Brian Wang | January 29, 2020
Nanosafety researchers at the Harvard T.H. Chan School of Public Health have developed a new intervention to fight infectious disease by more effectively disinfecting the air around us, our food, our hands, and whatever else harbors the microbes that make us sick.
They used a nano-enabled platform developed at the center to create and deliver tiny, aerosolized water nonodroplets containing non-toxic, nature-inspired disinfectants wherever desired.
ACS Sustainable Chem. Eng – Inactivation of Hand Hygiene-Related Pathogens Using Engineered Water Nanostructures
They take water and turn it into an engineered water nanoparticle, which carries its deadly payload, primarily nontoxic, nature-inspired antimicrobials, and kills microorganisms on surfaces and in the air.
You need 12 volts DC, and it is combined with electrospray and ionization to turn water into a nanoaerosol, in which these engineered nanostructures are suspended in the air. These water nanoparticles have unique properties because of their small size and also contain reactive oxygen species. These are hydroxyl radicals, peroxides, and are similar to what nature uses in cells to kill pathogens. These nanoparticles, by design, also carry an electric charge, which increases surface energy and reduces evaporation. That means these engineered nanostructures can remain suspended in air for hours. When the charge dissipates, they become water vapor and disappear.
They place nature-inspired antimicrobials into the engineered water nanostructures, their antimicrobial potency increases dramatically. But they do not use huge quantities of antimicrobials. They use about 1 percent or 2 percent by volume. Most of the engineered water nanostructure is still water.
Flu and tuberculosis are airborne diseases, respiratory diseases, which cause millions of deaths a year. Foodborne diseases also kill 500,000 people annually and cost our economy billions of dollars.
Hand hygiene is a critical public health issue associated with disease transmission worldwide. Here, a nanotechnology-based approach has been employed to enhance hand hygiene using engineered water nanostructures (EWNS) synthesized by electrospray and ionization of antimicrobial aqueous solutions. The EWNS possess unique properties: have a tunable size in the nanoscale, are electrically charged, which results in a lifespan of hours in room conditions, and can carry both antimicrobial agents and reactive oxygen species (ROS) from ionization of water. More importantly, EWNS are highly mobile, can be directed toward a surface of interest utilizing their electric charge, and can inactivate pathogens by delivering active ingredients (AIs) and ROS. In this study, a variety of AIs commonly used for hand sanitization and food safety, such as hydrogen peroxide, citric acid, lysozyme, and nisin, were utilized to synthesize various EWNS-based nanosanitizers and inactivate hand hygiene-related pathogens. A 0.5 min exposure to various EWNS-based nanosanitizers reduced Escherichia coli, Staphylococcus aureus, and bacteriophage MS2 by ∼3, 1, and 2 log, respectively. More importantly, such an aerosol-based nanocarrier platform, because of its targeted delivery manner, utilizes only nanograms of “nature-inspired” antimicrobials and leaves behind no chemical byproducts, making it an efficient approach for hand sanitization.