JPH0236684B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention provides bone defects and voids that have good compatibility with living organisms, have the ability to form new bone, and can be extremely easily adapted to bone defect sites with complex shapes. The present invention relates to a method for producing inorganic fiber as a filler. [Prior Art] In the field of surgery or orthopedics, bone defects or voids occur due to bone fractures or removal of osteomas, and in the field of dentistry, loss of jaw bone due to alveolar pyorrhea occurs. This is often encountered when a prosthesis is required for the area. Conventionally, in many cases, a method has been used in which the patient's own iliac bone or the like is removed and filled into the bone defect site to fill the bone tissue defect or gap and to hasten the recovery and healing of the tissue. However, using this method requires removing normal bone tissue other than the damaged area, which causes great pain to the patient.
Moreover, the surgery requires a great deal of effort. Furthermore, if the bone defect is large, it is not always possible to harvest a sufficient amount of autologous bone to fill it, and some kind of substitute must be used to make up for the shortage. As a substitute, for example, allogeneic bone and xenogeneic bone are available, but there are still problems such as rejection reactions with the implanted living tissue, and the postoperative course is not necessarily good. ,
It has not yet reached the practical stage. For this reason, when filled into bone defects and voids, it has excellent biocompatibility, promotes bone formation in the defect site and its surrounding area, and is an artificial prosthesis that repairs and restores the structural function of the bone tissue defect site. Development of materials is desired. Various metal alloys and organic substances have been used as hard tissue substitutes for living organisms, but they are said to deteriorate due to dissolution in the living environment, to be toxic to living organisms, and to be accompanied by foreign body reactions. Ceramic materials, which have excellent compatibility with living organisms and do not have the above-mentioned drawbacks, are now being used. Among these ceramic materials, artificial bones and artificial tooth roots made of sintered bodies or single crystals of alumina, carbon, tricalcium phosphate, or hydroxyavatite, which have excellent biocompatibility, are being developed and are attracting attention. [Objective of the present invention: Problems to be solved] However, all of these ceramic implant materials have the common drawbacks of being hard and brittle, and at present, they are not in a state where they can be put to practical use. I haven't reached it yet. Furthermore, attempts have been made to fill bone defects with ceramic blocks made of these sintered bodies or single crystals, but when filling bone defects with complex shapes, there is a gap between the block and the bone tissue. Because uniform gaps remain, the purpose of filling cannot be achieved.On the other hand, in the case of alumina, for example, since it is significantly harder than bone tissue, there are problems such as bone resorption due to stimulation around the filling material. However, it has not yet reached the level of practical use. Therefore, one object of the present invention is to have excellent biocompatibility and
Moreover, the first object of the present invention is to provide a method for manufacturing an inorganic fiber, which is a filling material for bone defects and voids, and which integrates with biological hard tissue in a short period of time without causing any foreign body reaction. Another object of the present invention is to provide a method for producing an inorganic fiber, which is a filling material for bone defects and voids, which promotes bone formation in the filling area and particularly quickly repairs and restores the structure and function of bone tissue defects. It's about doing. [Structure of the present invention: Means for solving the problem] According to the present invention, after melting, the Ca/P molar ratio is 0.3.
