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dc.contributor.advisorLawrence J. Bonassar, Ph.D.
dc.contributor.authorGenes, Nicholas G.
dc.date2022-08-11T08:08:46.000
dc.date.accessioned2022-08-23T16:07:32Z
dc.date.available2022-08-23T16:07:32Z
dc.date.issued2003-08-11
dc.date.submitted2006-08-09
dc.identifier.doi10.13028/fb6k-ev79
dc.identifier.urihttp://hdl.handle.net/20.500.14038/32267
dc.description<p>Some images did not scan well. Please see print version for images.</p>
dc.description.abstractThe mechanism of mechanotransduction in chondrocyte matrix metabolism is not well understood, in part because of the density of cartilage and in part because of limitations in in vitroculture systems. Using alginate covalently modified to include the integrin adhesion ligand R-G-D (arginine-glycine-aspartate) represents a unique approach to studying mechanotransduction in that it allows for exploration of the role of integrin adhesion in mediating changes to chondrocyte behavior. The hypothesis of this research was that chondrocytes will form a cytoskeletal adhesion to RGD-alginate mediated integrins, that this attachment will enable chondrocyte sensation of mechanical signals, and this signaling will alter chondrocyte matrix metabolism. The first aim of this research was to characterize chondrocyte attachment to RGD-alginate, and assess the role of substrate mechanics on chondrocyte attachment kinetics and morphology. Secondly, the effect of chondrocyte attachment to RGD-alginate in 3D culture on matrix biosynthesis was assessed, as were changes in substrate mechanics. Finally, this research aimed to determine the metabolic response of chondrocytes to changes in intrinsic and extrinsic mechanics. It was found that the RGD ligand functionalized the alginate scaffold, enabling chondrocytes to sense the mechanical environment. Attachment kinetics, morphology, and proteoglycan metabolism were found to adapt to hydrogel matrix stiffness when an integrin adhesion was present. Externally applied compression was transmitted through this integrin attachment, causing changes in proteoglycan synthesis. Components of media serum were found to modulate the effects of integrin mechanotransduction. These results were obtained by analyzing a novel approach with established techniques, such as the DMB dye assay for sulfated GAG content. The conclusions conform to diverse data from cartilage explant loading and monolayer culture studies, yet were accomplished using one versatile system in a straightforward manner. The potential of this system extends further, into identification of intracellular signaling pathways and extracellular modulation of matrix components. Seeded RGD-alginate is well suited for studying consequences of integrin attachment.
dc.language.isoen_US
dc.rightsCopyright is held by the author, with all rights reserved.
dc.subjectExtracellular Matrix
dc.subjectChondrocytes
dc.subjectOsteoarthritis
dc.subjectTransduction
dc.subjectGenetic
dc.subjectLigands
dc.subjectIntegrins
dc.subjectCarbohydrates
dc.subjectCells
dc.subjectChemical Actions and Uses
dc.subjectMusculoskeletal Diseases
dc.subjectMusculoskeletal System
dc.subjectTissues
dc.titleChondrocyte Adhesion to RGD-bonded Alginate: Effect on Mechanotransduction and Matrix Metabolism: a Dissertation
dc.typeDoctoral Dissertation
dc.identifier.legacyfulltexthttps://escholarship.umassmed.edu/cgi/viewcontent.cgi?article=1089&amp;context=gsbs_diss&amp;unstamped=1
dc.identifier.legacycoverpagehttps://escholarship.umassmed.edu/gsbs_diss/89
dc.legacy.embargo2017-04-24T00:00:00-07:00
dc.identifier.contextkey190799
refterms.dateFOA2022-08-26T03:22:46Z
html.description.abstract<p>The mechanism of mechanotransduction in chondrocyte matrix metabolism is not well understood, in part because of the density of cartilage and in part because of limitations in <em>in vitro</em>culture systems. Using alginate covalently modified to include the integrin adhesion ligand R-G-D (arginine-glycine-aspartate) represents a unique approach to studying mechanotransduction in that it allows for exploration of the role of integrin adhesion in mediating changes to chondrocyte behavior.</p> <p>The hypothesis of this research was that chondrocytes will form a cytoskeletal adhesion to RGD-alginate mediated integrins, that this attachment will enable chondrocyte sensation of mechanical signals, and this signaling will alter chondrocyte matrix metabolism. The first aim of this research was to characterize chondrocyte attachment to RGD-alginate, and assess the role of substrate mechanics on chondrocyte attachment kinetics and morphology. Secondly, the effect of chondrocyte attachment to RGD-alginate in 3D culture on matrix biosynthesis was assessed, as were changes in substrate mechanics. Finally, this research aimed to determine the metabolic response of chondrocytes to changes in intrinsic and extrinsic mechanics.</p> <p>It was found that the RGD ligand functionalized the alginate scaffold, enabling chondrocytes to sense the mechanical environment. Attachment kinetics, morphology, and proteoglycan metabolism were found to adapt to hydrogel matrix stiffness when an integrin adhesion was present. Externally applied compression was transmitted through this integrin attachment, causing changes in proteoglycan synthesis. Components of media serum were found to modulate the effects of integrin mechanotransduction.</p> <p>These results were obtained by analyzing a novel approach with established techniques, such as the DMB dye assay for sulfated GAG content. The conclusions conform to diverse data from cartilage explant loading and monolayer culture studies, yet were accomplished using one versatile system in a straightforward manner. The potential of this system extends further, into identification of intracellular signaling pathways and extracellular modulation of matrix components. Seeded RGD-alginate is well suited for studying consequences of integrin attachment.</p>
dc.identifier.submissionpathgsbs_diss/89
dc.contributor.departmentCenter for Tissue Engineering
dc.description.thesisprogramMD/PhD


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