Currently available anti-influenza drugs are often associated with limitations such as toxicity and the appearance of drug-resistant strains. Therefore, there is a pressing need for the development of novel, safe and more efficient antiviral agents. In this study, we evaluated the antiviral activity of zinc oxide nanoparticles (ZnO-NPs) and PEGylated zinc oxide nanoparticles against H1N1 influenza virus. The nanoparticles were characterized using the inductively coupled plasma mass spectrometry, x-ray diffraction analysis, and electron microscopy. MTT assay was applied to assess the cytotoxicity of the nanoparticles, and anti-influenza activity was determined by TCID50 and quantitative Real-Time PCR assays. To study the inhibitory impact of nanoparticles on the expression of viral antigens, an indirect immunofluorescence assay was also performed. Post-exposure of influenza virus with PEGylated ZnO-NPs and bare ZnO-NPs at the highest non-toxic concentrations could be led to 2.8 and 1.2 log10 TCID50 reduction in virus titer when compared to the virus control, respectively (P < 0.0001). At the highest non-toxic concentrations, the PEGylated and unPEGylated ZnO-NPs led to inhibition rates of 94.6% and 52.2%, respectively, which were calculated based on the viral loads. There was a substantial decrease in fluorescence emission intensity in viral-infected cell treated with PEGylated ZnO-NPs compared to the positive control. Taken together, our study indicated that PEGylated ZnO-NPs could be a novel, effective, and promising antiviral agent against H1N1 influenza virus infection, and future studies can be designed to explore the exact antiviral mechanism of these nanoparticles.

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Inhibition of H1N1 influenza virus infection by zinc oxide nanoparticles: another emerging application of nanomedicine

Infectious diseases account for more than 20% of global mortality and viruses are responsible for about one-third of these deaths. Highly infectious viral diseases such as severe acute respiratory (SARS), Middle East respiratory syndrome (MERS) and coronavirus disease (COVID-19) are emerging more frequently and their worldwide spread poses a serious threat to human health and the global economy. The current COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As of 27 July 2020, SARS-CoV-2 has infected over 16 million people and led to the death of more than 652,434 individuals as on 27 July 2020 while also causing significant economic losses. To date, there are no vaccines or specific antiviral drugs to prevent or treat COVID-19. Hence, it is necessary to accelerate the development of antiviral drugs and vaccines to help mitigate this pandemic. Non-Conventional antiviral agents must also be considered and exploited. In this regard, nanoparticles can be used as antiviral agents for the treatment of various viral infections. The use of nanoparticles provides an interesting opportunity for the development of novel antiviral therapies with a low probability of developing drug resistance compared to conventional chemical-based antiviral therapies. In this review, we first discuss viral mechanisms of entry into host cells and then we detail the major and important types of nanomaterials that could be used as antiviral agents. These nanomaterials include silver, gold, quantum dots, organic nanoparticles, liposomes, dendrimers and polymers. Further, we consider antiviral mechanisms, the effects of nanoparticles on coronaviruses and therapeutic approaches of nanoparticles. Finally, we provide our perspective on the future of nanoparticles in the fight against viral infections.

Antiviral Potential of Nanoparticles-Can Nanoparticles Fight Against Coronaviruses?

Public health events caused by viruses pose a significant risk to humans worldwide. From December 2019 till now, the rampant novel 2019 coronavirus (SAR-CoV-2) has hugely impacted China and over world. Regarding a commendable means of protection, mask technology is relatively mature, though most of the masks cannot effectively resist the viral infections. The key material of the mask is a non-woven material, which makes the barrier of virus through filtration. Due to the lack of the ability to kill the viruses, masks are prone to cross-infection and become an additional source of infection after being discarded. If the filteration and antiviral effects can be simultaneously integrated into the mask, it will be more effcient, work for a longer time and create less difficulty in post-treatment. This mini-review presents the advances in antiviral materials, different  mechanisms of their activity, and their potential applications in personal protective fabrics. Furthermore, the article addresses the future challenges and directions of mask technology.

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Progress and Perspective of Antiviral Protective Material

Inhibition of herpes simplex virus type 1 by copper oxide nanoparticles.

