Osteogenic Potential and Hemocompatibility of Rare-Earth-Doped Hydroxyapatite in Murine Preosteoblast Cells

We describe the osteogenic potential and hemocompatibility of rare-earth-doped hydroxyapatite in a murine preosteoblastic (MC3T3-E1) cell line, aiming to assess the osteoblast differentiation effect of ytterbium-, terbium-, cerium-, and europium-doped hydroxyapatite through alkaline phosphatase activity and the expression levels of osteogenic marker genes, including Runx2, ALP, OPN, and BMP2. Our findings reveal various levels of enhancement in early osteogenic activity across the four dopants. Among the dopants tested, europium- and ytterbium-doped hydroxyapatites produce the most pronounced effects, significantly enhancing ALP activity and upregulating multiple osteogenic genes. Cathodoluminescence spectroscopy confirms successful incorporation of all rare-earth ions in the HAp lattice, while hemocompatibility and cell viability assays demonstrate that all compositions are biocompatible and safe for contact with blood, providing a comparative framework for understanding how rare-earth dopants influence early osteogenic response. These findings demonstrate the potential of Eu- and Yb-doped hydroxyapatites as bioactive materials for bone regeneration.