Europium-Doped\n3D Dimensional Porous Calcium Phosphate\nScaffolds as a Strategy for Facilitating the Comprehensive Regeneration\nof Bone Tissue: In Vitro and In Vivo

In response to the challenges faced\nby clinicians treating\nbone\ndefects caused by various factors, various bone repair materials have\nbeen investigated, but the efficiency of bone healing still needs\nto be improved due to the acting of scaffolds only in a single stage\nof bone tissue regeneration. We investigated the potential of a novel\n3D scaffold to support different stages of bone tissue regeneration,\nincluding initial inflammation, proliferation, and remodeling. Eu\n(0, 0.5, 2, 3.5, 5, and 6.5%) was added to calcium polyphosphate to\nobtain 3D porous network-doped Eu calcium polyphosphate (EuCPP) scaffolds\nwith ideal mechanical strength and pore size. Both in vitro and in\nvivo experiments proved that Eu<sup>3+</sup> released from 5% EuCPP\nscaffolds could significantly promote the migration and proliferation\nof bone marrow stromal cells which effectively promote angiogenesis;\n5% EuCPP could significantly upregulate the ratio of OPG/RANKL in\nMC3T3-E1 and promote the secretion of osteogenic-related growth factors\n(ALP and OPN) from MC3T3-E1, indicating the potential of the scaffold\nto inhibit bone resorption and promote bone formation. In conclusion,\n5% EuCPP possesses the biological properties of pro-angiogenesis,\nanti-inflammation, pro-osteogenesis, and inhibiting bone resorption,\nwhich may provide a sustained positive effect throughout the process\nof bone tissue repair.