Synthesis, Characterization and Properties of Biocompatible Poly(glycerol sebacate) Pre-Polymer and Gel

Synthesis, characterization and properties of biocompatible poly(glycerol sebacate) pre-polymer and gel

Yuan Li¹, Wayne D Cook¹, Cornelis Moorhoff¹, Wen-Chao Huang¹, Qi-Zhi Chen¹

¹Department of Materials Engineering, Monash University, Clayton, Victoria

Poly(glycerol sebacate) (PGS) is an elastomer with potential biomedical applications for soft tissue engineering but it suffers from problems with irreproducible synthesis and the unacceptable toxicity of very soft PGS elastomers^1,2. To establish the reason for these problems, PGS has been synthesized at 150 ºC/8 hours or 130 °C/24h, but crosslinked at 130 ºC under vacuum for 24, 48, 72, 96, 144 or 168 hours, and the reaction monitored by titration of the unreacted carboxylic groups and measurement of the mass loss during synthesis. It was found that evaporation of glycerol was a major cause of irreproducibility of the elastomer synthesis and this was more significant at higher reaction temperatures. The polymer microstructure was analyzed by NMR and all twelve acylglyceride ¹³C-signals as well as two small extra peaks of the residual glycerol were observed in the prepolymer and for the PGS gel, the glyceride moieties were characterized by NMR for the first time, providing information on the crosslinked nature of the polymers. The modulus and ultimate tensile strength of the gel increased with longer cure times and at higher cure temperatures while the elongation to break decreased and this was interpreted in terms of network theory. The cell viability of mouse fibroblasts was better for PGS samples with a higher conversion³.

¹ J. P. Bruggeman, B. J. de Bruin, C. J. Bettinger, R. Langer, J. Biomaterials. 2008, 29, 4726-4735

² Q. Chen, A. Bismarck. U. Hansen, S. Junaid, M Q. Trande, S. Harding, N N. Ali, A R. Boccaccini. J. Biomaterials. 2008, 29, 47-57

³ Y. Li, C. Moorhoff, W. D Cook, W.-C. Huang, Q.-Z. Chen, Polymer Int., 2013, DOI 10.1002/pi.4419