"In Vitro Examination of Poly(glycerol sebacate) Degradation Kinetics: Effects of Porosity and Cure Temperature"
Department: Materials Science and Engineering Advisor: Professor Sabrina Jedlicka
Poly(glycerol sebacate) (PGS) is a biodegradable and biocompatible elastomer that has been used in a wide range of biomedical applications, including drug delivery, microfluidic devices, and tissue engineering scaffolds. The material possesses similar mechanical properties to those of soft body tissues and is mechanically tunable by altering cure temperature. An increased cure temperature correlates to an increased amount of cross-linking, resulting in a greater elastic modulus. While a porous format is preferred for scaffolds, to allow cell ingrowth, PGS degradation has been primarily studied in a nonporous format. The purpose of this research was to investigate the degradation of porous PGS at three frequently used cure temperatures: 120°C, 140°C, and 165°C. The thermal, chemical, mechanical, and morphological changes were examined using thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy, compression testing, and scanning electron microscopy. Over the course of the 16-week degradation study, the samples’ pores collapsed. The specimens cured at 120°C demonstrated the most degradation and became gel-like after 16 weeks. Thermal changes were most evident in the 120°C and 140°C cure PGS specimens, as shifts in the melting and recrystallization temperatures occurred. Porous samples cured at all three temperatures displayed a decrease in compressive modulus after 16 weeks. This in vitro study helped to elucidate the effects of porosity and cure temperature on the biodegradation of PGS and will be valuable for the design of future PGS scaffolds.
Nadia Krook, a Lehigh University junior expecting to graduate in May 2014, is pursuing a major in materials science and engineering and a minor in nanotechnology. She continues to conduct research under Dr. Sabrina Jedlicka’s direction at Lehigh University, performing biodegradation studies of porous poly(glycerol sebacate) (PGS) at various cure temperatures. During the summer of 2012, Nadia participated in a ten-week Research Experience for Undergraduates (REU) program at the University of Pennsylvania in Dr. Ritesh Agarwal’s laboratory. She investigated one-dimensional nanostructure growth in II-VI semiconductors, cadmium selenide (CdSe) and cadmium telluride (CdTe).
Nadia is a member of Tau Beta Pi, Student Materials Society, Material Advantage, Engineers Without Borders, and the Society of Women Engineers. Nadia’s leadership experiences at Lehigh University include Vice President of Giving for the 2014 Class Officers and her evolving roles in the Office of First Year Experie nce from orientation leader, to orientation coordinator, to an intern.