title: Prevention of experimental corneal allograft rejection in rabbits using cyclosporin-collagen shields.
abstract: Topical administration of cyclosporin A, a highly hydrophobic cyclic undecapeptide, has been relatively ineffective in preventing corneal allograft rejections due to poor drug penetration. Therefore, we investigated a new continuous-delivery system for cyclosporin A using collagen bandage shields fabricated from porcine scleral tissue. Collagen bandage shields containing 4 mg cyclosporin A were used for the treatment of four corneal allografts embedded in prevascularized rabbit corneas. Four controls were treated with shields containing no cyclosporin A. The shields were changed every 2nd day and signs of rejection were recorded. All controls were rejected by the end of the experiment. Treatment with collagen shields containing cyclosporin A effectively prevented such rejection. The clinical examinations were also confirmed with histopathological analysis. The results indicate that collagen shields can slowly release cyclosporin A and increase the penetration time for the drug. Thus, they are excellent delivery systems for hydrophobic drugs with poor penetration properties.
authors.affiliation: Laboratory of Immunology, Helsinki University Central Hospital, Finland.
authors.forename: K
authors.initials: K
authors.lastname: Mahlberg
authors.forename: R J
authors.initials: RJ
authors.lastname: Uusitalo
authors.forename: B
authors.initials: B
authors.lastname: Gebhardt
authors.forename: H E
authors.initials: HE
authors.lastname: Kaufman
mesh_terms: D000818:Animals; D001082:Aqueous Humor / Q000201:enzymology; D001684:Biological Dressings; D003094:Collagen; D003315:Cornea / Q000473:pathology; D003524:Cyclosporins / Q000493:pharmacokinetics / Q000627:therapeutic use*; D004195:Disease Models, Animal; D004337:Drug Carriers; D005451:Fluorescein Angiography; D006084:Graft Rejection / Q000187:drug effects*; D015948:Keratoplasty, Penetrating; D010740:Phospholipases / Q000378:metabolism; D011817:Rabbits; D014184:Transplantation, Homologous
chemical_list: D003524:Cyclosporins; D004337:Drug Carriers; D003094:Collagen; D010740:Phospholipases