Featured Research

from universities, journals, and other organizations

Bioimaging: Aim for the stars

Date:
October 25, 2012
Source:
The Agency for Science, Technology and Research (A*STAR)
Summary:
Glucose–amine rings turn star-shaped fluorescent dyes into powerful probes for imaging cancer cells in three dimensions.

A new fluorescent glucose-amine probe can make identification of cancer cells (green) using two-photon microscopy easier and safer.
Credit: © 2012 Guan Wang

Glucose-amine rings turn star-shaped fluorescent dyes into powerful probes for imaging cancer cells in three dimensions.Early detection of soft-tissue diseases, such as breast cancer, typically requires invasive biopsies. Now, a new self-assembled nanoparticle developed by Bin Liu at the A*STAR Institute of Materials Research and Engineering and co-workers may soon make biopsies obsolete. The team's material significantly enhances the safety of two-photon microscopy (TPM) -- a technique that uses fluorescent probes to generate three-dimensional pictures of cancer cell structures in living tissue.

Although TPM provides deep access to cell tissue without significant photo-damage, finding suitable substances to act as light-emitting probes is challenging. 'Quantum dots' made from nanoscale aggregates of elements such as cadmium and selenium are excellent cell-structure illuminators, thanks to their bright and stable fluorescence. However, their inherent toxicity restricts many possible biological applications.

Liu and her team therefore turned to conjugated organic molecules to produce less toxic dyes for TPM. While such small organic molecules are normally unable to absorb sufficient amounts of laser light to initiate fluorescence imaging, the team resolved this problem by synthesizing a star-shaped material known as a dendrimer. Consisting of a central triphenyl amine core and three 'arms' made from extended conjugated chains, this unique geometry can induce much larger cross sections that can absorb two-photons better than isolated fluorescent dyes.

To ensure biocompatibility between the star-shaped dendrimer and cell tissue, the researchers had to employ a chemical trick. Inspired by the versatile binding behavior of chitosan, a natural polysaccharide, the team used a mild bromide-thiol reaction to attach several glucose-amine sugar rings to the dendrimer's arms. According to Liu, this process lowered the cytotoxicity of the dye and enabled them to functionalize it with folic acid ligands that target the surfaces of a breast cancer cell line known as MCF-7.

The team's experiments showed that the dendritic dye self-assembled into dispersed nanoparticles when submerged in water -- a form that increases two-photon-absorption cross sections and provides a high yield of laser-induced fluorescence. When they incubated these nanoparticles into the MCF-7 cells, subsequent TPM imaging revealed a bright fluorescence localized inside the cancer cell cytoplasma (see image). This data indicates that specific binding occurs between the dendritic dye and folate receptors on the MCF-7 surface.

Cell viabilities close to 100% at dye concentrations used for imaging studies confirms that this strategy is a safe and promising way to increase the use of TPM imaging. "We are keen to expand the current in vitro imaging to in vivo applications," notes Liu.

The A*STAR-affiliated researchers contributing to this research are from the Institute of Materials Research and Engineering.


Story Source:

The above story is based on materials provided by The Agency for Science, Technology and Research (A*STAR). Note: Materials may be edited for content and length.


Journal Reference:

  1. Guan Wang, Xinhai Zhang, Junlong Geng, Kai Li, Dan Ding, Kan-Yi Pu, Liping Cai, Yee-Hing Lai, Bin Liu. Glycosylated Star-Shaped Conjugated Oligomers for Targeted Two-Photon Fluorescence Imaging. Chemistry - A European Journal, 2012; 18 (31): 9705 DOI: 10.1002/chem.201200849

Cite This Page:

The Agency for Science, Technology and Research (A*STAR). "Bioimaging: Aim for the stars." ScienceDaily. ScienceDaily, 25 October 2012. <www.sciencedaily.com/releases/2012/10/121025160856.htm>.
The Agency for Science, Technology and Research (A*STAR). (2012, October 25). Bioimaging: Aim for the stars. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2012/10/121025160856.htm
The Agency for Science, Technology and Research (A*STAR). "Bioimaging: Aim for the stars." ScienceDaily. www.sciencedaily.com/releases/2012/10/121025160856.htm (accessed October 23, 2014).

Share This



More Matter & Energy News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

3D Printed Instruments Make Sweet Music in Sweden

3D Printed Instruments Make Sweet Music in Sweden

Reuters - Innovations Video Online (Oct. 23, 2014) — Students from Lund University's Malmo Academy of Music are believed to be the world's first band to all use 3D printed instruments. The guitar, bass guitar, keyboard and drums were built by Olaf Diegel, professor of product development, who says 3D printing allows musicians to design an instrument to their exact specifications. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Chameleon Camouflage to Give Tanks Cloaking Capabilities

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Reuters - Innovations Video Online (Oct. 22, 2014) — Inspired by the way a chameleon changes its colour to disguise itself; scientists in Poland want to replace traditional camouflage paint with thousands of electrochromic plates that will continuously change colour to blend with its surroundings. The first PL-01 concept tank prototype will be tested within a few years, with scientists predicting that a similar technology could even be woven into the fabric of a soldiers' clothing making them virtually invisible to the naked eye. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Jet Sales Lift Boeing Profit 18 Pct.

Jet Sales Lift Boeing Profit 18 Pct.

Reuters - Business Video Online (Oct. 22, 2014) — Strong jet demand has pushed Boeing to raise its profit forecast for the third time, but analysts were disappointed by its small cash flow. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Internet of Things Aims to Smarten Your Life

Internet of Things Aims to Smarten Your Life

AP (Oct. 22, 2014) — As more and more Bluetooth-enabled devices are reaching consumers, developers are busy connecting them together as part of the Internet of Things. (Oct. 22) Video provided by AP
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