High-Performance Graphene-Modified Sensing Chip for SARS-CoV-2 Detection.

This sensing prototype model involves the development of a reusable, twofold graphene oxide (GrO)-glazed double inter-digitated capacitive (DIDC) detecting chip for detecting severe acute respiratory syndrome coronavirus 2 virus (SARS-CoV-2) specifically and rapidly. The fabricated DIDC comprises a Ti/Pt-containing glass substrate glazed with graphene oxide (GrO), which is further chemically modified with EDC-NHS to immobilize antibodies (Abs) hostile to SARS-CoV-2 based on the spike (S1) protein of the virus. The results of insightful investigations showed that GrO gave an ideal engineered surface for Ab immobilization and enhanced the capacitance to allow higher sensitivity and low sensing limits. These tunable elements helped accomplish a wide sensing range (1.0 mg/mL to 1.0 fg/mL), a minimum sensing limit of 1 fg/mL, high responsiveness and good linearity of 18.56 nF/g, and a fast reaction time of 3 s. Besides, in terms of developing financially viable point-of-care (POC) testing frameworks, the reusability of the GrO-DIDC biochip in this study is good. Significantly, the biochip is specific against blood-borne antigens and is stable for up to 10 days at 5 °C. Due to its compactness, this scaled-down biosensor has the potential for POC diagnostics of COVID-19 infection. This system can also detect other severe viral diseases, although an approval step utilizing other virus examples is under development.

Designing and developing a sensitive and specific SARS-CoV-2 RBD IgG detection kit for identifying positive human samples.

BACKGROUND: More than 3 y into the coronavirus 2019 (COVID-19) pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to undergo mutations. In this context, the Receptor Binding Domain (RBD) is the most antigenic region among the SARS-CoV-2 Spike protein and has emerged as a promising candidate for immunological development. We designed an IgG-based indirect enzyme-linked immunoassay (ELISA) kit based on recombinant RBD, which was produced from the laboratory to 10 L industry scales in Pichia pastoris. METHODS: A recombinant-RBD comprising 283 residues (31 kDa) was constructed after epitope analyses. The target gene was initially cloned into an Escherichia coli TOP10 genotype and transformed into Pichia pastoris CBS7435 muts for protein production. Production was scaled up in a 10 L fermenter after a 1 L shake-flask cultivation. The product was ultrafiltered and purified using ion-exchange chromatography. IgG-positive human sera for SARS-CoV-2 were employed by an ELISA test to evaluate the antigenicity and specific binding of the produced protein. RESULTS: Bioreactor cultivation yielded 4 g/l of the target protein after 160 h of fermentation, and ion-exchange chromatography indicated a purity > 95%. A human serum ELISA test was performed in 4 parts, and the ROC area under the curve (AUC) was > 0.96 for each part. The mean specificity and sensitivity of each part was 100% and 91.5%, respectively. CONCLUSION: A highly specific and sensitive IgG-based serologic kit was developed for improved diagnostic purposes in patients with COVID-19 after generating an RBD antigen in Pichia pastoris at laboratory and 10 L fermentation scales.

In vitro high-content tissue models to address precision medicine challenges.

The field of precision medicine allows for tailor-made treatments specific to a patient and thereby improve the efficiency and accuracy of disease prevention, diagnosis, and treatment and at the same time would reduce the cost, redundant treatment, and side effects of current treatments. Here, the combination of organ-on-a-chip and bioprinting into engineering high-content in vitro tissue models is envisioned to address some precision medicine challenges. This strategy could be employed to tackle the current coronavirus disease 2019 (COVID-19), which has made a significant impact and paradigm shift in our society. Nevertheless, despite that vaccines against COVID-19 have been successfully developed and vaccination programs are already being deployed worldwide, it will likely require some time before it is available to everyone. Furthermore, there are still some uncertainties and lack of a full understanding of the virus as demonstrated in the high number new mutations arising worldwide and reinfections of already vaccinated individuals. To this end, efficient diagnostic tools and treatments are still urgently needed. In this context, the convergence of bioprinting and organ-on-a-chip technologies, either used alone or in combination, could possibly function as a prominent tool in addressing the current pandemic. This could enable facile advances of important tools, diagnostics, and better physiologically representative in vitro models specific to individuals allowing for faster and more accurate screening of therapeutics evaluating their efficacy and toxicity. This review will cover such technological advances and highlight what is needed for the field to mature for tackling the various needs for current and future pandemics as well as their relevancy towards precision medicine.

