement in SARS-CoV-2 Diagnosis, Treatment, and Vaccine Formulation: a New Paradigm of Nanotechnology in Strategic Combating of COVID-19 Pandemic

Purpose of Review

The coronavirus disease-2019 (COVID-19) is a global pandemic which has not been seen in recent history, leaving behind deep socioeconomic damages and huge human losses with the disturbance in the healthcare sector. Despite the tremendous international effort and the launch of various clinical trials for the containment of this pandemic, no effective therapy has been proven yet.

Recent Findings

This review has highlighted the different traditional therapeutic techniques, along with the potential contribution of nanomedicine against the severe acute respiratory syndrome corovirus-2 (SARS-CoV-2). Repositioning of the drugs, such as remdesivir and chloroquine, is a rapid process for the reach of safe therapeutics, and the related clinical trials have determined effects against COVID-19. Various protein-based SARS-CoV-2 vaccine candidates have successfully entered clinical phases, determining positive results. The self-assembled and metallic nanovaccines mostly based on the antigenic properties of spike (S) protein are also approachable, feasible, and promising techniques for lowering the viral burden.

Summary

There are number of NP-based diagnostic systems have been reported for coronaviruses (CoVs) and specifically for SARS-CoV-2. However, extensive studies are still necessary and required for the nanoparticle (NP)-based therapy.

New insights into application of nanoparticles in the diagnosis and screening of novel coronavirus (SARS-CoV-2)

Novel coronavirus disease 2019 (COVID-19) is by far the worst pandemic disease in the current millennium. The first human-to-human transmission was observed in December 2019 in China and is caused by the highly contagious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has infected millions of people within months across the globe. SARS-CoV-2 is a spike protein enveloped virus with particle-like characteristics and a diameter of 60-140 nm. Real-time PCR, reverse transcriptase PCR, isothermal PCR, immunological-based detection technique and nano-based diagnostic system have been explained for the identification and differentiation of different types of virus including SARS-COV-2. Synthetic nanoparticles can closely mimic the virus and interact strongly with its virulent proteins due to their morphological similarities. Some of the antiviral nanomaterials are also discussed, for example zinc oxide nanoparticle is an antiviral agent with a tetrapod morphology that mimics the cell surface by interacting with the viral capsid. It suppressed the viral proteins upon UV radiation due to reaction caused by photocatalysis. Hence, nanoparticle-based strategies for tackling viruses have immense potential. The second part of the review points to the latest in vitro and in vivo procedures for screening viral particles and the usage of nanoparticles in diagnostic and therapeutics. This would be beneficial for early detection and assists for the safe and effective therapeutic management of COVID-19.

COVID-19: Pathophysiology, treatment options, nanotechnology approaches, and research agenda to combating the SARS-CoV2 pandemic

The recent corona virus disease (COVID-19) outbreak has claimed the lives of many around the world and highlighted an urgent need for experimental strategies to prevent, treat and eradicate the virus. COVID-19, an infectious disease caused by a novel corona virus and no approved specific treatment is available yet. A vast number of promising antiviral treatments involving nanotechnology are currently under investigation to aid in the development of COVID-19 drug delivery. The prospective treatment options integrating the ever-expanding field of nanotechnology have been compiled, with the objective to show that these can be potentially developed for COVID-19 treatment. This review summarized the current state of knowledge, research priorities regarding the pandemic and post COVID-19. We also focus on the possible nanotechnology approaches that have proven to be successful against other viruses and the research agenda to combat COVID-19.

Nano-based approaches in the development of antiviral agents and vaccines

Outbreaks and the rapid transmission of viruses, such as coronaviruses and influenza viruses, are serious threats to human health. A major challenge in combating infectious diseases caused by viruses is the lack of effective methods for prevention and treatment. Nanotechnology has provided a basis for the development of novel antiviral strategies. Owing to their large modifiable surfaces that can be functionalized with multiple molecules to realize sophisticated designs, nanomaterials have been developed as nanodrugs, nanocarriers, and nano-based vaccines to effectively induce sufficient immunologic memory. From this perspective, we introduce various nanomaterials with diverse antiviral mechanisms and summarize how nano-based antiviral agents protect against viral infection at the molecular, cellular, and organismal levels. We summarize the applications of nanomaterials for defense against emerging viruses by trapping and inactivating viruses and inhibiting viral entry and replication. We also discuss recent progress in nano-based vaccines with a focus on the mechanisms by which nanomaterials contribute to immunogenicity. We further describe how nanotechnology may improve vaccine efficacy by delivering large amounts of antigens to target immune cells and enhancing the immune response by mimicking viral structures and activating dendritic cells. Finally, we provide an overview of future prospects for nano-based antiviral agents and vaccines.

