Proliferation and differentiation of cultured MC3T3-E1 osteoblasts on surface-layer modified hydroxyapatite ceramic with acid and heat treatments

Effects of functionally gradient calcium phosphate consisting of hydroxyapatite (HAP) and α-tricalcium phosphate (α-TCP) on proliferation and differentiation of osteoblasts were evaluated using MC3T3-E1 cells. There were no significant differences in the proliferation of MC3T3-E1 cells among HAP- α-TCP functionally gradient calcium phosphate, pure HAP, and cell culture plastic wells. mRNA expressions of type I collagen, alkaline phosphate, and osteocalcine were evaluated as indexes of initial, mid-stage, and late-stage osteoblastic differentiation. Basically, HAP- α-TCP functionally gradient calcium phosphate and pure HAP enhanced the expressions of the three markers when compared with that of cell culture plastic wells. For type I collagen and alkaline phosphate expressions, HAP- α-TCP functionally gradient calcium phosphate showed the same expression level as pure HAP. For osteocalcine expression, HAP- α-TCP functionally gradient calcium phosphate showed a higher level than pure HAP. We concluded, therefore, HAP- α-TCP functionally gradient calcium phosphate has good potential to be a bone filler material with high osteoconductivity.