Abstract: Although the toughening of Calcium phosphate (CaP) scaffold by the addition of fiber has been well recognized, integrated mechanical, structural and functional considerations have been neglected in the design and fabrication of CaP scaffold implant. The emerging 3D printing provides a promising technique to construct CaP scaffold with precise size and elaborate microstructure. However, the most challenge is to extrude smoothly the CaP paste containing fibers for frequently-used extrusion-based 3D printing. In this study, frozen section and chemical dispersant (Pluronic F127, F127) were employed jointly to prepare non-aggregated polylactic-co-glycolic acid (PLGA) fibers. The injectability of CaP pastes with well dispersed PLGA fibers was more than 90% when the content of PLGA fibers was no more than 3 wt%. Meanwhile rheological property of CaP pastes with well dispersed fibers showed shear thinning, which were both beneficial to extrude CaP paste with well dispersed fibers for 3D printing. Moreover, these CaP scaffolds showed ductile fracture behavior due to the pullout and bridging effect of PLGA fibers. The cell proliferation and alkaline phosphatase (ALP) activity indicated that 3D printed CaP scaffold containing PLGA fibers possesses excellent biocompatibility and facilitate osteogenic differentiation ability. Thus, it was feasible to print CaP pastes with well dispersed PLGA fibers to construct toughening CaP scaffolds with the higher shape fidelity and complex structures, which had significant clinical potentials in osteoanagenesis due to their higher toughness and excellent biocompatibility.

Key words: CaP scaffold, extrusion-based 3D printing, PLGA fiber, toughening, biocompatibility