3D printing of biomedical devices with soft and biocompatible elastomers

Abstract

Additive manufacturing (AM) which is commonly known as 3D printing is evolving quickly during the last decades. It has been utilized in various areas including biomedical applications, such as tissue engineering, therapeutic delivery, surgical planning and implant designs. The possibility to fabricate complex geometries allows us to solve many problems that cannot be done using traditional methods. In this thesis, we explored possible applications of 3D printing in biomedical engineering. The first application was using 3D printing to address challenges in treatments for congenital heart diseases (CHD). 1.35 million infants are born with CHD each year in the world, reconstruction of right ventricle–to–pulmonary artery (RVPA) continuity is an integral part of various surgical procedures commonly performed in neonates and young infants to treat CHD. However, these conduits need multiple open-chest replacement surgeries because the size of the conduits cannot grow as infants grow. We addressed the lack of growth potential of RV-PA conduits using novel 3D-printed conduits that can change their shape in response to the physiological changes during pediatric growth. We utilized thermoplastic polycarbonate-based polyurethane as a filament material in a fused filament fabrication printing process. We characterized the material to determine the suitable printing parameters, then developed a customized bench-top fluidic set up to study the in-vitro functionalities of the 3D-printed conduits. The conduits can increase the effective diameters as the RV pressure increases during growth to accommodate increased blood flow rate. The second application was utilizing the same material to address the technique difficulties in vascular and microvascular anastomosis. Traditional suture method requires surgeons to have a long-time training before they can perform vascular anastomosis, and the surgeries usually last for hours, the sewing material may cause further damage to blood vessels after the surgery. To address these issues, we developed a 3D-printed device that can connect blood vessels together and allow a broader access of vascular and microvascular anastomosis by making the process simpler, faster, and safer. We believe that using 3D printing technology, we can provide new aspects in designing patient specific biomedical devices and develop experience of both patients and surgeons.