(July 14, 2015) North
Carolina State University researchers have developed an effective and
environmentally benign method to combat bacteria by engineering nanoscale
particles that add the antimicrobial potency of silver to a core of lignin, a
ubiquitous substance found in all plant cells. The findings introduce ideas for
better, greener and safer nanotechnology and could lead to enhanced efficiency
of antimicrobial products used in agriculture and personal care.
In a study published in Nature Nanotechnology, NC State
engineer Orlin Velev and colleagues show that silver-ion infused lignin
nanoparticles, which are coated with a charged polymer layer that helps them
adhere to the target microbes, effectively kill a broad swath of bacteria,
including E. coli and other harmful microorganisms.
As the nanoparticles wipe out the targeted bacteria, they
become depleted of silver. The remaining particles degrade easily after
disposal because of their biocompatible lignin core, limiting the risk to the
environment.
“People have been interested in using silver nanoparticles
for antimicrobial purposes, but there are lingering concerns about their
environmental impact due to the long-term effects of the used metal
nanoparticles released in the environment,” said Velev, INVISTA Professor of
Chemical and Biomolecular Engineering at NC State and the paper’s corresponding
author. “We show here an inexpensive and environmentally responsible method to
make effective antimicrobials with biomaterial cores.”