Defining cellular microenvironments using multiphoton lithography

To understand the chemistry of life processes in detail is largely a challenge of resolving them in their native, cellular environment. Cell culture, first developed a century ago, has proven to be an essential tool for reductionist studies of cellular biochemistry and development. However, for the technology of cell culture to move forward and address increasingly complex problems, in vitro environments must be refined to better reflect the cellular environment in vivo. This dissertation work has focused on the development of methods to define cellular microenvironments using the high resolution, 3D capabilities of multiphoton lithography. Here, site-specific photochemistry using multiphoton excitation is applied to the photocrosslinking of proteins, providing the means to organize bioactive species into well-defined 3D microenvironments. Further, conditions have been identified that enable microfabrication to be performed in the presence of cells -- allowing cell outgrowth and motility to be directed in real time. In addition to the intrinsic chemical functionality of microfabricated protein structures, 3D protein matrices are shown to respond mechanically to changes in the chemical environment, enabling new avenues for micro-scale actuation to be explored. Complex 2D and 3D protein photocrosslinking is further facilitated by integrating transparency and automated reflectance photomasks into the fabrication system. These advances could be transformative in efforts to fabricate precise cellular scaffolding that replicates the morphological (and potentially biochemical) features of in vivo tissue microenvironments. Finally, these methods are applied to the study of microorganism behavior with single-cell resolution. Microarchitectures are designed that allow the position and motion of motile bacterial to generate directional microfluidic flow -- providing a foundation to develop micro-scale devices powered by cells.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Biochemistry

Grantor

The University of Texas at Austin

Year dc:date.issued

2007

Author dc:creator

• Kaehr, Bryan James, 1975-

Advisor dc:contributor.advisor

• Shear, Jason B.

Statement dc:rights

• Copyright is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works.

Language dc:language.iso

eng

Identifier

b68896347

OAI identifier oai:identifier

oai:repositories.lib.utexas.edu:2152/3264