Fabrication and characterization of toughness-enhanced scaffolds comprising β-TCP/POC using the freeform fabrication system with micro-droplet jetting

A novel elastomeric material, poly(1,8-octanediol-co-citrate) (POC), has demonstrated tremendous versatility because of its advantageous toughness, tunable degradation properties, and efficient drug release capability. In this study, POC was used to improve the mechanical performance of beta-tricalcium phosphate (beta-Ca3(PO4)2, beta-TCP). (3D) beta-TCP/POC composite scaffolds were fabricated by a 3D printing technique based on the freeform fabrication system with micro-droplet jetting (FFS-MDJ). The physiochemical properties, compressive modulus, drug release behavior, and cell response of beta-TCP/POC composite scaffolds were systematically investigated. The results showed that beta-TCP/POC scaffolds had uniform macropores of 300-400 mu m, porosity of approximately 45%, biodegradability in phosphate-buffered saline, and high compressive modulus of 50-75 MPa. With the incorporation of POC into beta-TCP, the toughness of the composite scaffolds was improved significantly. Moreover, beta-TCP/POC scaffolds exhibited sustained drug (ibuprofen (IBU)) release capability. Additionally, beta-TCP/POC scaffolds facilitated C2C12 cell attachment and proliferation. It was indicated that the 3D-printed porous beta-TCP/POC scaffolds with high compressive modulus and good drug delivery performance might be a promising candidate for bone defect repair.