(574g) Surface Modification of Hydroxyapatite Scaffolds for Preosteoblast Growth and Differentiation

The demand in bone tissue engineering is increasing in the treatment of large-scale bone defects to regenerate damaged tissue and restore function. Three dimensional (3D) scaffolds with appropriate mechanical strength, pore structure, and biocompatibility are needed to allow proliferation and differentiation of osteogenic cells. To improve the scaffold interaction with preosteoblasts, we engineered 3D hydroxyapatite scaffolds with ultra-thin hydrogels and biomineralized nano-hydroyapatites. Polyampholyte hydrogels promoted the preosteoblast differentiation, as reflected in the 180% increase in the 14-day alkaline phosphatase activity. The nano-hydroyapatites up-regulated the alkaline phosphatase activity and the expression of osteogenic marker osteocalcin by 50-110%. The results indicated the importance of surface chemistry and topography of scaffolds in the osteogensis process. The preosteoblast cells grew along the preferred orientation directed by the patterning in the 3D scaffolds. MTT proliferation assay did not show any distinct difference (p < 0.05) in cell viability after the hydrogel and nano-hydroyapatite modification of scaffolds.