Available at: http://digitalcommons.calpoly.edu/theses/1194
Date of Award
MS in Biomedical Engineering
Biomedical and General Engineering
Kristen O'Halloran Cardinal, PhD
“Blood vessel mimics” (BVMs) are tissue-engineered constructs that serve as in vitro preclinical testing models for intravascular devices. The Cal Poly Tissue Engineering lab specifically uses BVMs to test the cellular response to stent implantation. PLGA scaffolds are electrospun in-house using the current “Standard Protocol” and used as the framework for these constructs. The performance of BVMs greatly depends on material and mechanical properties of the scaffolds. It is desirable to create BVMs with reproducible properties so that they can be consistent models that ultimately generate more reliable results for intravascular device testing. Reproducibility stems from the consistency of the scaffolds. Thus, scaffolds with consistent material and mechanical properties are necessary for creating reproducible BVMs.
The aim of this thesis was to characterize the reproducibility of the electrospun PLGA scaffolds using fiber diameter measurements and compliance testing. Initial work in this investigation involved designing and testing several experimental electrospinning protocols to obtain smaller fiber diameters, which have been shown to elicit more ideal cellular responses. The most successful protocol in that regard was then analyzed for the reproducibility of fiber diameters and compared to the reproducibility of the Standard Protocol. After determining that the Standard Protocol produced scaffolds with more consistent fibers, a large-scale reproducibility study was performed using this protocol. In this expanded study, both fiber diameter and compliance were analyzed and used to characterize the scaffolds. It was established that the scaffolds demonstrated inconsistent mean fiber diameter and mean compliance. The current standard electrospinning protocol therefore does not create PLGA scaffolds with statistically reproducible properties. Future modifications should be made to the electrospinning parameters in order to reduce variability between the scaffolds and future studies should be performed to determine the acceptable range of properties.