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Polysaccharide-based nanostructures for growth factor delivery and mesenchymal stem cell activation

dc.contributor.authorAlmodovar Montanez, Jorge Luis, author
dc.contributor.authorKipper, Matt J., advisor
dc.contributor.authorBailey, Travis S., committee member
dc.contributor.authorKisiday, John D., committee member
dc.contributor.authorPrasad, Ashok, committee member
dc.date.accessioned2007-01-03T05:47:33Z
dc.date.available2007-01-03T05:47:33Z
dc.date.issued2011
dc.description.abstractMesenchymal stem cells (MSCs) are very promising in tissue engineering and regenerative medicine because of their ability to differentiate into different type of cells including bone and cartilage. MSCs differentiation can be modulated using both chemical (i.e. proteins) and physical cues (ie. topography). This thesis presents work performed evaluating polysaccharide-based nanostructures for growth factor delivery and MSCs activation. Different polysaccharide-based nanostructures were developed and characterized including polyelectrolyte multilayers (PEMs) and electrospun nanofibers. On flat gold-coated glass surfaces, PEMs were constructed using the polycations chitosan and N,N,N -trimethyl chitosan, and the polyanions hyaluronan, chondroitin sulfate, and heparin. An exhaustive spectroscopic study was performed on all of the PEMs pairs to investigate the effects of polyelectrolyte charge density on thickness, swelling, composition, and ion-pairing. The results demonstrated that hydrophilicity and swelling are reduced when one polyelectrolyte is strong and the other is weak, while ion pairing is increased. The stability of adsorbed proteins to PEMs was also investigated using IR spectroscopy. Construction of PEMs and adsorption of basic fibroblast growth factor (FGF-2) was evaluated on heparin chitosan PEMs constructed on gold-coated glass, tissue culture polystyrene (TCPS), and titanium. In vitro testing of the FGF-2-loaded PEM constructed on TCPS and titanium was performed using ovine bone marrow-derived MSCs. It was noted that FGF-2 activity is enhanced, with regards to MSCs proliferation, when delivered from PEMs compared to delivery in solution. Chitosan nanofibers were successfully electrospun from a trifluoroacetic acid and dichloromethane solution. A new technique was developed to modify electrospun chitosan nanofibers with polyelectrolyte multilayers using N,N,N -trimethyl chitosan and heparin. Controlled release of bioactive FGF-2, complexed with heparin-chitosan polyelectrolyte complex nanoparticles, from electrospun chitosan nanofiber mats was achieved with zero order kinetics over a period of 27 days. When the nanofibers are further modified with a single PEM bilayer (PEM, composed of N,N,N -trimethyl chitosan and heparin), the release is completely prevented. The mitogenic activity of the released FGF-2 was also evaluated, with respect to the proliferation of ovine bone marrow-derived MSCs. The effect on osteogenic differentiation of bone marrow-derived ovine and equine MSCs seeded on electrospun chitosan nanofibers versus flat TCPS was investigated. The effect of dexamethasone on osteogenic differentiation was also investigated. We found that we can successfully grow and maintain both equine and ovine MSCs on electrospun chitosan nanofibers. Also, both MSCs exhibit higher differentiation markers (alkaline phosphatase activity) when cultured on chitosan nanofibers compared to flat TCPS surfaces. This work demonstrates new systems for stabilizing and controlling the delivery of heparin-binding growth factors for the activation of bone marrow-derived MSCs, using polysaccharide-based nanomaterials. These novel materials have potential applications in musculoskeletal tissue regeneration.
dc.format.mediumborn digital
dc.format.mediumdoctoral dissertations
dc.identifierAlmodovar_colostate_0053A_10557.pdf
dc.identifier.urihttp://hdl.handle.net/10217/50661
dc.languageEnglish
dc.language.isoeng
dc.publisherColorado State University. Libraries
dc.relation.ispartof2000-2019
dc.rightsCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.
dc.subjectglycosaminoglycans
dc.subjectgrowth factors
dc.subjectmesenchymal stem cells
dc.subjectMSC
dc.subjectnanofibers
dc.subjectpolysaccharides
dc.titlePolysaccharide-based nanostructures for growth factor delivery and mesenchymal stem cell activation
dc.typeText
dcterms.rights.dplaThis Item is protected by copyright and/or related rights (https://rightsstatements.org/vocab/InC/1.0/). You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
thesis.degree.disciplineChemical and Biological Engineering
thesis.degree.grantorColorado State University
thesis.degree.levelDoctoral
thesis.degree.nameDoctor of Philosophy (Ph.D.)

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