This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).

INTELLECTUAL MERIT: Silica aerogels are mesoporous materials formed as wet silica gels and dried by supercritical fluid extraction of the pore-filling gelation solvent. They are lightweight with high porosity but typically have low mechanical strength. Recently, Co-PI Leventis developed a method to nanoencapsulate 3D silica nanostructures under a conformal polymer coating without clogging the pores. This novel lightweight material, termed crosslinked aerogel (X-aerogel), has a significantly improved mechanical strength and possesses surface chemistry resembling biocompatible polyurethane. It is proposed here to develop this material as a leaflet material for artificial heart valves, typically made now of pyrolytic carbon. It is hypothesized that the lighter weight of X-aerogel valve leaflets will lead to lower transvalvular pressures and reduced cavitation in the blood. This hypothesis will be tested through the following specific aims: (1) To determine the biocompatibility of X-aerogels towards plasma, blood cells (especially platelets) and vascular endothelial cells. (2) To characterize the mechanical behavior and chemical stability of X-aerogels under compressive, tensile, shear, and bi-axial stress states; creep, relaxation, fracture, and fatigue of the material will also be tested. (3) To manufacture an X-aerogel monoleaflet heart valve and determine its hemodynamic performances in a flow chamber with dynamic properties matching the in vivo circulation.

BROADER IMPACTS: In view of the prevalence of heart valve defects requiring surgical valve replacement and the projected continuing need for artificial heart valves, this materials development proposal has the potential for significant clinical impact. The project is headed by a very interdisciplinary team, and it provides excellent opportunities for training of students across the boundaries of chemistry, materials science, and biomedical engineering. Both graduate students and undergraduate students will be trained on the project. Provisions have been made for visits by PIs and students between the Oklahoma State and Missouri Rolla sites.

Agency
National Science Foundation (NSF)
Institute
Division of Materials Research (DMR)
Type
Standard Grant (Standard)
Application #
0907291
Program Officer
mohan srinivasarao
Project Start
Project End
Budget Start
2009-08-15
Budget End
2013-07-31
Support Year
Fiscal Year
2009
Total Cost
$425,000
Indirect Cost
Name
Oklahoma State University
Department
Type
DUNS #
City
Stillwater
State
OK
Country
United States
Zip Code
74078