Role of HA and BG in engineering poly(ε-caprolactone) porous scaffolds for accelerating cranial bone regeneration

Effects of varied bioactive fillers on the biological behavior of porous polymer/inorganic composite scaffolds are lack of comprehensive comparison and remain elusive. Moreover, composite scaffolds with high porosity suffer from inferior mechanical performance. Herein, high-pressure molding and salt leaching were employed to prepare poly(ε-caprolactone) (PCL) composite porous scaffolds loaded with hydroxyapatite (HA) and bioactive glass (BG), respectively. Structural analysis indicated all the porous scaffolds presented interconnected open-pore structure with the porosity of ~87% and pore size of ~180 μm, hinging on the amounts and size of porogen. Compared to PCL/HA scaffolds, PCL/BG scaffolds showed ~2.3-fold augment in the water absorption. Attributing to the compact framework, the PCL/HA and PCL/BG porous scaffolds exhibited outstanding compressive modulus, which was notably higher than other PCL composite porous scaffolds reported in literatures. Cells culture results demonstrated that PCL/BG scaffolds displayed higher expression of osteogenic differentiation than PCL and PCL/HA scaffolds. Furthermore, in vivo results showed that more mature bone was formed within PCL/BG scaffolds than PCL/HA scaffolds, manifesting that the introduction of BG accelerated cranial bone regeneration to obtain complete bone healing within a short time. Therefore, these data indicate that PCL/BG scaffolds are more competitive for bone tissue engineering application. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 654-662, 2019.