Engineering tissue for external ear reconstruction could replace the standard and painful method of harvesting and carving costal cartilage. This thesis provides a critical analysis of the literature and investigates several significant challenges ahead including finding adequate sources of cells, generating auricular cartilage, and exploring cartilage/material interactions to generate flexible cartilage characteristic of the external ear. Chondrocytes form cadaveric sources could provide potentially limitless cell numbers and avoid donor site morbidity but the antigenicity of these cells is unknown. Contrary to previously published findings, human chondrocytes were found to express class II major histocompatibility antigens as well as class I antigens possibly limiting their potential use clinically if they stimulate immune rejection by the host. The adhesion and integration of engineered cartilage to various substrates was studied to explore: 1) cartilage fixation;2) infrastructure to strengthen the engineered cartilage; and 3) lamination of the engineered cartilage with materials to add flexibility to the engineered cartilage. In all settings, cartilage was engineered by encapsulating porcine chondrocytes in fibrin scaffolds that were polymerized with thrombin and placed in vivo for up to three months. Engineered cartilage placed between discs of bone or porous polythylene (PPE) formed mechanically functional bonds with the substrate as determined by mechanical testing in tension. Those data validate cartilage formation by chondrocytes from different sources. Integration of the neocartilage with substrates would permit fixation to bone and possible lamination with PPE to strengthen the new tissue. Additional studies are presented showing that coating PPE with collagen or polylysine permits enhanced cell attachment in the early phases and may be a favourable adjunct for chondrocyte/material interaction. Lastly, laminating constructs with a perichondrium or psedo-perichondrium, such as fascia, collagen sheeting, small intestinal submucosa, or lyophilized perichondrium, added flexibility to the engineered construct. These laminates in combination with a core of PPE could provide a composite model for flexible cartilaginous construct for auricular reconstruction.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:505196 |
| Date | January 2008 |
| Creators | O'Sullivan, Niamh-Anna |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/17225/ |
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