Core–Shell Bioactive Ceramic Robocasting: Tuning Component Distribution Beneficial for Highly Efficient Alveolar Bone Regeneration and Repair

Biodegradable ceramic (composite) scaffolds have inspired worldwide efforts in bone regenerative medicine. However, balancing the biodegradation with the bone's natural healing time scale remains difficult; in particularl, there is a lack of strategy to control component distribution and bioactive ion release favorable for stimulating alveolar bone tissue ingrowth in situ within an expected time window. Here we aimed to develop the robocasting core-shell bioceramic scaffolds and investigate their physicochemical properties and osteostimulative capability in beagle alveolar bone defect model. The β-tircalcium phosphate (TCP) and 5% Mg-doped calcium silicate (CSi-Mg5) were used to fabricate the core-shell-typed TCP@TCP, CSi-Mg5@CSi-Mg5 and TCP@CSi-Mg5 porous scaffolds. Both in vitro and in vivo studies show that the CSi-Mg5 shell readily contributed to the initial mechanical strength and early-stage osteogenic activity of the TCP@CSi-Mg5 scaffolds, including tunable ion release, enhanced biodegradation, and outstanding osteogenesis capacity in comparison with the CSi-Mg5@CSi-Mg5 scaffolds and clinically available Bio-Oss granules in alveolar bone defects. Therefore, the presented core-shell robocasting of bioceramic technology and porous scaffold biomaterials enables an accurate preparation of highly bioactive and biodegradable scaffolds with a large freedom of design, and thereby may be beneficial for fabricating osteostimulation-tuned porous scaffolds for the challengeable alveolar bone defect reconstruction medicine.