Abstract: With an elemental composition similar to bone mineral, and the ability to release phosphorus and calcium that beneft bone regeneration, Calcium Phosphate Glass (CPG) serves as a promising component of bone tissue engineering scafolds. However, the degradation of CPG composites typically results in increased acidity, and its impact on bone-forming activity is less studied. In this work, we prepared 3D-printed composite scafolds comprising CPG, Poly-ε-caprolactone (PCL), and various Magnesium Oxide (MgO) contents. Increasing the MgO content efectively suppressed the degradation of CPG, maintaining a physiological pH of the degradation media. While the degradation of CPG/PCL scafolds resulted in upregulated apoptosis of Rat Bone Marrow-derived Stem Cells (rBMSC), scafolds containing MgO were free from these negative impacts, and an optimal MgO content of 1 wt% led to the most pronounced osteogenic diferentiation of rBMSCs. This work demonstrated that the rapid degradation of CPG impaired the renewability of stem cells through the increased acidity of the surrounding media, and MgO efectively modulated the degradation rate of CPG, thus preventing the negative efects of rapid degradation and supporting the proliferation and osteogenic diferentiation of the stem cells.

Key words: Phosphate glass , · Polymer composites , · 3D printing , · Bone tissue engineering , · Scafolds