From painful prison to hopeful purification : changing images of purgatory in selected U.S. Catholic periodicals, 1909-1960

Timothy G. Dillon


The growing demand for superior materials that function as scaffolds for tissue repair and regeneration has served as a catalyst in medicine. The need for artificial or natural replacement or repair of organs, limbs and tissue presents an opportunity to deliver materials with superior biologics, architecture and mechanical properties. Current biomaterials utilized to repair damaged tissue or augment function commonly fail to meet the optimal combination of biomechanical and healing potential. Additionally, limited donor tissue availability and the increased cost of healthcare are driving factors for improving material processing and diagnostic assessment. Currently, metallic materials, such as titanium and stainless steel, function as implants and reinforcements. However, these materials are permanent and rigid and may inhibit natural healing of damaged tissue. Moreover, metallic implants corrode and fracture, causing repetitive injury and excess scar tissue formation. Conversely, polymer-based materials have shown promising results. A limited number of polymer biomaterials have been approved for scaffold and implant applications. Additionally, some polymers have the ability to degrade, an advantageous characteristic for biological applications. Nevertheless, most natural and synthetic biopolymers lack high strength and cannot be utilized as primary scaffolds in load bearing applications.The materials described earlier present shortcomings. The importance of the presented work is that it utilized mass producible materials, modified them for unique cellular environments and developed a computational model to predict cell behavior and facilitate future design endeavors. Specifically, the current analysis focused on preparing carbon-based scaffolds from monolithic, textile, composite, and nanoartifact derivatives. This work was the first to present an understanding between critical properties of carbon materials: crystallinity, orientation, surface roughness, and surface area and surface chemistry and the cellular environment. Additionally, both gravity and bioreactor driven models were investigated to demonstrate growth process enhancement. Scaffolds were characterized using experimental and computational techniques and cell behavior was investigated on both soft and hard tissue environments. This work presented Cellular Automata models that predicted cell behavior on carbon scaffolds. This exploration supported the preparation of scaffolds that enhanced biological and mechanical performance and promoted integration of tissue for hard and soft tissue applications