Inhibition of SARS-CoV-2 Alpha Variant and Murine Noroviruses on Copper-Silver Nanocomposite Surfaces.

With the continued scenario of the COVID-19 pandemic, the world is still seeking out-of-the-box solutions to break its transmission cycle and contain the pandemic. There are different transmission routes for viruses, including indirect transmission via surfaces. To this end, we used two relevant viruses in our study. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing the pandemic and human norovirus (HuNV), both known to be transmitted via surfaces. Several nanoformulations have shown attempts to inhibit SARS-CoV-2 and other viruses. However, a rigorous, similar inactivation scheme to inactivate the cords of two tedious viruses (SARS-CoV-2 Alpha variant and HuNV) is lacking. The present study demonstrates the inactivation of the SARS-CoV-2 Alpha variant and the decrease in the murine norovirus (MNV, a surrogate to HuNV) load after only one minute of contact to surfaces including copper-silver (Cu-Ag) nanocomposites. We thoroughly examined the physicochemical characteristics of such plated surfaces using diverse microscopy tools and found that Cu was the dominanting element in the tested three different surfaces (~56, ~59, and ~48 wt%, respectively), hence likely playing the major role of Alpha and MNV inactivation followed by the Ag content (~28, ~13, and ~11 wt%, respectively). These findings suggest that the administration of such surfaces within highly congested places (e.g., schools, public transportations, public toilets, and hospital and live-stock reservoirs) could break the SARS-CoV-2 and HuNV transmission. We suggest such an administration after an in-depth examination of the in vitro (especially on skin cells) and in vivo toxicity of the nanocomposite formulations and surfaces while also standardizing the physicochemical parameters, testing protocols, and animal models.

Copper-Silver Nanohybrids: SARS-CoV-2 Inhibitory Surfaces.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains a severe health threat. The COVID-19 infections occurring in humans and animals render human-animal interfaces hot spots for spreading the pandemic. Lessons from the past point towards the antiviral properties of copper formulations; however, data showing the "contact-time limit" surface inhibitory efficacy of copper formulations to contain SARS-CoV-2 are limited. Here, we show the rapid inhibition of SARS-CoV-2 after only 1 and 5 min on two different surfaces containing copper-silver (Cu-Ag) nanohybrids. We characterized the nanohybrids' powder and surfaces using a series of sophisticated microscopy tools, including transmission and scanning electron microscopes (TEM and SEM) and energy-dispersive X-ray spectroscopy (EDX). We used culturing methods to demonstrate that Cu-Ag nanohybrids with high amounts of Cu (~65 and 78 wt%) and lower amounts of Ag (~7 and 9 wt%) inhibited SARS-CoV-2 efficiently. Collectively, the present work reveals the rapid SARS-CoV-2 surface inhibition and the promising application of such surfaces to break the SARS-CoV-2 transmission chain. For example, such applications could be invaluable within a hospital or live-stock settings, or any public place with surfaces that people frequently touch (i.e., public transportation, shopping malls, elevators, and door handles) after the precise control of different parameters and toxicity evaluations.

Could Nanotheranostics be the Answer to the Coronavirus Crisis?

The COVID-19 pandemic is expanding worldwide. This pandemic associated with COVID-19 placed the spotlight on how bacterial (e.g., methicillin-resistant Staphylococcus aureus) co-infections may impact responses to coronavirus. In this review the ways in which nanoparticles can contain and rapidly diagnose COVID-19 under the umbrella of nanotheranostics (i.e., smart, single agents combining nanodiagnostics and nanotherapeutics) are elaborated. The present work provides new insights into the promising incorporation of antiviral nanotheranostics into nanostructured materials, including electrospun fibers with tailored pore sizes and hydrophobicity, namely "superhydrophobic self-disinfecting electrospun facemasks/fabrics (SSEF)." SSEFs are proposed as smart alternatives to address the drawbacks of N95 respirators. The challenges of coronavirus containment are underscored, literature is reviewed, and "top-five suggestions" for containing COVID-19 are offered, including: i) preventive appraisals-avoiding needless hospital admission and practicing frequent hand washing (from 20 to 60 s). ii) Diagnostics-highly recommending nanodiagnostics, detecting COVID-19 within 10 min. iii) Therapeutics-expanding nanotherapeutics to treat COVID-19 and bacterial co-infections after safety assessments and clinical trials. iv) Multipronged and multinational, including China, collaborative appraisals. v) Humanitarian compassion to traverse this pandemic in a united way.

COVID-19 Pandemic: What about the Safety of Anti-Coronavirus Nanoparticles?

Every day, new information is presented with respect to how to best combat the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This manuscript sheds light on such recent findings, including new co-factors (i.e., neuropilin-1) and routes (i.e., olfactory transmucosal) allowing cell entry of SARS-CoV-2 and induction of neurological symptoms, as well as the new SARS-CoV-2 variants. We highlight the SARS-CoV-2 human-animal interfaces and elaborate containment strategies using the same vaccination (i.e., nanoparticle "NP" formulations of the BNT162b2 and mRNA-1273 vaccines) for humans, minks, raccoon dogs, cats, and zoo animals. We investigate the toxicity issues of anti-CoV NPs (i.e., plasmonic NPs and quantum dots) on different levels. Namely, nano-bio interfaces (i.e., protein corona), in vitro (i.e., lung cells) and in vivo (i.e., zebrafish embryos) assessments, and impacts on humans are discussed in a narrative supported by original figures. Ultimately, we express our skeptical opinion on the comprehensive administration of such antiviral nanotheranostics, even when integrated into facemasks, because of their reported toxicities and the different NP parameters (e.g., size, shape, surface charge, and purity and chemical composition of NPs) that govern their end toxicity. We believe that more toxicity studies should be performed and be presented, clarifying the odds of the safe administration of nanotoxocological solutions and the relief of a worried public.