Fabrication and Characterization of Polymeric Aortic Vessels Anusha Aggarwal Vidhya Dhar anusha.peace@gmail.com vdhar131@gmail.com Anna Effenberger Jade Greenberg Tyler Lee anna@effenberger.com greenbjad@gmail.com tlee7141@gmail.com Dr. N. Sanjeeva Murthy* murthy@dls.rutgers.edu Dr. Thomas Emge* emge@rci.rutgers.edu New Jersey Governor’s School of Engineering and Technology July 27, 2018 *Corresponding Author Abstract—Polymers are attractive candidates for synthetic organ replacement because of their biodegradable and biocom- patible properties. This study creates and evaluates a polymeric aortic vessel replacement designed to help those with connec- tive tissue disorders, such as Marfan syndrome, by preventing potentially fatal aortic enlargement and rupture. Differential scanning calorimetry, extrusion, tensile strength tests, and X- ray diffraction were used to ascertain the effect of different tests on the molecular and physical characteristics of polymers. Following these experiments, fused deposition 3D printing was used to create an aortic vessel replacement prototype. I. INTRODUCTION Polymers are a broad class of materials with a wide range of possible characteristics. They can be easily processed at lower temperatures and pressures in shorter amounts of time relative to other materials, such as metals or ceramics [1]. Con- sequently, the use of polymers to design effective biomedical devices is rising. Current biomedical research lends itself towards total tissue replacement as a method of treatment for chronic connec- tive tissue disorders. However, synthetic replacements using polymers have accelerated development and have the potential to be more reliable and customizable. Combined with the potential capabilities of 3D printing technology, many view the future of polymeric biomedical devices with optimism [2]. This project aims to address a specific complication of Marfan syndrome and other connective tissue diseases via the characterization and fabrication of a polymeric blood vessel, specifically the aorta. To improve the prognosis of patients with these disorders, the device needs to be customizable, efficient, and inexpensive. The first step was to experiment with the given polymers to find the optimal parameters to design and manufacture the device. Experimentation in the lab with differential scanning calorimetry (DSC), extrusion, tensile strength testing, and X-ray diffraction were used to evaluate the proper polymer for the success of the device. Two biocompatible polymers which are able to function alongside the body’s tissues were utilized in the prototype of the biomed- ical device. Thermoplastic polyurethane (TPU), specifically the commercialized NinjaFlex, was used to mimic the elastic inner layer of the aorta, and polylactic acid (PLA) was used to act as the strong, rigid outer layer. II. BACKGROUND A. Cardiovascular manifestations of Marfan syndrome Marfan syndrome is one of the most well-known genetic connective tissue disorders, affecting approximately 1 in every 5,000 people [4]. It is an autosomal dominant disorder that compromises the body’s ability to create structurally sound connective tissue throughout the entire body, including the skin, intestines, and blood vessels [3]. This inability to create effective connective tissue is especially critical in the aorta, the first blood vessel through which oxygenated blood leaves the heart, as it is subject to the highest blood pressure. All blood vessels, including the aorta, are comprised of three layers attached by connective tissue. When the connective tissue is weak, as in Marfan syndrome, the pressure the heart exerts on blood vessels can cause the vessels to expand; this expansion is known as an aortic aneurysm. This expansion and subsequent thinning of the vessel walls leads to a higher risk of aortic dissection, where a tear forms in a layer of the 1