Enhanced Osteogenic Properties of Bone Repair Scaffolds through Synergistic Effects of Mechanical and Biochemical Stimulation

Abstract

Herein, the osteogenic properties of bone repair scaffolds are improved by combining mechanical and biochemical stimulations. In the bone microenvironment, fluid shear stress (FSS) is the primary mechanical stimulation. The FSS of the cells is closely related to the scaffold structure. Scaffolds with the same wall thickness (400 μm) and different pore sizes (700, 800, and 900 μm) are established. The FSS of the cells on the scaffold surface is analyzed using the two‐way fluid–structure interaction (FSI) method to obtain the ideal structure. The 400–900 polylactic acid (PLA) scaffold with optimal mechanical stimulation is fabricated using selective laser sintering (SLS). BMP‐2/PLGA microspheres are loaded onto the 400–900 scaffold to further enhance the osteogenic properties through the synergistic effect of biochemical stimulations. The results indicate that the FSS of cells decreases with an increase in the pore size, and the pore size of 900 μm yields the best osteogenic differentiation. At 8 weeks after implantation, the 400–900 microspheres scaffold have the highest ratio of bone volume to total volume (BV/TV) and a uniform distribution of new bone. The results show that BMP‐2/PLGA microspheres can accelerate the formation of new bone.