BIOENGINEERING APPROACHES FOR IMPROVED DIFFERENTIATION OF CULTURED RETINAL TISSUES FROM PLURIPOTENT STEM CELLS

Abstract

Sight is the most powerful of all human senses. For the vast majority of people on Earth, the loss of that sense would be unimaginable. Without assistive technology, it would separate them from their ability to work, their ability to travel, and their ability to interact with their loved ones. And yet, this extraordinary process, carefully refined by billions of years of evolution, is threatened for millions of people all over the world from a wide array of diseases of the retina. Many of these diseases arise from malnutrition and infection and are being rapidly eradicated. However, many dozens more result from convoluted permutations of genetics, age, and diet that threaten blindness for millions more with little hope of treatment, even with the best of modern medicine. As our life expectancies extend and our population ages, these diseases will only become more prevalent. In humanity's ever-present pursuit of medicine and knowledge to improve our quality of life, cutting-edge treatments offer promise that one day soon, even these diseases may be eradicated. One key technology capable of treating these devastating illnesses, on the precipice of being translated to real-world clinical treatments, is pluripotent stem cell-derived therapies. Patient-specific pluripotent stem cells, meaning pluripotent stem cells sourced directly from the patient, have a wealth of applications ranging from drug identification to disease modeling to implantation and regeneration. This research has been developed and advanced remarkably in the approximately two decades since the early isolation of pluripotent stem cells. Naturally, this advancement has predominantly been focused on cell and molecular biology. However, this focus has left significant research questions to be answered from engineering perspectives across a wide latitude of sub-disciplines. This dissertation explores three independent avenues of engineering principles as they relate to improving 2D and 3D retinal tissues derived from pluripotent stem cells in materials, devices, and computation. The first aim explores how plant protein-based nanofibrous scaffolds can marry the advantages and minimize the disadvantages of synthetic and animal-derived scaffolds for the culture of 2D retinal pigment epithelium (RPE) constructs. The second aim describes the development and testing of a novel, perfusing rotating wall vessel (RWV) bioreactor to support culture of 3D retinal organoids. Finally, the third aim performs a meta-analysis of published RNA-Seq datasets to determine the precise mechanisms by which bioreactors support organoid growth and extrapolate how these conclusions can support future experiments.