JPH01148812A - Production of inorganic fiber - Google Patents

Abstract

PURPOSE:To obtain an inorganic fiber, containing calcium phosphate and having excellent biocompatibility, by blending raw materials, having a constant molar ratio after melting and capable of providing a constant wt.% of (CaO+P2O5), melting the obtained blend, then refining the blend and blowing a high-pressure gas thereon. CONSTITUTION:Raw materials consisting of tetracalcium phosphate, hydroxyapatite, quick lime, slaked lime, etc., having 0.3-4.0 molar ratio (Ca/P) after melting and capable of providing 80-15wt.% (CaO+P2O5) are suitably blended, then placed in a crucible having a nozzle at the bottom and melted. Bubbles, etc., are scattered to refine the melt. The resultant refined melt is subsequently discharged from the above-mentioned nozzle and a high-pressure gas is blown thereon to afford the aimed fiber. Furthermore, the afore-mentioned fiber is preferably dipped in a solution at pH 2-7 containing phosphoric acid groups.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention has good compatibility with living organisms, has the ability to form new bone, and is extremely easily adapted to bone defect sites with complex shapes. The present invention relates to a method for producing inorganic fibers as fillers for bone defects and voids.

[Conventional technology J] In the field of surgery or orthopedics, fractures and osteomas
Defects or voids are created in the bone due to removal of teeth, and in the field of dentistry, wear-and-tear defects of the jawbone due to tooth loss occur, which often requires prosthesis. 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 removal of normal bone tissue other than the damaged area, which causes great pain to people with HA and requires a great deal of labor during the surgery.

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. , has not yet reached the practical stage.

For this reason, when filling bone defects and voids, it has excellent biocompatibility, promotes the function of ashes in the defect and its surrounding area, and restores and restores the structural function of the bone ml and defect. 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 environment of living organisms, have coagulability with living organisms, and are accompanied by foreign body reactions. Currently, ceramic materials are being used that have excellent compatibility with living organisms and do not have the above-mentioned drawbacks. Among these ceramic materials, artificial bones 9 and artificial tooth roots made of sintered bodies or single crystals of alumina, carbon, tricalcium phosphate, or hydroxyapatite, which have excellent biocompatibility, are being developed. ing.

[Part 1: Problem to be solved] However, all of these ceramic implant materials have the common drawback of being hard and brittle.
At present, these materials have not yet reached a state where they can be put to practical use.6 Furthermore, attempts have been made to fill bone defects with ceramic blocks made of these sintered bodies or single diseased bodies; When filling a bone defect with a different shape, the purpose of filling cannot be achieved because uneven gaps remain between the block and the bone tissue.For example, in the case of alumina, Since it is significantly harder than bone tissue, there are problems such as bone resorption due to stimulation around the filling material, and it has not yet reached the level of practical use.

Therefore, one object of the present invention is to first provide a method for manufacturing an inorganic fiber that is a material for filling bone defects and voids, which has excellent biocompatibility and integrates with the biological hardness M1m in a short period of time without any foreign body reaction. It is in.

Book 9. Another object of the present invention is to provide a method for producing an inorganic fiber as a filling material for bone defects and voids, which promotes the ashes action in the filling area and particularly quickly repairs and restores the structure and aging of bone tissue defects. There is a particular thing.

[Structure of the present invention: Means for solving the problem] According to the present invention, the Ca/P molar ratio after melting is 0.3 or more and 4.0.
and Cao+P2O5 is 80 weight [96j
Less than 15! A method for producing an inorganic fiber is provided, in which a raw material having an amount of at least 10% is made into fibers by melting and fiberizing steps. Further, there is provided a method for producing inorganic fibers having particularly increased osteogenic ability by immersing fibers made into fibers by the production method having the above-mentioned structure into a solution containing phosphate groups and having a pH of 2 to 7. be done.

As raw materials for the JSS rough eye bar phosphorus and calcium of the present invention, compounds containing tetracalcium phosphate, hydroxyapatite, tricalcium phosphate, prussia; , compounds containing calcium such as calcium carbonate, or triammonium phosphate, phosphoric acid
1 selected from compounds containing ammonium hydrogen, sodium phosphate, potassium phosphate, and phosphorus lv'v phosphorus
It is possible to appropriately use a species or a mixture of two or more thereof, and one or a mixture of two or more selected from each of the calcium-containing compound and phosphorous-containing compound. Further, the raw material for making the total content of components other than CaO and P2O5 20 [%] or more and less than 1185 [%] is aluminum.

