Design, Fabrication, and Characterization of Three Dimensional Complete Scaffolds for Bone Tissue Engineering

dc.contributor.authorAndric, Teaen
dc.contributor.committeechairFreeman, Joseph W.en
dc.contributor.committeememberWhittington, Abby R.en
dc.contributor.committeememberGoldstein, Aaron S.en
dc.contributor.committeememberDahlgren, Linda A.en
dc.contributor.committeememberRylander, M. Nicholeen
dc.contributor.departmentBiomedical Engineeringen
dc.date.accessioned2017-04-06T15:45:08Zen
dc.date.adate2012-05-02en
dc.date.available2017-04-06T15:45:08Zen
dc.date.issued2012-03-03en
dc.date.rdate2016-09-27en
dc.date.sdate2012-04-05en
dc.description.abstractSkeletal loss and bone deficiencies are major worldwide problem that is only expected to increase due to increase in aging population. As current standards in treatment autografts and allografts are not without drawbacks, there is a need for alternative bone grafts substitutes. The goal of this project was to utilize electrospinning and heat sintering techniques to create biodegradable full thickness three dimensional biomimetic polymeric scaffolds with macro and nano architecture similar to natural bone for bone tissue engineering. First we have investigated pretreatment with 0.1M NaOH and electrospinning gelatin/PLLA blends as means to increase overall mineral precipitation and distribution throughout the scaffolds when incubated in concentrated simulated body fluid (SBF)10XSBF. Mixture of 10% gelatin and PLLA resulted in the significantly higher degree of mineralization, increased mechanical properties, and scaffolds that supported cellular adhesion and proliferation. In the next step we applied heat sintering technique to fabricate 3D electrospun scaffolds that were used to evaluate effects of mineralization and fiber orientation on scaffold strength. Fiber orientation can make a slight difference in nanofibrous scaffold compressive mechanical properties, but this difference is not as profound as the difference seen with increased mineralization. We also developed a technique to fabricate scaffolds that mimic the organization of an osteon, the structural unit of cortical bone. Resulting scaffolds consisted of concentric layers of electrospun gelatin/PLLA nanofibers wrapped around microfiber core with diameters that ranged from 200-600µm. Individual osteon-like scaffolds were heat sintered to fabricate three dimensional scaffolds contained a system of channels running parallel to the length of the scaffolds, as found naturally in bone tissue. Finally we combined two previously fabricated structures, sintered electrospun sheets and individual osteon-like scaffolds, to create novel scaffolds that mimic dual structural organization of natural bone with cortical and trabecular regions. Mineralization for 24 hr significantly increased mechanical properties of the scaffolds, both yield stress and compressive modulus under physiological conditions. Both nonminerlized and mineralized scaffolds were found to support cellular attachment and proliferation over 28 days in culture, but scaffolds mineralized for 24hr were found to better support osteoblastic differentiation and mineral deposition.en
dc.description.degreePh. D.en
dc.identifier.otheretd-04052012-110604en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-04052012-110604/en
dc.identifier.urihttp://hdl.handle.net/10919/77346en
dc.language.isoen_USen
dc.publisherVirginia Techen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectCalcium Phosphateen
dc.subjectElectrospinningen
dc.subjectBoneen
dc.subjectTissue Engineeringen
dc.titleDesign, Fabrication, and Characterization of Three Dimensional Complete Scaffolds for Bone Tissue Engineeringen
dc.typeDissertationen
dc.type.dcmitypeTexten
thesis.degree.disciplineBiomedical Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

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