Fabrication of a bio-inspired beta-Tricalcium phosphate/collagen scaffold based on ceramic stereolithography and gel casting for osteochondral tissue engineering

Purpose - The purpose of this paper is to fabricate and characterize osteochondral beta-tricalcium phosphate/collagen scaffold with bio-inspired design by ceramic stereolithography (CSL) and gel casting. Design/methodology/approach - Histological analysis was applied to explore the morphological characteristics of the transitional structure between the bone and the cartilage. The acquired data were used to design biomimetic biphasic scaffolds, which include the bone phase, cartilage phase, and their transitional structure. The engineered scaffolds were fabricated from beta-TCP-collagen by CSL and gel casting. The cartilage phase was added to the ceramic phase by gel-casting and freeze drying. Findings - The resulting ceramic scaffolds were composed of a bone phase with the following properties: 700-900 mu m pore size, 200-500 mu m interconnected pores size, 50-65 percent porosity, fully interconnected, similar to 12 Mpa compressive strength. A suitable binding force between cartilage phase and ceramic phase was achieved by physical locking that was created by the biomimetic transitional structure. Cellular evaluation showed satisfactory results. Research limitations/implications - This study is the first try to apply CSL to fabricate biological implants with beta-TCP and type-I collagen. There are still some defects in the composition of the slurry and the fabrication process. Practical implications - This strategy of osteochondral scaffold fabrication can be implemented to construct an osteochondral complex that is similar to native tissue. Originality/value - The CSL technique is highly accurate, as well as biologically secure, when fabricating ceramic tissue engineering scaffolds and may be a promising method to construct hard tissue with delicate structures. The present strategy enhances the versatility of scaffold fabrication by RP.