Sialylglycan-Assembled Supra-Dots for Ratiometric Probing and Blocking of Human-Infecting Influenza Viruses

Discovery of novel potent drugs for influenza by inhibiting the vital function of neuraminidase via fragment-based drug design (FBDD) and molecular dynamics simulation strategies

The current work describes a fragment linking methodology to generate new neuraminidase inhibitors. A total number of 28,977 fragments from Zinc 20 have been obtained and screened for neuraminidase receptor affinity. Using Schrödinger software, the highest-scoring 270 fragment hits (with scores greater than -7.6) were subjected to fragment combining to create 100 new molecules. These 100 novel compounds were studied using XP docking to evaluate the molecular interaction modes and their binding affinity to neuraminidase receptor. The top ten molecules were selected, for ADMET, drug-likeness features. Based on these characteristics, the best four developed molecules and Zanamivir were submitted to a molecular dynamics simulation investigation to estimate their dynamics within the neuraminidase receptor using Gromacs software. All MD simulation findings show that the generated complexes are very stable when compared to the clinical inhibitor (Zanamivir). In addition, the four designed neuraminidase inhibitors formed very stable complexes with neuraminidase receptor (with total binding energies ranging from -83.50 to -107.85 Kj/mol) according to the total binding energy calculated by MM-PBSA. For the objective of developing new influenza medications, these novel molecules have the potential to be further evaluated in vitro and in vivo for influenza drug discovery.Communicated by Ramaswamy H. Sarma.

Nanomaterials for virus sensing and tracking

The effect of the on-going COVID-19 pandemic on global healthcare systems has underlined the importance of timely and cost-effective point-of-care diagnosis of viruses. The need for ultrasensitive easy-to-use platforms has culminated in an increased interest for rapid response equipment-free alternatives to conventional diagnostic methods such as polymerase chain reaction, western-blot assay, etc. Furthermore, the poor stability and the bleaching behavior of several contemporary fluorescent reporters is a major obstacle in understanding the mechanism of viral infection thus retarding drug screening and development. Owing to their extraordinary surface-to-volume ratio as well as their quantum confinement and charge transfer properties, nanomaterials are desirable additives to sensing and imaging systems to amplify their signal response as well as temporal resolution. Their large surface area promotes biomolecular integration as well as efficacious signal transduction. Due to their hole mobility, photostability, resistance to photobleaching, and intense brightness, nanomaterials have a considerable edge over organic dyes for single virus tracking. This paper reviews the state-of-the-art of combining carbon-allotrope, inorganic and organic-based nanomaterials with virus sensing and tracking methods, starting with the impact of human pathogenic viruses on the society. We address how different nanomaterials can be used in various virus sensing platforms (e.g. lab-on-a-chip, paper, and smartphone-based point-of-care systems) as well as in virus tracking applications. We discuss the enormous potential for the use of nanomaterials as simple, versatile, and affordable tools for detecting and tracing viruses infectious to humans, animals, plants as well as bacteria. We present latest examples in this direction by emphasizing major advantages and limitations.

Recent Advances in the Development and Applications of Conjugated Polymer dots

Conjugated polymer dots or semiconducting polymer nanoparticles (Pdots) are nanoparticles prepared based on organic polymers. Pdots have the advantages of lower cost, simple preparation process, good biocompatibility, excellent stability, easy...

Conjugated Polymers-based Luminescent Probes for Ratiometric Detection of Biomolecules

Accurate monitoring of the biomolecular changes in biological and physiological environments is of great significance for pathogenesis, development, diagnosis and treatment of diseases. Compared with traditional luminescent probes on the...

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.

Optical Biosensors for Virus Detection: Prospects for SARS-CoV-2/COVID-19

The recent pandemic of the novel coronavirus disease 2019 (COVID-19) has caused huge worldwide disruption due to the lack of available testing locations and equipment. The use of optical techniques for viral detection has flourished in the past 15 years, providing more reliable, inexpensive, and accurate detection methods. In the current minireview, optical phenomena including fluorescence, surface plasmons, surface-enhanced Raman scattering (SERS), and colorimetry are discussed in the context of detecting virus pathogens. The sensitivity of a viral detection method can be dramatically improved by using materials that exhibit surface plasmons or SERS, but often this requires advanced instrumentation for detection. Although fluorescence and colorimetry lack high sensitivity, they show promise as point-of-care diagnostics because of their relatively less complicated instrumentation, ease of use, lower costs, and the fact that they do not require nucleic acid amplification. The advantages and disadvantages of each optical detection method are presented, and prospects for applying optical biosensors in COVID-19 detection are discussed.