A review of treating viral outbreaks with self-assembled nanomaterial-like peptides: From Ebola to the Marburg virus

Cases of the Marburg virus have started to rise and there is an urgent need to find a cure or therapy before another world-wide quarantine is introduced. There are no treatments for this virus other than giving infected people plenty of water due to excessive bleeding. Here, we report a growing strategy to use self-assembled nano peptides to attach to and inhibit viruses from replicating. Specifically, we summarize the research of others who have used this approach for Ebola, SARS-CoV-2, and other viruses and even provide our own eight octapeptides that show interference with the Marburg virus and viral RNA. These peptides self-assemble in a similar matter as the virus itself self-assembling along the viral RNA. These eight octapeptides (KLVVGDRAS, GDRASIEK, EILLAREL, ARELTLRK, FLSFCSLF, CSLFLPKL, WITWMTIW, and MTIWIPEI) were selected based on a conserved nanoparticle core sequence containing both N- and C- terminal lobes. The total atomic contact energy of these peptides as determined through computational modeling are: -110.97501, -118.57263, -99.82477, -120.60967, -17.14494, -52.11275, -14.02828, and -45.64357 kcal/mol, respectively. Collectively with results from other researchers who have designed self-assembled nano peptides to passivate other viruses, this report summarizes the strong attraction that can occur between candidate peptides to the Marburg virus. Further in vitro and in vivo studies of these peptides are needed to fully evaluate their efficacy to treat the Marburg virus, but clearly this review article demonstrates that there is a strong future for using self-assembled nano peptides to prevent and treat viral outbreaks.

Targeting the Conserved Sequence of the Substrate for the Proteinase of Severe-Acute-Respiratory-Syndrome-Coronavirus-2 (SARS-CoV-2) Using Nano-Networks: Efficacy, Stability, and No Cytotoxicity.

Herein, we designed a nano peptide that contains three important motifs for targeting the chemotrypsin-like cysteine protease (3CLpro) which is the enzyme responsible for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) replication. The novel nano peptide contains the Nap Phe-Phe motif that is responsible for peptide self-assembly, an octapeptide (Ser-Ala-Val-Leu-Gln-Ser-Gly-Phe) motif where the enzyme recognizes the substrate and induces enzyme sensitivity, and a tetrapeptide motif which is positively charged containing the peptide (Lys)4 that facilitates penetration into a cell. The nano peptide was characterized using Proton Nuclear Magnetic Resonance (H-NMR) and Liquid Chromatography-Mass Spectrometry (LC-MS) to confirm its structure. In vitro results showed that the presently formulated nano peptide was not cytotoxic to fibroblasts for up to 72 hours, bound to 3CLpro, inhibited SARS-CoV-2 Omicron variant virus replication, and was stable for binding for up to one week in culture. In this manner, this timely study demonstrates that this novel nano peptide should be studied for a wide range of Coronavirus Disease (COVID-19) prophylactic or therapeutic applications.

Inhibiting Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Variants: Targeting the Spike and Envelope Proteins Using Nanomaterial Like Peptides.

Coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused significant death, economic crisis, and the world to almost completely shut down. This present study focused on targeting the novel SARS-CoV-2 envelope protein, which has not been frequently mutating, and the S protein with a much larger peptide capable of inhibiting virus-mammalian cell attraction. In doing so, molecular dynamics software was used here to model six peptides including: NapFFTLUFLTUTE, NapFFSLAFLTATE, NapFFSLUFLSUTE, NapFFTLAFLTATE, NapFFSLUFLSUSE, and NapFFMLUFLMUME. Results showed that two of these completely hydrophobic peptides (NapFFTLUFLTUTE and NapFFMLUFLMUME) had a strong ability to bind to the virus, preventing its binding to a mammalian cell membrane, entering the cell, and replicating by covering many cell attachment sites on SARS-CoV-2. Further cell modeling results demonstrated the low toxicity and suitable pharmacokinetic properties of both peptides making them ideal for additional in vitro and in vivo investigation. In this manner, these two peptides should be further explored for a wide range of present and future COVID-19 therapeutic and prophylactic applications.

