Graphene-enhanced PPE for COVID-19

Due to the ongoing COVID-19 pandemic, wearing masks and other personal protective equipment (PPE) reduces the spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus into the air and causes infection. It has become a new standard for reducing risk. ..

The worldwide lack of availability of N-95 masks has led to the use of large-scale cloth masks. COVID-19 is highly infectious even before symptoms appear, so more prophylactic PPE kits and face masks are urgently needed.

To address this need, Italian nanotechnology researchers have proposed using two-dimensional graphene to improve existing PPE kits.Their research is published on the preprint server medRxiv*.

Graphene and its derivatives have received a great deal of attention in recent years due to their interaction with microorganisms. The increased surface area of ​​the original graphene, a single carbon atom arranged in a hexagon, binds to the virus using hydrogen bonds, electrostatic interactions, or redox reactions. The presence of oxygen groups on graphene oxide makes the surface hydrophilic and stimulates interaction with organic molecules. Graphene derivatives can also destroy the SARS-CoV-2 membrane by adsorbing charged lipids.

Functionalization of graphene

Researchers first demonstrated the ability of graphene oxide (GO) in solution to bind and capture SARS-CoV-2 virus particles by incubating approximately 105 virus particles / mL for 2 hours while increasing the concentration of GO. I investigated. After incubation, the solution was centrifuged and the supernatant was used to incubate VERO (ATCC CCL-81) cells and measure virus infectivity. Incubation of SARS-CoV-2 virus particles in GO and suspension is reflected in the reduced cytopathic effect of the virus and increased cell survival, even at the lowest levels of GO (0.06 mg / mL). Dramatically reduced power.

GO also significantly reduced the load on viral particles, as assessed by immunofluorescent labeling with anti-SARS-CoV-2. Spike protein Reduction of antibody and cytotoxicity measured by both crystal violet staining and lactate dehydrogenase (LDH) release. These data show that water-soluble GO interacts with SARS-CoV-2 virus particles and reduces viral infectivity in the live SARS-CoV-2 in vitro virus model. They found that low concentrations of graphene oxide in suspension reduced viral invading cells.

Graphene oxide (GO) captures the SARS-CoV-2 virus and prevents infection. (A) A schematic design of experiments is provided to assess GO’s ability to trap viruses in solution. The SARS-CoV-2 clinical isolate was suspended in phosphate buffered saline (PBS) at approximately 105 virus particles / mL, increasing the concentration of GO (0.06, 0.12, 0.25, and 0.5 mg / mL). , Or was incubated without GO (untreated). ) As a positive control. After 2 hours, GO was removed by centrifugation and the supernatant was used to infect Vero cells. Cell viability is monitored daily and 72 hours after infection, visualization of cell density by (B) light microscopy or (C) typical fluorescence microscopy of cells after immunofluorescent labeling of cells with antiviral spike (S) protein antibody. I took an image. (D) Cell viability was also assayed by crystal violet staining. ImageJ software was used to analyze (E) fluorescence and (F) crystal violet stained images to quantify infected cells and cytotoxicity, respectively. (G) Lactate dehydrogenase (LDH) was quantified in the cell supernatant and SARS-CoV-2 mediated cytotoxicity was measured. The data was graphed as the average of SD. All experiments were analyzed using one-way ANOVA followed by Tukey correction (p <0.05 = *; p <0.01 = **; p <0.001 = ***).

Virus containment and minimization Viral load Graphene oxide can be used to prevent the invasion of SARS-CoV-2 virus, which suggests potential applications in PPE kits.

This was followed by investigating the efficiency of graphene and GO functionalization in different PPE materials, both cotton and polyurethane.

The incorporation of graphene and GO into cotton and polyurethane materials during culturing of virus suspensions when cultivated directly or through filtered media significantly reduced viral infectivity, the researchers said.

Studies have also shown that graphene and GO functionalization reduces bacterial spread after comparing standard surgical mask materials with graphene-integrated materials.

After visualizing the functionalization of nanomaterials under a scanning electron microscope (SEM) with both cotton and polyurethane materials, the team considers graphene and GO to be highly relevant PPE materials. ..

Researchers have tested the ability of cells to survive and remain unchanged in the presence of graphene and GO materials. They found that graphene and GO were not toxic to cells. Since the SARS-CoV-2 virus is known to be excreted through infectious patients, GO offers future applications in wastewater plants to reduce the spread of the virus in the environment. .. The ability of graphene-functionalized materials to bind to nucleic acids and microorganisms makes it possible to identify biomarkers for the prediction of COVID-19 and the development of rapid diagnostic tools.

Face mask

For optimal protection, three layers are used in the design of the surgical face mask. The first layer is for absorbing sweat and other droplets, the second polar layer is for retaining microorganisms in the mask, and the third non-polar layer is for the fluid’s external environment. It is to prevent the escape of. Graphene is ideal for PPE materials because it is non-polar and allows fluids to be trapped in the external environment.

Scanning electron microscope (SEM) images of materials functionalized with graphene (G) and graphene oxide (GO). Cotton, cotton + G, and cotton + GO at 60X (A, B, and C, respectively), 100X (D, E, and F, respectively), and 750X (G, H, and I, respectively). A typical SEM image is shown. Similar images are PU, PU + G, and at 60X (J, K, and L, respectively), 100X (M, N, and O, respectively), and 750X (P, Q, and R, respectively). Shown about PU + GO. ).

Conclusion

Due to the widespread use of face masks during the COVID-19 pandemic, graphene-functionalized PPE materials help reduce the spread of the virus and stop the infection. Graphene functionalization of PPE materials provides a wide range for increasing the efficiency of face masks, thereby contributing to the universal mission of stopping the spread of COVID-19. Graphene and its associated nanomaterials offer great potential to help combat pandemics in many applications, from PPE kits to new strategies for sewage treatment and diagnostics.

*Important Notices

medRxiv Publish preliminary scientific reports that should not be considered definitive as they have not been peer-reviewed, guide clinical practice / health-related behaviors, and should not be treated as established information.