Preparation and characterization of novel lithium magnesium phosphate bioceramic scaffolds facilitating bone generation.

Both magnesium and lithium are able to stimulate osteogenic and angiogenic activities. In this study, lithium magnesium phosphate (Li 0.5 Mg 2.75 (PO 4 ) 2 , Li 1 Mg 2.5 (PO 4 ) 2 and Li 2 Mg 2 (PO 4 ) 2 ) biomaterials were synthesized by a solid-state reaction method, and their bioceramic blocks and scaffolds were fabricated by compression molding and 3D printing, respectively. The results indicated that the lithium magnesium phosphates consisted of the Mg 3 (PO 4 ) 2 phase and/or LiMgPO 4 phase. Compared with the lithium-free Mg 3 (PO 4 ) 2 bioceramics, the lithium magnesium phosphate bioceramics showed a lower porosity and consequently a higher compressive strength, and stimulated in vitro cellular proliferation, osteogenic differentiation and proangiogenic activity. In vivo results manifested that the Li 2 Mg 2 (PO 4 ) 2 bioceramic scaffolds efficiently promoted bone regeneration of critical-size calvarial defects in rats. Benefiting from the high compressive strength and capacity of stimulating osteogenesis and angiogenesis, the Li 2 Mg 2 (PO 4 ) 2 bioceramic scaffolds are considered promising for efficiently repairing the bone defects.