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dc.contributor.authorCooke, Shelley Lynnen_US
dc.date.accessioned2015-07-11T06:00:41Z
dc.date.available2015-07-11T06:00:41Z
dc.date.issued2014-01-16en_US
dc.identifier.othervt_gsexam:1837en_US
dc.identifier.urihttp://hdl.handle.net/10919/54540
dc.description.abstractHigh levels of ionizing radiation are known to cause degradation and/or cross-linking in polymers. Lower levels of ionizing radiation, such as x-rays, are commonly used in the treatment of cancers. Material characterization has not been fully explored for polymeric materials exposed to therapeutic radiation levels. This study investigated the effects of therapeutic radiation on three porous scaffolds: polycaprolactone (PCL), polyurethane (PU) and gelatin. Porous scaffolds were fabricated using solvent casting and/or salt leaching techniques. Scaffolds were placed in phosphate buffered saline (PBS) and exposed to a typical cancer radiotherapy schedule. A total dose of 50 Gy was broken into 25 dosages over a three-month period. PBS was collected over time and tested for polymer degradation through high performance liquid chromatography (HPLC) and bicinchoninic acid (BCA) protein assay. Scaffolds were characterized by changes in microstructure using Scanning Electron Microscopy (SEM), and crystallization using Differential Scanning Calorimetry (DSC). Additionally, gelatin ε-amine content was analyzed using Trinitrobenzene Sulfonic Acid Assay (TNBSA). Gelatin scaffolds immersed in PBS for three months without radiation served as a control. Each scaffold responded differently to radiation. PCL showed no change in molecular weight or microstructure. However, the degree of crystallinity decreased 32% from the non-irradiated control. PU displayed both changes in microstructure and a decrease in crystallinity (85.15%). Gelatin scaffolds responded the most dramatically to radiotherapy. Samples were observed to swell, yet maintain shape after exposure. As gelatin was considered a tissue equivalent, further studies on tissues are needed to better understand the effects of radiotherapy.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.rightsThis Item is protected by copyright and/or related rights. Some uses of this Item may be deemed fair and permitted by law even without permission from the rights holder(s), or the rights holder(s) may have licensed the work for use under certain conditions. For other uses you need to obtain permission from the rights holder(s).en_US
dc.subjectradiation agingen_US
dc.subjectgelatinen_US
dc.subjectpolycaprolactoneen_US
dc.subjectpolyurethaneen_US
dc.subjectporous scaffoldsen_US
dc.subjecttissue engineeringen_US
dc.titleEffects of Therapeutic Radiation on Polymeric Scaffoldsen_US
dc.typeThesisen_US
dc.contributor.departmentMaterials Science and Engineeringen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineMaterials Science and Engineeringen_US
dc.contributor.committeechairWhittington, Abby Rebeccaen_US
dc.contributor.committeememberCorcoran, Sean G.en_US
dc.contributor.committeememberEdgar, Kevin J.en_US


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