Passivating the Omicron SARS-CoV-2 variant with self-assembled nano peptides: Specificity, stability, and no cytotoxicity

The SARS-CoV-2 Omicron variant is called a “variant of concern” (VOC) which has spread all over the world at a faster rate than even the first SARS-CoV-2 outbreak despite travel restrictions. In order to combat the health consequences from a SARS-CoV-2 Omicron variant infection, the objective of the present in vitro study was to develop self-assembled nano peptides to attach to the virus and inhibit its attachment and entry into mammalian cells for replication. For this purpose, two amphipathic peptides containing hydrophobic and hydrophilic peptides and an unnatural amino acid (such as 2-aminoisobutyric acid (U)) were designed to attach to the less mutated virus envelope rather than more frequently mutated S-protein region: NapFFTLUFLTUTEKKKK and NapFFMLUFLMUMEKKKK. These peptides were synthesized using the solid phase peptide synthesis method and were characterized for mammalian cell infection using well-established pseudo virus assays. In vitro results showed that the two self-assembled nano peptides significantly inhibited the ability of the SARS-CoV-2 Omicron variant virus to infect mammalian cells and replicate with IC50 values of 0.5 and 360 mg/ml for NapFFTLUFLTUTEKKKK and NapFFMLUFLMUMEKKKK, respectively. Most impressively, 1 mg/ml of NapFFTLUFLTUTEKKKK resulted in a 2 log reduction in pseudovirus replication after just 15 min at a viral load of 106 copies/ml. Results further confirmed that the peptides continued to passivate the SARS-CoV-2 Omicron variant for up to one week and were stable in cell culture media before being added to the virus. Mechanistically, in vitro results showed selective binding of the peptides to the SARS-CoV-2 Omicron variant envelop protein over the more frequently mutated spike protein up to one week demonstrating the stability of the peptides. Cytotoxicity studies with fibroblasts also showed no toxicity when exposed to the peptides for 72 h. In summary, the present results strongly suggest that the two peptides developed in this study should be further researched for a wide range of anti-SARS-CoV-2 virus applications, including the present Omicron and future mutations.

The promising use of nano-molecular imprinted templates for improved SARS-CoV-2 detection, drug delivery and research.

Molecular imprinting (MI) is a technique that creates a template of a molecule for improving complementary binding sites in terms of size and shape to a peptide, protein, bacteria, mammalian cell, or virus on soft materials (such as polymers, hydrogels, or self-assembled materials). MI has been widely investigated for over 90 years in various industries but is now focused on improved tissue engineering, regenerative medicine, drug delivery, sensors, diagnostics, therapeutics and other medical applications. Molecular targets that have been studied so far in MI include those for the major antigenic determinants of microorganisms (like bacteria or viruses) leading to innovations in disease diagnosis via solid-phase extraction separation and biomimetic sensors. As such, although not widely investigated yet, MI demonstrates much promise for improving the detection of and treatment for the current Coronavirus Disease of 2019 (COVID-2019) pandemic as well as future pandemics. In this manner, this review will introduce the numerous applications of MI polymers, particularly using proteins and peptides, and how these MI polymers can be used as improved diagnostic and therapeutic tools for COVID-19.

From Bulk to Nanoparticles: An Overview of Antiviral Materials, Its Mechanisms, and Applications

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.)

Nanotechnology against the novel coronavirus (severe acute respiratory syndrome coronavirus 2): diagnosis, treatment, therapy and future perspectives.

COVID-19, as an emerging infectious disease, has caused significant mortality and morbidity along with socioeconomic impact. No effective treatment or vaccine has been approved yet for this pandemic disease. Cutting-edge tools, especially nanotechnology, should be strongly considered to tackle this virus. This review aims to propose several strategies to design and fabricate effective diagnostic and therapeutic agents against COVID-19 by the aid of nanotechnology. Polymeric, inorganic self-assembling materials and peptide-based nanoparticles are promising tools for battling COVID-19 as well as its rapid diagnosis. This review summarizes all of the exciting advances nanomaterials are making toward COVID-19 prevention, diagnosis and therapy.

Potential immuno-nanomedicine strategies to fight COVID-19 like pulmonary infections.

COVID-19, coronavirus disease 2019, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a pandemic. At the time of writing this (October 14, 2020), more than 38.4 million people have become affected, and 1.0 million people have died across the world. The death rate is undoubtedly correlated with the cytokine storm and other pathological pulmonary characteristics, as a result of which the lungs cannot provide sufficient oxygen to the body's vital organs. While diversified drugs have been tested as a first line therapy, the complexity of fatal cases has not been reduced so far, and the world is looking for a treatment to combat the virus. However, to date, and despite such promise, we have received very limited information about the potential of nanomedicine to fight against COVID-19 or as an adjunct therapy in the treatment regimen. Over the past two decades, various therapeutic strategies, including direct-acting antiviral drugs, immunomodulators, a few non-specific drugs (simple to complex), have been explored to treat Acute Respiratory Distress Syndrome (ARDS), Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS), influenza, and sometimes the common flu, thus, correlating and developing specific drugs centric to COVID-19 is possible. This review article focuses on the pulmonary pathology caused by SARS-CoV-2 and other viral pathogens, highlighting possible nanomedicine therapeutic strategies that should be further tested immediately.