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1.
Front Bioeng Biotechnol ; 10: 858156, 2022.
Article in English | MEDLINE | ID: covidwho-1952235

ABSTRACT

Antiviral and non-toxic effects of silver nanoparticles onto in vitro cells infected with coronavirus were evaluated in this study using High-Resolution Magic-Angle Spinning Nuclear Magnetic Resonance (HR-MAS NMR) spectroscopy. Silver nanoparticles were designed and synthesized using an orange flavonoid-hesperetin (HST)-for reduction of silver(I) and stabilization of as obtained nanoparticles. The bio-inspired process is a simple, clean, and sustainable way to synthesize biogenic silver nanoparticles (AgNP@HST) with diameters of ∼20 nm and low zeta potential (-40 mV), with great colloidal stability monitored for 2 years. The nanoparticles were used for the fabrication of two types of antiviral materials: colloids (AgNP@HST spray) and 3D flexible nanostructured composites. The composites, decorated with AgNP@HST (0.05 mmol L-1), were made using cellulose nanofibers (CNF) obtained from orange peel and graphene oxide (GO), being denominated CNF@GO@AgNP@HST. Both materials showed high virucidal activity against coronaviruses in cell infection in vitro models and successfully inhibited the viral activity in cells. HR-MAS 1H-NMR technique was used for determining nanomaterials' effects on living cells and their influences on metabolic pathways, as well as to study viral effects on cells. It was proven that none of the manufactured materials showed toxicity towards the intact cells used. Furthermore, viral infection was reverted when cells, infected with the coronavirus, were treated using the as-fabricated nanomaterials. These significant results open possibilities for antiviral application of 3D flexible nanostructured composite such as packaging papers and filters for facial masks, while the colloidal AgNP@HST spray can be used for disinfecting surfaces, as well as a nasal, mouth, and eye spray.

2.
Viruses ; 13(12)2021 12 06.
Article in English | MEDLINE | ID: covidwho-1598685

ABSTRACT

Newcastle disease virus (NDV) can infect over 250 bird species with variable pathogenicity; it can also infect humans in rare cases. The present study investigated an outbreak in feral pigeons in São Paulo city, Brazil, in 2019. Affected birds displayed neurological signs, and hemorrhages were observed in different tissues. Histopathology changes with infiltration of mononuclear inflammatory cells were also found in the brain, kidney, proventriculus, heart, and spleen. NDV staining was detected by immunohistochemistry. Twenty-seven out of thirty-four tested samples (swabs and tissues) were positive for Newcastle disease virus by RT-qPCR test, targeting the M gene. One isolate, obtained from a pool of positive swab samples, was characterized by the intracerebral pathogenicity index (ICPI) and the hemagglutination inhibition (HI) tests. This isolate had an ICPI of 0.99, confirming a virulent NDV strain. The monoclonal antibody 617/161, which recognizes a distinct epitope in pigeon NDV strains, inhibited the isolate with an HI titer of 512. A complete genome of NDV was obtained using next-generation sequencing. Phylogenetic analysis based on the complete CDS F gene grouped the detected isolate with other viruses from subgenotype VI.2.1.2, class II, including one previously reported in Southern Brazil in 2014. This study reports a comprehensive characterization of the subgenotype VI.2.1.2, which seems to have been circulating in Brazilian urban areas since 2014. Due to the zoonotic risk of NDV, virus surveillance in feral pigeons should also be systematically performed in urban areas.


Subject(s)
Columbidae , Disease Outbreaks/veterinary , Newcastle Disease/epidemiology , Newcastle disease virus/genetics , Animals , Brazil/epidemiology , Genome, Viral , Genotype , High-Throughput Nucleotide Sequencing , Newcastle Disease/pathology , Newcastle Disease/virology , Newcastle disease virus/classification , Newcastle disease virus/isolation & purification , Newcastle disease virus/pathogenicity , Phylogeny , Virulence , Whole Genome Sequencing
3.
Lancet Microbe ; 2(10): e527-e535, 2021 10.
Article in English | MEDLINE | ID: covidwho-1307293

