Bioelectronic Systems In Studying Tissue Engineering, Real-Time Biophysical Monitoring Of Birds And Point-Of-Care Diagnostics
The field of bioelectronics started about 18th century with the frog experiments of Luigi Galvani by moving the detached leg of frog with the application of a small voltage. Today there are variety of bioelectronic devices available in many different areas such as pacemakers, continuous glucose sensors, implantable brain tissue interfaces, that show how far we have gone since the Galvani experiments. This dissertation introduces bioelectronic systems for different research areas such as tissue engineering, biophysical monitoring of birds and point-of-care diagnostics. First, we have introduced a device depends on organic bioelectronics, a growing research field that integrates organic electronic materials with biological systems, and used it for tissue engineering purposes. We have developed a planar device that contains a conducting polymer stripe and achieves a continuum of microenvironments for cell growth under the influence of an applied bias. Marked differences are observed in the migration behaviors of bovine aortic endothelial cells (EC) as a function of location along the polymer stripe, and 3-fold variation is achieved in EC migration speed and directional persistence time. A gradient in adsorbed fibronectin indicates that a spatial variation in cell adhesion is at play. We have used our device to modulate the cell adhesion and changed cell density gradients of normal and cancerous cell lines by inducing electrically which can be used as a tool for the study of cell-cell interactions. Next, we have developed a real-time in vivo uric acid biosensor system, Labon-a-Bird, for biophysical monitoring of birds. The metabolism of birds is finely tuned to their activities and environments, and thus research on avian systems can play an important role in understanding organismal responses to environmental changes and ecological investigations. After characterization of the sensor system, we demonstrated the autonomous operation of the system by collecting in vivo extracellular uric acid measurements on a domestic chicken. We then show how the device can be used to monitor, in real time, the effects of short-term flight and rest cycles on the uric acid levels of pigeons. In addition, we demonstrate that our device has the ability to measure uric acid level increase in homing pigeons while they fly freely to back home. Successful application of the sensor in migratory birds could open up a new way of studying birds in flight which would lead to a better understanding of the ecology and biology of avian movements. Finally, we have presented a Cholera-Detect system for point-of-care detection of Vibrio Cholerae which is a comma-shaped, gram negative bacterium and the cause of an acute diarrhoeal disease in humans called "Cholera". Even though up to 80% of the cases can be successfully treated with oral rehydration salts, around 100,000 - 120,000 of the cases come to an end as deaths. This indicates that early and rapid detection of the cholera is necessary to prevent spread of disease, increase the efficiency of treatments and decrease the intensity of epidemics. Cholera-Detect system has the ability to do rapid, and on-field molecular diagnosis of cholera without need for extensive laboratory equipment and chemicals which would potentially make possible improved health care in outbreak situations.
Bioelectronics; Biophysical monitoring; Point-of-care diagnostics
Manohar, Rajit; Winkler, David Ward; Baeumner, Antje J
Ph. D., Electrical Engineering
Doctor of Philosophy
dissertation or thesis