Fabrication of poly (1, 8-octanediol-co-Pluronic F127 citrate)/chitin nanofibril/bioactive glass (POFC/ChiNF/BG) porous scaffold via directional-freeze-casting

Abstract

Abstract The citrate-based thermoset elastomer is a promising candidate for bone scaffold material, but the harsh curing condition made it difficult to fabricate porous structure. Recently, poly (1, 8-octanediol-co-Pluronic F127 citrate) (POFC) porous scaffold was creatively fabricated by chitin nanofibrils (ChiNFs) supported emulsion-freeze-casting. Thanks to the supporting role of ChiNFs, the lamellar pore structure formed by directional freeze-drying was maintained during the subsequent thermocuring. Herein, bioactive glass (BG) was introduced into the POFC porous scaffolds to improve bioactivity. It was found the complete replacement of ChiNF particles with BG particles could not form a stable porous structure; however, existing at least 15 wt% ChiNF could ensure the formation of lamellar pore, and the interlamellar distance increased with BG ratios. Thus, the BG granules did not contribute to the formation of pore structure like ChiNFs, however, they surely endowed the scaffolds with enhanced mechanical properties, improved osteogenesis bioactivity, better cytocompatibility as well as quick degradation rate. Reasonably adjusting BG ratios could balance the requirements of porous structure and bioactivity.