Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chemists mimic nature to design better medical tests

15.02.2012
Over their 3.8 billion years of evolution, living organisms have developed countless strategies for monitoring their surroundings.

Chemists at UC Santa Barbara and University of Rome Tor Vergata have adapted some of these strategies to improve the performance of DNA detectors. Their findings may aid efforts to build better medical diagnostics, such as improved HIV or cancer tests.

Their research is described in an article published this week in the Journal of the American Chemical Society.

Nature often serves as a source of inspiration for the development of new technologies. In the field of medical diagnostics, for example, scientists have long taken advantage of the high affinity and specificity of biomolecules such as antibodies and DNA to detect molecular markers in the blood. These molecular markers allow them to monitor health status and to guide treatments for diseases, including HIV, cancer, and diabetes.

Kevin W. Plaxco, a professor of chemistry at UCSB, whose group carried out the research, notes that despite their great attributes, a main limitation of such biosensors is their precision, which is confined to a fixed, well-defined "dynamic range" of target concentrations. Specifically, the useful dynamic range of typical biomolecule binding events spans an 81-fold range of target concentrations

"This fixed dynamic range complicates –– or even precludes –– the use of biosensors in many applications," said Plaxco. "To monitor HIV progression and provide the appropriate medication, for example, physicians need to measure the levels of viruses over five orders of magnitude. Likewise, the two orders-of-magnitude range displayed by most biosensors is too broad to precisely monitor the concentrations of the highly toxic drugs used to treat many cancers. Our goal was, therefore, to create sensors with extended (for applications needing a broad dynamic range) or narrowed (for applications needing high measurement precision) dynamic ranges at will."

The key breakthrough underlying their new approach came from the simple observation of nature. "All living organisms monitor their environments in an optimized way by using sensing molecules that respond to either wide or narrow change in target concentrations," said Alexis Vallée-Bélisle, a postdoctoral fellow and the first author of the study. "Nature does so by combining in a very elegant way multiple receptors, each displaying a different affinity for their common target".

Inspired by the optimized behaviors of these natural sensors, the UCSB research group teamed up with Francesco Ricci, professor at the University of Rome Tor Vergata to do their own mixing and matching of biomolecules to manipulate biosensors' dynamic ranges. To validate their approach, they used a widely employed DNA-based biosensor used for detecting mutations in DNA called a "molecular beacon."

By combining sets of molecular beacons all binding the same target molecule but with differing affinities, the international team was able to create sensors with rationally "tuned" dynamic ranges. In one case, they developed a sensor that monitors DNA concentrations over a six orders of magnitude range. In another example, they developed an ultrasensitive sensor that precisely detects small changes in target concentration over only a five-fold dynamic range. Finally, they also built sensors characterized by complex, "custom-made" dynamic ranges in which the sensor is insensitive within a window of desired concentrations (e.g., the clinically "normal" concentration range of a drug) and very sensitive above or below this "appropriate" concentration range. The researchers believe that these strategies can be in principle applied to a wide range of biosensors, which may significantly impact efforts to build better point-of-care biosensors for the detection of disease biomarkers.

This work was funded by the National Institute of Health, the Fond Québécois de la Recherche sur la Nature et les Technologies, the Italian Ministry of University, and Research (MIUR) project "Futuro in Ricerca."

Andrea Estrada | EurekAlert!
Further information:
http://www.ucsb.edu

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton 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: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>