4.0 or less, and CaO + P ₂ O ₅ is less than 80 weight [%] and 15 weight [%] or more, and
1 or 2 selected from Al ₂ O ₃ , SiO ₂ , Na ₂ O
A method for producing an inorganic fiber is provided, in which a raw material having a content of 20% by weight or more and less than 85% by weight is made into fiber by a melting step and a fiber forming step. Further, by immersing the fiber formed into a fiber by the manufacturing method having the above structure in a solution containing a phosphate group and having a [PH] of 2 to 7, a calcium phosphate compound can be added to the surface of the inorganic fiber. In particular, a method for producing an inorganic fiber with increased osteogenic capacity is provided. As raw materials for phosphorus and calcium for the inorganic fiber of the present invention, compounds containing phosphorus and calcium such as tetracalcium phosphate, hydroxyapatite, tricalcium phosphate, prussiaite, and monetite may be used alone or in combination with quicklime, slaked lime, calcium carbonate, etc. Further, one or more mixtures of phosphorus-containing compounds selected from calcium-containing compounds or phosphorus-containing compounds such as triammonium phosphate, ammonium monohydrogen phosphate, sodium phosphate, potassium phosphate, phosphoric acid, etc. One type or a mixture of two or more types selected from each of a calcium-containing compound and a phosphorus-containing compound can be used as appropriate. In addition, as raw materials for which the total content of components other than CaO and P ₂ O ₅ is 20 [%] or more and less than 85 [%], one or more kinds selected from compounds containing aluminum, silicon, sodium, etc. It is necessary to select and use the components while adjusting them so that the mixture can be made into fibers or spun. In place of these, naturally occurring substances such as animal bones and kaolin can also be used as long as they do not contain components harmful to living organisms such as arsenic, cadmium, etc., or the content thereof is small. The inorganic fiber of the present invention can be produced, for example, by appropriately mixing the above-mentioned raw materials, melting the mixture in a crucible with a nozzle at the bottom, clarifying it, letting the melt flow out from the nozzle at the bottom, and blowing high-pressure gas onto it. By this, a flocculent fiber can be obtained, while by winding the effluent in a drum, a long fiber can be obtained. The inorganic fiber has a Ca/P molar ratio of 0.3 or more and 4.0
and the CaO + P ₂ O ₅ content must be in the range of less than 80 [%] and 15 [%] or more.
Further, it is necessary that the content of one or more selected from Al ₂ O ₃ , SiO ₂ , and Na ₂ O is in a range of 20 weight [%] or more and less than 85 weight [%]. Ca／
This is because when P is less than 0.3, the viscosity of the melt becomes too small and it is difficult to form a fiber, and when Ca/P exceeds 4.0 and CaO
When the +P ₂ O ₅ content is 80 [%] or more, the melting point of both raw materials becomes extremely high, making it impossible to melt them, or even if they can be melted, the viscosity of the melt becomes a fiber, so it is difficult to make fibers. This is because it is not possible. On the other hand, if the CaO + P ₂ O ₅ content is less than 15 [%], it is not preferable because the biocompatibility will be poor and the ability to generate new bone will also be low, making the repair and recovery of bone tissue slow. If the content of one or more selected from Al ₂ O ₃ , SiO ₂ , and Na ₂ O is less than 20% by weight, it may be difficult to melt the raw material or the viscosity of the melt may be high. This makes it difficult to make fibers,
Moreover, if it exceeds 85% by weight, the calcium phosphate content becomes too small and the biocompatibility decreases too much, so the above-mentioned component content range is necessary. The method for producing the inorganic fiber of the present invention is preferably a method in which a calcium phosphate compound is added to the surface of the inorganic fiber.The effect of adding a calcium phosphate compound to the surface of the inorganic fiber is to further improve the biocompatibility of the inorganic fiber and to generate new bone. By increasing the performance, the repair and recovery of living bone tissue and the integration of bone tissue and filling material are made faster. As a method of providing a calcium phosphate compound on the surface of an inorganic fiber, the inorganic fiber is mixed with an aqueous solution of phosphoric acid and aqueous ammonia, or an aqueous solution of ammonium monohydrogen phosphate, ammonium dihydrogen phosphate, or triammonium phosphate or these or a mixed solution of these with an aqueous solution of phosphoric acid or aqueous ammonia to obtain the desired [PH], and by immersing it in this solution, the phosphoric acid groups present in the solution and the calcium ions eluted from the inorganic fibers are combined. A method can be used in which a calcium phosphate compound is precipitated on the surface of the fiber by reaction. It is necessary that the [PH] of the solution containing a phosphate group to precipitate a calcium phosphate compound on the surface of the inorganic fiber is between 2 and 7. This is because when the [PH] of the solution is less than 2, the inorganic fiber deteriorates and the strength of the fiber decreases significantly, making it impossible to obtain a fiber with sufficient strength to be used as a filler. On the other hand, when [PH] exceeds 7, very little calcium phosphate compound precipitates on the surface of the inorganic fiber, so that almost no effect of surface modification can be expected. In addition, as a method for providing a calcium phosphate compound on the surface of an inorganic fiber, a slurry of a calcium phosphate compound such as brutziaite, tricalcium phosphate, hydroxyapatite, etc. is adhered to the surface of the inorganic fiber, and this is dried to form a phosphorus compound. A method of fixing a calcium acid compound to the surface of the fiber may also be used. Surface modification can be performed not only on fibers but also on the aforementioned long fibers in the form of a woven fabric, and this surface-modified woven fabric can be used in methods such as wrapping around bone defects. Of course, it is also possible to do so. [Function] In the production method of the present invention, raw materials are mixed and melted in a crucible with a nozzle at the bottom, and after being clarified by scattering air bubbles, etc., it is flowed out from the nozzle.