One kind or a mixture of two or more compounds selected from compounds containing silicon, sodium, etc. can be used as appropriate. 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 by, for example, 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. Cotton-like fibers can be obtained by this process, and long fibers can be obtained by winding the actual effluent on a drum.

The inorganic fiber has a Ca/P molar ratio of 0.3 or more4
．． 0 or less, and the CaO+P20s content is 80 [
%] and 15[%] or more. This is because when Ca/P is less than 0.3, the viscosity of the melt becomes too small, making it difficult to form fibers. o, and Ca
When the O+P205 content is 80 [%] or more, the melting point of both raw materials becomes extremely high, and it becomes impossible to melt, or even if it can be melted, the viscosity of the melt is too high to make it fine. This is because fibers cannot be created. On the other hand, if the CaO+PzO5 content is less than 15%, it is not preferable because the biocompatibility is poor and the ability to generate new bone is also low, which slows down the repair and recovery of bone tissue.

The method for producing the inorganic fiber of the present invention is preferably a method in which a calcium phosphate compound is provided on the surface of the inorganic fiber.The effect of providing a calcium phosphate compound on the surface of the inorganic fiber is to further improve the biocompatibility of the S* fiber and to promote new bone formation. The aim is to repair and recover living bone tissue and to integrate bone tissue and filling material more quickly by increasing the production capacity.

Methods for providing a calcium phosphate compound on the surface of inorganic fibers include mixing the inorganic fiber with an aqueous solution of phosphoric acid and aqueous ammonia, or using an aqueous solution of ammonium hydrogen phosphate, ammonium dihydrogen phosphate, or trianthonium phosphate. Or a mixed solution of these, or a mixture of these and an aqueous solution of phosphoric acid or aqueous ammonia to achieve the desired pH.
A method can be used in which a calcium phosphate compound is precipitated on the surface of the fiber by immersing it in the solution to cause the phosphoric acid groups present in the solution to react with the calcium ions eluted from the inorganic fiber.

It is necessary that the pH of the solution containing a phosphoric acid group to precipitate a calcium phosphate compound on the surface of the inorganic fiber is between 2 and 7. This is because if the [pH] of the solution is less than 2, the inorganic fibers will deteriorate and the strength of the fibers will drop significantly, making it impossible to obtain a fiber with sufficient strength to be used as a filler. On the other hand, when pH 1 exceeds 7, very little calcium phosphate compound precipitates on the surface of the inorganic fibers, so the effect of surface modification is hardly expected.゛The method of applying a calcium phosphate compound to the surface of the Atsuki fiber is to apply a slurry of calcium phosphate compounds such as wurtzcheid, tricalcium phosphate, hydroxyapatite, etc. to the surface of the inorganic fiber, and then dry it. A method of fixing a calcium phosphate compound to the surface of the fiber can 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, melted in a crucible with a nozzle at the bottom, air bubbles etc. are scattered and clarified, and then flowed out from the nozzle, but components such as Al2O3 and SiO2 are considerably contained. Since it is very easy to spin, it can be made into fibers with almost no 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 i.

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 filler by forming it into the shape,
Continuous pores can be created, allowing the osteogenic components to penetrate into the filling material, which significantly improves the repair and recovery of bone tissue defects and the integration of the living hard tissue and the filling material. You can hasten it.

Although the type of calcium phosphate compound deposited on the surface of the inorganic fiber cannot be determined in detail, x! From the results of the l analysis, it seems that when the pH of the solution containing phosphate groups is low, wurtzcheid 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 were mixed and melted in a crucible having a nozzle at the bottom, and after the melt was sufficiently clarified, the melt was flowed out from the nozzle of the crucible and the flow was wound in a drum. We attempted to create long fibers by taking the following steps. The results are shown in Table 1.

As a result, it was not possible to form fibers 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, Ca/
When P is 0.3 or l-7, CaO + P2O5 is 90
In the case of [%], it becomes a molten product, but when producing fibers, it was often difficult to break the fibers and continuously form them into fibers. Ca/P is 4
．． 0, and when Ca O + P205 is 90 [%] and Ca / P is 5.0, it is 1700 ['C]
However, the mixed raw materials did not melt and no fiber could be obtained.

In any case other than those listed above,
Long fibers could be produced without cutting.

