Degradation Behavior of 3D Porous Polydioxanone-b-Polycaprolactone Scaffolds Fabricated Using the Melt-Molding Particulate-Leaching Method

Recently, polydioxanone (PDO) and polycaprolactone (PCL) have been applied in applications for tissue engineering owing to their flexibility, as well as biocompatibility and biodegradability, even though their degradation rates are usually either too fast or too slow for many applications. In this study, we synthesized poly(dioxanone-b-caprolactone) co-polymers (PDOCLs) with different DO/CL ratio (0:10-10:0) by ring-opening polymerization. The synthesized co-polymers were characterized by H-1-NMR, the measurement of inherent viscosity (IV), GPC and DSC. PDOCL scaffolds with different DO/CL ratio were fabricated by a melt-molding particulate-leaching method without using any organic solvents during the scaffold fabrication process. The degradation behavior (in vitro) of the PDOCL scaffolds was evaluated in PBS at 37 degrees C for up to 56 days by the changes in molecular weight, mechanical strength, gross weight and pH. It was observed that the degradation rate of PDOCL scaffolds could be controlled by adjusting the DO/CL ratio of the co-polymers (increasing CL composition leads to slower degradation rate). The PDOCL scaffolds did not lead to a significant drop in pH during the degradation, not even for the PDO-dominant PDOCL scaffolds showing a fast degradation rate, indicating the formation of a small amount of acidic by-products compared to the PLGA scaffolds. From the results, it was expected that the PDOCLs can be a new flexible scaffolding material with different degradation rate for various tissue-engineering applications. (C) Koninklijke Brill NV, Leiden, 2011