Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists create dual-modality microbeads to improve identification of disease biomarkers

16.02.2007
Analyzing human blood for a very low virus concentration or a sample of water for a bioterrorism agent has always been a time-consuming and difficult process. Researchers at the Georgia Institute of Technology and Emory University have developed an easier and faster method to detect these types of target molecules in liquid samples using highly porous, micron-sized, silica beads.

The researchers developed a technique to simultaneously or sequentially add optical and magnetic nanoparticles into the beads. Adding magnetic nanoparticles allows the use of a magnetic field to attract and easily remove the beads from a liquid sample.

"These nanoparticles enter the pores of the microbeads so quickly and so completely -- essentially more than 99 percent of the nanoparticles go into the pores of the beads," explained Shuming Nie, the head researcher on the project and the Wallace H. Coulter Distinguished Chair in Biomedical Engineering and director of Emory-Georgia Tech Nanotechnology Center.

The beads are mixed in a liquid such as urine. Viruses, proteins or other biomarkers are captured on the bead surface. After the beads are removed from the liquid, optical imaging is used to determine the concentration of a specific protein or virus in the liquid sample based on the number of proteins or viruses attached to the surface of the beads.

Tushar Sathe, a graduate student in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, described the process of creating these novel beads and their clinical applications on Jan. 20 at SPIE Photonics West in San Jose, California. The work was also published in the Aug. 15 issue of Analytical Chemistry.

The technology involves embedding fluorescent quantum dots and magnetic iron oxide nanoparticles inside the beads to create dual-modality magneto-optical beads. Nie and Sathe synthesize the quantum dots in different colors by varying their size, giving the beads a unique optical signature. Having different color beads allows the researchers to detect several target molecules at the same time in the same liquid sample.

"We use the quantum dots to create a set of beads that are unique and can be distinguished from each other. It’s similar to bar-coding -- once you barcode the beads and put them in the urine or blood sample, you can remove them and decode what proteins or viruses have attached to individual beads based on their spectral signature," explained Sathe.

The process of creating these beads is quite simple, according to Sathe. The surface of the beads contains a long-chain carbon molecule that makes the beads hydrophobic, meaning they repel water. The beads are dissolved in butanol and washed several times. Then the beads are counted and optical and magnetic nanocrystals are added to the suspension either simultaneously or sequentially.

After 15-20 minutes, the butanol is removed to get rid of any remaining nanoparticles that didn’t get incorporated into the beads and the beads are washed with ethanol. Then the beads are coated with a polymer that creates a hydrophilic surface on the beads. This allows the beads to be functionalized by adding antibodies or DNA molecules to the surface that will capture the target molecules.

These beads are dual-function -- both optical and magnetic -- but according to Sathe, more functions can be added to the beads. "Adding them is as easy as adding the nanoparticles into the solution. You just have to make sure the nanoparticle surface is hydrophobic so that it interacts with the beads," said Sathe.

The primary biomedical applications for this new technology will be to detect cancer and neurological diseases by identifying certain molecules present in human blood or urine that indicate specific diseases, according to Nie, who is also professor of biomedical engineering, chemistry, materials science & engineering, and hematology and oncology at Emory University and the Georgia Institute of Technology.

"Some of the biomarkers for Alzheimer’s disease have very low concentrations in the blood so you need highly sensitive techniques that can find a specific molecule to diagnose this disease," explained Nie. "Our technique could also be used to monitor therapeutic response. For example, if the viral level decreases in samples taken at later dates, then we know the drug is probably working."

This new technology allows the researchers to analyze very low concentrations of target molecules. "Instead of analyzing a liter of sample where the concentration could be very dilute and you might not see the target molecule you’re looking for, you can let the beads capture the molecules on their surface, remove them from the liquid, and then just measure the number of molecules attached to the beads," said Nie.

John Toon | EurekAlert!
Further information:
http://www.gatech.edu

Further reports about: Disease Magnetic Sathe biomarkers concentration nanoparticle

More articles from Life Sciences:

nachricht The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

nachricht Transforming plant cells from generalists to specialists
07.12.2016 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>