Recent progress in chemical approaches for the development of novel neuraminidase inhibitors

Influenza virus is the main cause of an infectious disease called influenza affecting the respiratory system including the throat, nose and lungs. Neuraminidase inhibitors are reagents used to block the enzyme called neuraminidase to prevent the influenza infection from spreading. Neuraminidase inhibitors are widely used in the treatment of influenza infection, but still there is a need to develop more potent agents for the more effective treatment of influenza. Complications of the influenza disease lead to death, and one of these complications is drug resistance; hence, there is an urgent need to develop more effective agents. This review focuses on the recent advances in chemical synthesis pathways used for the development of new neuraminidase agents along with the medicinal aspects of chemically modified molecules, including the structure-activity relationship, which provides further rational designs of more active small molecules.

The Inhibition of H1N1 Influenza Virus-Induced Apoptosis by Surface Decoration of Selenium Nanoparticles with β-Thujaplicin through Reactive Oxygen Species-Mediated AKT and p53 Signaling Pathways

β-Thujaplicin possess a variety of biological activities. The use of modified biological nanoparticles (NPs) to develop novel anti-influenza drugs has increased in recent years. Selenium nanoparticles (SeNPs) with antiviral activity have attracted increasing attention for biomedical intervention. Functionalized SeNPs by β-thujaplicin (Se@TP) surface modified with superior antiviral activity were synthesized in this study. Compared to a virus group (43%), when treated with Se@TP (88%), the cell survival rate of MDCK cells was 45% higher. Se@TP could inhibit H1N1 from infecting Madin-Darby canine kidney (MDCK) cells and block chromatin condensation and DNA fragmentation. Se@TP obviously prevented MDCK cells from generating reactive oxygen species. Furthermore, Se@TP prevents lung injury in H1N1-infected mice through eosin staining and hematoxylin in vivo. Mechanistic investigation revealed that Se@TP inhibited H1N1 influenza virus from infecting MDCK cells through induction of apoptosis via suppressing AKT and p53 signaling pathways through immunohistochemical assay. Our results suggest that β-thujaplicin-modified SeNPs as carriers are an efficient way to achieve an antiviral pharmaceutical candidate for H1N1 influenza.

Self-assembled sialyllactosyl probes with aggregation-enhanced properties for ratiometric detection and blocking of influenza viruses

Infection and dissemination of influenza viruses (IVs) causes serious health concerns worldwide. However, effective tools for the accurate detection and blocking of IVs remain elusive. Here, we develop a new sialyllactosyl probe with self-assembled core-shell structure for the ratiometric detection and blocking of IVs. N,N'-diaryl-dihydrodibenzo[a,c]phenazines were used to form the core structure by hydrophobic assembly in an aqueous solution with an aggregation-enhanced blue fluorescence mission. Subsequently, dicyanomethylene-4H-pyran-based sialyllactosides were used for self-assembly with the core structure, producing the sialyllactosyl probe that emits a red fluorescence due to Förster resonance energy transfer. The probe developed has been proven to be available for (1) the fluorescence ratiometric detection of IVs through selective interaction with the sialyllactosyl-binding proteins on the virus surface, and (2) effectively blocking the invasion of human-infecting IVs towards host cells as accentuated by the sialyllactosides on the surface of the probes.

Inhibition of H1N1 influenza virus-induced apoptosis by selenium nanoparticles functionalized with arbidol through ROS-mediated signaling pathways

As an effective antiviral agent, the clinical application of arbidol is limited by the appearance of drug-resistant viruses.

Inhibition of H1N1 influenza virus-induced apoptosis by functionalized selenium nanoparticles with amantadine through ROS-mediated AKT signaling pathways

Introduction

As a therapeutic antiviral agent, the clinical application of amantadine (AM) is limited by the emergence of drug-resistant viruses. To overcome the drug-resistant viruses and meet the growing demand of clinical diagnosis, the use of biological nanoparticles (NPs) has increased in order to develop novel anti-influenza drugs. The antiviral activity of selenium NPs with low toxicity and excellent activities has attracted increasing attention for biomedical intervention in recent years.

Methods and results

In the present study, surface decoration of selenium NPs by AM (Se@AM) was designed to reverse drug resistance caused by influenza virus infection. Se@ AM with less toxicity remarkably inhibited the ability of H1N1 influenza to infect host cells through suppression of the neuraminidase activity. Moreover, Se@AM could prevent H1N1 from infecting Madin Darby Canine Kidney cell line and causing cell apoptosis supported by DNA fragmentation and chromatin condensation. Furthermore, Se@AM obviously inhibited the generation of reactive oxygen species and activation of phosphorylation of AKT.

Conclusion

These results demonstrate that Se@AM is a potentially efficient antiviral pharmaceutical agent for H1N1 influenza virus.