Volume 89 Issue 51 | p. 14
Issue Date: December 19, 2011

Cover Stories: Chemical Year In Review 2011

Nanomaterials In The Food Chain

As the tiny particles transfer to higher organisms in the food web, they increase in concentration, studies showed
Department: Science & Technology
Keywords: nanomaterials, food chain transfer, nanotechnology safety, biomagnification, bioaccumulation, environmental science
[+]Enlarge
A hornworm caterpillar feeds on tobacco leaves containing gold nanoparticles; in the inset, a cross-sectional X-ray fluorescence map shows the nanoparticles (yellow and orange) collected around the caterpillar’s gut.
Credit: Courtesy of Paul Bertsch & Jonathan Judy
This micrograph shows nanoparticles in a caterpillar's gut as a result of consuming tobacco leaves.
 
A hornworm caterpillar feeds on tobacco leaves containing gold nanoparticles; in the inset, a cross-sectional X-ray fluorescence map shows the nanoparticles (yellow and orange) collected around the caterpillar’s gut.
Credit: Courtesy of Paul Bertsch & Jonathan Judy
[+]Enlarge
The large, filled food vacuoles (arrow) indicate that the protozoa in these optical micrographs have more trouble digesting bacterial meals cultured with quantum dots (right) than those cultured without them (left).
Credit: Nat. Nanotechnol.
These vacuoles show how protozoa have trouble digesting bacterial meals with quantum dots
 
The large, filled food vacuoles (arrow) indicate that the protozoa in these optical micrographs have more trouble digesting bacterial meals cultured with quantum dots (right) than those cultured without them (left).
Credit: Nat. Nanotechnol.

Nanoparticles show tremendous promise for drug delivery, and they are already being used as functional materials in consumer products such as paint and cosmetics. But scientists demonstrated this year that the tiny materials warrant additional scrutiny as they’ve begun to swirl down drains and otherwise end up in the environment. Studies showed that not only do some nanoparticles transfer from organism to organism in the food chain but that they also increase in concentration, or biomagnify, as they transfer (C&EN, March 14, page 44). “As nanotechnology marches on,” said Paul M. Bertsch of the University of Kentucky, “researchers need to get in front of potential environmental implications so there’s not a big public backlash.” Bertsch’s group showed that a tobacco plant grown in a solution containing gold nanoparticles accumulated the tiny materials in its leaves and then imparted them to feeding caterpillars (Environ. Sci. Technol., DOI: 10.1021/es103031a). Researchers led by Patricia A. Holden of the University of California, Santa Barbara, observed the transfer of cadmium selenide quantum dots from Pseudomonas aerugi­nosa bacteria to predator protozoa (Nat. Nanotechnol., DOI: 10.1038/nnano.2010.251). The innards of both the caterpillars and the protozoa contained a higher concentration of the nanomaterials than those of the organisms they ingested. Bertsch cautioned against judging nanoparticle safety from his team’s results but added that understanding bioavailability will help scientists design safer materials.

 
Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society

Leave A Comment

*Required to comment