Papers by Author: Katsuko S. Furukawa

Abstract: HAp (Hydroxyapatite) and α-TCP (alpha tribasic calcium phosphate) are non-toxic to human cells and, thus, have been studied for applications as biomaterials. HAp is a bioactive material that is not readily absorbed by the body; it offers both high strength and better tissueadhesive properties than α-TCP. In contrast, α-TCP is highly bioabsorbable; it is quickly absorbed by the body, and, therefore, for example, disappears before bone is completely replaced. If porous beads could be fabricated that would take advantage of the useful properties of α-TCP and HAp, they could be used as excellent scaffolds for cultivating cells. In the present study, ceramic beads with α-TCP at the center were fabricated and coated with a functionally graded film of HAp. A scaffold based on this configuration would be expected to have the following characteristics: good cell adhesion; strong beads; and a rate of absorption into the body that would be easy to control. In addition, to accelerate the formation of porous structure, some acid solutions were used to dissolve the beads surface layer and to penetrate pores toward inside of the bead. HAp formation through hydrolytic reaction seemed to be promoted by these acid solutions.

Abstract: Fibronectin (FN)-apatite composite layers were formed on a hydroxyapatite (HAP) ceramic using supersaturated calcium phosphate (CP) solutions. The surface roughness of the composite layer could be controllable by changing the magnesium (Mg) concentration in the CP solution. The higher the Mg concentration, the smaller the apatite crystals in the layer were. The thickness of the layer formed in the CP solution containing 1.5 mM Mg decreased to 68% that formed in the Mg-free CP solution. The amount of FN immobilized in the layer was almost constant regardless of Mg concentration in the CP solution in the range from 0 to 1.5 mM. The results of the present study revealed that a thin FN-apatite composite layer with a smooth surface and a high protein content is formed in a CP solution at a Mg concentration of 1.5 mM.