ABSTRACT

BACKGROUND: Mutations accrued by SARS-CoV-2 lineage P.1-first detected in Brazil in early January, 2021-include amino acid changes in the receptor-binding domain of the viral spike protein that also are reported in other variants of concern, including B.1.1.7 and B.1.351. We aimed to investigate whether isolates of wild-type P.1 lineage SARS-CoV-2 can escape from neutralising antibodies generated by a polyclonal immune response. METHODS: We did an immunological study to assess the neutralising effects of antibodies on lineage P.1 and lineage B isolates of SARS-CoV-2, using plasma samples from patients previously infected with or vaccinated against SARS-CoV-2. Two specimens (P.1/28 and P.1/30) containing SARS-CoV-2 lineage P.1 (as confirmed by viral genome sequencing) were obtained from nasopharyngeal and bronchoalveolar lavage samples collected from patients in Manaus, Brazil, and compared against an isolate of SARS-CoV-2 lineage B (SARS.CoV2/SP02.2020) recovered from a patient in Brazil in February, 2020. Isolates were incubated with plasma samples from 21 blood donors who had previously had COVID-19 and from a total of 53 recipients of the chemically inactivated SARS-CoV-2 vaccine CoronaVac: 18 individuals after receipt of a single dose and an additional 20 individuals (38 in total) after receipt of two doses (collected 17-38 days after the most recent dose); and 15 individuals who received two doses during the phase 3 trial of the vaccine (collected 134-230 days after the second dose). Antibody neutralisation of P.1/28, P.1/30, and B isolates by plasma samples were compared in terms of median virus neutralisation titre (VNT50, defined as the reciprocal value of the sample dilution that showed 50% protection against cytopathic effects). FINDINGS: In terms of VNT50, plasma from individuals previously infected with SARS-CoV-2 had an 8·6 times lower neutralising capacity against the P.1 isolates (median VNT50 30 [IQR <20-45] for P.1/28 and 30 [<20-40] for P.1/30) than against the lineage B isolate (260 [160-400]), with a binominal model showing significant reductions in lineage P.1 isolates compared with the lineage B isolate (p≤0·0001). Efficient neutralisation of P.1 isolates was not seen with plasma samples collected from individuals vaccinated with a first dose of CoronaVac 20-23 days earlier (VNT50s below the limit of detection [<20] for most plasma samples), a second dose 17-38 days earlier (median VNT50 24 [IQR <20-25] for P.1/28 and 28 [<20-25] for P.1/30), or a second dose 134-260 days earlier (all VNT50s below limit of detection). Median VNT50s against the lineage B isolate were 20 (IQR 20-30) after a first dose of CoronaVac 20-23 days earlier, 75 (<20-263) after a second dose 17-38 days earlier, and 20 (<20-30) after a second dose 134-260 days earlier. In plasma collected 17-38 days after a second dose of CoronaVac, neutralising capacity against both P.1 isolates was significantly decreased (p=0·0051 for P.1/28 and p=0·0336 for P.1/30) compared with that against the lineage B isolate. All data were corroborated by results obtained through plaque reduction neutralisation tests. INTERPRETATION: SARS-CoV-2 lineage P.1 might escape neutralisation by antibodies generated in response to polyclonal stimulation against previously circulating variants of SARS-CoV-2. Continuous genomic surveillance of SARS-CoV-2 combined with antibody neutralisation assays could help to guide national immunisation programmes. FUNDING: São Paulo Research Foundation, Brazilian Ministry of Science, Technology and Innovation and Funding Authority for Studies, Medical Research Council, National Council for Scientific and Technological Development, National Institutes of Health. TRANSLATION: For the Portuguese translation of the abstract see Supplementary Materials section.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Neutralizing , Antibodies, Viral , Brazil/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines , Humans , SARS-CoV-2/genetics , United States , Vaccination
4.
Particle & Particle Systems Characterization ; : 1, 2021.
Article in English | Academic Search Complete | ID: covidwho-1281246

ABSTRACT

Infectious diseases caused by viruses are a global health concern and have become prominent in light of the recent COVID‐19 pandemic. Considering the limitations of drugs and prophylactic methods used in current medicine, antiviral materials are a useful strategy in preventing the spread of viruses and enhancing treatment efficiency. Thus, this review highlights the state‐of‐the‐art antiviral materials, describes the scientific landscape of the primary antiviral materials used based on bibliometric analysis, presents their mechanisms of action, and discusses their clinical applications. The mechanisms of action underlying the broad‐spectrum antiviral properties of metals, ceramics, polymers, and composites are also discussed. Polyanions, polycations, oxides, and metal‐based materials, from bulk to nanoparticles, have good potential in antiviral applications that may help prepare the world for future viral breakouts. [ABSTRACT FROM AUTHOR] Copyright of Particle & Particle Systems Characterization is the property of John Wiley & Sons, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

5.
Journal of the American Ceramic Society ; n/a(n/a), 2021.
Article in English | Wiley | ID: covidwho-1201660

ABSTRACT

Abstract The sanitary crisis caused by the SARS-CoV-2 has increased the demand for bioactive materials to mitigate coronavirus spread. The use of masks has been reported as an essential strategy to prevent coronavirus transmission, but masks can become contaminated rapidly after use. Metals species containing compounds, especially those from the copper group, present properties that can be explored to suppress viral activity. Natural polymers, like alginate, can improve biocompatibility and adjust metal ion availability on hybrid coatings. This study assesses iron, copper, silver, and gold salts and their combination with biopolymers to design surfaces with virucidal properties. Viral inactivation assays with MHV-3 coronavirus strain and cytotoxicity tests with L929 cells were conducted to the hybrid coatings on polypropylene masks. These coatings were characterized by scanning electron microscopy with energy dispersive spectroscopy, Fourier-transform infrared spectroscopy with attenuated total reflectance device, and atomic absorption spectroscopy techniques. Multilayer coatings of alginate-copper sulfate presented 99.99% viral inactivation in a timely release of copper ions.

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