Abstract: The present invention provides a method for producing a calcium phosphate coating film on the surface of a substrate, even a substrate which has poor heat resistance. The method comprises the steps of soaking a substrate in a first solution containing phosphate ions, inter alia, aqueous solutions of a basic phosphate salt such as Na.sub.3 PO.sub.4 or Na.sub.2 HPO.sub.4 ; removing the substrate and drying it; and soaking the substrate in a second solution (aqueous solution) containing calcium ions, to thereby obtain a coating film comprising hydroxyapatite or a mixture containing hydroxyapatite and a hydroxyapatite precursor. The substrate removed from the second solution may be soaked in a third solution (aqueous solution) containing an apatite component at a substantially saturated or supersaturated concentration, to thereby form a hydroxyapatite coating film. There may be used substrates formed of metals, ceramics, organic polymer materials, etc.

Abstract: A method for the production of a composite consisting of cellulose fibers coated with a calcium phosphate compound consists essentially of phosphorylating the surface of cellulose fibers, immersing the surface-phosphorylated cellulose fibers in an aqueous solution containing calcium ions and hydroxyl ions, removing the cellulose fibers from the aqueous solution and subsequently immersing them in an aqueous solution containing calcium ions and phosphoric acid ions, and then removing the cellulose fibers from the aqueous solution. Also disclosed is a composite produced by the method.

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: A platelike hydroxyapatite is produced by preparing from a phosphate and a calcium salt an aqueous slurry of amorphous calcium phosphate having an atomic ratio of calcium atoms to phosphorus atoms in the range of 1.3:1 to 2.0:1, adding to the aqueous slurry not less than 10% by weight of alcohol based on the amount of the aqueous slurry, and subjecting the resultant mixture to a hydrothermal treatment.

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.