The importance of zinc as a trace metal in the human body has long been overlooked. We now gradually discover that the impact of zinc on the health of our body might be as far-reaching as that of iron. Concurrently, nanomaterials containing zinc, in particular zinc oxide nanoparticles (ZnO NPs), are becoming increasingly attractive as innovative agents for medical applications. Zinc oxide is characterized by a good biocompatibility which allows the exploitation of its antibacterial, antifungal, antiviral, and anti-cancer qualities in a therapeutic setting. This perspective outlines the current state of knowledge concerning the interaction of zinc oxide nanoparticles with eukaryotic cells and the human body. Furthermore, it sheds light on the importance of zinc under physiological conditions. This helps to place the in vivo behavior of zinc oxide nanoparticles in the proper context. We evaluate the potential of zinc oxide nanoparticles as innovative anti-tumor agents by summarizing important results of current studies in this field and discuss the proposed mechanisms that give zinc oxide nanoparticles a selective toxicity for tumor cells.

Zinc oxide nanoparticles for therapeutic purposes in cancer medicine.

Polyethylene glycol-coated zinc oxide nanoparticle: an efficient nanoweapon to fight against herpes simplex virus type 1.

In this paper, the shear deformation behavior of A286 Iron-based superalloy was studied with an emphasis on the influence of η phase on shear strength. The η (Ni3Ti) phase precipitates at high temperature heat treatment or during services at the expense of gamma prime phase. According to the microstructural features, no evidences of η phase were found at 650 and 720°C. η phase precipitated at 780 and 840°C and the amount of it increased with an increase the time and temperature. Because of using the alloy as fasteners, investigation of shear properties and the influence of η phase on it are indispensable. The shear strength of the alloy with different volume fractions of η was examined. It was found that, with an increase of η volume fraction, the ultimate shear strength decreases. The shear punch fracture surfaces were also examined by the scanning electron microscopy. The fracture surfaces of sheared samples indicated that low and high volume fraction of η phase result in interior cracks and grain boundary decohesion, respectively. In fact, the fracture of weak grain boundary films (η phase) produces this kind of decohesive cracking.

Effect of η Phase on Mechanical Properties of the Iron-based Superalloy Using Shear Punch Testing

In the present research, effects of cold rolling and subsequent annealing on the microstructure and shear response of A286 superalloy were investigated. The present report has begun with a discussion on the alloy when it is cold-worked, with special emphasis on the formation of deformation bands. Next, following an annealing process in the temperature range of 900–1050 °C for 2–20 min, we have proceeded to depict static recrystallization, grain growth and precipitation phenomena. The mechanical properties evolution and the fracture surface analysis showed the occurrence of softening phenomenon in the temperature range of 900–950 °C as a result of either partial or full recrystallization. At 1050 °C, precipitation of Nb-rich phase caused an increase in ultimate shear strength of the alloy. Additionally, shear punch fracture surfaces of the samples annealed at 900–1000 °C represented dimple mode, with grain boundary decohesion being seen to occur at higher temperatures.

Effect of Annealing Temperature on Punching Shear Strength of Nb-A286 Superalloy

Time–temperature–precipitation diagram of eta phase formation was established for an Fe–Ni based superalloy by means of mathematical-thermodynamic analysis, kinetic investigation, and microstructural observation The eta phase started to precipitate at the expense of the γ′ phase after prolonged aging On the basis of thermodynamic prediction, the interaction between Gibbs free energy of eta phase formation and activation energy for diffusion of elements, especially titanium, was considered The tip of TTP diagram was obtained at 817 °C, on the basis of mathematical-thermodynamic prediction, and 825–840 and 840 °C, on the basis of microstructural evolution and kinetic analysis, respectively Kinetic investigations predicted that the eta transformation started with diffusion of Ti into Ni This indicated that, with the progress of transformation, as n in Avrami’s equation predicts, other eta formation mechanisms such as γ′ to eta transformation, instant nucleation from the matrix, coincidence of eta lamellas, etc increased n and activation energy

Peyman Sahrapour

Papers

Polyethylene glycol-coated zinc oxide nanoparticle: an efficient nanoweapon to fight against herpes simplex virus type 1.

Effect of η Phase on Mechanical Properties of the Iron-based Superalloy Using Shear Punch Testing

Effect of Annealing Temperature on Punching Shear Strength of Nb-A286 Superalloy

Mathematical-Thermodynamic Prediction and Kinetics of Eta Phase Formation in Fe–Ni-Based Superalloys