Selection of materials for biodegradable heart plug prototype

Abstract

Patent Foramen Ovale (PFO) is a defect in the wall between the two atriums of heart, allowing blood to flow from right to left atrium. It is associated with the occurrence of cryptogenic stroke, hypoxemia and migraine headaches. One preferred closure method is percutaneous device closure, which is done without open heart surgery. PFO occluders that are currently available in the market contain metal, which is not desirable as it can cause toxicity and allergic reaction. Thus, fully biodegradable device is widely researched and developed. Spurring by this trend, the team of School of Materials Science & Engineering has developed two devices, namely Double Umbrella and Chinese Lantern, which can be delivered transcutaneously. However, developing novel material for better endothelialization and mechanical properties is still needed to improve the performance of the device, especially for Double Umbrella design.

In this project, four in-house synthesized biodegradable polymers are evaluated and compared against PURAC PLC7015. Twelve weeks of in-vitro degradation study as well as mechanical properties tests were performed. In addition, MTS assays with L-929 and HUVEC cells were done to check the compatibility of the polymers with the cells. From the four polymers, triblock copolymer of PLLA/PCL (75/25) – PCL/PLLA (75/25) – PLLA/PCL (75/25) (targeted molecular weight (kDa): 40-40-40) shows a potential to be used for PFO device application.