scholarly journals Nebulized delivery of a broadly neutralizing SARS-CoV-2 RBD-specific nanobody prevents clinical, virological and pathological disease in a Syrian hamster model of COVID-19

2021 ◽  
Author(s):  
Thomas J Esparza ◽  
Yaozong Chen ◽  
Negin P Martin ◽  
Helle Bielefeldt-Ohmann ◽  
Richard A Bowen ◽  
...  
Keyword(s):  
Syrian Hamster ◽  
Low Cost ◽  
Unmet Need ◽  
Lung Pathology ◽  
Hamster Model ◽  
Angiotensin Converting Enzyme 2 ◽  
In Vitro Characterization ◽  
Pathological Disease

There remains an unmet need for globally deployable, low-cost therapeutics for the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Previously, we reported on the isolation and in vitro characterization of a potent single-domain nanobody, NIH-CoVnb-112, specific for the receptor binding domain (RBD) of SARS-CoV-2. Here, we report on the molecular basis for the observed broad in vitro neutralization capability of NIH-CoVnb-112 against variant SARS-CoV-2 pseudoviruses, including the currently dominant Delta variant. The structure of NIH-CoVnb-112 bound to SARS-CoV-2 RBD reveals a large contact surface area overlapping the angiotensin converting enzyme 2 (ACE2) binding site, which is largely unencumbered by the common RBD mutations. In an in vivo pilot study, we demonstrate effective reductions in weight loss, viral burden, and lung pathology in a Syrian hamster model of COVID-19 following nebulized delivery of NIH-CoVnb-112. These findings support the further development of NIH-CoVnb-112 as a potential adjunct preventative therapeutic for the treatment of SARS-CoV-2 infection.

scholarly journals The SARS-CoV-2 Omicron (B.1.1.529) variant exhibits altered pathogenicity, transmissibility, and fitness in the golden Syrian hamster model

2022 ◽  
Author(s):  
Shuofeng Yuan ◽  
Zi-Wei Ye ◽  
Ronghui Liang ◽  
Kaiming Tang ◽  
Anna Jinxia Zhang ◽  
...  
Keyword(s):  
Syrian Hamster ◽  
Neutralizing Antibodies ◽  
Selection Pressure ◽  
Immune Selection ◽  
Hamster Model ◽  
Golden Syrian Hamster ◽  
New Variant ◽  
Contact Transmission

The newly emerging SARS-CoV-2 Omicron (B.1.1.529) variant first identified in South Africa in November 2021 is characterized by an unusual number of amino acid mutations in its spike that renders existing vaccines and therapeutic monoclonal antibodies dramatically less effective. The in vivo pathogenicity, transmissibility, and fitness of this new Variant of Concerns are unknown. We investigated these virological attributes of the Omicron variant in comparison with those of the currently dominant Delta (B.1.617.2) variant in the golden Syrian hamster COVID-19 model. Omicron-infected hamsters developed significantly less body weight losses, clinical scores, respiratory tract viral burdens, cytokine/chemokine dysregulation, and tissue damages than Delta-infected hamsters. The Omicron and Delta variant were both highly transmissible (100% vs 100%) via contact transmission. Importantly, the Omicron variant consistently demonstrated about 10-20% higher transmissibility than the already-highly transmissible Delta variant in repeated non-contact transmission studies (overall: 30/36 vs 24/36, 83.3% vs 66.7%). The Delta variant displayed higher fitness advantage than the Omicron variant without selection pressure in both in vitro and in vivo competition models. However, this scenario drastically changed once immune selection pressure with neutralizing antibodies active against the Delta variant but poorly active against the Omicron variant were introduced, with the Omicron variant significantly outcompeting the Delta variant. Taken together, our findings demonstrated that while the Omicron variant is less pathogenic than the Delta variant, it is highly transmissible and can outcompete the Delta variant under immune selection pressure. Next-generation vaccines and antivirals effective against this new VOC are urgently needed.

scholarly journals Persimmon-derived tannin has antiviral effects and reduces the severity of infection and transmission of SARS-CoV-2 in a Syrian hamster model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryutaro Furukawa ◽  
Masahiro Kitabatake ◽  
Noriko Ouji-Sageshima ◽  
Yuki Suzuki ◽  
Akiyo Nakano ◽  
...  
Keyword(s):  
Oral Administration ◽  
Syrian Hamster ◽  
Carboxymethyl Cellulose ◽  
Plaque Assay ◽  
Control Group ◽  
Dependent Manner ◽  
Hamster Model ◽  
Antiviral Effects

AbstractCoronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread across the world. Inactivating the virus in saliva and the oral cavity represents a reasonable approach to prevent human-to-human transmission because the virus is easily transmitted through oral routes by dispersed saliva. Persimmon-derived tannin is a condensed type of tannin that has strong antioxidant and antimicrobial activity. In this study, we investigated the antiviral effects of persimmon-derived tannin against SARS-CoV-2 in both in vitro and in vivo models. We found that persimmon-derived tannin suppressed SARS-CoV-2 titers measured by plaque assay in vitro in a dose- and time-dependent manner. We then created a Syrian hamster model by inoculating SARS-CoV-2 into hamsters’ mouths. Oral administration of persimmon-derived tannin dissolved in carboxymethyl cellulose before virus inoculation dramatically reduced the severity of pneumonia with lower virus titers compared with a control group inoculated with carboxymethyl cellulose alone. In addition, pre-administration of tannin to uninfected hamsters reduced hamster-to-hamster transmission of SARS-CoV-2 from a cohoused, infected donor cage mate. These data suggest that oral administration of persimmon-derived tannin may help reduce the severity of SARS-CoV-2 infection and transmission of the virus.

scholarly journals Activity of Galidesivir in a Hamster Model of SARS-CoV-2

Viruses ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 8
Author(s):  
Ray Taylor ◽  
Richard Bowen ◽  
James F. Demarest ◽  
Michael DeSpirito ◽  
Airn Hartwig ◽  
...  
Keyword(s):  
Public Health ◽  
Global Economy ◽  
Medical Intervention ◽  
Health Concern ◽  
Lung Pathology ◽  
Hamster Model ◽  
Antiviral Compound ◽  
The Impact

Coronavirus disease 2019 (COVID-19) has claimed the lives of millions of people worldwide since it first emerged. The impact of the COVID-19 pandemic on public health and the global economy has highlighted the medical need for the development of broadly acting interventions against emerging viral threats. Galidesivir is a broad-spectrum antiviral compound with demonstrated in vitro and in vivo efficacy against several RNA viruses of public health concern, including those causing yellow fever, Ebola, Marburg, and Rift Valley fever. In vitro studies have shown that the antiviral activity of galidesivir also extends to coronaviruses. Herein, we describe the efficacy of galidesivir in the Syrian golden hamster model of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Treatment with galidesivir reduced lung pathology in infected animals compared with untreated controls when treatment was initiated 24 h prior to infection. These results add to the evidence of the applicability of galidesivir as a potential medical intervention for a range of acute viral illnesses, including coronaviruses.

scholarly journals The Coming Age of Flavonoids in the Treatment of Diabetic Complications

2020 ◽  
Vol 9 (2) ◽  
pp. 346 ◽  
Author(s):  
Teresa Caro-Ordieres ◽  
Gema Marín-Royo ◽  
Lucas Opazo-Ríos ◽  
Luna Jiménez-Castilla ◽  
Juan Antonio Moreno ◽  
...  
Keyword(s):  
Diabetic Complications ◽  
Low Cost ◽  
Scientific Evidence ◽  
Experimental Studies ◽  
Unmet Need ◽  
In Vivo Studies ◽  
Antioxidant Compounds ◽  
Randomized Controlled Studies

Diabetes mellitus (DM), and its micro and macrovascular complications, is one of the biggest challenges for world public health. Despite overall improvement in prevention, diagnosis and treatment, its incidence is expected to continue increasing over the next years. Nowadays, finding therapies to prevent or retard the progression of diabetic complications remains an unmet need due to the complexity of mechanisms involved, which include inflammation, oxidative stress and angiogenesis, among others. Flavonoids are natural antioxidant compounds that have been shown to possess anti-diabetic properties. Moreover, increasing scientific evidence has demonstrated their potential anti-inflammatory and anti-oxidant effects. Consequently, the use of these compounds as anti-diabetic drugs has generated growing interest, as is reflected in the numerous in vitro and in vivo studies related to this field. Therefore, the aim of this review is to assess the recent pre-clinical and clinical research about the potential effect of flavonoids in the amelioration of diabetic complications. In brief, we provide updated information concerning the discrepancy between the numerous experimental studies supporting the efficacy of flavonoids on diabetic complications and the lack of appropriate and well-designed clinical trials. Due to the well-described beneficial effects on different mechanisms involved in diabetic complications, the excellent tolerability and low cost, future randomized controlled studies with compounds that have adequate bioavailability should be evaluated as add-on therapy on well-established anti-diabetic drugs.

