The objective of this thesis was to relate and link the physiological responses of the cells to the electrical responses or output obtained from the TSM acoustic wave sensor. In particular, the device was applied to the study of immortalized murine hypothalamic neurons (mHypoE-38 and -46 cell models) under a variety of conditions and stimuli. Cellular studies which lead to the production of detectable neuronal responses include neuronal deposition, adhesion and proliferation, alteration in the extent of specific cell-surface interactions, actin filament and microtubule cytoskeletal disruptions, effects of cell depolarization, solution tonicity, inhibition of the Na+-K+ pump via ouabain, effects of neuronal synchronization and the effects ligand-receptor interaction (glucagon). In addition, the introduction of drugs, neurotrophic factors (forskolin and beterferon), toxicity agents (NaOH, EtOH) and TiO2 nanoparticles were similarly investigated. A preliminary study conducted with mouse embryonic stem cells showed that not all cell lines are suitable for investigation with the TSM sensor at the current stage of sensor development.
It has been found that control studies conducted with water as the solvent and the bare sensor substrate is insufficient to model the behavior of the sensor in the absence of cells. When biological buffers are used in addition to protein coatings the sensor responses are altered in magnitude and direction.
To analyze the full range of cellular changes observed on the TSM sensor, the full impedance spectrum is required. As such in this thesis, the series and parallel resonant frequencies, the motional resistance, the maximum phase of the impedance and the static capacitance (fs, fp, Rm, θmax and Co were used to characterize the cellular responses observed. In the presence of cells fs shifts are largely influenced by the damping of the TSM resonator. The formation of cell-surface interactions and hence the increase in coupling and acoustic energy dissipation can be modeled as an additional resistor in the BVD model. Further sensor and cellular changes can be obtained by negating the effects of damping from fs with the use of Rm and θmax.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/32683 |
| Date | 20 August 2012 |
| Creators | Cheung, Shilin |
| Contributors | Thompson, Michael |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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