Modulated Degradation Rates of Bone Mineral-Like Calcium Phosphate Glass to Support the Proliferation and Osteogenic Differentiation of Bone Marrow-Derived Stem Cells

Abstract

With an elemental composition similar to bone mineral, and the ability to release phosphorus and calcium that benefit bone regeneration, Calcium Phosphate Glass (CPG) serves as a promising component of bone tissue engineering scaffolds. 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 scaffolds comprising CPG, Poly-ε-caprolactone (PCL), and various Magnesium Oxide (MgO) contents. Increasing the MgO content effectively suppressed the degradation of CPG, maintaining a physiological pH of the degradation media. While the degradation of CPG/PCL scaffolds resulted in upregulated apoptosis of Rat Bone Marrow-derived Stem Cells (rBMSC), scaffolds containing MgO were free from these negative impacts, and an optimal MgO content of 1 wt% led to the most pronounced osteogenic differentiation 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 effectively modulated the degradation rate of CPG, thus preventing the negative effects of rapid degradation and supporting the proliferation and osteogenic differentiation of the stem cells.