Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New technique yields fast results in drug, biomedical testing

10.10.2014

A new technique makes it possible to quickly detect the presence of drugs or to monitor certain medical conditions using only a single drop of blood or urine, representing a potential tool for clinicians and law enforcement.

The technique works by extracting minute quantities of target molecules contained in specimens of blood, urine or other biological fluids, and then testing the sample with a mass spectrometer.


A new technique called slug flow microextraction makes it possible to quickly detect the presence of drugs or to monitor certain medical conditions using only a single drop of blood or urine. The technique involves drawing a specimen into a glass capillary that also contains an organic solvent and rocking the capillary back and forth several times to extract target molecules from the biological sample into the solvent. (Purdue University image/Weldon School of Biomedical Engineering)

Testing carried out with the technology takes minutes, whereas conventional laboratory methods take hours or days to yield results and require a complex sequence of steps, said Zheng Ouyang (pronounced Jung O-Yong), an associate professor in Purdue University's Weldon School of Biomedical Engineering.

"We've converted a series of operations into a single extraction process requiring only a pinprick's worth of blood," he said.

The method, called "slug flow microextraction," could be used to detect steroids in urine for drug screening in professional sports and might be combined with a miniature mass spectrometer also being commercialized. The combined technologies could bring a new class of compact instruments for medicine and research, Ouyang said.

Findings are detailed in a paper appeared online Oct. 5 in the research journal Angewandte Chemie International Edition. The paper was authored by graduate student Yue Ren, undergraduate student Morgan N. McLuckey, former postdoctoral research associate Jiangjiang Liu and Ouyang.

The researchers demonstrated the technique, using it to perform therapeutic-drug monitoring, which has potential applications in drug development and personalized therapy; to monitor enzyme function, as demonstrated for acetylcholinesterase, which is directly related to the symptoms and therapy for Alzheimer's disease; to detect steroids, yielding results in one minute; and to test for illicit drugs.

"In the future, for example, parents might be able to test their children's urine for drugs with a simple cartridge they would take to the corner drug store, where a desktop mass spectrometer would provide results in a few minutes," Ouyang said.

The technique involves drawing a specimen into a glass capillary that also contains the organic solvent ethyl acetate.

Like oil and water, the two fluids are immiscible, and an interface is formed between the specimen and the solvent. Gently rocking the capillary back and forth several times causes small amounts of target molecules in the biological sample to cross this interface into the solvent side without mixing the two fluids.

"You don't want to mix these two, you want to extract only the biomarkers you are looking for and leave the junk behind because mass spectrometry is very sensitive to impurities," Ouyang said.

Then the solvent containing the biomarkers is subjected to a high-voltage current, ionizing the sample so that it can be analyzed with mass spectrometry.

Researchers have used microextraction for other applications.

"I think this is the first time it has been applied to a biological sample for mass spectrometry," Ouyang said. "You just use a pinprick of blood, and the analysis is completed in minutes.”

When combined with the miniature mass spectrometer also developed at Purdue the method represents a mobile system for medical professionals, researchers and law enforcement.

Mass spectrometry works by turning molecules into ions, or electrically charged versions of themselves, inside the instrument's vacuum chamber. Once ionized, the molecules can be more easily manipulated, detected and analyzed based on their masses. The new approach uses a method called nanoESI – or nano electrospray ionization - in which the ionization step is performed in the air or directly on surfaces and does not require a vacuum chamber.

Although the research was conducted using a conventional laboratory mass spectrometer, the same nanoESI operation could be carried out with the new miniature mass spectrometer. Whereas conventional mass spectrometers are bulky instruments that weigh more than 300 pounds, Purdue researchers have recently completed their latest version of the miniature mass spectrometer, the Mini 12, which weighs 40 pounds, is 12.5 inches wide and 16 inches high.

"The sampling ionization technologies like slug flow microextraction could make the miniature mass spectrometers perform the actual testing without requiring other equipment for sample treatment," Ouyang said.  "This will bring a new class of compact medical instruments."

The research has been funded by the National Institutes of Health.

The work to develop the miniature mass spectrometer has been supported by the NIH and National Science Foundation and is led by Ouyang and R. Graham Cooks, the Henry Bohn Hass Distinguished Professor of Chemistry in Purdue's College of Science.

U.S. patent applications have been filed for the microextraction and miniature mass spectrometry. The technologies may be commercialized through a new company formed after partnership agreements were signed in 2013 by Purdue and Tsinghua University.

"The overall goal is to use this technology for developing disposable sample cartridges to work with our mini mass spectrometry system in clinical and especially the point-of-care applications in a doctor's office," Ouyang said. 

Writer: Emil Venere, 765-494-4709, venere@purdue.edu

Source: Zheng Ouyang, 765-494-2214, ouyang@purdue.edu   

ABSTRACT

Direct Mass Spectrometry Analysis of Biofluid Samples Using Slug Flow Microextraction NanoESI**     

Yue Ren, Morgan N. McLuckey, Jiangjiang Liu and Zheng Ouyang*

* Weldon School of Biomedical Engineering, Purdue University

** This research was supported by Nation Institutes of Health   

Direct mass spectrometry (MS) analysis of bioluids with simple procedures, such as using the ambient ionization, represents a key step for translation of MS technologies to the clinical and point-of-care applications. The current study reports the development of a single-step method using slug flow micro extraction and nanoESI (electrospray ionization) for MS analysis of organic compounds in blood and urine. High sensitivity and quantitation precision have been achieved for analysis of therapeutic and illicit drugs in 5 μL samples. Real-time chemical derivatization has been incorporated for analyzing anabolic steroids. The monitoring of enzymatic functions of wet blood has also been demonstrated with the cholinesterase. The reported development encourages the future design of highly functioning but simple devices, in replacement of traditional complex lab procedures for MS analysis of biological samples.

Emil Venere | Eurek Alert!
Further information:
http://www.purdue.edu/newsroom/releases/2014/Q4/new-technique-yields-fast-results-in-drug,-biomedical-testing.html

More articles from Medical Engineering:

nachricht A first look at interstitial fluid flow in the brain
05.07.2018 | American Institute of Physics

nachricht A sentinel to watch over ocular pressure
04.07.2018 | Fraunhofer Institute for Microelectronic Circuits and Systems

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>