Since it contains a considerable amount of components such as Al ₂ O ₃ and SiO ₂ , it is very easy to spin, so it can be made into fibers with almost no yarn breakage. By having such a shape, the shape can be changed very easily and freely when used as a filling material for bone defects and voids.
Furthermore, since the surface area can be made larger than that of a lump, the amount of new bone produced can also be increased. Furthermore, when the fiber is used as a filling material, continuous pores can be provided due to this shape, and as a result, bone forming components can penetrate into the inside of the filling material. Repair and recovery of the defect site, as well as integration of the living hard tissue and the filling material, can be significantly accelerated. Although the type of calcium phosphate compound deposited on the surface of the inorganic fiber cannot be determined in detail,
From the results of X-ray analysis, it seems that when the [PH] of the solution containing phosphate groups is low, bruschite is the main component, and when the [PH] is high, the main component is apatite. The present invention will be explained in more detail below with reference to Examples. Example 1 The raw materials shown in Table 1 are mixed and melted in a crucible having a nozzle at the bottom, and after the melt is sufficiently clarified, the melt is flowed out from the nozzle of the crucible and the flow is wound around a drum. An attempt was made to create a long fiber using this method. The results are shown in Table 1. As a result, fibers could not be formed in any case where Ca/P was 0.2, but this was because the viscosity of the melt when these were melted was too low.
On the other hand, when Ca/P is 0.3 or 1.7, CaO+P ₂ O ₅ is
In the case of 90 [%], it becomes a molten product, but when producing fibers from these, it was difficult to frequently break the threads and continuously form them into fibers. Ca/P is 4.0 and CaO+P ₂ O ₅ is 90
[%] and when Ca/P is 5.0, 1700 [℃]
However, the mixed raw materials did not melt and no fiber could be obtained. In all cases other than those listed above, long fibers could be produced with almost no breakage.

【table】

[Table] Example 2 Test No. 7, 9, 11, 13, 17, 19 in Example
The fibers prepared were filled into a bone defect (3mmφ7×4mmL) that was artificially created in the dog's femur.
