Author ORCID Identifier
0009-0009-0043-6676
Defense Date
2024
Document Type
Thesis
Degree Name
Master of Science
Department
Mechanical and Nuclear Engineering
First Advisor
Joao S. Soares, PhD
Second Advisor
Casey Grey, PhD
Third Advisor
Michael J. McClure, PhD
Abstract
Electrospun polymeric biodegradable scaffolds are essential in tissue engineering, particularly for Engineered Tissue Vascular Grafts (ETVGs), which promise advancements in treating coronary artery disease, peripheral arterial disease, congenital cardiovascular defects, and renal disease. These scaffolds present a solution to issues with autologous graft availability and durability. While large-diameter grafts in low-pressure environments have seen success, small-diameter grafts in high-flow scenarios remain challenging. Understanding polymeric scaffold degradation and behavior during incubation, especially under dynamic mechanical loading, is vital for clinical translation of small-caliber ETVGs.
This research focuses on characterizing the mechanical and microstructural properties of electrospun polycaprolactone (PCL) scaffolds and their degradation profile under dynamic mechanical stimulation in vitro. PCL, a biocompatible and biodegradable aliphatic polyester, degrades primarily through hydrolysis, with degradation rates influenced by dynamic mechanical loading. Despite its common use, the kinetics of PCL degradation under load are understudied.
Electrospinning produces porous, biodegradable scaffolds, with adjustments in parameters like needle position, collector shape, voltage, and flow rate tailoring scaffold characteristics. Manufacturing parameters such as translation and rotation of the collecting mandrel control fiber orientation, ensuring proportional fiber distribution.
To enhance tissue scaffold research efficiency and understand mechanical environment impacts on degradation, we developed an in vitro accelerated degradation model using custom-designed chambers replicating culture conditions under mechanical stimulation. Evaluating the mechanical properties is crucial for scaffold design and performance. We conducted a parametric study of manufacturing parameters and performed tensile mechanical testing on virgin and degraded scaffolds under various mechanical conditions using custom small-scale uniaxial and biaxial tensile testers.
Rights
© Caleb B. Wells
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
6-7-2024
Included in
Biology and Biomimetic Materials Commons, Biomaterials Commons, Biomechanical Engineering Commons, Mechanics of Materials Commons, Polymer and Organic Materials Commons