Abstract: A plasminogen activator such as urokinase or tissue plasminogen activator is covalently bonded to a porous body composed of calcium phosphate to form a plasminogen activator-porous body complex. The tricalcium phosphate can be .alpha.-tricalcium phosphate, .beta.-tricalcium phosphate, hydroxyapatite, tetracalcium phosphate, octacalcium phosphate and mixtures thereof. In a preferred embodiment, .beta.-tricalcium phosphate which has excellent biocompatibility with the body or a mixture of .beta.-tricalcium phosphate and hydroxyapatite is used. Preferably, synthetic calcium phosphate is used is to avoid impurities contained by natural calcium phosphate. Covalent bonding is by crosslinking with glutaraldehyde, bismaleimides, dihalogenic aryls or diisocyanates, or by using cyanogen bromide, diazotization or periodic acid. The complex can be filled into a column to form a bioreactor.

Abstract: Powdery calcium carbonate and a powdery dihydrate of calcium monohydrogenohosphate are weighed to get a Ca/P ratio of 1.45 to 1.67. The powdery mixture thus prepared is then added pure water at a temperature of 30.degree. C. or higher to obtain an aqueous slurry having a concentration of about 10% by weight. Thereafter, the aqueous slurry is subjected to a rotational attrition by using a ball mill to conduct a mechanochemical reaction of the calcium carbonate with the dihydrate of calcium monohydrogenphosphate. The slurry is then dried completely at 80.degree. C., followed by pulverization to yield a dry powder of calcium phosphate hydrate. The dry powder is calcinated at a temperature ranging from 720.degree. to 1,150.degree. C. for 1-10 hours or more to give calcium phosphate powder, which is molded in a desired shape and is sintered at a certain temperature to obtain a sintered body of calcium phosphate.

Abstract: A fibrinolytic enzyme such as urokinase, tissue plasminogen activator or streptokinase is covalently bounded to a bioadaptable porous crystalline glass to produce a thrombolytic material. Production of the glass involves combining 40-50 mol% calcium oxide, 20-30 mol% titanium dioxide and 25-35 mol% diphosphorous pentoxide to form a mixture, and combining the mixture with 0.5-4.0 mol% disodium oxide. A bioreactor for converting plasminogen in blood into plasmin can be prepared by packing the material in a column. When finely comminuted, the material can be administered into the blood of a patient for removing blood clots.

Abstract: A powder for coating the surface of a titanium metal is obtained by mixing compounds as raw materials for CaO, TiO.sub.2, and P.sub.2 O.sub.5 with a small amount of a Na.sub.2 O-containing compound, fusing the resultant mixture, and solidifying and pulverizing the fused mixture. A coating of a calcium phosphate compound adhering with great fastness to the surface of the titanium metal is formed by preparing an aqueous slurry containing the powder mentioned above, applying the aqueous slurry to the surface of the titanium metal, and heat-treating the coated titanium metal.

Abstract: A dense coating of a calcium phosphate compound is formed on the surface of a bioadaptable ceramic substrate by applying to the ceramic calcium metaphosphate alone or a mixture of calcium metaphosphate with calcium pyrophosphate, heat-treating the applied layer thereby fusing the applied layer to the surface of the ceramic, then applying to the fused layer a slurry resulting from the mixture of calcium metaphosphate with tetracalcium phosphate, and subsequently heat-treating the applied layer of the slurry thereby inducing reaction of the slurry.

Abstract: A composition produced as a result of mixing alumina, silica, and a calcium phosphate compound in a specific ratio exhibits high affinity for bioceramics. When a bioceramic is coated with this composition and the coated bioceramic is heated, the composite is fused fast with the bioceramic to produce a composition bioceramic which is active to vital tissues.

Abstract: Sintered article suitable for artificial bones, for example, containing a calcium phosphate compound as a main component and additionally containing spinel or magnesium oxide formed by sintering magnesium oxalate dihydrate. This sintered article is produced by adding alumina and silica or magnesium oxalate dihydrate to a calcium phosphate compound and firing the resultant mixture.

Abstract: A method of forming a rigid film of calcium phosphate compound having good bio-conformance on a surface of a ceramic or metal substrate is disclosed. According to this method, a slurry of a fine powder of phosphate-series glass of CaO-Na.sub.2 O-P.sub.2 O.sub.5 -Al.sub.2 O.sub.3 is applied to the surface of the substrate and is dried and heat-treated to form a binder layer which covers the surface of the substrate. A peptisation agent such as ammonium polyacrylate and water are mixed with a fine powder of a calcium phosphate compound having a particle size of 1 .mu.m or less to prepare a slurry, and this slurry is applied to the surface of the binder layer. The slurry on the binder layer is dried and heat-treated to form a film of the calcium phosphate compound. The film of the calcium phosphate compound formed by this method is uniform and has high adhesion strength with the substrate.

Abstract: Porous spheres of calcium phosphate compound are produced by preparing an aqueous solution containing a water-soluble calcium salt, a calcium ion complexing agent, and a water-soluble phosphate, adjusting the pH of the aqueous solution, adding hydrogen peroxide to the aqueous solution, and heating the resultant mixture.

Abstract: A microfine .beta.-tricalcium phosphate powder is produced by mixing hydrogen calcium phosphate powder, calcium carbonate powder, and water in amounts calculated to give a slurry having a solids concentration in the range of 5 to 15% by weight and a CA:P atomic ratio in the range of 1:1.4.about.1.6 and subjecting the slurry to attrition.