Corneal Tissue Engineering: New Applications for Corneal Stromal Stem Cells

The WHO estimates 10 million people in the World are blinded by corneal disease. For many conditions, transplantation of a donor cornea may restore vision. However, there is a global shortage of suitable tissue and a high risk of rejection. The potential of stem cell therapies and tissue engineering approaches to address this significant unmet clinical need was investigated. Limbal epithelial stem cells (LESC) maintain the epithelium, the outermost layer of the cornea, and can be successfully transplanted to restore vision. However, when scarring occurs, transplantation of corneal stroma is required. Human corneal stromal stem cells (CSSC) are involved in stroma maintenance and have previously been shown to restore transparency in cloudy mouse corneas without rejection. This study investigated the development of a surgeon friendly tissue equivalent (TE) for the therapeutic delivery of CSSC and LESCs. For the first time, human corneal rims were rendered transparent for imaging under the iDISCO protocol. CSSC were successfully isolated and characterised with mesenchymal stem cell (MSC) properties confirmed. RAFT-TE, a potential artificial ocular surface, has been extensively investigated by our group using research grade collagen (First Link; not suitable for clinical use). In this thesis, a comparative study was performed to show that Koken collagen (Good Manufacturing Practice compliant) is a suitable replacement for research grade collagen as it did not compromise RAFT-TE properties. Next, co-culture conditions for LESC and CSSC in RAFT-TE were optimised. First, the idea of co-delivering CSSC together with LESCS to the surface of RAFT-TE as a mixed population was trialled. This resulted in unexpected epithelial cell peeling. To overcome this challenge, CSSC were successfully cultured for the first time inside Koken RAFT-TE. CSSC formed cell clusters, remodelled the matrix, and migrated to the surface of the TE. It was also shown that they can be induced to differentiate towards the keratocyte lineage inside the TE. This work highlights the importance of considering clinical manufacturing standards early in the process of development. Overall, it provides valuable insights to develop personalised autologous therapies and off the shelf allogeneic strategies for restoring vision in patients with corneal blindness

Occupational respiratory diseases

Shipping list no.: 87-222-P."September 1986."S/N 017-033-00425-1 Item 499-F-2Also available via the World Wide Web.Includes bibliographies and index