Featured Research

from universities, journals, and other organizations

Nanoparticles glow through thick layer of tissue

Date:
September 28, 2012
Source:
University at Buffalo
Summary:
Novel, biocompatible nanoparticles glow through more than 3 centimeters of biological tissue, demonstrating the promise of nanotechnology in biomedical imaging.

A transmission electron microscopy image of nanoparticles designed for deep-tissue imaging. Each particle consists of a core encased inside a square, calcium-fluoride shell.
Credit: Zhipeng Li

An international research team has created unique photoluminescent nanoparticles that shine clearly through more than 3 centimeters of biological tissue -- a depth that makes them a promising tool for deep-tissue optical bioimaging.

Though optical imaging is a robust and inexpensive technique commonly used in biomedical applications, current technologies lack the ability to look deep into tissue, the researchers said.

This creates a demand for the development of new approaches that provide high-resolution, high-contrast optical bioimaging that doctors and scientists could use to identify tumors or other anomalies deep beneath the skin.

The newly created nanoparticles consist of a nanocrystalline core containing thulium, sodium, ytterbium and fluorine, all encased inside a square, calcium-fluoride shell.

The particles are special for several reasons. First, they absorb and emit near-infrared light, with the emitted light having a much shorter wavelength than the absorbed light. This is different from how molecules in biological tissues absorb and emit light, which means that scientists can use the particles to obtain deeper, higher-contrast imaging than traditional fluorescence-based techniques.

Second, the material for the nanoparticles' shell --calcium fluoride -- is a substance found in bone and tooth mineral. This makes the particles compatible with human biology, reducing the risk of adverse effects. The shell is also found to significantly increase the photoluminescence efficiency.

To emit light, the particles employ a process called near-infrared-to-near-infrared up-conversion, or "NIR-to-NIR." Through this process, the particles absorb pairs of photons and combine these into single, higher-energy photons that are then emitted.

One reason NIR-to-NIR is ideal for optical imaging is that the particles absorb and emit light in the near-infrared region of the electromagnetic spectrum, which helps reduce background interference. This region of the spectrum is known as the "window of optical transparency" for biological tissue, since the biological tissue absorbs and scatters light the least in this range.

The scientists tested the particles in experiments that included imaging them injected in mice, and imaging a capsule full of the particles through a slice of pork more than 3 centimeters thick. In each case, the researchers were able to obtain vibrant, high-contrast images of the particles shining through tissue.

The results of the study appeared online on Aug. 28 in the ACS Nano journal. The international collaboration included researchers from the University at Buffalo and other institutions in the U.S., China, South Korea and Sweden. It was co-led by Paras N. Prasad, a SUNY Distinguished Professor and executive director of UB's Institute for Lasers, Photonics and Biophotonics (ILPB), and Gang Han, an assistant professor at University of Massachusetts Medical School.

"We expect that the unprecedented properties in the core/shell nanocrystals we designed will bridge numerous disconnections between in vitro and in vivo studies, and eventually lead to new discoveries in the fields of biology and medicine," said Han, expressing his excitement about the research findings.

Study co-author Tymish Y. Ohulchanskyy, a deputy director of ILPB, believes the 3-centimeter optical imaging depth is unprecedented for nanoparticles that provide such high-contrast visualization.

"Medical imaging is an emerging area, and optical imaging is an important technique in this area," said Ohulchanskyy. "Developing this new nanoplatform is a real step forward for deeper tissue optical bioimaging."

The paper's first authors were Guanying Chen, research assistant professor at ILPB and scientist at China's Harbin Institute of Technology and Sweden's Royal Institute of Technology and Jie Shen of the University of Massachusetts Medical School. Other institutions that contributed included Roswell Park Cancer Institute, the University of North Carolina at Chapel Hill and Korea University at Seoul.

The next step in the research is to explore ways of targeting the nanoparticles to cancer cells and other biological targets that could be imaged. Chen, Shen and Ohulchanskyy said the hope is for the nanoparticles to become a platform for multimodal bioimaging.


Story Source:

The above story is based on materials provided by University at Buffalo. Note: Materials may be edited for content and length.


Journal Reference:

  1. Guanying Chen, Jie Shen, Tymish Y. Ohulchanskyy, Nayan J. Patel, Artem Kutikov, Zhipeng Li, Jie Song, Ravindra K. Pandey, Hans Εgren, Paras N. Prasad, Gang Han. (α-NaYbF4:Tm3 )/CaF2Core/Shell Nanoparticles with Efficient Near-Infrared to Near-Infrared Upconversion for High-Contrast Deep Tissue Bioimaging. ACS Nano, 2012; 6 (9): 8280 DOI: 10.1021/nn302972r

Cite This Page:

University at Buffalo. "Nanoparticles glow through thick layer of tissue." ScienceDaily. ScienceDaily, 28 September 2012. <www.sciencedaily.com/releases/2012/09/120928125103.htm>.
University at Buffalo. (2012, September 28). Nanoparticles glow through thick layer of tissue. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2012/09/120928125103.htm
University at Buffalo. "Nanoparticles glow through thick layer of tissue." ScienceDaily. www.sciencedaily.com/releases/2012/09/120928125103.htm (accessed October 20, 2014).

Share This



More Matter & Energy News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Robotic Eyes' Helps Japan's Bipedal Bot Run Faster

'Robotic Eyes' Helps Japan's Bipedal Bot Run Faster

Reuters - Innovations Video Online (Oct. 16, 2014) — Japanese researcher uses an eye-sensor camera to enable a bipedal robot to balance itself, while running on a treadmill. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
Lockheed Martin's Fusion Concept Basically An Advertisement

Lockheed Martin's Fusion Concept Basically An Advertisement

Newsy (Oct. 15, 2014) — Lockheed Martin announced plans to develop the first-ever compact nuclear fusion reactor. But some experts said the excitement is a little premature. Video provided by Newsy
Powered by NewsLook.com
First Confirmed Case Of Google Glass Addiction

First Confirmed Case Of Google Glass Addiction

Buzz60 (Oct. 15, 2014) — A Google Glass user was treated for Internet Addiction Disorder caused from overuse of the device. Morgan Manousos (@MorganManousos) has the details on how many hours he spent wearing the glasses, and what his symptoms were. Video provided by Buzz60
Powered by NewsLook.com
Science Proves Why Pizza Is So Delicious

Science Proves Why Pizza Is So Delicious

Buzz60 (Oct. 15, 2014) — The American Chemical Society’s latest video about chemistry in every day life breaks down pizza, and explains exactly why it's so delicious. Gillian Pensavalle (@GillianWithaG) has the video. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins