title: Tuna cornea as biomaterial for cardiac applications.
abstract: Among available biomaterials, cornea is almost completely devoid of cells and is composed only of collagen fibers oriented in an orderly pattern, which contributes to low antigenicity. Thunnus thynnus, the Atlantic bluefin tuna, is a fish with large eyes that can withstand pressures of approximately 10 MPa. We evaluated the potential of this tuna cornea in cardiac bioimplantation. Eyes from freshly caught Atlantic bluefin tuna were harvested and preserved in a fixative solution. Sterilized samples of corneal stroma were embedded in paraffin and stained with hematoxylin and eosin, and the histologic features were studied. Physical and mechanical resistance tests were performed in comparison with bovine pericardial strips and porcine mitral valves. Corneal material was implanted subcutaneously in 7 rats, to evaluate in vivo calcification rates. Mitral valves made from tuna corneal leaflets were implanted in 9 sheep. We found that the corneal tissue consisted only of parallel collagen fibers without evidence of vascular or neural structures. In tensile strength, the tuna corneal specimens were substantially similar to bovine pericardium. After 23 days, the rat-implanted samples showed no calcium or calcium salt deposition. Hydrodynamic and fatigue testing of valve prototypes yielded acceptable functional and long-term behavioral results. In the sheep, valvular performance was stable during the 180-day follow-up period, with no instrumental sign of calcification at the end of observation. We conclude that low antigenicity and favorable physical properties qualify tuna cornea as a potential material for durable bioimplantation. Further study is warranted.
authors: Department of Cardiovascular Surgery, University of Modena and Reggio Emilia, 41124 Modena, Italy. roberto.parravicini@unimore.it
authors: Roberto
authors: R
authors: Parravicini
authors: Flavio
authors: F
authors: Cocconcelli
authors: Alessandro
authors: A
authors: Verona
authors: Valeriano
authors: V
authors: Parravicini
authors: Enrico
authors: E
authors: Giuliani
authors: Alberto
authors: A
authors: Barbieri
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001705:Bioprosthesis; D002114:Calcinosis / Q000473:pathology; D002417:Cattle; D003315:Cornea / Q000276:immunology / Q000473:pathology / Q000601:surgery*; D006087:Graft vs Host Reaction; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D057446:Hydrodynamics; D008297:Male; D008422:Materials Testing; D008943:Mitral Valve / Q000637:transplantation*; D010496:Pericardium / Q000637:transplantation; D011474:Prosthesis Design; D051381:Rats; D012756:Sheep; D040521:Subcutaneous Tissue / Q000473:pathology / Q000601:surgery; D013552:Swine; D013718:Tensile Strength; D014183:Transplantation, Heterologous; D014413:Tuna
chemical_list: D001672:Biocompatible Materials