{"514771":{"#nid":"514771","#data":{"type":"event","title":"PhD Defense by  Nathan Evans","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003EMSE PhD Defense - Nathan Evans\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ETime:\u0026nbsp;March 31\u003Csup\u003Est\u003C\/sup\u003E, 1:00-3:00pm\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;Location:\u0026nbsp;\u003Cstrong\u003ERoom 114, Callaway Manufacturing Research Building\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003E\u0026nbsp;Committee Members:\u003C\/strong\u003E\u003Cbr \/\u003E Dr. Ken Gall, ME\/MSE, Duke University (advisor)\u003Cbr \/\u003E Dr. Robert Guldberg, ME\u003Cbr \/\u003E Dr. Satish Kumar, MSE\u003Cbr \/\u003E Dr. David McDowell, ME\/MSE\u003Cbr \/\u003E Dr. Meisha Shofner, MSE\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;Title:\u003Cstrong\u003E\u0026nbsp;Processing-Structure-Property Relationships of Surface Porous Polymers for Orthopaedic Applications\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EAbstract:\u003C\/strong\u003E \u003C\/p\u003E\u003Cp\u003EThe use of polymers in orthopaedics is steadily increasing. In some markets, such as spinal fusion and soft tissue anchors, the polymer polyetheretherketone (PEEK) is already the material of choice in the majority of implants. Despite PEEK\u2019s widespread use, it is often associated with poor osseointegration, which can lead to implant loosening and ultimately failure of the device. Many attempts have been explored to improve the osseointegration of PEEK but none have had widespread clinical success.\u003C\/p\u003E\u003Cp\u003EIn this dissertation, a novel surface porous structure has been created, where limiting the porosity to the surface maintains adequate mechanical properties for load bearing applications while providing a surface for improved osseointegration. Careful control of the processing parameters resulted in tunable porous microstructures optimized for bone ingrowth: highly interconnected 200-500\u00b5m pores with porosity ranging from 60-85% and pore layers from 300-6000\u00b5m thick.\u0026nbsp; Mechanical characterization, including monotonic tensile and compression, tensile fatigue, shear, interfacial shear, and abrasion tests, were used to probe the effects of the surface porosity on the relevant mechanical properties of the material.\u003C\/p\u003E\u003Cp\u003EIn addition, the effect of surface porosity and surface roughness on the mechanical properties of a range of thermoplastics with varying chemistries and crystallinities was explored. This research showed that there is a great disparity in the notch sensitivity of polymers that correlates to the polymers fracture toughness as well as trends in the monotonic stress-strain curve. The results illustrate that care must be taken in the design of polymeric implants, especially when introducing topographical changes to promote osseointegration, in order to ensure they maintain adequate load-bearing capacity.\u003C\/p\u003E\u003Cp\u003EFinally, preliminary in vitro and in vivo data demonstrated the ability of PEEK-SP to promote osseointegration. Cells grown on PEEK-SP demonstrated enhanced mineralization and differentiation, suggesting the ability of PEEK-SP to facilitate bone ingrowth. The potential of PEEK-SP was further demonstrated by implantation in a rat femoral segmental defect model which demonstrated bone ingrowth and reduced formation of a fibrous capsule.\u003C\/p\u003E\u003Cp\u003E \u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Processing-Structure-Property Relationships of Surface Porous Polymers for Orthopaedic Applications"}],"uid":"27707","created_gmt":"2016-03-17 09:12:12","changed_gmt":"2016-10-08 02:17:06","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2016-03-31T14:00:00-04:00","event_time_end":"2016-03-31T16:00:00-04:00","event_time_end_last":"2016-03-31T16:00:00-04:00","gmt_time_start":"2016-03-31 18:00:00","gmt_time_end":"2016-03-31 20:00:00","gmt_time_end_last":"2016-03-31 20:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}