Ability of Essential Oil Vapours to Reduce Numbers of Culturable Aerosolised Coronavirus, Bacteria and Fungi

Antiviral Natural Products, Their Mechanisms of Action and Potential Applications as Sanitizers and Disinfectants

Plant extracts, natural products and plant oils contain natural virucidal actives that can be used to replace active ingredients in commercial sanitizers and disinfectants. This review focuses on the virucidal mechanisms of natural substances that may exhibit potential for indoor air and fomite disinfection. Review of scientific studies indicates: (1) most natural product studies use crude extracts and do not isolate or identify exact active antiviral substances; (2) many natural product studies contain unclear explanations of virucidal mechanisms of action; (3) natural product evaluations of virucidal activity should include methods that validate efficacy under standardized disinfectant testing procedures (e.g., carrier tests on applicable surfaces or activity against aerosolized viruses, etc.). The development of natural product disinfectants requires a better understanding of the mechanisms of action (MOA), chemical profiles, compound specificities, activity spectra, and the chemical formulations required for maximum activity. Combinations of natural antiviral substances and possibly the addition of synthetic compounds might be needed to increase inactivation of a broader spectrum of viruses, thereby providing the required efficacy for surface and air disinfection.

Development of corneal contact lens materials and current clinical application of contact lenses: A review

Unlike conventional glasses, corneal contact lenses (CLs) can directly contact the surface of the tear film through the application of biopolymer materials, to achieve therapeutic and cosmetic purposes. Since the advent of polymethylmethacrylate, a material that has gained widespread use and attention, statistically, there are now more than 150 × 106 people around the world who wear corneal contact lenses. However, the associated complications caused by the interaction of contact lenses with the ocular surface, tear film, endogenous and environmental microorganisms, and components of the solution affect nearly one-third of the wearer population. The application of corneal contact lenses in correcting vision and myopia control has been widely recognized. With the development of related materials, corneal contact lenses are applied to the treatment of ocular surface diseases, including corneal bandage lenses, drug-loaded corneal contact lenses, biosensors, and other new products, while minimizing the side effects associated with CL wear. This paper summarized the development history and material properties of CLs, focused on the current main clinical applications and mechanisms, as well as clarified the possible complications in wearing therapeutic contact lenses and the direction for improvement in the future.

Mechanisms, Techniques and Devices of Airborne Virus Detection: A Review

Airborne viruses, such as COVID-19, cause pandemics all over the world. Virus-containing particles produced by infected individuals are suspended in the air for extended periods, actually resulting in viral aerosols and the spread of infectious diseases. Aerosol collection and detection devices are essential for limiting the spread of airborne virus diseases. This review provides an overview of the primary mechanisms and enhancement techniques for collecting and detecting airborne viruses. Indoor virus detection strategies for scenarios with varying ventilations are also summarized based on the excellent performance of existing advanced comprehensive devices. This review provides guidance for the development of future aerosol detection devices and aids in the control of airborne transmission diseases, such as COVID-19, influenza and other airborne transmission viruses.

Antifungal activity and mechanism of action of natural product derivates as potential environmental disinfectants

There have been a considerable number of antifungal studies that evaluated natural products (NPs), such as medicinal plants and their secondary metabolites, (phenolic compounds, alkaloids), essential oils, and propolis extracts. These studies have investigated natural antifungal substances for use as food preservatives, medicinal agents, or in agriculture as green pesticides because they represent an option of safe, low-impact, and environmentally friendly antifungal compounds; however, few have studied these NPs as an alternative to disinfection/sanitation for indoor air or environmental surfaces. This review summarizes recent studies on NPs as potential fungal disinfectants in different environments and provides information on the mechanisms of inactivation of these products by fungi. The explored mechanisms show that these NPs can interfere with ATP synthesis and Ca++ and K+ ion flow, mainly damaging the cell membrane and cell wall of fungi, respectively. Another mechanism is the reactive oxygen species effect that damages mitochondria and membranes. Inhibition of the overexpression of the efflux pump is another mechanism that involves damage to fungal proteins. Many NPs appear to have potential as indoor environmental disinfectants.

ONE-SENTENCE SUMMARY

This review shows the latest advances in natural antifungals applied to different indoor environments. Fungi have generated increased tolerance to the mechanisms of traditional antifungals, so this review also explores the various mechanisms of action of various natural products to facilitate the implementation of technology.