The Rise of Electroactive Materials in Face Masks for Preventing Virus Infections

Electroactive nanofibrous membrane with antibacterial and deodorizing properties for air filtration

Water vapor from respiration can severely accelerate the charge dissipation of the face mask, reducing filtration efficiency. Moreover, the foul odor from prolonged mask wear tends to make people remove their masks, leading to the risk of infection. In this study, an electro-blown spinning electroactive nanofibrous membrane (Zn/CB@PAN) with antibacterial and deodorization properties was prepared by adding zinc (Zn) and carbon black (CB) nanoparticles to the polyacrylonitrile (PAN) nanofibers, respectively. The filtration efficiency of Zn/CB@PAN for PM0.3 was > 99% and could still maintain excellent durability within 4 h in a high-humidity environment (25 ℃ and RH = 95%). Moreover, the bacterial interception rate of the Zn/CB@PAN could reach 99.99%, and it can kill intercepted bacteria. In addition, the deodorization rate of Zn/CB@PAN in the moist state for acetic acid was 93.75% and ammonia was 95.23%, respectively. The excellent filtering, antibacterial, and deodorizing performance of Zn/CB@PAN can be attributed to the synergistic effect of breath-induced Zn/CB galvanic couples' electroactivity, released metal ions, and generated reactive oxygen species. The developed Zn/CB@PAN could capture and kill airborne environmental pathogens under humid environments and deodorize odors from prolonged wear, holding promise for broad applications as personal protective masks.

Changes in total charge on spike protein of SARS-CoV-2 in emerging lineages

Motivation

Charged amino acid residues on the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been shown to influence its binding to different cell surface receptors, its non-specific electrostatic interactions with the environment, and its structural stability and conformation. It is therefore important to obtain a good understanding of amino acid mutations that affect the total charge on the spike protein which have arisen across different SARS-CoV-2 lineages during the course of the virus' evolution.

Results

We analyse the change in the number of ionizable amino acids and the corresponding total charge on the spike proteins of almost 2200 SARS-CoV-2 lineages that have emerged over the span of the pandemic. Our results show that the previously observed trend toward an increase in the positive charge on the spike protein of SARS-CoV-2 variants of concern has essentially stopped with the emergence of the early omicron variants. Furthermore, recently emerged lineages show a greater diversity in terms of their composition of ionizable amino acids. We also demonstrate that the patterns of change in the number of ionizable amino acids on the spike protein are characteristic of related lineages within the broader clade division of the SARS-CoV-2 phylogenetic tree. Due to the ubiquity of electrostatic interactions in the biological environment, our findings are relevant for a broad range of studies dealing with the structural stability of SARS-CoV-2 and its interactions with the environment.

Availability and implementation

The data underlying the article are available in the Supplementary material.

Modulating SARS-CoV-2 Spike Protein Reactivity through Moderate Electric Fields: A Pathway to Innovative Therapies

In the quest for effective COVID-19 treatments and vaccines, traditional biochemical methods have been paramount, yet the challenge of accommodating diverse viral mutants persists. Recent simulations propose an innovative physical strategy involving an external electric field applied to the SARS-CoV-2 spike protein, demonstrating a reduced viral binding potential. However, limited empirical knowledge exists regarding the characteristics of the spike protein after E-field treatment. Our study addresses this gap by employing diverse analytical techniques to elucidate the impact of low/moderate E-field intensity on the binding of the SARS-CoV-2 spike protein to the ACE2 receptor. Through comprehensive analysis, we unveil a substantial reduction in the spike protein binding capacity validated via enzyme-linked immunosorbent assay and quartz crystal microbalance experiments. Remarkably, the E-field exposure induces significant protein structure rearrangement, leading to an enhanced negative surface zeta potential confirmed by dynamic light scattering. Circular dichroism spectroscopy corroborates these structural changes, showing alterations in the secondary protein structures. This study provides insights into SARS-CoV-2 spike protein modification under an E-field pulse, potentially paving the way for nonbiochemical strategies to mitigate viral reactivity and opening avenues for innovative therapeutic and preventive approaches against COVID-19 and its evolving variants.