Hard Nanomaterials in Time of Viral Pandemics

The SARS-Cov-2 pandemic has spread worldwide during 2020, setting up an uncertain start of this decade. The measures to contain infection taken by many governments have been extremely severe by imposing home lockdown and industrial production shutdown, making this the biggest crisis since the second world war. Additionally, the continuous colonization of wild natural lands may touch unknown virus reservoirs, causing the spread of epidemics. Apart from SARS-Cov-2, the recent history has seen the spread of several viral pandemics such as H2N2 and H3N3 flu, HIV, and SARS, while MERS and Ebola viruses are considered still in a prepandemic phase. Hard nanomaterials (HNMs) have been recently used as antimicrobial agents, potentially being next-generation drugs to fight viral infections. HNMs can block infection at early (disinfection, entrance inhibition) and middle (inside the host cells) stages and are also able to mitigate the immune response. This review is focused on the application of HNMs as antiviral agents. In particular, mechanisms of actions, biological outputs, and limitations for each HNM will be systematically presented and analyzed from a material chemistry point-of-view. The antiviral activity will be discussed in the context of the different pandemic viruses. We acknowledge that HNM antiviral research is still at its early stage, however, we believe that this field will rapidly blossom in the next period.

Glycofullerenes Inhibit Particulate Matter Induced Inflammation and Loss of Barrier Proteins in HaCaT Human Keratinocytes

Exposure to particulate matter (PM) has been linked to pulmonary and cardiovascular dysfunctions, as well as skin diseases, etc. PM impairs the skin barrier functions and is also involved in the initiation or exacerbation of skin inflammation, which is linked to the activation of reactive oxygen species (ROS) pathways. Fullerene is a single C₆₀ molecule which has been reported to act as a good radical scavenger. However, its poor water solubility limits its biological applications. The glyco-modification of fullerenes increases their water solubility and anti-bacterial and anti-virus functions. However, it is still unclear whether it affects their anti-inflammatory function against PM-induced skin diseases. Hence, glycofullerenes were synthesized to investigate their effects on PM-exposed HaCaT human keratinocytes. Our results showed that glycofullerenes could reduce the rate of PM-induced apoptosis and ROS production, as well as decrease the expression of downstream mitogen-activated protein kinase and Akt pathways. Moreover, PM-induced increases in inflammatory-related signals, such as cyclooxygenase-2, heme oxygenase-1, and prostaglandin E2, were also suppressed by glycofullerenes. Notably, our results suggested that PM-induced impairment of skin barrier proteins, such as filaggrin, involucrin, repetin, and loricrin, could be reduced by pre-treatment with glycofullerenes. The results of this study indicate that glycofullerenes could be potential candidates for treatments against PM-induced skin diseases and that they exert their protective effects via ROS scavenging, anti-inflammation, and maintenance of the expression of barrier proteins.

Nano-based approach to combat emerging viral (NIPAH virus) infection

Emergence of new virus and their heterogeneity are growing at an alarming rate. Sudden outburst of Nipah virus (NiV) has raised serious question about their instant management using conventional medication and diagnostic measures. A coherent strategy with versatility and comprehensive perspective to confront the rising distress could perhaps be effectuated by implementation of nanotechnology. But in concurrent to resourceful and precise execution of nano-based medication, there is an ultimate need of concrete understanding of the NIV pathogenesis. Moreover, to amplify the effectiveness of nano-based approach in a conquest against NiV, a list of developed nanosystem with antiviral activity is also a prerequisite. Therefore the present review provides a meticulous cognizance of cellular and molecular pathogenesis of NiV. Conventional as well several nano-based diagnosis experimentations against viruses have been discussed. Lastly, potential efficacy of different forms of nano-based systems as convenient means to shield mankind against NiV has also been introduced.

Ramified derivatives of 5-(perylen-3-ylethynyl)uracil-1-acetic acid and their antiviral properties

The propargylamide of N3-Pom-protected 5-(perylen-3-ylethynyl)uracil acetic acid, a universal precursor, was used in a CuAAC click reaction for the synthesis of several derivatives, including three ramified molecules with high activities against tick-borne encephalitis virus (TBEV). Pentaerythritol-based polyazides were used for the assembly of molecules containing 2⋯4 antiviral 5-(perylen-3-ylethynyl)uracil scaffolds, the first examples of polyvalent perylene antivirals. Cluster compounds showed enhanced absorbance, however, their fluorescence was reduced due to self-quenching. Due to the solubility issues, Pom group removal succeeded only for compounds with one peryleneethynyluracil unit. Four compounds, including one ramified cluster 9f, showed remarkable 1⋯3 nM EC₅₀ values against TBEV in cell culture.

Ramified clusters of antiviral perylenylethynyl scaffold were prepared using CuAAC reaction of 5-(perylen-3-ylethynyl)-3-pivaloyloxymethyl-1-(propargylamidomethyl)uracil with azides. Compounds inhibited TBEV reproduction at nanomolar concentrations.