Sticky nanopollen particles pack an antibacterial punch

Supersticky nanoparticles that mimic the shape of pollen grains can deliver lysozyme—a protein found in tears and saliva—directly to bacteria in lab tests, boosting the protein’s antibacterial potency (J. Am. Chem. Soc. 2016, DOI: 10.1021/jacs.6b00243). To make the particles, Chengzhong Yu of the University of Queensland and colleagues first created a polymer core and then coated it with a layer of silica mixed with the same polymer. Burning away the polymer left a hollow silica particle with a spiky, negatively charged surface to which the positively charged lysozyme molecules could stick. When naked spiky particles were incubated with Escherichia coli bacteria, almost 10 times as many adhered to the bacteria as smooth silica nanoparticles. Then when loaded with lysozyme, the spiky nanopollen particles completely inhibited bacterial activity for three days in culture, whereas smooth particles or free-floating lysozyme failed to fully inhibit bacterial growth. Yu’s team plans to test the lysozyme-loaded particles in place of antibiotics in animal feed as a way to combat the problem of antibiotic overuse in factory farming.