Synthesis and degradation of 3D biodegradable polyurethane foam scaffolds based on poly (propylene fumarate) and poly (R)-3-hydroxybutyrate]

• Main Authors: Naureen, Bushra, Haseeb, A. S. M. A., Basirun, Wan Jefrey, Muhamad, Farina
• Format: Article
• Published: Elsevier 2021
• Subjects: QD Chemistry; TJ Mechanical engineering and machinery
• Online Access: http://eprints.um.edu.my/26666/

Tissue degeneration due to diseases, accidents, and wars is a worldwide issue. One of the methods used by regenerative medicine (RM) to aid tissue repair is by using a biodegradable tissue engineering scaffold (TES). Different body tissues have variable regeneration abilities, and hence, they require TES with variable degradation rates. This paper focuses on synthesising four polyurethane foam scaffolds (PUFS) with variable degradation rates based on the concentration of incorporated chain extender (CE) poly(R)-3-hydroxybutyrate] (P3HB). The polyol employed is poly (propylene fumarate) (PPF) along with aliphatic 1,6-hexamethylene diisocyanate (HDI). GPC provided the molecular weight (M-n = 455.67 g mol(-1), M-w = 587.15 g mol(-1)) and PDI (1.29) of the PPF. FTIR and H-1 and C-13 NMR confirmed the proposed structures (C=C, COOR, and NHCOO) of the PUFS. The FESEM images revealed a bimodal pore structure, with random, irregular, interconnected pores (242-340 mu m) and discrete void spaces (735-860 mu m). The size of PUFS pores and void spaces (PU4 > PU3 > PU2 > PU1) is directly proportional to their respective degradation rates. The TGA/DTA curves show a decrease of an onset thermal decomposition temperature from PU1 to PU4 (267.17 degrees C PU1, 267.28 degrees C PU2, 256.01 degrees C PU3 and 240.72 degrees C PU4) due to the respective increase in CE concentration. The results of in-vitro degradation analysis at day 70, revealed significant difference between the weight loss (%) of each group (PU1 = 4.09 +/- 0.18%, PU2 = 8.03 +/- 0.17%, PU3 = 13.14 +/- 0.12% and PU4 = 20.21 +/- 0.19%). Thus, PUFS with a higher concentration of P3HB have a faster degradation rate due to the associated P3HB hydrolysable ester/-COOR functional group within the PUFS backbone. The chemical structure, bimodal morphology, and variable degradation rate of these PUFS could be employed for various RM applications.