Table 1 [Example 2] Test No. in Example, 7.9, 11, 13.17.
The fiber prepared in step 19 was filled into a bone defect (3 mm mφ7 x 4 mm L) artificially created in the femur of a dog.
The condition of the bone defect area was observed after 2 iJ had passed. As a result, when F-bar of test No. 7.9°13.17.19 was used, in all cases, it was almost integrated with the surrounding bone tissue, and the filling material and surrounding bone tissue The boundaries were not clear. However, when test No. 1 fibers were used, only slight new bone formation was observed on the filled fiber surface, and the surrounding bone tissue and the filling material could be clearly distinguished.

[Example 3] Using raw materials having the same composition as Test No. 7.13.19 in Example 1, a melt was prepared in a crucible having a nozzle at the bottom in the same manner as in Example 1, and the melt was poured into a crucible at the bottom. An attempt was made to produce cotton-like fibers by blowing high-pressure air onto the flow from a nozzle.

As a result, flocculent fibers could be obtained in all cases.

These were artificially created bone defects (3 m
mφ x 4 mmL), and the subsequent progress was observed.

As a result, in all cases, it was found that a large amount of new bone had already been generated on the surface of the filled fibers 4 weeks after filling.

[Example 41 Using the fibers prepared in Test No. 7.13.19 in Example 1, the fibers were treated with phosphoric acid.
In phosphoric acid or ammonia water containing 10E% ammonium hydrogen [pH] 1.0°2.0, 4.0.6-0.7
．． The fibers were surface-treated by immersing them in aqueous solutions adjusted to 0 and 8.0 for 30 minutes, respectively. When the surface of the fiber thus obtained was observed using a scanning electron microscope, in all cases, the fiber surface was attacked and large irregularities were observed for the fibers treated at pH 11.0. Almost no precipitates were observed on the fiber surface of the fibers treated at [pH] a and o. The fiber surface was covered with precipitates when treated at [pH] 2.0°, 4.0, 6.0, and 7.0; In the treated sample, one surface was more uniformly covered with precipitates.

The fibers prepared in Test No. 13 were subjected to each of the above [pH 1
Table 2 shows the tensile strength when treated with .

Table 2 Table 2 (Continued) According to the results, the tensile strength was significantly reduced when pH 1 was 1.0.

[Example %] The fiber produced in Test No. 7.19 in Example 1 and the fiber in the same manner as in Example 4,
[Using fibers surface-treated at pH 12, 0, 4, 0, 6, 0, 7, 0, 8, 0, it was filled into a bone defect (3 mmφ x 4 mm L) artificially created in the great circle bone of a dog. After 3 weeks, the state of new bone formation was observed.

As a result, the surface-treated fiber had a [pH] of 8.0 compared to the case where the fiber was not surface-treated.
In all cases, a larger amount of new bone was generated, except when the surface was treated with . [When the surface was treated at pH 18.0, it was almost the same as when it was used without surface treatment.] [Effects of the present invention j (1) The method for producing inorganic fibers of the present invention was invented. As a result, for the first time, a new inorganic fiber containing calcium phosphate and excellent bone-forming ability, which did not exist before, has been developed.
1 was issued.

(2) The method for producing the inorganic fiber of the present invention includes A1203. Since the amount equivalent to 5iO2tt is used, long wA and Il can be produced with almost no yarn breakage during melting, refining, and spinning.

(3) The effects of the product produced by the production method of the present invention are as follows:
The long fibers can be used as they are as a filling material for bone defects, etc., but by making them into a fabric, they can be used in the same manner or by being wrapped around the defect or fracture site.

By filling the bone defect with fibers and wrapping the fibers around it in the form of a fabric, the treatment period for repairing or restoring the bone defect can be shortened compared to when the bone defect is only filled with fibers. 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 ridge drop after tooth extraction, or bone loss around the tooth root caused by alveolar pyorrhea, etc. Of course, it can also be used as a water treatment material containing phosphoric acid groups.

Claims (2)

[Claims] (1) A raw material with a Ca/P molar ratio of 0.3 or more and 4.0 or less after melting and a CaO+P_2O_5 of less than 80 weight [%] and 15 weight [%] or more is processed through a melting process, a clarification process, and a fiberization process. A method for producing an inorganic fiber, characterized by forming the fiber into a fiber by a process. (2) A method for producing an inorganic fiber, characterized by immersing the fiber produced by the production method according to claim 1 in a solution containing a phosphoric acid group and having a pH of 2 to 7. .