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Show 6 Jessica Ashmead college of engineering The goal of this project was to create a cardiac tissue model using a polyurethane substrate to mimic functional parameters of human cardiac tissue. One important parameter is stiffness. To evaluate stiffness using a model, a 3D construct is necessary. The construct was created by culturing cells on a substrate enclosed in a perfusion bioreactor. The bioreactor provided nutrients to the cells through perfusion; however, due to flow, the cells may be washed away during culture. We investigated two solutions: (1) substrate coating with fibronectin to increase cell attachment, and (2) altering the flow parameters to prevent the cells from being washed out. Before the bioreactor was used, its performance had to be validated with the following tests: (1) Sterility- the bioreactor was submerged in a tank of water and was pressurized with air to observe leaks; (2) Hydrau-lic permeability-a constant pressure was maintained during equilibrium flow through the bioreactor. The flow was measured and used to calculate hydraulic permeability; (3) Cell environment-the bioreactor was run under normal culture conditions inside an incubator without cells for one week to evaluate its stability. After the bioreactor was validated, three tests were run to determine flow rate conditions that prevent fibroblasts from being washed out of the substrate during perfusion. Each test consisted of six bioreac-tors, three of which were coated with fibronectin. The following flow conditions were evaluated: (1) 1 mL/ min with no dwell between cycles, (2) 10 mL/min with no dwell between cycles, (3) 10 mL/min with a 10 minute dwell between cycles. After culture, the substrates were removed from the bioreactor, tested for stiffness using the Instron and imaged to determine the cell density. Sterility tests proved that the bioreactor could maintain sterility. Hydraulic permeability of this new design resulted in a consistent flow rate of 1.83 ± 0.28 g/min. The bioreactor was also able to maintain a viable cell environment during cell culture. Cell culture has yet to show if a specific flow condition combined with protein coating with result in improved cell attachment. DEVELOPMENT OF A BIOREACTOR AS A PLATFORM FOR CARDIAC TISSUE MODEL Jessica Ashmead (Robert Hitchcock) Department of Bioengineering University of Utah UNDERGRADUATE RESEARCH ABSTRACTS Robert Hitchcock |
