| In SLS of (3-TCP, sintering temperature is usually high to achieve densification in the very short sintering time. Thus, the sintering temperature is normally much higher than the phase transition temperature of β-to α-TCP (about1180℃), resulting in a large amount of α-TCP in the prepared scaffold. Introducing liquid phase is a general approach to decrease the sintering temperature of ceramic which will inhibit the phase transformation from β-to α-TCP. In this study, a small amount (1wt%) of poly (L-lactic acid)(PLLA) is added into [3-TCP powder to facilitate TCP particles rearrangement by introducing the transient liquid phase of melting PLLA in SLS. Moreover, the small amount PLLA will gradually decompose and completely disappear with laser irradiation. TCP scaffolds with interconnected porous structure are fabricated using this method. The main research and innovations in the paper are shown as follows:1. TCP scaffolds with interconnected porous structure are fabricated via selective laser sintering (SLS). Studies are carried out on the influence of laser energy density and PLLA addition content on the microstructure of TCP scaffolds.2. Influence of sintering parameters on the mechanical of TCP scaffolds is investigated. The fracture toughness of the scaffold prepared with mixture powder containing1wt%PLLA increases by18.18%and the compressive strength increases by4.45%compared to the scaffold prepared from β-TCP powder.3. The bioactivity and degradability of the TCP scaffold are evaluated through the simulated body fluid (SBF) cultivation experiment. The formation of a carbonate apatite layer on the surface after immersion is demonstrated.4. Scaffolds with different surface structure are fabricated by chemical selective etching. Through the cell adhesion experiment, the effects of surface structure on biocompatibility of scaffolds are researched. The etched surface of scaffold with40%β-TCP shows the best cell adhesion, which is treble of the scaffold with10%β-TCP. |
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