Development of Particle Size-Controlled Horse Bone Cements for Bone Regeneration

Abstract

Since their initial development in the 1980s, calcium phosphate cements (CPCs) have been one of the most used biomaterial in clinical use for bone healing. They consisted of two main component, powder, which contains calcium phosphate materials, and liquid that contains various types of polymers for setting. So far, manipulating powder particle sizes were known for enhancement of mechanical strength of CPCs. However, poor research was investigated to verify the relationship between powder particle size of CPCs and cellular function. Consequently, in this research, CPCs with various particles size distribution were fabricated and various cells were seeded on the CPCs to reveal the association with particle size of CPCs and their cellular behaviors. First, CPCs were fabricated using horse bone powder with various powder size and chitosan solution. Their surface topography were measured numerically and showed that the higher particles sizes of starting powder led to higher surface roughness whilst smaller particle sizes led to lower surface roughness. Next, cell behaviors on the CPCs were observed. In these results, high surface roughness led to better proliferation of cells, in contrast, high surface roughness led to better osteogenic differentiation. In conclusion, regulation of particle size could control surface roughness, and subsequently changed cellular behaviors, especially in osteogenic differentiation. Changing surface roughness of CPCs would be a promising method for regulating bone regeneration.