Photoactive conjugated polymer-based strategy to effectively inactivate RNA viruses

To efficiently combat viral infectious diseases, it is important to develop broadly applicable countermeasures, and efficient antiviral systems can be developed by elaborating the relationship of antiviral efficiency with the interactions between antiviral agents and viruses. In the present study, conjugated polymer (CP)-based photodynamic therapy was used to inhibit RNA virus infections. A severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudotyped virus composed of an SARS-CoV-2 envelope coated with the S protein and luciferase RNA genome was employed to assess antiviral efficiency. Three cationic CPs with different backbone structures, fluorene-co-phenylene (PFP), thiophene (PMNT), and phenylene vinylene (PPV), exhibit different photoinactivation effects. The highly efficient photoinactivation of PPV and PMNT is derived from the complete photodegradation of spike proteins, nucleocapsid proteins and nucleic acids of SARS-CoV-2 after binding to the viral spike proteins. Although PFP showed the highest efficiency in the photodegradation of spike proteins due to its strong binding affinity, ineffective viral inhibition was observed, which occurred because the viral gene was partially damaged under light irradiation and the process of delivering the viral gene to cells received assistance. This work preliminarily reveals the effect of CP-virus interactions on their photoinactivation activity and should be beneficial for further research on the development of highly efficient antiviral PDT agents.In this work, a photodynamic therapy system based on conjugated polymers (CPs) is developed to inhibit the infection of RNA viruses. Three cationic CPs with different backbone structures fluorene-co-phenylene (PFP), thiophene (PMNT), and phenylene vinylene (PPV) exhibit different photoinactivation effects. PPV and PMNT cause effective inactivation of viruses under light irradiation, while SARS-CoV-2 pseudotyped viruses keep infectious after treated by PFP, which is determined by the interactions between CPs with the proteins and gene of viruses. This work preliminarily reveals the effect of CP-virus interactions on their photoinactivation activity and would be beneficial to develop high-efficient antiviral PDT agents.

Highly Twisted Conformation Thiopyrylium Photosensitizers for In Vivo Near Infrared‐II Imaging and Rapid Inactivation of Coronavirus

Despite significant effort, a majority of heavy‐atom‐free photosensitizers have short excitation wavelengths, thereby hampering their biomedical applications. Here, we present a facile approach for developing efficient near‐infrared (NIR) heavy‐atom‐free photosensitizers. Based on a series of thiopyrylium‐based NIR‐II (1000–1700 nm) dyads, we found that the star dyad HD with a sterically bulky and electron‐rich moiety exhibited configuration torsion and significantly enhanced intersystem crossing (ISC) compared to the parent dyad. The electron excitation characteristics of HD changed from local excitation (LE) to charge transfer (CT)‐domain, contributing to a ≈6‐fold reduction in energy gap (ΔEST), a ≈10‐fold accelerated ISC process, and a ≈31.49‐fold elevated reactive oxygen species (ROS) quantum yield. The optimized SP@HD‐PEG2K lung‐targeting dots enabled real‐time NIR‐II lung imaging, which precisely guided rapid pulmonary coronavirus inactivation.

Employing functionalized graphene quantum dots to combat coronavirus and enterovirus.

The ongoing COVID-19 (i.e., coronavirus) pandemic continues to adversely affect the human life, economy, and the world's ecosystem. Although significant progress has been made in developing antiviral materials for the coronavirus, much more work is still needed. In this work, N-functionalized graphene quantum dots (GQDs) were designed and synthesized as the antiviral nanomaterial for Feline Coronavirus NTU156 (FCoV NTU156) and Enterovirus 71 (EV71)) with ultra-high inhibition (>99.9%). To prepare the GQD samples, a unique solid-phase microwave-assisted technique was developed and the cell toxicity was established on the H171 and H184 cell lines after 72 h incubation, indicating superior biocompatibility. The surface functionality of GQDs (i.e., the phenolic and amino groups) plays a vital role in interacting with the receptor-binding-domain of the spike protein. It was also found that the addition of polyethylene glycol is advantageous for the dispersion and the adsorption of functionalized GQDs onto the virus surface, leading to an enhanced virus inhibition. The functionality of as-prepared GQD nanomaterials was further confirmed where a functionalized GQD-coated glass was shown to be extremely effective in hindering the virus spread for a relatively long period (>20 h).

The Impacts of Chlorine and Disinfection Byproducts on Antibiotic-Resistant Bacteria (ARB) and Their Conjugative Transfer

Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are emerging contaminants leading to severe worldwide health problems. Chlorination, a widely used procedure, was extensively explored as one of the main methods to remove ARB and ARGs in recent years. In this study, to enrich the analyses of chlorination, several comprehensive effects of the chlorine disinfection system on ARB and their conjugative transfer ability were explored. The results presented that the low dose of chlorine (<3-log inactivation rate) had little influence on the survival of bacteria in terms of their capacity for conjugative transfer and antibiotic resistance. The high dose of chlorine (>3-log inactivation rate) triggered cell membrane changes, with little influence on the bacteria in terms of their antibiotic resistance. However, their capacity for conjugative transfer sharply decreased. Minor consumption of chloramphenicol was achieved with the chlorine dose applied in the disinfection system. Monochloroacetonitrile (MCAN) had limited effects on the frequency of conjugative transfer, indicating that the existence of MCAN would not aggravate the dissemination of ARGs by conjugative transfer. The overall impacts of the chlorine disinfection system with different containments on antibiotic resistance need further investigation.

