Development and Optimization of Imaging and Image Quantification Techniques for Tissue-Engineered Blood Vessel Mimics

Blood vessels mimics (BVMs) are tissue-engineered blood vessels used to test vascular devices in an environment that mimics some simple anatomical factors of native blood vessels. It is important to accurately and consistently assess tissue-engineered blood vessels, although there is currently a lack of standardization in Cal Poly’s Tissue Engineering Lab and in the entirety of the field. The goal of this thesis was to develop and optimize imaging and image quantification techniques for tissue-engineered blood vessels. The first aim of this thesis optimized and compared imaging and assessment techniques for electrospun scaffolds. Images from different SEMs were compared to determine the benefits and drawbacks of each microscope. Several materials were also imaged using these microscopes to characterize polymers at the microscopic scale and to compare the quality of images from different SEMs. The second aim of this thesis validated and implemented a MATLAB-based automatic fiber diameter measurement tool. Fiber measurements were obtained from a manual ImageJ method, a semi-automatic DiameterJ method, and a new automatic MATLAB method and compared to evaluate accuracy and user variability of the MATLAB tool. The results of this aim validated the accuracy of the MATLAB tool and showed that it resulted in lower user variability as compared to other fiber diameter measurement methods. The third aim of this thesis developed imaging techniques for novel silicone BVMs at each stage of development. Evaluation techniques to quantify cell adhesion and coverage on silicone BVMs using SEM, widefield fluorescent imaging, and immunochemistry were developed. After refining those methods, they were applied and adapted to silicone BVMs with deployed devices. BBI, H&E, and PECAM-1 staining were all found to be effective assessment methods for silicone BVMs. Overall, the work described in this thesis increased the consistency, standardization, and accuracy of scaffold and BVM assessment in Cal Poly’s Tissue Engineering Lab