Poster T18 - Alternative Bioreactor model for Atherosclerosis Study

Introduction: Atherosclerosis: Chronic inflammation within arterial walls, leading to plaque and cardiovascular events like heart attacks and strokes.
Foremost cause of morbidity in the United States and a global health concern [1-3].
Annual heart disease-related deaths in the United States: approximately 610,000 [2].
Manifests in specific diseases: PAD, CAD, renal artery stenosis, carotid artery disease, mesenteric artery disease, and vertebral artery disease [1-2].
Nearly 50% of Americans exhibit risk factors like high blood pressure contributing to arterial plaque [3-4].
Deeper insights are needed into the causes and impacts of vascular diseases.
In vitro modeling and testing are essential due to their complexity and wide occurrence.
Bioreactors offer controlled, physiological environments for accurate replication and investigation of cellular responses, growth, and arterial changes.

Objective: To develop a bioreactor that can mimic the environment of atherosclerotic arteries.

Materials and

Methods: Fluid Flow Analysis (CFX) on Ansys program.
Sketch the geometry to include a circle with a diameter of 1 inch extruded to a length of 10 inches [5].
Generate a mesh selecting every surface of the artery.
For the flow analysis, the setup includes a steady-state flow simulation with non-slip wall conditions.
Three boundaries were selected and labeled for this simulation: Inlet, outlet, and wall.
The inlet has a velocity of 0.1 for the normal speed.
The outlet, which is the face selected opposite of the inlet, has a relative pressure of 0.
The material to be inserted into the artery will be labeled as “blood”, with the dynamic viscosity being 3.6 Pa.s and the density being 1,060 kg m^-3 [6]. This material will have no heat transfer and will have laminar flow.

Results, Conclusions, and Discussions: Fig 3. The artery in this simulation is 10 inches in length and has a diameter of 1 inch, as this is the standard diameter of a carotid artery [6]. The occlusion in the artery has a height of 0.5 in, which is half the diameter of the carotid artery in the simulation. The velocity starting at the inlet is shown with the velocity vectors at the inlet in green, indicating a medium level of velocity. The velocity plane inserted shows the large amount of blue/green color, which is a medium-to-low level of velocity due to the occlusion in the middle. The velocity increases at the level of the occlusion due to the pressure and size decrease from the inlet to the outlet. Included in this image is a close-up image of the occlusion area. The close-up view shows the velocity vectors in green arrows. The results of this image taken from the red line running straight across the chamber is also depicted on the graph shown on the left with the velocity reaching its greatest affect at the occlusion.
Fig 4. This image depicts the artery in the simulation described above focusing on its axial velocity gradient on the axis parallel to the artery and wall shear stress (WSS), specifically around the occlusion. The axial velocity stays relatively steady until it hits the occlusion, where there is an area before it that shows a slower axial velocity as well as the area right after having the highest axial velocity. This image includes a close-up image of the occlusion focusing on the WSS depicted with arrows. The results of this image taken from the red line running along the wall is depicted in the form of a graph on the left, showing the change in WSS as it is affected by the occlusion.

Acknowledgements (Optional): This work has been partially supported by NSU PFRDG (President's Faculty Research Development Grant) 334883 and Broward County Grant BCCARES-006837.