A Low-Cost Impedance-Based Detection System for Immune-Mediated Cytotoxicity Targeting Tumor Cells
| dc.contributor.advisor | Tohid, Didar | |
| dc.contributor.author | Ashkar, Raheleh | |
| dc.contributor.department | Biomedical Engineering | en_US |
| dc.date.accessioned | 2025-10-01T18:08:03Z | |
| dc.date.available | 2025-10-01T18:08:03Z | |
| dc.date.issued | 2025 | |
| dc.description | This study was an exciting intersection between cancer Immunotherapy and Engineering to tackle critical challenges in real-time cell analysis. | en_US |
| dc.description.abstract | This study presents the design and application of a microfabricated, impedance-based biosensor for real-time, label-free assessment of immune cell-mediated cytotoxicity against adherent cancer cells. The sensor features four series of interdigitated electrodes constructed via photolithography and gold sputtering, incorporating a titanium adhesion layer. Polydimethylsiloxane (PDMS) reservoirs were fabricated and bonded to glass substrates through oxygen plasma treatment to facilitate cell culture. Electrical impedance measurements were conducted using the PalmSens4 potentiostat. During assays, the sensor was maintained within the incubator of an inverted microscope to provide optimal environmental conditions. To test this system, we conducted experiments using two types of immune cells (NK and γδT cells) against SKOV3 ovarian cancer cell line at varying ratios (1:1 and 10:1) and A549 lung cancer cell line at 1:1 and 5:1 . Control conditions included immune cells alone and cancer cells alone, ensuring that observed effects were due to immune cell-mediated cytotoxicity. Impedance readings indicated increased resistance correlating with tumor cell proliferation, followed by a decrease upon immune-mediated cytolysis and subsequent cell detachment. These findings validate the sensor's capability to monitor dynamic cytotoxic interactions effectively. The developed biosensor offers a cost-effective, reusable, and less labor-intensive alternative to conventional cytotoxicity assays such as flow cytometry and xCELLigence systems.Its simplicity and affordability make it particularly suitable for resource-limited laboratories and clinical settings engaged in immunotherapeutic research and applications. | en_US |
| dc.description.degree | Master of Applied Science (MASc) | en_US |
| dc.description.degreetype | Thesis | en_US |
| dc.description.layabstract | Cancer treatments are advancing rapidly, with immunotherapy emerging as one of the most promising approaches. This method uses the body's immune system to target and destroy cancer cells. Two important immune cell types involved in this process are Natural Killer (NK) cells and Gamma Delta T (γδT) cells. In this research, we developed a cost- effective and reusable biosensor to monitor how immune cells, specifically natural killer (NK) and gamma delta T cells, destroy ovarian cancer cells (SKOV3) and lung cancer cells (A549). The sensor comprises four wells fabricated using lithography and gold sputtering techniques, with a titanium adhesive layer. We created reservoirs from PDMS and bonded them to glass slides using oxygen plasma treatment.For real-time monitoring, we employed the PalmSens4 potentiostat to measure electrical impedance, which reflects cell behavior on the sensor's electrodes. As cancer cells attach and proliferate, impedance increases; when immune cells induce cancer cell death, the cells detach, leading to a decrease in impedance. This setup allows continuous tracking of immune-mediated cytotoxicity without the need for labels or complex reagents. Our sensor offers a simpler, more affordable alternative to traditional methods like flow cytometry and xCELLigence systems, making it accessible for smaller laboratories and clinics focusing on immunotherapy. | en_US |
| dc.identifier.uri | http://hdl.handle.net/11375/32462 | |
| dc.language.iso | en_US | en_US |
| dc.subject | Cytotoxicity | en_US |
| dc.subject | Impedance spectroscopy | en_US |
| dc.subject | Immune cells | en_US |
| dc.subject | Tumor cells | en_US |
| dc.title | A Low-Cost Impedance-Based Detection System for Immune-Mediated Cytotoxicity Targeting Tumor Cells | en_US |
| dc.type | Thesis | en_US |