Early Osteogenic Transcriptional Response of Pre-Osteoblastic Cells on Biomorphic Mg2+-Doped Biphasic Calcium Phosphate Scaffolds

Critical-sized bone defects remain a major clinical challenge because of their limited regenerative capacity and the high incidence of delayed healing and non-union. Biomorphic calcium phosphate scaffolds have emerged as promising bone tissue engineering (BTE) platforms owing to their ability to reproduce the hierarchical architecture of trabecular bone while providing a bioactive environment for bone regeneration. In the present study, the early osteogenic transcriptional response of biomorphic magnesium-doped hydroxyapatite (HA)/β-tricalcium phosphate (β-TCP) scaffolds obtained through biomorphic transformation of a rattan wood template was investigated to evaluate their ability to support the early osteogenic response of pre-osteoblastic cells. Porous scaffolds preserving the hierarchical architecture of the rattan template and exhibiting different HA/β-TCP phase compositions were obtained through a multistep biomorphic transformation process followed by controlled magnesium incorporation. Cytocompatibility was assessed using MC3T3-E1 pre-osteoblastic cells by evaluating cell viability, adhesion and proliferation. The early osteogenic response was investigated by analyzing the expression of representative osteogenic marker genes in cells cultured on the scaffolds under basal and osteogenic conditions. All scaffold formulations were cytocompatible and supported cell adhesion and proliferation. Culture on biomorphic Mg2+-doped HA/β-TCP scaffolds promoted the expression of osteogenic marker genes, and this response was further enhanced following osteogenic stimulation. No statistically significant differences among the investigated formulations were detected in cell viability or osteogenic marker gene expression. Overall, these findings demonstrate that biomorphic Mg2+-doped HA/β-TCP scaffolds provide a favorable microenvironment for pre-osteoblastic cell growth and early osteogenic transcriptional commitment. The present work also establishes a simplified experimental model for investigating the contribution of magnesium to the early osteogenic transcriptional response of biomorphic calcium phosphate scaffolds, providing a rational basis for the development of next-generation bone graft substitutes.