The Burrill Report


Academic researchers developing an experimental sensor for continuous monitoring of drug concentrations in blood have created a promising tool for the practice of personalized medicine.

The disposable microfluidic sensing chip could one day help doctors tailor drug dosing for individual patients, maximizing efficacy and minimizing side-effects while making periodic blood draws to assess a drug's concentration in the blood unnecessary.

As proof of concept, researchers at the University of California, Santa Barbara Institute for Collaborative Biotechnologies used their device to measure in vivo concentrations of the chemotherapeutic doxorubicin in human whole blood and the blood of live rats. They were also able to achieve real-time measurement of the antibiotic kanamycin simply by changing the probes in the chip, demonstrating its flexibility.

"A universal architecture that can continuously measure in vivo concentrations of a wide range of circulating biomolecules would enable many potentially transformative applications in medicine," writes Brian Scott Ferguson, first author of a research article documenting the work, published in the journal Science Translational Medicine.

Ferguson says the device could be used for continuous monitoring of cardiac markers, predict an oncoming heart attack, and even facilitate continuous optimization of chemotherapy drugs for maximum efficacy and minimal side effects for a specific cancer patient.

The researchers have called their creation MEDIC, an acronym for microfluidic electrochemical detector for in vivo continuous monitoring. Inserted into a vein, a probe tipped with a gold electrode and an aptamer can detect changes in electrical charge as the circulating drug binds to the aptamer. An aptamer is a single-stranded DNA or RNA molecule capable of specifically binding to proteins or other cellular targets. Within the MEDIC chip, a specialized filter prevents blood cells from clogging the sensor’s surface during operation and protects the aptamer probes.

Translating the technology for the clinic will take more work. The sensor, tested over multiple hours, may need changes to enable it to operate for longer periods of time. Although the sensor was tested in whole blood, it has not yet been tested directly in human patients.

Ultimately though, "MEDIC’s real-time measurement capabilities could establish a new paradigm in therapeutic drug monitoring," says Ferguson. "The entry of continuous glucose monitoring technology into the clinical market over the past decade offers an invaluable precedent and will be used as a model for us to translate our technology."

December 13, 2013
http://www.burrillreport.com/article-scientists_create_drug_response_biosensor_.html