Ethanol is one of the most widespread psychotropic agents in western society. While its psychoactive effects are mainly associated to GABAergic and glutamatergic systems, the positive reinforcing properties of ethanol are related to activation of mesolimbic dopaminergic pathways resulting in a release of dopamine in the nucleus accumbens. Given these neurobiological implications, the detection of ethanol in brain extracellular fluid (ECF) is of great importance. In this study we describe the development and characterization of an implantable biosensor for the amperometric detection of brain ethanol in real time. Ten different designs were characterized in vitro in terms of Michaelis–Menten kinetics (VMAX and KM), sensitivity (linear region slope, LOD and LOQ), and electroactive interference blocking. The same parameters were monitored in selected designs up to 28 days after fabrication in order to quantify their stability. Finally, the best performing biosensor design was selected for implantation in the nucleus accumbens and coupled with a previously-developed telemetric device for the real-time monitoring of ethanol in freely moving, untethered rats. Ethanol was then administered systemically to animals, either alone or in combination with ranitidine (an alcohol dehydrogenase inhibitor) while the biosensor signal was continuously recorded. The implanted biosensor, integrated in a low-cost telemetry system, was demonstrated to be a reliable device for the short-time monitoring of exogenous ethanol in brain ECF, and represents a new generation of analytical tools for studying ethanol toxicokinetics and the effect of drugs on brain ethanol levels.
Dr. Williams obtained his undergraduate degree with a double major in Biomedical and Electrical Engineering at Vanderbilt University. He was then awarded a Keck Fellowship for graduate school at the University of Pittsburgh where he obtained his Master’s degree in Bioengineering.
Dr. Williams went on to obtain his medical degree at Drexel University in Philadelphia and completed 5 years of Fellowship training in both Cardiovascular Diseases and Clinical Cardiac Electrophysiology at the University of Pittsburgh Medical Center.
His unique background and extensive knowledge of both engineering and cardiology have earned Dr. Williams many accolades in both clinical and academic settings. He’s published over 20 manuscripts and abstracts in the field of cardiology/electrophysiology and has received awards from both the American College of Cardiology Foundation and the National Institutes of Health.
Dr. Williams started in the Invasive Electrophysiology Laboratory at The Good Samaritan Hospital in 2008 and, in the last three years, the Heart Rhythm Center has published outcomes on pacemaker and defibrillator implantations as well as the safety and efficacy of high frequency jet ventilation during EP studies with ablation under his direction.
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