Date of Award
Master of Science (MS)
Groff, Richard E
Burg , Timothy C
Burg , Karen JL
The study of cell-cell interactions is crucial in the understanding of cell behaviors such as tumor genesis, proliferation, migration, metastasis, and apoptosis. To break down the complex web of signals in vivo, researchers must replicate some parts of this environment with in vitro tissue test systems, composed of multiple cell types arranged close enough to communicate with their neighbors, i.e. high-resolution co-culture patterns. The field of bioprinting is specifically focused on creating co-culture patterns for the purposes of cell studies, but the sample resolutions of most bioprinting systems are still too coarse to permit cell communication. No way currently exists to compare the sample fidelity between the technologies that have succeeded in creating high-resolution co-culture patterns..
This work introduces a quantitative metric for measuring co-culture patterning fidelity for use in comparing systems or tracking changes in fidelity with experiment conditions. The 'biopatterning fidelity index' (BFI) measures the performance of a system by fitting a scaled mask of the sample pattern over an image of the printed pattern and classifying the cells as correctly or incorrectly placed. A simple model is also introduced to provide a theoretical upper bound on the expected fidelity. The BFI and model were used to assess the performance of a custom bioprinter system. The performance of the system varied between the different cell types. The results indicate that the post-processing procedures were disturbing the fidelity of the patterns. New procedures should be developed that would not disturb the initial pattern fidelity. The best samples came very close to the model's predicted upper bound. As the number of capable technologies increases, the BFI will provide a quantitative, technology-independent method to assess the fidelity of patterned co-cultures.
The last section of this work examines the ability of the bioprinting system to create multiple slides of samples with similar cell distributions. It was shown that cartridges which had been exposed to less usage and cleaning had a more consistent cell output, enabling the bioprinting system to create biological comparable samples.
Pepper, Matthew, "A Quantitative, Technology Independent, Fidelity Metric for Evaluating Bioprinted Patterned Co-cultures" (2011). All Theses. 1124.