Available at: https://digitalcommons.calpoly.edu/theses/2938
Date of Award
11-2024
Degree Name
MS in Biomedical Engineering
Department/Program
Biomedical Engineering
College
College of Engineering
Advisor
Christopher Heylman
Advisor Department
Biomedical Engineering
Advisor College
College of Engineering
Abstract
The Microphysiological Systems Laboratory aims to develop colorectal cancer tumor models under a hypoxic environment to assess model response to pharmaceutical compounds in vitro. To perform relevant studies, researchers have attempted to use different hypoxic inducing strategies such as a nitrogen pod and hypoxic incubator to recreate in vivo physiological responses to hypoxia. However, studies would be interrupted due to incubator functionality failure. To ensure successful and physiologically relevant studies, I improved and verified the robustness and reliability of a hypoxic incubator previously designed and manufactured in the lab. Through the testing and iterating design processes, I engineered and implemented solutions for the problems identified and validated these solutions through a series of functionality and reliability tests. PCB design on EAGLE software, outsourced manufacturing, and integration through component soldering and wire reconfiguration ensured permanent, robust, and reliable device electrical circuity. Sensor component replacement allowed for a more accurate hypoxic environment. Functionality and reliability tests were conducted to ensure the device was able to meet threshold values in startup phase, maintain these values throughout chronic hypoxia experiments, and sufficiently recover threshold conditions from interferences caused by chamber door opening. Improvements in user experience, device usability, and operator repeatability and reproducibility were made through the design and implementation of a simple and effective user interface. To assess the physiological efficacy of a hypoxic incubator an experiment was conducted using the designed incubator. The goal of the study was to observe the Warburg effect, a physiological phenomenon in cancer cells under hypoxia. 3T3 mouse fibroblast and SW620 colorectal cancer cells were cultured under three environmental conditions: nitrogen induced hypoxia pod, hypoxia with CO2 control, and normoxia incubation. Cell count was analyzed through inverted microscope fluorescent imaging and ImageJ processing to quantify cell proliferation activity. Data was analyzed using JMP to determine statistical significance in study results. The incubator maintained hypoxic conditions throughout the 7-day testing period as well as passed all functionality tests. The hypoxic incubator efficacy study resulted in a successful recreation of the Warburg effect observing the maintained proliferation ability of cancer cells under hypoxia which negatively impacted 3T3 cell proliferation. These results verified a robust, reliable, and effective hypoxic incubator for use in the MPS Lab to develop accurate tumor models and conduct relevant cancer research.
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Bioimaging and Biomedical Optics Commons, Biological Engineering Commons, Biomedical Commons, Biomedical Devices and Instrumentation Commons, Computer-Aided Engineering and Design Commons, Controls and Control Theory Commons, Electro-Mechanical Systems Commons, Molecular, Cellular, and Tissue Engineering Commons, Other Biomedical Engineering and Bioengineering Commons, Other Electrical and Computer Engineering Commons, Systems and Integrative Engineering Commons, VLSI and Circuits, Embedded and Hardware Systems Commons