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dc.contributor.advisor Klitzman, Bruce en_US
dc.contributor.author Prichard, Heather Ledbetter en_US
dc.date.accessioned 2008-08-01T12:53:18Z
dc.date.available 2008-08-01T12:53:18Z
dc.date.issued 2008-03-18 en_US
dc.identifier.uri http://hdl.handle.net/10161/662
dc.description Dissertation en_US
dc.description.abstract <p>Many implanted devices fail due to the formation of an avascular capsule. Fat is known to promote healing and vascularization. It is possible that isolating and attaching ASCs (adipose stem cells) to an implanted device improves the healing in the adjacent tissue. </p><p> Various attachment methods were studied, and the fibronectin treatment was found comparable to or better than other treatments. Next, bare and ASC coated polyurethane were implanted into rats. The fibrous capsule surrounding the bare polyurethane was thicker and contained more collagen at 8 weeks. Additionally, the microvessel density in the tissue surrounding the ASC coated polyurethane was significantly higher at 4 and 8 weeks. Quantification of glucose sensor response following ASC attachment for 1 week found no measurable significant differences in function.</p><p> The bioluminescence technique, which quantifies the tissue glucose concentration around the implant at the moment of freezing, was used to determine if ASC attachment to biomaterials impacts the tissue glucose concentration profile. ASC attachment to polyurethane and to glucose sensors did not significantly change the glucose profiles in the tissue. However, a quantifiable glucose concentration profile was observed around all glucose sensors.</p><p> The final experiments were performed to identify a possible mechanism that adipose tissue uses to alter the foreign body response. In vitro experiments showed that VEGF (VEGF-A specifically) secretion following ASC attachment to polyurethane was 10-20 times higher than with fibroblast attachment after three days and 40-70 times higher after six days. This high secretion of VEGF would likely have in vivo physiological affects on microvasculature.</p><p> In conclusion, the attachment of ASCs to polyurethane reduced the thickness and collagen content of the fibrous capsule surrounding ASC coated implants and increased the microvessel density in adjacent tissue. In addition, ASC attachment did not enhance glucose sensor function, nor did it decrease the glucose concentration in the adjacent tissue. Finally, ASCs were found to secrete high amounts of pro-vascular cytokines, which likely plays a key role in the observed improvement of the foreign body response.</p> en_US
dc.format.extent 15033921 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US
dc.subject Engineering, Biomedical en_US
dc.subject adipose stem cells en_US
dc.subject foreign body response en_US
dc.subject biomaterial en_US
dc.subject implant en_US
dc.subject vascularity en_US
dc.title Adipose Stem Cells Improve the Foreign Body Response en_US
dc.type Dissertation en_US
dc.department Biomedical Engineering en_US
duke.embargo.months 12 en_US
dc.date.accessible 2009-08-02T05:00:05Z

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