Removal of virus aerosols by the combination of filtration and UV-C irradiation

The COVID-19 pandemic remains ever prevalent and afflicting—partially because one of its transmission pathways is aerosol. With the widely used central air conditioning systems worldwide, indoor virus aerosols can rapidly migrate, thus resulting in rapid infection transmission. It is therefore important to install microbial aerosol treatment units in the air conditioning systems, and we herein investigated the possibility of combining such filtration with UV irradiation to address virus aerosols. Results showed that the removal efficiency of filtration towards f2 and MS2 phages depended on the type of commercial filter material and the filtration speed, with an optimal velocity of 5 cm/s for virus removal. Additionally, it was found that UV irradiation had a significant effect on inactivating viruses enriched on the surfaces of filter materials;MS2 phages had greater resistance to UV-C irradiation than f2 phages. The optimal inactivation time for UV-C irradiation was 30 min, with higher irradiation times presenting no substantial increase in inactivation rate. Moreover, excessive virus enrichment on the filters decreased the inactivation effect. Timely inactivation is therefore recommended. In general, the combined system involving filtration with UV-C irradiation demonstrated a significant removal effect on virus aerosols. Moreover, the system is simple and economical, making it convenient for widespread implementation in air-conditioning systems.

Graphene-based nanocomposite using new modeling molecular dynamic simulations for proposed neutralizing mechanism and real-time sensing of COVID-19

A new virus, the coronavirus (COVID-19), is causing serious respiratory infections in humans. Rapid, specific, and sensitive diagnostic techniques for early-stage detection of SARS-CoV-2 viral protein are developing as a necessary response for effective smart diagnostics, treatment optimization, and exploration of therapeutics with better effectiveness in the fight against the COVID-19 pandemic. Keeping the considerations mentioned above, we propose a new modeling graphene nanocomposite-based biosensing device for detecting COVID-19 at the site of the epidemic as the best way to manage the pandemic. It is important to address the problems of COVID-19 management. With the challenges and aspects of COVID-19 management in mind, we present in this review a collective approach involving electrochemical COVID-19 biosensing required for early-stage COVID-19 diagnosis and the direct interaction with viral surface glycoproteins and metal nanoparticles that can enter cells and neutralize viruses by interacting directly with the viral genome (ribonucleic acid), which identifies the COVID-19 spike protein and antiviral procedure including virus inactivation, host cell receptor inactivation, electrostatic entrapment, and physicochemical destruction of viral species by nucleotide ring opening. The interactions between the graphene composite and virus may be boosted by functionalization of the carbon surface and decoration of metallic components that enhance these interactions. Our proposed new modeling molecular dynamic simulation-based neutralizing mechanism and real-time detection of COVID-19 on graphene nanocomposite-based biosensors are suitable for point-of-care diagnostic applications, and this sensing platform can be modified for the early diagnosis of severe viral infections using real samples. For the potential application, the suggested one is the chemical reaction and bond breaking between the metallic component and molecule of COVID19 with computer simulation data.

Zinc Oxide Nanoparticles as a Potential Agent for Antiviral Drug Delivery Development: A Systematic Literature Review

Viral infection is a worldwide health problem, which has negatively affected global activity in recent years. There is no specific medication for most of the viral infections and the treatments are based on symptom management. Nanoparticles (NPs) in recent years have shown promising antibacterial and antiviral properties, among which metal oxide NPs have shown superiority. In the present study, we aimed to systematically review all available literature supporting the efficiency of zinc oxide (ZnO)NPs in the treatment of viral infections. For this purpose, a systematic literature search was performed in scientific literature databases, including PubMed, Scopus, Web of Science, Science Direct, Ovid, Embase, and Google Scholar by using “viral infections”, “antiviral effects” and “ZnO NPs” in addition to all their equivalent terms as keywords. Due to the lack of human studies, no strict inclusion criteria were defined and all available relevant studies were included. A total of 14 documents that fully met the inclusion criteria were retrieved and used for data synthesis. The results showed that ZnO NPs due to specific physicochemical properties can be a promising approach in developing antiviral agents and nano vaccines, especially against RNA viruses, such as human immunodeficiency virus (HIV) and severe acute respiratory syndrome coronavirus. The most probable antiviral mechanistic pathways of ZnO NPs include blocking the virus entry into the cells and deactivation of the virus through virostatic potential. Based on the findings of the included studies, it is suggested that ZnO NPs and other metal oxide-based NPs may be potential antiviral agents;however, further human studies are required to confirm such efficiency in clinical practice.

Effective antiviral coatings for deactivating SARS-CoV-2 virus on N95 respirator masks or filters.

