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The rapid spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposed the absence of wide-spectrum antiviral drugs. Owing to this limitation, the worldwide infection rate of SARS-CoV-2 could not be pharmacologically slowed down. The current situation has also exposed the medical vulnerability to viral infections that may lead to another pandemic.
In the past, nanotechnology has offered various direct and indirect solutions to combat viral diseases such as HIV, herpes simplex, respiratory viruses, and human papillomavirus. This article discusses how nanotechnology is being used to combat the current COVID-19 pandemic.
Nanotechnology and COVID-19
The immune system is the most vital line of defense of the human body. SARS-CoV-2 is most severely affecting the immunocompromised people or those with underlying conditions such as cardiovascular diseases or diabetes.
The antimicrobial and antiviral formulations based on nanotechnology have proved to be effective against SARS-CoV-2 viral dissemination. The implementation of sensitive nano biosensors and detection or nanodiagnostic platforms could also contribute to controlling and preventing COVID-19 infection.
Scientists believe several nanotechnology-based approaches could be used to tackle the current pandemic as well as prevent any future pandemics. Some of the nanotechnology-based approaches are stated below:
- Development of novel vaccines and drugs. Nanomaterials can be used to deliver broad-spectrum antiviral drugs to targeted sites.
- Development of highly specific, sensitive, and rapid viral detection system for early diagnosis of the disease.
- Development of efficient or superfine filters for face masks, that could act as the first line of prevention against harmful airborne pathogens.
- Development of fine blood filters
- Development of novel surface coatings with dual effect, i.e., resistance to viral adhesion and inactivation of the virus.
- Development of viral disinfectants
Some of the recent nanotechnology-based approaches to combat the SARS-CoV-2 pandemic are discussed below.
Inactivation of SARS-CoV-2
Primarily SARS-CoV-2 targets the respiratory tract. It also affects other organs such as the gut and kidney. While studying the mechanism of this virus, scientists found that the virus reaches the alveolar epithelial type II cells via alveoli which acts as the reservoir, from where they spread to the entire lung and severely impairs its function.
Researchers believe that the development of airborne nanomaterials such as aerosols, that can readily penetrate the deep lung, owing to their physicochemical properties, would be highly effective in inactivating the virus in the lung. Pulmonary delivery of nanomedicines (drugs, therapeutic proteins, and mRNAs) using nanodevices would also be beneficial.
Vaccine Development and Immunomodulation
Several nanomaterials have the capability to boost the host’s immune response. Production of vaccines is a long-term remedy for various diseases. Nanomaterials also act as promising tools for immune modulation, i.e., either activating or suppressing the immune response.
Controlling the Cytokine Storm
SARS-CoV-2 stimulates the cytokine storm in the body, which is also known as cytokine release syndrome (CRS). Such stimulation causes an excessive immune response which in turn leads to worsening of patients’ health conditions. This inflammatory storm also causes acute respiratory distress syndrome and multiple organ failure. Researchers have created nanosystems that have the ability to improve the accuracy and efficiency of immunosuppressants delivery to the target immune cells. The target specificity subsequently leads to:
- A reduction in drug dose
- A minimal effect on the non-target tissues and organs
- A reduction in associated side effects
After analyzing the virus transmission routes, scientists have strongly suggested sterilizing air, skin, or surrounding surfaces. Several nanoparticles can be used as disinfectants against SARS-CoV-2 for their intrinsic antiviral properties such as the production of reactive oxygen species and photo-thermal properties.
These nanomaterials can promote surface oxidation and release toxic ions that prevent the dissemination of the virus by either inhibiting adherence of viral components to the substrate or by restricting the entry of viral particles. Metallic nanoparticles such as copper, silver, and titanium dioxide possess a broad range of antiviral activity at a much lower dosage. Recent research has shown that face masks with nanoparticle coatings, for example, silver nanocluster or silica composite coating, impart viricidal effects against SARS-CoV-2.
Companies such as NanoTechSurface, Italy, and FN Nano Inc., USA, have developed nanotechnology-based formulations that possess strong antiviral properties.
Researchers at Queensland University of Technology, Australia, have created a disposable and breathable filter cartridge using cellulose nanofibers. These can filter particles that are smaller than 100 nanometres. Similarly, LIGC Applications Ltd., USA, has also developed a reusable face mask from microporous conductive graphene foam. These materials trap microorganisms and destroy them using electrical charges.
The early detection of an infected person is extremely important as it aids the process of preventing the dissemination of viruses and hence in controlling the pandemic. Generally, nanomaterials functionalized with antibodies or nucleic acids via colorimetric or antigen-binding assays are the main ingredients of nano-based detection tools.
Scientists have recently developed various diagnostic tools for the rapid detection of SARS-CoV-2. For example, researchers from the University of Maryland, USA, have developed a colorimetric assay based on gold nanoparticles capped with suitably designed thiol-modified DNA antisense oligonucleotides specific for N-gene (nucleocapsid phosphoprotein) of SARS-CoV-2. These oligonucleotides detect positive COVID-19 cases within 10 minutes of obtaining the isolated RNA samples.
Korea Basic Science Institute has also developed a rapid and accurate detection process of SARS-CoV-2 in clinical samples, based on an ultra-sensitive field-effect transistor (FET)-based biosensing device. Researchers believe that the cumulative effect of diagnostics, vaccines, disinfectants, and a wide spectrum of antiviral drugs would stop or prevent the further escalation of COVID-19 or any future pandemics.
References and Future Readings
Weiss, C., et al. (2020) Toward Nanotechnology-Enabled Approaches against the COVID-19 Pandemic. ACS Nano. 14 (6), 6383-6406. https://doi.org/10.1021/acsnano.0c03697
Talebian, S., et al. (2020) Nanotechnology-based disinfectants and sensors for SARS-CoV-2. Nat. Nanotechnol. 15, 618–621. https://doi.org/10.1038/s41565-020-0751-0