Date of Award

Spring 1998

Document Type

Thesis

Degree Name

Master of Science in Applied Chemistry - (M.S.)

Department

Chemical Engineering, Chemistry and Environmental Science

First Advisor

David S. Kristol

Second Advisor

Lev N. Krasnoperov

Third Advisor

Shlomo Gabbay

Abstract

Valvular failure due to calcification and leaflet disruption of artificial bioprostheses is still a major concern in valve replacement surgery. Previous studies have shown that Glutaraldehyde, a chemical used in the treatment of artificial valves promotes calcification. In this investigation glutaraldehyde and No-React® treated tissue samples of pericardium, cusp and the aortic wall were tested for cytocompatibility using live mouse fibroblast cultures. The samples were cut into 3 X 3 mm2 washed in phosphate buffered saline solution, transferred into cell culture flask containing cells that had been cultured for 24 hours and incubated at 37 "C in 5 % CO2. Cell viability was monitored after 24 hours by dye exclusion method. The concentration of glutaraldehyde released from the tissues was monitored by incubating 3 X 3 mm2 glutaraldehyde treated tissue samples in cell culture media at 37 "C and 5 % CO2. The media was then analyzed for glutaraldehyde using UV/Visible spectrometer. The toxic levels of glutaraldehyde was monitored by first incubating the cell for 24 hours in cell culture media at 37 "C and 5 % CO2 and then injecting various know concentrations of standard glutaraldehyde and the viability monitored by use of dye exclusion method.

Experimental results showed that detoxified (No-React®) pericardium and cusp from Shelhigh Inc. had the highest cytocompatibility as compared to the aortic wall. There was high cell mortality in glutaraldehyde treated tissues and most of the cell die close to the tissue. They also show that glutaraldehyde concentrations less than 10 ppm does not have significant cell mortality. No glutaraldehyde was detected from the tissues tested for its release.

From the results it can be concluded that glutaraldehyde is one, but not the only factor responsible for cell death in fibroblast culture and that the aortic wall is much more difficult to detoxify as compared to pericardium and cusp. Lack of high glutaraldehyde release from incubated tissue and high cell mortality closer to the tissue shows that surface toxicity may play a part in cell mortality.

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Chemistry Commons

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