Design of a Uniform and Tunable Light Source for Photolysis-based Expansion of 3D Cultured Mesenchymal Stem Cells; Equitable Implementation and Responsible Innovation of Stem Cell Engineering Technology; 348 views

Three dimensional stem cell culture requires scaffolding for cell growth. To harvest the cells for therapeutic or research purposes, the scaffolding must be removed. The current method of degrading the scaffold is enzymolysis, but proteolytic enzymes can degrade the extracellular matrix and surface proteins of stem cells, which is detrimental for stem cell growth, proliferation, and differentiation. A microporous annealed particle (MAP) gel was created that is degradable via application of a 365 nm light which does not harm the cells. However, the current device used to expose the MAP hydrogel scaffold and cells is inefficient, as it can only uniformly expose one well of a 96 well plate at a time. The concept of this project is to create a uniform and tunable light source platform to aid in the photolysis-based expansion of mesenchymal stem cells (MSCs). The light source platform was designed, 3D printed, assembled using LEDs and made uniform using a light diffuser. The final device was tested to show 10.7% variability of light intensity across the area of the 96 well plate. The diffuser provided 4.38 times more uniform light distribution. The longevity of the intensity of the LEDs was tested and had insignificant changes with a standard deviation of 0.011 mW/cm2. Qualitative gel degradation and quantitative polymer degradation kinetics were conducted to validate the gel degradation capabilities of the device. There was no significant difference in degradation kinetics across the plate, further validating the uniformity. Time trials found a 20 fold time difference between the current device for light exposure and the new light platform. All tests confirmed the light source platform is a uniform source of light that can be used for a more efficient and high throughput degradation of MAP gel scaffolding for the 3D culture of MSCs. Stem cell engineering is an exciting and quickly growing field which holds immense potential for scientific advancements with applications in nearly every medical condition. Clinical stem cell research has the potential for significant societal ramifications. Scientific advancements which yield medical benefits don’t exist in a bubble; the systems in which these technologies are developed and actualized determine their effect on the world. As such, it’s essential to ensure that innovation is a vehicle for social bettering, and not assume this to be inherent to scientific advancement. This research will examine sociopolitical implications of stem cell research and will apply the framework of responsible innovation in order to guide the stem cell engineering field towards positive social impact. Through this research, I will show that scientific progress isn’t truly progress at all if not implemented equitably. I will argue that stem cell science advancements can, and should, be a vehicle for social change.

BS (Bachelor of Science)

School of Engineering and Applied Science Bachelor of Science in Biomedical Engineering Technical Advisor: Donald Griffin STS Advisor: Joshua Earle Technical Team Members: Golnar Mostashari, Alexandra Rashid

English

All rights reserved (no additional license for public reuse)

2022-05-13