The state of the bone defect was observed after 12 weeks. As a result, when the fibers of Test Nos. 7, 9, 13, 17, and 19 were used, in all cases, they were almost integrated with the surrounding bone tissue, and the boundary between the filling material and the surrounding bone tissue was was not clear. However, test No.11
When using this fiber, only a small amount of new bone was observed on the surface of the filled fiber, and the surrounding bone tissue and the filling material could be clearly distinguished. Example 3 Using raw materials with the same composition as Test Nos. 7, 13, and 19 in Example 1, a melt was prepared in a crucible with a nozzle at the bottom in the same manner as in Example 1, and the melt was poured from the nozzle at the bottom. An attempt was made to fabricate cotton-like fibers by blowing high-pressure air onto the flow. As a result, flocculent fibers could be obtained in all cases. These were filled into a bone defect (3 mm φ 4 mm L) artificially created in the femur of a dog, and the subsequent progress was observed. As a result, in both cases, after filling 4
It was observed that a large amount of new bone had already been generated on the filled fiber surface within a week. Example 4 Using the fibers prepared in Test Nos. 7, 13, and 19 in Example 1, the fibers were treated with phosphoric acid or aqueous ammonia containing 10% ammonium monohydrogen phosphate [PH] 1.0, 2.0，4.0，6.0，
The fibers were surface-treated by immersing them in aqueous solutions at concentrations of 7.0 and 8.0 for 30 minutes each. When the surfaces of the fibers thus obtained were observed using a scanning electron microscope, it was found that in all cases, the surfaces of the fibers treated with [PH] 1.0 were corroded and large irregularities were observed. Almost no precipitates were observed on the fiber surface of the fiber treated at [PH] 8.0. [PH] 2.0, 4.0, 6.0,
The fiber surface was covered with precipitates when treated at [PH] 4.0,
In those treated with 6.0, the surface was more uniformly covered with precipitates. The fiber produced in Test No. 13 was tested for each of the above [PH]
Table 2 shows the tensile strength when treated with .

[Table] According to the results, when [PH] was 1.0, the tensile strength was significantly reduced. Example 5 The fibers produced in Test Nos. 7 and 19 in Example 1 and the fibers were subjected to surface treatment at [PH] of 2.0, 4.0, 6.0, 7.0, and 8.0 in the same manner as in Example 4. A bone defect (3 mmφ x 4 mm L) artificially created in a dog's femur was filled with ivy fibers, and the new bone formation was observed after 3 weeks. As a result, fibers with surface treatment have a
In all cases, a larger amount of new bone was generated, except when surface treatment was performed at [PH] 8.0.
When the surface was treated at [PH] 8.0, it was almost the same as when used without surface treatment. [Effects of the present invention] (1) By inventing the method for producing inorganic fibers of the present invention, a new inorganic fiber containing calcium phosphate and having excellent bone-forming ability, which did not previously exist, was created for the first time. (2) The method for producing inorganic fibers of the present invention uses considerable amounts of Al ₂ O ₃ and SiO ₂ in addition to calcium phosphate, so during melting, fining, and spinning, long fibers can be produced with almost no breakage. can be manufactured. (3) As for the effects of the product produced by the manufacturing method of the present invention, long fibers can be used as fillers in bone defects, etc. as they are, but by making them into a fabric, they can be used in the same manner or in It can be used by wrapping it around an area. By filling the bone defect with fiber and wrapping it around it in the form of a fabric, the repair or recovery of the bone defect or the treatment period can be shortened compared to just filling the bone defect with fiber. Ru. (4) The inorganic fiber according to the present invention can be used not only in the fields of surgery and orthopedics, but also in dentistry to prevent alveolar ridge deterioration after tooth extraction, or to remove teeth around the roots caused by alveolar pyorrhea. Naturally, it can be used for bone defects, etc., and it can also be used as a treatment material for water containing phosphate groups.

Claims (1)

[Claims] 1. After melting, the Ca/P molar ratio is 0.3 or more and 4.0 or less, and CaO + P ₂ O ₅ is less than 80 weight [%] and 15 weight [%] or more, and Al ₂ O ₃ , SiO ₂ , 1 or 2 or more selected from Na ₂ O is 20% by weight or more
A method for producing an inorganic fiber, characterized in that a raw material having a weight of less than 85% is made into fiber through a melting process, a clarification process, and a fiber forming process. 2 After melting, the Ca/P molar ratio is 0.3 or more and 4.0 or less, and CaO + P ₂ O ₅ is less than 80 weight [%] and 15 weight [%] or more, and from Al ₂ O ₃ , SiO ₂ , Na ₂ O Selected 1 or 2 or more is 20% by weight or more
By immersing a fiber produced by a melting process, a clarification process, and a fiberization process in a solution containing a phosphate group and having a [PH] of 2 to 7, using a raw material having a weight of less than 85%. . A method for producing an inorganic fiber, which comprises adding a calcium phosphate compound to the surface of the inorganic fiber.