Magnesium oxide regulates the degradation behaviors and improves the osteogenesis of poly(lactide-co-glycolide) composite scaffolds

Poly (lactic-co-glycolic acid) (PLGA) is a star biodegradable polymer widely studied and applied in the biomedical field. Improving the acidic microenvironment caused by its degradation products and regulating its degradation behavior are still urgent scientific and technological problems to be solved. In this study, to regulate the degradation behaviors of PLGA and improve its bioactivity, hydroxyapatite (HA) and magnesium oxide (MgO) were incorporated into PLGA substrate in different proportions and a series of 3D-printing PLGA/HA/MgO (PHM) composite porous scaffolds were prepared. Then the physicochemical properties, degradation behaviors, in vitro and in vivo biological performance of fabricated scaffolds were systematically studied. The in vitro experimental results showed that PHM composite scaffolds exhibited hydrophilic and mechanical properties similar to natural bone, the presence of MgO could effectively neutralize the acidic environment, and promote bone marrow stromal cells (BMSCs) adhesion, proliferation, and differentiation. The in vivo osteogenic experiments demonstrated that the PHM5 (25 wt% HA, 5 wt% MgO) scaffold could reduce the inflammatory response and promote new bone formation. This study provides a new idea for the regulation of the degradation behavior and the improvement of osteogenic properties of PLGA-based biomaterials. The prepared 3D-printed PHM5 scaffold shows great application potential in the bone repair field.