The application of antiviral coatings to masks and respirators is a potential mitigating step toward reducing viral transmission during the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pandemic. The use of appropriate masks, social distancing, and vaccines is the immediate solution for limiting the viral spread and protecting people from this virus. N95 respirator masks are effective in filtering the virus particles, but they cannot kill or deactivate the virus. We report a possible approach to deactivating SARS-CoV-2 by applying an antimicrobial coating (Goldshield 75) to masks and respirators, rendering them suitable for repeated use. Masks coated with Goldshield 75 demonstrated continuous inactivation of the Alpha and Beta variants of the SARS-CoV-2 over a 3-day period and no loss of inactivation when stored at temperatures at 50 °C.

Design and model of facemask to inactivate the novel coronavirus

Due to the novel coronavirus spread (COVID-19) globally, governments across the world recommended the mandatory use of facemasks. The facemask helps people prevent and control the spread of virus infection. In this paper, we propose a design and model of facemask to inactivate the virus particles present in our surroundings. The proposed facemask is able to purify the air when a person inhales and exhales. The proposed mask is cost-effective, reusable, washable, and possesses the ability to disinfect the surface of facemask. The mask has the capability to trap all dust particles and virus present in the air, drastically decreasing the chance of infection. The mask is well-designed on the concept of activated carbon and copper filter.

Discussion on Influencing Factors and Control Range of Disinfection Effect in Waterworks during the COVID-19 Outbreak

This paper studied the influencing factors of disinfection effect in water purification process and the influence of external demand on the water purification process to ensure that the effective virus inactivation rate of waterworks can meet the requirements of microbiological safety during the COVID-19 outbreak. The results showed that the effluent turbidity should be no more than 0. 3 NTU to meet the requirements of coagulation sedimentation filtration process for virus 2-lg removal rate under the condition of the fixed source water temperature and pH value. On the basis of the above,with the monitoring of the effluent turbidity,water level of clean water tank,water quantity of waterworks and residual chlorine by real-time online instruments,the CT value of the clean water tank was controlled and adjusted within an appropriate range in real time,so that it not only met the 4-lg virus inactivation rate but also reduced the risk of disinfection by-products. Finally,a virus reduction rate of above 6-lg was achieved with the treatment process of waterworks,which could meet the biological safety requirements of drinking water during the epidemic,and have a sufficient safety margin.

Effect of UV Radiation on Optical Properties and Hardness of Transparent Wood.

Optically transparent wood is a type of composite material, combining wood as a renewable resource with the optical and mechanical properties of synthetic polymers. During this study, the effect of monochromatic UV-C (λ-250 nm) radiation on transparent wood was evaluated. Samples of basswood were treated using a lignin modification method, to preserve most of the lignin, and subsequently impregnated with refractive-index-matched types of acrylic polymers (methyl methacrylate, 2-hydroxyethyl methacrylate). Optical (transmittance, colour) and mechanical (shore D hardness) properties were measured to describe the degradation process over 35 days. The transmittance of the samples was significantly decreased during the first seven days (12% EMA, 15% MMA). The average lightness of both materials decreased by 10% (EMA) and 17% (MMA), and the colour shifted towards a red and yellow area of CIE L*a*b* space coordinates. The influence of UV-C radiation on the hardness of the samples was statistically insignificant (W+MMA 84.98 ± 2.05; W+EMA 84.89 ± 2.46), therefore the hardness mainly depends on the hardness of used acrylic polymer. The obtained results can be used to assess the effect of disinfection of transparent wood surfaces with UV-C radiation (e.g., due to inactivation of SARS-CoV-2 virus) on the change of its aesthetic and mechanical properties.

Deactivation of prospective memory intentions: Examining the role of the stimulus-response link.

Successful prospective remembering involves formation of a stimulus (e.g., bottle of medication and/or place where the bottle is kept)-response (e.g., taking a medication) link. We investigated the role of this link in the deactivation of no-longer-relevant prospective memory intentions, as evidenced by commission error risk. Experiment 1a contrasted two hypotheses of intention deactivation (degree of fulfillment and response frequency) by holding constant the degree of intention fulfillment (e.g., participants responded to one of two target words) while manipulating the number of times the intention was performed. Findings supported the response frequency hypothesis. Experiment 1b employed novel lure trials to examine what "stimulus" participants link the prospective memory response to-target words and/or the salient contextual cue-and compared commission errors to Experiment 1a. Findings suggested the salient context alone does not always function as the stimulus. Collectively these findings, in conjunction with those of Experiment 2 (a within-experiment replication) and a combined analysis, suggest that (a) intention deactivation is facilitated by prior responding (formation/strengthening of stimulus-response links), but additional research is needed to establish the robustness of this effect, and (b) when responding frequently to targets, participants are more likely to bind the response to the context alone than to the target or target/context combination, possibly because they learn to rely on context to predict target occurrence. The latter finding was robust and indicates that deactivation of the appropriate stimulus (target and/or context)-response link may be a critical component of reducing commission errors.