Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Tiny, brightly shining silicon crystals could be safe for deep-tissue imaging: In a new study, the crystals had no toxic effects in non-human primates

Bright light emission from silicon quantum dots in a cuvette. The image is from a camera that captures the near-infrared light that the quantum dots emit. The light emission shown is a psuedo color, as near-infrared light does not fall in the visible spectrum. Credit: Folarin Erogbogbo
Bright light emission from silicon quantum dots in a cuvette. The image is from a camera that captures the near-infrared light that the quantum dots emit. The light emission shown is a psuedo color, as near-infrared light does not fall in the visible spectrum.

Credit: Folarin Erogbogbo

Abstract:
Tiny silicon crystals caused no health problems in monkeys three months after large doses were injected, marking a step forward in the quest to bring such materials into clinics as biomedical imaging agents, according to a new study.

Tiny, brightly shining silicon crystals could be safe for deep-tissue imaging: In a new study, the crystals had no toxic effects in non-human primates

Buffalo, NY | Posted on July 31st, 2013

The findings, published online July 10 in the journal ACS Nano, suggest that the silicon nanocrystals, known as quantum dots, may be a safe tool for diagnostic imaging in humans. The nanocrystals absorb and emit light in the near-infrared part of the spectrum, a quality that makes them ideal for seeing deeper into tissue than traditional fluorescence-based techniques.

"Quantum dots, or nanocrystals, are very, very promising for biomedical imaging applications, but everyone's worried about the toxicity and what will happen to them if they degrade," said co-lead author Folarin Erogbogbo, PhD, a University at Buffalo research assistant professor who has since accepted a new position as an assistant professor of biomedical engineering at San Jose State University. "Silicon nanocrystals can be the solution to that because they don't contain materials like cadmium that are found in other quantum dots, and are generally considered to be nontoxic."

The study was a collaboration between UB, Chinese PLA General Hospital in China, San Jose State University, Nanyang Technological University in Singapore and Korea University in South Korea. It's part of a larger body of research that many of the team members have been conducting to investigate the effect of various nanoparticles in animal models.

The researchers tested the silicon quantum dots in rhesus macaques and mice, injecting each animal with 200 milligrams of the particles per kilogram of the animal's weight.

Blood tests taken for three months afterward showed no signs of toxicity in either the mice or monkeys, and all of the animals appeared healthy over the course of the study. The subjects ate, drank, groomed, explored and urinated normally.

The silicon crystals did, however, gather and stay in the livers and spleens of the mice, resulting in side effects including inflammation and spotty death of liver cells.

Interestingly, the same thing did not happen with the rhesus macaques: The monkeys' organs appeared normal, without the damage seen in the mice.

This discrepancy raises the question of how useful toxicity studies on mice can be in determining a nanocrystal's potential effect on humans, said co-author Paras Prasad, PhD, SUNY Distinguished Professor in chemistry, physics, electrical engineering and medicine at UB, and executive director of UB's Institute for Lasers, Photonics and Biophotonics.

Quantum dots and other nanoparticles — because of their tiny size — can access parts of the body where larger particles just can't go. Due to this and other factors, the differences in anatomic scale between mice and primates may matter more in nanomedicine than in other pharmaceutical fields, Prasad said.

"Even at high doses, we didn't see any adverse side effects at all in monkeys despite the problems in mice," Prasad said. "This is the first test of these silicon quantum dots in primates, and the research results mark a step forward toward potential clinical applications."

The fact that the silicon did not biodegrade in the mice was very surprising, said co-author Mark Swihart, PhD, a UB professor of chemical and biological engineer and co-director of UB's New York State Center of Excellence in Materials Informatics.

"Generally, people assume that silicon quantum dots will biodegrade," Swihart said. "We didn't see that happen, and we think this might be due to the fact that we capped the surface with organic, FDA-approved molecules to keep the quantum dots from degrading too fast.

"We may have done too good of a job of protecting them," Swihart continued. "If you really kept your car beautifully waxed all the time, it would never rust. That's what we've done with these quantum dots."

####

For more information, please click here

Contacts:
Charlotte Hsu
Media Relations Manager
Architecture, Economic Development
Sciences, Urban and Regional Planning

716-645-4655
Twitter: @UBScience
Pinterest: UB Science

Copyright © University at Buffalo

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Download article:

Related News Press

News and information

Simple attraction: Researchers control protein release from nanoparticles without encapsulation: U of T Engineering discovery stands to improve reliability and fabrication process for treatments to conditions such as spinal cord damage and stroke May 28th, 2016

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Doubling down on Schrödinger's cat May 27th, 2016

Deep Space Industries and SFL selected to provide satellites for HawkEye 360’s Pathfinder mission: The privately-funded space-based global wireless signal monitoring system will be developed by Deep Space Industries and UTIAS Space Flight Laboratory May 26th, 2016

The next generation of carbon monoxide nanosensors May 26th, 2016

Imaging

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Discoveries

Simple attraction: Researchers control protein release from nanoparticles without encapsulation: U of T Engineering discovery stands to improve reliability and fabrication process for treatments to conditions such as spinal cord damage and stroke May 28th, 2016

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Doubling down on Schrödinger's cat May 27th, 2016

Finding a new formula for concrete: Researchers look to bones and shells as blueprints for stronger, more durable concrete May 26th, 2016

Announcements

Simple attraction: Researchers control protein release from nanoparticles without encapsulation: U of T Engineering discovery stands to improve reliability and fabrication process for treatments to conditions such as spinal cord damage and stroke May 28th, 2016

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Doubling down on Schrödinger's cat May 27th, 2016

Deep Space Industries and SFL selected to provide satellites for HawkEye 360’s Pathfinder mission: The privately-funded space-based global wireless signal monitoring system will be developed by Deep Space Industries and UTIAS Space Flight Laboratory May 26th, 2016

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Simple attraction: Researchers control protein release from nanoparticles without encapsulation: U of T Engineering discovery stands to improve reliability and fabrication process for treatments to conditions such as spinal cord damage and stroke May 28th, 2016

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Doubling down on Schrödinger's cat May 27th, 2016

Finding a new formula for concrete: Researchers look to bones and shells as blueprints for stronger, more durable concrete May 26th, 2016

Safety-Nanoparticles/Risk management

PETA science group publishes a review on pulmonary effects of nanomaterials: Archives of Toxicology publishes a review of scientific studies on fibrotic potential of nanomaterials May 26th, 2016

Common nanoparticle has subtle effects on oxidative stress genes May 11th, 2016

Non-animal approach to predict impact of nanomaterials on human lung published Archives of Toxicology publishes workshop recommendations May 2nd, 2016

Scientists propose non-animal tools for assessing the toxicity of nanomaterials: Particle and Fibre Toxicology publishes recommendations from expert group meeting April 26th, 2016

Quantum Dots/Rods

Supercrystals with new architecture can enhance drug synthesis May 24th, 2016

ORNL demonstrates large-scale technique to produce quantum dots May 21st, 2016

First single-enzyme method to produce quantum dots revealed: Biological manufacturing process, pioneered by three Lehigh University engineers, produces equivalent quantum dots to those made chemically--but in a much greener, cheaper way May 9th, 2016

Superfast light source made from artificial atom April 28th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic