Abstract
Purpose: :
Corneal transplantation is the most common form of tissue transplantation. However, shortage of donor corneas still remains an unsolved problem, and the development of artificial corneas therefore is a warrantable approach to provide replacement tissue for corneal grafting. Recently, a fishscale-derived collagen scaffold has been developed as an alternative biodegradable material for corneal regeneration (BioCornea). The BioCornea will be in the end resolved and replaced by the patient’s own cornea after performed transplantation. As corneal neovascularization is the main risk factor for immune rejections after corneal grafting, the aim of this experiment was to evaluate the pro- or antihem- and lymphangiogenic properties of the BioCornea in the transplant situation.
Methods: :
We performed corneal transplantations in mice. BioCornea grafts were prepared as buttons of 1.5 mm in diameter and 100µm thickness. Graft beds were prepared in the recipient eye of BALB/c mice; the BioCorneas were then placed in this central cavity and secured in place with eight equidistant single sutures (11-0 nylon) along the graft-host interface. Antibiotic ointment was placed on the surface and eyelids were closed with 7-0 sutures to avoid graft injury. Eyelid sutures were removed 3 days later. Low risk allogeneic transplantations (C57BL/6 to BALB/c) served as controls and were performed as previously described. After 7 (n=5) and 14 days (n=5) mice were sacrificed and the harvested corneas were stained and morphometrically analyzed for blood and lymphatic vessels.
Results: :
We analysed the total area of corneal vascularization including recipient bed and graft (total), only the recipient bed (recipient) and only the graft (graft) 7 and 14 days after keratoplasty. For the total area and the recipient bed no differences in hem- and lymphvascularization were found between BioCornea recipients and control recipients after 7 and 14 days (n=5 each; p>0.05). In contrast, the BioCornea transplant showed significant less hem and lymphangiogenesis after 7 and 14 days in comparison to control recipients (p<0.05).
Conclusions: :
The BioCornea transplantation procedure initiates a similar hem- and lymphangiogenic response in the recipient bed as an allogeneic graft. The Biocornea itself, in contrast, seems to be much less accessible for blood and lymphatic vessels than allogeneic grafts. Using the BioCornea in high risk situations could therefore be beneficial by maintaining its transparency more stable than donor tissue.
Keywords: transplantation • cornea: basic science • keratoprostheses