scholarly journals Silencing of SARS-CoV-2 with modified siRNA-peptide dendrimer formulation

2021 ◽  
Author(s):  
Musa Khaitov ◽  
Alexandra Nikonova ◽  
Igor Shilovskiy ◽  
Ksenia Kozhikhova ◽  
Ilya Kofiadi ◽  
...  
Keyword(s):  
Unmet Need ◽  
Virus Titer ◽  
Firefly Luciferase ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Hamster Model ◽  
Infected Cells ◽  
Peptide Dendrimer

Background. First vaccines for prevention of Coronavirus disease 2019 (COVID-19) are becoming available but there is a huge and unmet need for specific forms of treatment. In this study we aimed to evaluate the potent anti-SARS-CoV-2 effect of siRNA both in vitro and in vivo. Methods. To identify most effective molecule out of a panel of 15 in silico designed siRNAs, an in vitro screening system based on vectors expressing SARS-CoV-2 genes fused with the firefly luciferase reporter gene and SARS-CoV-2-infected cells was used. The most potent siRNA, siR-7, was modified by Locked nucleic acids (LNAs) to obtain siR-7-EM with increased stability and was formulated with the peptide dendrimer KK-46 for enhancing cellular uptake to allow topical application by inhalation of the final formulation - siR-7-EM/KK-46. Using the Syrian Hamster model for SARS-CoV-2 infection the antiviral capacity of siR-7-EM/KK-46 complex was evaluated. Results. We identified the siRNA, siR-7, targeting SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) as the most efficient siRNA inhibiting viral replication in vitro. Moreover, we have shown that LNA-modification and complexation with the designed peptide dendrimer enhanced the antiviral capacity of siR-7 in vitro. We demonstrated significant reduction of virus titer and total lung inflammation in the animals exposed by inhalation of siR-7-EM/KK-46 in vivo. Conclusions. Thus, we developed a therapeutic strategy for COVID-19 based on inhalation of a modified siRNA-peptide dendrimer formulation.

THE ROLE OF POLYETHYLENIMINE IN ENHANCING PERFORMANCE OF GLUTAMATE BIOSENSORS

2018 ◽  
Vol 8 (3) ◽  
pp. 36-41
Author(s):  
Diep Do Thi Hong ◽  
Duong Le Phuoc ◽  
Hoai Nguyen Thi ◽  
Serra Pier Andrea ◽  
Rocchitta Gaia
Keyword(s):  
First Generation ◽  
Good Reproducibility ◽  
Complex Matrices ◽  
Long Term Stability ◽  
In Vitro Characterization ◽  
Glutamate Oxidase

Background: The first biosensor was constructed more than fifty years ago. It was composed of the biorecognition element and transducer. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples Glutamate is important biochemicals involved in energetic metabolism and neurotransmission. Therefore, biosensors requires the development a new approach exhibiting high sensibility, good reproducibility and longterm stability. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples. The aims of this work: To find out which concentration of polyethylenimine (PEI) exhibiting the most high sensibility, good reproducibility and long-term stability. Methods: We designed and developed glutamate biosensor using different concentration of PEI ranging from 0% to 5% at Day 1 and Day 8. Results: After Glutamate biosensors in-vitro characterization, several PEI concentrations, ranging from 0.5% to 1% seem to be the best in terms of VMAX, the KM; while PEI content ranging from 0.5% to 1% resulted stable, PEI 1% displayed an excellent stability. Conclusions: In the result, PEI 1% perfomed high sensibility, good stability and blocking interference. Furthermore, we expect to develop and characterize an implantable biosensor capable of detecting glutamate, glucose in vivo. Key words: Glutamate biosensors, PEi (Polyethylenimine) enhances glutamate oxidase, glutamate oxidase biosensors

Asymmetric synthesis and in vivo/in vitro characterization of new hybrid anticonvulsants derived from (2,5-dioxopyrrolidin-1-yl)phenylacetamides

2021 ◽  
Vol 109 ◽  
pp. 104751
Author(s):  
Michał Abram ◽  
Anna Rapacz ◽  
Gniewomir Latacz ◽  
Bartłomiej Szulczyk ◽  
Justyna Kalinowska-Tłuścik ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
In Vitro Characterization
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