A polyconvex continuum-level proteoglycan Cauchy stress function was developed based on the continuum electromechanical Poisson-Boltzmann unit cell model for proteoglycan interactions. The resulting proteoglycan model was combined with a novel collagen fibril model and a ground substance matrix material to create a polyconvex constitutive finite element model of articular cartilage. The true collagen fibril modulus , and the ground substance matrix shear modulus , were varied to obtain the best fit to experimental tension, confined compression, and unconfined compression data for native explants and explants cultured in insulin-like growth factor-1 (IGF-1) and transforming growth factor-β1 (TGF-β1). Results indicate that culture in IGF-1 results in a weakening of the COL fibers compared to native explants, and culture in TGF-β1 results in a strengthening of the COL fibers compared to native explants. These results elucidate the biomechanical changes in collagen fibril modulus, and ground matrix shear modulus following in vitro culture with IGF-1 and TGF-β1. Understanding the constitutive effects of growth factor stimulated culture may have applications in AC repair and tissue engineering.
","abstract_html":"<p><a> </a> A polyconvex continuum-<a>level</a><a id="x-_anchor_2"></a><a> </a><a id="x-_anchor_3"></a> proteoglycan Cauchy stress function was developed based on the continuum electromechanical Poisson-Boltzmann unit cell model for proteoglycan interactions. The resulting proteoglycan model was combined with a novel collagen fibril model and a ground substance matrix material to create a polyconvex constitutive finite element model of a<a>rticular </a>cartilage. The true collagen fibril modulus , and the ground substance matrix shear modulus , were varied to obtain the best fit to experimental tension, confined compression, and unconfined compression data for native explants and explants cultured in insulin-like growth factor-1 (IGF-1) and transforming growth factor-β1 (TGF-β1). Results indicate that culture in IGF-1 results in a weakening of the COL fibers compared to native explants, and culture in TGF-β1 results in a strengthening of the COL fibers compared to native explants. These results elucidate the biomechanical changes in collagen fibril modulus, and ground matrix shear modulus following <em>in vitro</em> culture with IGF-1 and TGF-β1. Understanding the constitutive effects of growth factor stimulated culture may have applications in AC repair and tissue engineering.</p> <a></a>","abstract_has_math":false,"creators":["Stender, Michael"],"institution":null,"degree_name":"MS in Mechanical Engineering","degree_level":null,"degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":["Stephen Klisch"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-03-01T08:00:00Z","date_published":"2011-03-01T08:00:00Z","updated_at":"2026-07-24T01:31:11Z","subjects":["Articular Cartilage","Finite Element Modeling","Cartilage growth","Collagen Fiber Modulus.","Biomechanical Engineering","Mechanical Engineering"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["10.15368/theses.2011.19"],"render_values":[{"text":"10.15368/theses.2011.19","href":"https://doi.org/10.15368/theses.2011.19","code":true}]}]},"links":{"outbound_url":"https://digitalcommons.calpoly.edu/theses/463","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Stephen Klisch"]},{"key":"dc:creator","label":"Author","values":["Stender, Michael"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2011-03-18T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_name","label":"Degree Name","values":["MS in Mechanical Engineering"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Articular Cartilage","Finite Element Modeling","Cartilage growth","Collagen Fiber Modulus.","Biomechanical Engineering","Mechanical Engineering"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalcommons.calpoly.edu/theses/463","10.15368/theses.2011.19"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["A polyconvex continuum-level proteoglycan Cauchy stress function was developed based on the continuum electromechanical Poisson-Boltzmann unit cell model for proteoglycan interactions. The resulting proteoglycan model was combined with a novel collagen fibril model and a ground substance matrix material to create a polyconvex constitutive finite element model of articular cartilage. The true collagen fibril modulus , and the ground substance matrix shear modulus , were varied to obtain the best fit to experimental tension, confined compression, and unconfined compression data for native explants and explants cultured in insulin-like growth factor-1 (IGF-1) and transforming growth factor-β1 (TGF-β1). Results indicate that culture in IGF-1 results in a weakening of the COL fibers compared to native explants, and culture in TGF-β1 results in a strengthening of the COL fibers compared to native explants. These results elucidate the biomechanical changes in collagen fibril modulus, and ground matrix shear modulus following in vitro culture with IGF-1 and TGF-β1. Understanding the constitutive effects of growth factor stimulated culture may have applications in AC repair and tissue engineering.
"]},{"key":"dc:title","label":"Title","values":["Predicting Articular Cartilage Constituent Material Properties Following In Vitro Growth Using a Proteoglycan-Collagen Mixture Model"]}]}],"canonical_facts":{"dc:contributor":["Stephen Klisch"],"dc:creator":["Stender, Michael"],"dc:date.available":["2011-03-18T07:00:00Z"],"dc:description.abstract":["A polyconvex continuum-level proteoglycan Cauchy stress function was developed based on the continuum electromechanical Poisson-Boltzmann unit cell model for proteoglycan interactions. The resulting proteoglycan model was combined with a novel collagen fibril model and a ground substance matrix material to create a polyconvex constitutive finite element model of articular cartilage. The true collagen fibril modulus , and the ground substance matrix shear modulus , were varied to obtain the best fit to experimental tension, confined compression, and unconfined compression data for native explants and explants cultured in insulin-like growth factor-1 (IGF-1) and transforming growth factor-β1 (TGF-β1). Results indicate that culture in IGF-1 results in a weakening of the COL fibers compared to native explants, and culture in TGF-β1 results in a strengthening of the COL fibers compared to native explants. These results elucidate the biomechanical changes in collagen fibril modulus, and ground matrix shear modulus following in vitro culture with IGF-1 and TGF-β1. Understanding the constitutive effects of growth factor stimulated culture may have applications in AC repair and tissue engineering.
"],"dc:identifier":["https://digitalcommons.calpoly.edu/theses/463","10.15368/theses.2011.19"],"dc:subject":["Articular Cartilage","Finite Element Modeling","Cartilage growth","Collagen Fiber Modulus.","Biomechanical Engineering","Mechanical Engineering"],"dc:title":["Predicting Articular Cartilage Constituent Material Properties Following In Vitro Growth Using a Proteoglycan-Collagen Mixture Model"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_name":["MS in Mechanical Engineering"]},"updated_at":"2026-07-24T01:31:11Z"}