title: Mechanical evaluation and design of a multilayered collagenous repair biomaterial.
abstract: One method of fabricating implantable biomaterials is to utilize biologically derived, chemically modified tissues to form constructs that are both biocompatible and remodelable. Rigorous mechanical characterization is a necessary component in material evaluation to ensure that the constructs will withstand in vivo loading. In this study we performed an in-depth biaxial mechanical and quantitative structural analysis of GraftPatch (GP), a biomaterial constructed by assembling chemically treated layers of porcine small intestinal submucosa (SIS). The mechanical behavior of GP was compared to both native SIS and to glutaraldehyde-treated bovine pericardium (GLBP) as a reference biomaterial. Under biaxial loading, GP was found to be stiffer than native SIS and mechanically anisotropic, with the preferred fiber direction demonstrating greater stiffness. Quantitative structural analysis using small-angle light scattering indicated a uniform fiber structure similar to GLBP and SIS. To enable test-protocol-independent quantitative comparisons, the biaxial mechanical data were fit to an orthotropic constitutive model, which indicated a similar degree of mechanical anisotropy between the three groups. We also demonstrate how the constitutive model can be used to design layered biocomposite materials that can undergo large deformations.
authors.affiliation: Tissue Mechanics Laboratory, Department of Bioengineering, 749 Benedum Hall, 3700 O'Hara Street, Pittsburgh, Pennsylvania 15261, USA.
authors.forename: D C
authors.initials: DC
authors.lastname: Gloeckner
authors.forename: M S
authors.initials: MS
authors.lastname: Sacks
authors.forename: K L
authors.initials: KL
authors.lastname: Billiar
authors.forename: N
authors.initials: N
authors.lastname: Bachrach
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D002417:Cattle; D003094:Collagen; D007413:Intestinal Mucosa; D008954:Models, Biological; D019736:Prostheses and Implants; D013499:Surface Properties; D013552:Swine
chemical_list: D001672:Biocompatible Materials; D003094:Collagen