Nanotechnology in the COVID-19 era: Carbon-based nanomaterials as a promising solution.

The Coronavirus Disease 2019 (COVID-19) pandemic has led to collaboration between nanotechnology scientists, industry stakeholders, and clinicians to develop solutions for diagnostics, prevention, and treatment of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections. Nanomaterials, including carbon-based materials (CBM) such as graphene and carbon nanotubes, have been studied for their potential in viral research. CBM unique effects on microorganisms, immune interaction, and sensitivity in diagnostics have made them a promising subject of SARS-CoV-2 research. This review discusses the interaction of CBM with SARS-CoV-2 and their applicability, including CBM physical and chemical properties, the known interactions between CBM and viral components, and the proposed prevention, treatment, and diagnostics uses.

Evaluation of Novel Guanidino-Containing Isonipecotamide Inhibitors of Blood Coagulation Factors against SARS-CoV-2 Virus Infection.

Coagulation factor Xa (fXa) and thrombin (thr) are widely expressed in pulmonary tissues, where they may catalyze, together with the transmembrane serine protease 2 (TMPRSS2), the coronaviruses spike protein (SP) cleavage and activation, thus enhancing the SP binding to ACE2 and cell infection. In this study, we evaluate in vitro the ability of approved (i.e., dabigatran and rivaroxaban) and newly synthesized isonipecotamide-based reversible inhibitors of fXa/thr (cmpds 1-3) to hinder the SARS-CoV-2 infectivity of VERO cells. Nafamostat, which is a guanidine/amidine antithrombin and antiplasmin agent, disclosed as a covalent inhibitor of TMPRSS2, was also evaluated. While dabigatran and rivaroxaban at 100 µM concentration did not show any effect on SARS-CoV-2 infection, the virus preincubation with new guanidino-containing fXa-selective inhibitors 1 and 3 did decrease viral infectivity of VERO cells at subtoxic doses. When the cells were pre-incubated with 3, a reversible nanomolar inhibitor of fXa (Ki = 15 nM) showing the best in silico docking score toward TMPRSS2 (pdb 7MEQ), the SARS-CoV-2 infectivity was completely inhibited at 100 µM (p < 0.0001), where the cytopathic effect was just about 10%. The inhibitory effects of 3 on SARS-CoV-2 infection was evident (ca. 30%) at lower concentrations (3-50 µM). The covalent TMPRSS2 and the selective inhibitor nafamostat mesylate, although showing some effect (15-20% inhibition), did not achieve statistically significant activity against SARS-CoV-2 infection in the whole range of test concentrations (3-100 µM). These findings suggest that direct inhibitors of the main serine proteases of the blood coagulation cascade may have potential in SARS-CoV-2 drug discovery. Furthermore, they prove that basic amidino-containing fXa inhibitors with a higher docking score towards TMPRSS2 may be considered hits for optimizing novel small molecules protecting guest cells from SARS-CoV-2 infection.

3D-printed graphene polylactic acid devices resistant to SARS-CoV-2: Sunlight-mediated sterilization of additive manufactured objects.

Additive manufacturing has played a crucial role in the COVID-19 global emergency allowing for rapid production of medical devices, indispensable tools for hospitals, or personal protection equipment. However, medical devices, especially in nosocomial environments, represent high touch surfaces prone to viral infection and currently used filaments for 3D printing can't inhibit transmission of virus [1]. Graphene-family materials are capable of reinforcing mechanical, optical and thermal properties of 3D printed constructs. In particular, graphene can adsorb near-infrared light with high efficiency. Here we demonstrate that the addition of graphene nanoplatelets to PLA filaments (PLA-G) allows the creation of 3D-printed devices that can be sterilized by near-infrared light exposure at power density analog to sunlight. This method has been used to kill SARS-CoV-2 viral particles on the surface of 3D printed PLA-G by 3 min of exposure. 3D-printed PLA-G is highly biocompatible and can represent the ideal material for the production of sterilizable personal protective equipment and daily life objects intended for multiple users.

Principles for optimization and validation of mRNA lipid nanoparticle vaccines against COVID-19 using 3D bioprinting.

BioNTech/Pfizer's Comirnaty and Moderna's SpikeVax vaccines consist in mRNA encapsulated in lipid nanoparticles (LNPs). The modularity of the delivery platform and the manufacturing possibilities provided by microfluidics let them look like an instant success, but they are the product of decades of intense research. There is a multitude of considerations to be made when designing an optimal mRNA-LNPs vaccine. Herein, we provide a brief overview of what is presently known and what still requires investigation to optimize mRNA LNPs vaccines. Lastly, we give our perspective on the engineering of 3D bioprinted validation systems that will allow faster, cheaper, and more predictive vaccine testing in the future compared with animal models.

Graphene nanoplatelet and graphene oxide functionalization of face mask materials inhibits infectivity of trapped SARS-CoV-2.

Recent advancements in bidimensional nanoparticles production such as graphene (G) and graphene oxide (GO) have the potential to meet the need for highly functional personal protective equipment (PPE) against SARS-CoV-2 infection. The ability of G and GO to interact with microorganisms provides an opportunity to develop engineered textiles for use in PPE and limit the spread of COVID-19. PPE in current use in high-risk settings for COVID transmission provides only a physical barrier that decreases infection likelihood and does not inactivate the virus. Here, we show that virus pre-incubation with soluble GO inhibits SARS-CoV-2 infection of VERO cells. Furthermore, when G/GO-functionalized polyurethane or cotton was in contact SARS-CoV-2, the infectivity of the fabric was nearly completely inhibited. The findings presented here constitute an important innovative nanomaterial-based strategy to significantly increase PPE efficacy in protection against the SARS-CoV-2 virus that may implement water filtration, air purification, and diagnostics methods.

Face masks and nanotechnology: Keep the blue side up.

Coronavirus Disease 2019 (COVID-19) is one of the biggest challenges of the 21st century. While researchers are working on vaccine development and elucidating the mechanism of action and evolution of the harmful SARS-CoV-2, the current most important public health measure, second only to social distancing, is the obligatory wearing of facial protection. The Centers for Disease Control and Prevention recommended in April 2020 that the public wear face coverings in areas with high rates of transmission based on epidemiological evidence on the strong relationship between mask wearing and pandemic control. This protection against SARS-CoV-2 and other airborne pathogens, boost the design and production of innovative solutions by industry stakeholders. Nanoparticles, nanofibers, and other pioneering technologies based on nanomaterials have been introduced in mask production chains to improve performance and confer antiviral properties. During an emergency like COVID-19, these products directly available to the public should be carefully analyzed in terms of efficacy and possible long-term effects on the wearers' skin and lungs as well as on the environment. This opinion paper provides a wealth of information on the role of nanotechnologies in improving the performance of facial masks and on possible future consequences caused by a poorly regulated use of nanotechnology in textiles.