Takeshi Yabutsuka

Fabrication of Bioactive Apatite Nuclei Precipitated Ti-15Mo-5Zr-3Al Alloy by Using Doubled Sandblasting Process

Micropores were formed on the surface of Ti-15Mo-5Zr-3Al alloy plate by doubled sandblasting process using silicon carbide particles with 14.0 μm and/or 3.0 µm average particle size by changing the combination of the size of particles. Apatite Nucleus (AN) was precipitated in the pores. By these treatments, bioactive AN precipitated Ti alloys were fabricated. Bioactivity of the Ti alloys was examined by soaking in SBF. Formed hydroxyapatite showed highest adhesive strength in the case of sandblasting using 14.0 μm particles then using 3.0 μm particles.

Fabrication of Encapsulated Silicagel Microsphere with Hydroxyapatite for Sustained-Release

Apatite nuclei were precipitated in the pores of silicagel microspheres by raising pH of simulated body fluid (SBF). By a soak in SBF, hydroxyapatite (HAp) was induced from the apatite nuclei and spread over whole surface area of the silicagel microspheres. Then encapsulated silicagel microspheres with HAp were fabricated.

Development of Bioactive Titanium-Apatite Nuclei Composite

Apatite nuclei were precipitated in the pores of titanium in simulated body fluid (SBF) and titanium-apatite nuclei composite was obtained. Apatite was induced by the apatite nuclei inside the pores of the composite and apatite layer was formed on the composite surface by soaking in SBF. The apatite layer showed high adhesive strength to the composite due to a mechanical interlocking effect between the composite and the apatite.

Development of Bioactive Polyethylene-Apatite Nuclei Composite

Apatite nuclei were precipitated in the pores of the porous polyethylene matrix in 2.0SBF. Apatite was induced by the apatite nuclei inside the pores and on the surface of the composite and grew to the surface of the composite by a soak in 1.0SBF. The formed apatite showed high adhesive strength to the composite probably due to a mechanical interlocking effect between the matrix and the apatite.

Fabrication of Hydroxyapatite Microcapsule Containing Vitamin B12 for Sustained-Release

When either the pH or temperature of simulated body fluid (SBF) are raised, fine particles of calcium phosphate are precipitated. We found that these fine particles actively induce hydroxyapatite formation from body fluid or SBF and named the particles Apatite Nuclei. In this study, we fabricated hollow hydroxyapatite microcapsules by using Apatite Nuclei. We inserted vitamin B12 in the hollow microcapsule and examined thesustained-release properties.

Fabrication of Magnetic Hydroxyapatite Microcapsule for Protein Collection

When pH or temperature of simulated body fluid (SBF) is raised, fine particles of calcium phosphate are precipitated. We found that this fine particle actively induces hydroxyapatite from body fluid or SBF and named the particle Apatite Nucleus (AN). In this study, we attached AN on the surface of γ-Fe2O3 nanoparticles and soaked them in SBF. By this treatment, hydroxyapatite was induced from AN and covered the whole surface of the γ-Fe2O3 nanoparticles, then hydroxyapatite microcapsule encapsulated γ-Fe2O3 was fabricated. We dispersed the microcapsules in urease solution, and collected the microcapsules by neodymium magnet. It was indicated that the urease was adsorbed to the hydroxyapatite microcapsules and collected by the magnetism of γ-Fe2O3 successfully.

Fabrication of Bioactive Apatite Nuclei Precipitated Polylactic Acid by Using Sandblasting Process

Micropores were formed on the surface of polylactic acid (PLA) plate by doubled sandblasting process using alumina particles with 14.0 μm for average particle size as first process, then using the particles with 3.0 μm for average particle size as second process. Apatite Nucleus (AN) was precipitated in the pores. By these treatments, bioactive AN precipitated PLA was fabricated. Bioactivity of the AN precipitated PLA was examined by soaking in SBF and it was observed that hydroxyapatite was induced on the surface of the PLA within 1 d. High adhesive strength of hydroxyapatite layer was achieved due to a mechanical interlocking effect between hydroxyapatite formed in the micropores and the PLA plate.

Fabrication of Bioactive Apatite Nuclei-Precipitated Titanium Alloys by Using Sandblasting

Micropores were formed on the surface of Ti metal, Ti-15Mo-5Zr-3Al alloy, Ti-12Ta-9Nb-3V-6Zr-O alloy plate by doubled sandblasting process using silicon carbide particles with 14.0 μm for average particle size as first process, then using the particles with 3.0 μm for average particle size as second process. Apatite Nuclei (AN) were precipitated in the pores. By these treatments, bioactive AN-precipitated Ti alloys were fabricated. Bioactivity of the AN-precipitated Ti alloys was examined by soaking in SBF and it was observed that hydroxyapatite was induced on the surface of the Ti alloys within 1 d. High adhesive strength of hydroxyapatite layer was achieved due to a mechanical interlocking effect between hydroxyapatite formed in the micropores and the plate.

Fabrication of Bioactive Apatite Nuclei-Precipitated Composites

Many micropores were formed on the surface of a Ti-15Mo-5Zr-3Al alloy plate and a polyethylene terephthalate (PET) plate by sandblasting, Apatite Nuclei were precipitated in the pores, then bioactive Apatite Nuclei-precipitated composites were fabricated. In order to examine the bioactivity, the composites were soaked in SBF and it was observed that hydroxyapatite was induced on the whole surface within 1 d. The hydroxyapatite layer possessed high adhesive strength to the plate due to a mechanical interlocking effect between hydroxyapatite in the micropores and the plate.

Development of Bioactive Organic Polymer Composite by Electrophoretic Deposition

By electrophoretic deposition, wollastonite particles were deposited in pores of porous ultrahigh molecular weight polyethylene (UHMWPE). The UHMWPE-wollastonite composite thus fabricated was soaked in a simulated body fluid. As a result, apatite was formed inside the pores as well as on the surface of the UHMWPE-wollastonite composite. The formed apatite showed high adhesive strength to the composite.