A novel nanoparticle spray coating process has been shown to all but eliminate the growth of some of the world’s most dangerous bacteria in air filtration systems, significantly reducing the risk of airborne bacterial and viral infections.

That’s the principal finding of a study, led by researchers from IMDEA Materials Institute in collaboration with scientists from the Networking Biomedical Research Center in Respiratory Diseases (CIBERES) and Rey Juan Carlos University (URJC) in Madrid, Spain. The study was published in Materials Chemistry and Physics.

The study, “Control of microbial agents by functionalization of commercial air filters with metal oxide particles,” tested various spray coatings of silver (Ag₂O), copper (CuO) and zinc (ZnO) oxides as low-cost antiviral and antibacterial filters when applied to commercially available air filtration systems.

The humble membranes that enclose our cells have a surprising superpower: They can push away nano-sized molecules that happen to approach them. A team including scientists at the National Institute of Standards and Technology (NIST) has figured out why, by using artificial membranes that mimic the behavior of natural ones. Their discovery could make a difference in how we design the many drug treatments that target our cells.

The team’s findings, which appear in the Journal of the American Chemical Society, confirm that the powerful electrical fields that cell membranes generate are largely responsible for repelling nanoscale particles from the surface of the cell.

This repulsion notably affects neutral, uncharged nanoparticles, in part because the smaller, charged molecules the electric field attracts crowd the membrane and push away the larger particles. Since many drug treatments are built around proteins and other nanoscale particles that target the membrane, the repulsion could play a role in the treatments’ effectiveness.