Diseases of the human vascular system are the leading cause of death and hospitalization in the United States. Surgical treatments for vascular complications, such as bypassing or replacing occluded arteries, are complicated by the lack of healthy tissue available for grafting. The feasibility of using xenografts and allografts has recently been demonstrated as an alternative to DACRON and expanded polytetraflouroethylene (ePTFE) biomaterials, which lose patency after a short time. Through decellularization procedures, vascular tissue can be reduced to a sterilized scaffold, seeded with the transplant recipient's endothelial cells, and implanted with a low risk of rejection. Enzymatic-detergent treatments used to lyse vascular smooth muscle cells (VSMCs) may use deoxycholic acid, TritonX-100/EDTA, or SDS, which disrupt cellular adhesion integrins. These treatments may significantly impact the mechanical properties of the extracellular matrix scaffold and contribute to graft compliance mismatch. Native and decellularized longitudinal arterial tissue samples cut from similar crosssections were tested in uniaxial tension to observe changes in mechanical behavior resulting from decellularization protocols published in Rieder et al., (2004), Schaner et al., (2004), and Bader et al., (1998). Rectangular parellepiped arterial wall samples were analyzed as membranes in terms of engineering stress. Experimental uniaxial stressstretch data were fit to a modified form of the Yeoh rubber model by least-squares curve fitting. The Yeoh parameters generated by the least-squares fit for native and decellularized sections were then assessed for statistical significance using a paired t-test analysis. The TritonX-100/EDTA and 0.075% SDS treatments resulted in highly variable mechanical changes and did not effectively lyse VSMCs, as determined by H&E staining. The 0.25% deoxycholic acid treatment reported in Rieder et al., (2004) showed minimal changes in mechanical behavior and effectively lysed VSMCs. The data suggests a 0.25% deoxycholic acid treatment has minimal effects on mechanical properties of aortic tissue while effectively lysing VSMCs and is therefore a more effective option than TritonX-100/EDTA and SDS treatments for the preparation of xenografts and allografts.
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Title
Effect of decellularization protocol on the mechanical behavior of porcine descending aorta
Creators
John Charles Fitzpatrick - DU
Contributors
Franco M. Capaldi (Advisor) - Drexel University (1970-)
Awarding Institution
Drexel University
Degree Awarded
Master of Science (M.S.)
Publisher
Drexel University; Philadelphia, Pennsylvania
Resource Type
Thesis
Language
English
Academic Unit
College of Engineering (1970-2026); Mechanical Engineering (and Mechanics) [Historical]; Drexel University