LEADER 00000nam  2200421   4500 
001    AAI3469772 
005    20121128085312.5 
008    121128s2011    ||||||||||||||||| ||eng d 
020    9781124860961 
035    (UMI)AAI3469772 
040    UMI|cUMI 
100 1  Tefft, Brandon James 
245 10 Enhancement of Endothelial Cell Retention on Vascular 
       Constructs by siRNA-Mediated Gene Silencing 
300    362 p 
500    Source: Dissertation Abstracts International, Volume: 72-
       12, Section: B, page: 7513 
500    Adviser: Shu Q. Liu 
502    Thesis (Ph.D.)--Northwestern University, 2011 
520    Tissue engineered vascular grafts hold great promise as 
       alternative graft sources for vascular bypass surgery. 
       Fulfilling this promise requires a strategy to improve the
       retention of vascular endothelial cells within the lumen 
       of these grafts upon implantation. Here, a novel gene 
       silencing strategy for increasing endothelial cell 
       adhesion is presented and tested using a custom variable-
       width parallel plate flow chamber 
520    The protein tyrosine phosphatases SHP-1 and SHP-2 are 
       known to inhibit cell adhesion. By treating human 
       umbilical vein endothelial cells with siRNA specific for 
       SHP-1 or SHP-2 mRNA, it is possible to knockdown the 
       expression of SHP-1 or SHP-2, respectively, and thus 
       enhance endothelial cell adhesion. Endothelial cells that 
       had been untreated, treated with scrambled siRNA, treated 
       with SHP-1 specific siRNA, or treated with SHP-2 specific 
       siRNA were seeded onto fibronectin-coated ePTFE membranes 
       and exposed to a range of pulsatile fluid shear stresses 
       for 1 hour and 6 hours. Fluid shear stress was generated 
       in a custom variable-width parallel plate flow chamber, 
       which was validated both experimentally and 
       computationally. Treatment with SHP-1 or SHP-2 specific 
       siRNA resulted in significantly improved cell retention 
       when compared to the untreated and scrambled siRNA treated
       controls. For example, after exposure to 6 hours of 15 dyn
       /cm2 average shear stress, cell retention was 
       significantly higher for SHP-1 siRNA treated cells (72%) 
       and SHP-2 siRNA treated cells (86%) when compared to 
       untreated cells (30%) and scrambled siRNA treated cells 
       (35%) 
520    Furthermore, treatment with SHP-1 or SHP-2 specific siRNA 
       resulted in a 17% increase in focal contact density per 
       cell area compared to untreated and scrambled siRNA 
       treated controls. In addition, neither treatment with SHP-
       1 specific siRNA nor SHP-2 specific siRNA significantly 
       altered the expression of the endothelial cell markers VE-
       cadherin, VEGFR-2, and PECAM-1 compared to untreated and 
       siRNA treated controls 
520    This study demonstrates that gene silencing may be an 
       effective strategy for improving the retention of 
       endothelial cells within tissue engineered vascular grafts
590    School code: 0163 
650  4 Biology, Molecular 
650  4 Applied Mechanics 
650  4 Engineering, Biomedical 
690    0307 
690    0346 
690    0541 
710 2  Northwestern University.|bBiomedical Engineering 
773 0  |tDissertation Abstracts International|g72-12B 
856 40 |uhttp://pqdd.sinica.edu.tw/twdaoapp/servlet/
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