DLP 3D printed silica-doped HAp ceramic scaffolds inspired by the trabecular bone structure

HAp has drawn great attention in recent years for its similarity to the inorganic component of bone. However, the application is limited due to its poor shape ability, low mechanical property, and biodegradability. In this work, silica-doped HAp ceramic scaffolds are 3D printed with a natural optimized trabecular bone structure. Specifically, with the addition of silica, composite scaffolds sintered at 1200 degrees C exhibit a decrease of pores and increase of grain size, yielding a compressive strength increased from 3.93 +/- 0.75 MPa to 12.94 +/- 0.70 MPa, comparable to the trabecular bone. Results of XRD and SEM illustrate that the addition of silica promotes the formation of the bioactive TCP phase. Biological characterization in SBF illustrates that the in vitro bioactivity of the silica-doped scaffolds is superior to that of the pure HAp, and the scaffolds are biodegradable. Cytocompatibility study revealed that there is no potential cytotoxicity for L929 cells on all groups of scaffolds. Trabecular bone structure-mimicking silica-doped ceramic scaffolds with high strength and in vitro bioactive are developed. The Silica-doped ceramic scaffolds can be tailored to certain biological response requirements as a promising material for bone defect regeneration.