Engineered methods for studying and manipulating in vitro culture systems
Abstract/Contents
- Abstract
- The development of new cell culture techniques allows in vitro cell cultures to replicate in vivo biology more faithfully. In this thesis, I will discuss two projects that broadly seek to expand the modalities for manipulating cell cultures and interrogating cell behavior. Magnetogenetics is a new field that leverages genetically encoded proteins and protein assemblies that are sensitive to magnetic fields to study and manipulate cell behavior. Theoretical studies show that many proposed magnetogenetic proteins do not contain enough iron to generate substantial magnetic forces. Here, we have engineered a genetically encoded ferritin-containing protein crystal that grows inside mammalian cells. Each of these crystals contains more than 10 million ferritin subunits and is capable of mineralizing substantial amounts of iron. When isolated from cells and loaded with iron in vitro, these crystals generate magnetic forces that are 9 orders of magnitude larger than the forces from the single ferritin cages used in previous studies. These protein crystals are attracted to an applied magnetic field and move toward magnets even when internalized into cells. While additional studies are needed to realize the full potential of magnetogenetics, these results demonstrate the feasibility of engineering protein assemblies for magnetic sensing. Brain organoids are an emerging three-dimensional cell culture system that models human brain development. Derived from clusters of induced pluripotent stem cells, brain organoids develop over many months and recapitulate key aspects of brain organization, such as cell identity and diversity, gene expression, and functional characteristics such as electrical activity. As a result, they have been employed to model various neurodevelopmental disorders. To date, electrophysiology in brain organoids has employed traditional techniques, such as multi-elecrode recordings and patch clamp. Here, we have developed a flexible mesh electrode for the long-term chronic integration of electrodes into the growing organoid. Over two generations of meshes, one made from SEBS and PEDOT:PSS and one made from SU-8 and gold, we have demonstrated that such electrodes have good biocompatibility, and are able to electrically stimulate organoids. Work is currently ongoing to establish consistent extracellular recordings of action potentials using the mesh.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2021; ©2021 |
| Publication date | 2021; 2021 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Li, Thomas Letao |
|---|---|
| Degree supervisor | Cui, Bianxiao |
| Degree supervisor | Pasca, Sergiu |
| Thesis advisor | Cui, Bianxiao |
| Thesis advisor | Pasca, Sergiu |
| Thesis advisor | Boxer, Steven G. (Steven George), 1947- |
| Degree committee member | Boxer, Steven G. (Steven George), 1947- |
| Associated with | Stanford University, Department of Chemistry |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Thomas Li. |
|---|---|
| Note | Submitted to the Department of Chemistry. |
| Thesis | Thesis Ph.D. Stanford University 2021. |
| Location | https://purl.stanford.edu/kt607mx8679 |
Access conditions
- Copyright
- © 2021 by Thomas Letao Li
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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