title: In Vitro Model of a Fibrosa Layer of a Heart Valve.
abstract: The fibrosa layer of a cardiac aortic valve is composed mostly of a dense network of type I collagen fibers oriented in circumferential direction. This main layer bears the tensile load and responds to the high stress on a leaflet. The inner fibrosa layer is also the site of pathophysiologic changes that result in valvular dysfunction, including stenosis and regurgitation. In vitro studies of these changes are limited by the absence of a substrate that mimics the circumferentially oriented structure of the fibrosa layer. In heart valve tissue engineering, generation of this layer is challenging. This study aimed to develop an artificial fibrosa layer of a native aortic leaflet. A unique morphologically biomimicked, pliable, but standalone substrate with circumferentially oriented nanofibers was fabricated by electrospinning on a novel collector designed for this study. The substrate had low-bulk tensile stiffness and ultimate strength; thus, cultured valvular interstitial cells (VICs) showed a fibroblast phenotype that is generally observed in a healthy aortic leaflet. Furthermore, gene and protein expression and morphology of VICs in substrates were close to those in the fibrosa layer of a native aortic leaflet. This artificial fibrosa layer can be useful for in vitro studies of valvular dysfunctions.
authors: Division of Cardiovascular Diseases, Mayo Clinic , 200 First Street SW, Rochester, Minnesota 55905, United States.
authors: Soumen
authors: S
authors: Jana
authors: Division of Cardiovascular Diseases, Mayo Clinic , 200 First Street SW, Rochester, Minnesota 55905, United States.
authors: Amir
authors: A
authors: Lerman
authors: School of Medicine, University of Kansas , 3901 Rainbow Boulevard, Kansas City, Kansas 66160, United States.
authors: Robert D
authors: RD
authors: Simari
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D001021:Aortic Valve / Q000166:cytology* / Q000378:metabolism; D049109:Cell Proliferation; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism; D004548:Elasticity; D008954:Models, Biological; D057139:Nanofibers / Q000737:chemistry; D011091:Polyesters / Q000737:chemistry; D013552:Swine; D013718:Tensile Strength; D023822:Tissue Engineering; D054457:Tissue Scaffolds; D014746:Vimentin / Q000378:metabolism
chemical_list: D000199:Actins; D024042:Collagen Type I; D011091:Polyesters; D014746:Vimentin; C016240:polycaprolactone
keywords: cardiac valve; fibrosa layer; nanofibrous substrate; tissue engineering; valvular interstitial cells