A recent review article examines the potential of nanotechnologies in the fight against severe acute respiratory syndrome 2 (SARS-CoV-2), with several possible strategies in therapy, vaccines and prevention.
The review article, published in the journal Nanomaterials provides information on recent studies using metallic nanocomposites as antivirals. In addition to discussing SARS-CoV, Respiratory Middle East (MERS) -CoV, and coronaviruses, other enveloped and RNA viruses are also included as targets for metallic nanomaterials in this review.
The new coronavirus, SARS-CoV-2, which appeared at the end of December 2019 in Wuhan, China, is responsible for the 2019 coronavirus disease (COVID-19). Belonging to the Coronaviridae family, seven viruses are capable of infecting humans: the human coronavirus 229E (HCoV-229E) and the human coronavirus NL63 (HCoV-NL63), (belonging to the genus Alphacoronavirus), and human coronavirus OC43 (HCoV-OC43), human coronavirus HKU1 (HCoV-HKU1), Middle East respiratory virus (MERS-CoV), SARS-CoV and SARS-CoV-2 (belonging to kind Beta-coronavirus).
Of these, SARS-CoV, MERS-CoV, and SARS-CoV-2 cause severe respiratory disease with a complex pathophysiology associated with multiple organ failure, sepsis and death. Despite a low mutation rate (compared to the influenza virus), variants with increased transmissibility, increased severity and reduced neutralization of antibodies for COVID-19 are identified as emerging around the world.
The versatility of nanocomposites and nanoparticles allows them to fight infections and prevent viruses, including VOCs, without selective toxicity or adverse effects. In addition, the fact that the virus uses the machinery of the host cell for its replication is essential for developing an antiviral drug that does not harm the host.
The unique size, high surface-to-volume ratio, surface plasmon resonance, and malleable optical absorption spectra of metal nanoparticles are some of the benefits of using nanotechnology for antiviral strategies – bioconjugation, nanocarriers, or stabilization. of drugs, production of host reactive oxygen species (ROS). ), etc.
General replication of the human pathogenic coronavirus. Attachment and entry via binding of protein S to a specific host receptor. The positive sense viral RNA is released and the polymerase is translated. Viral RNA is replicated and the structural core protein (N) is synthesized in the cytoplasm, and the S protein, membrane (M) and envelope (E) are transcribed / translated in the endoplasmic reticulum (ER) and transported to the Golgi apparatus. Viral components are packaged and assembled into a mature virion structure which is then released
Metal nanoparticles as antivirals
Metal nanoparticles can attack multiple viral targets with minimal subsequent resistance development.
The best metal nanoparticles that are effective against bacteria and viruses are silver nanoparticles (AgNPs). The antiviral and inhibitory activity of AgNPs is shown against TGEV, porcine coronavirus, as a model of CoV and feline coronavirus (FCoV). AgNPs synthesized by curcumin have been shown to be less toxic than AgNPs than citric acid.
Graphene oxide (GO) has also been shown to be effective against coronaviruses (porcine epidemic diarrhea virus – PEDV) and FCoV.
A complex of gold nanoparticles (AuNP) has been shown to interact with the dengue virus coat protein (DENV-2), permanently inhibiting the virus. Studies have also shown that porous AuNPs without surfactants decreased the infectivity of various strains of influenza viruses (H1N1, H3N2 and H9N2).
The reviewers presented various studies involving metallic nanomaterials as antivirals and proposed mechanisms of action.
Nanoparticulate delivery systems against viruses
Difficulties with common antiviral drugs include solubility, permeability, and absorption, affecting the bioavailability of the drug. Nanoparticulate delivery systems for bioactive compounds, immunogenic drugs or proteins, can overcome these challenges. Nanocarriers are well studied and effective against HIV and dengue virus (DENV) with a cationic AuNP-siRNA complex.
Since no known drug effectively interferes with the replication of SARS-CoV-2, the reviewers did not directly treat it as a drug nanotransporter for SARS-CoV-2.
In the current pandemic, vaccination has been the most effective medical intervention to control infection. Nanoparticles are widely explored as adjuvants to vaccines, for example, lipid and polymer nanomaterials.
Gold nanoparticles conjugated at 100 nm with the S-glycoprotein (spike) of the avian coronavirus elicited a robust immune response in mouse models.
A recent study proposed a vaccine that unites the immunomodulation of AuNPs, capped with antiviral polysaccharides and loaded with S or N proteins (nucleocapsid) of SARS-CoV-2.
Metal nanoparticles in the diagnosis of COVID-19
Combining diagnostics with the ability to tailor a metallic nanomaterial with specific properties could be a vital weapon in the fight against COVID-19.
Currently, the diagnosis of COVID-19 can be made based on viral sequences, patient antibodies, or detection of SARS-CoV-2 antigens from nasopharyngeal or oropharyngeal swab specimens from patients (the gold standard of sampling).
Likewise, magnetic nanoparticles are easy and effective in detecting SARS-CoV-2 through electrochemical, fluorescence or magnetic resonance properties. Magnetic particles can be used to extract SARS-CoV-2 RNA from samples and help increase the sensitivity of detection based on amplification methods.
Metal nanoparticles in personal protective equipment
Despite the deployment of vaccination, personal protective equipment (PPE) is mandatory to stop the viral spread via carriers. Reports have demonstrated anti-SARS-CoV-2 activity consisting of incorporating metallic nanoparticles into these PPE. Various nanomaterials such as silver nanoparticles, copper oxide, iodine, titanium oxide are discussed for use in these PPE products.
Developing an antiviral drug for viruses which are obligate intracellular parasites that depend on the host cell’s machinery for replication is difficult, so nanotechnology may be a potential solution.
The adjustable properties and demonstrated potential of nanomaterials make them a promising alternative to current antivirals. The use of these tools could be used to prevent future epidemics and pandemics.