JP2007236802A - Material for implant inclination - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material for implant inclination excellent in a bonding property with living bone tissue and reconstructability, to be used for treating an articular bone cartilage disorder or the like and reinforcing the bone articulation attaching part of ligament or the like. <P>SOLUTION: The material 10 for implant inclination is composed of the continuous porous complex 1 of an in vivo degradable and absorptive polymer containing in vivo absorptive and bioactive bioceramics powder, and porosity is successively changed so as to be higher from the surface layer part 1a on one side of the complex 1 to the surface layer part 1b on the opposite side or from the intermediate part or center part of the complex 1 to the surface layer part on both sides or the periphery within the range of 10-90%. The surface layer part 1b of the high porosity is promptly hydrolyzed, is replaced with the living (cartilage) bone tissue while being bonded with the tissue and disappears in a short time. The surface layer part or the intermediate part or the center part of the low porosity maintains strength for a certain degree of a period, is finally replaced with the living (cartilage) bone tissue and disappears, and thus the tissue is reconstructed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an implant gradient material used for the treatment of osteoarticular cartilage disorders such as femoral head necrosis of the hip joint and knee head necrosis of the knee joint, and reinforcement of the bone joint attachment portion of the ligament.

  Conventionally, various techniques of regenerative medicine have been studied for the reconstruction, regeneration, or reinforcement of bones and cartilage that have been greatly destroyed or damaged. In essence, the reconstruction of a damaged site with a certain shape requires the form required to avoid mechanical load from the outside, cytological and physiological invasion during the period until tissue regeneration is completed. It is widely recognized that a scaffold is needed to form, maintain and complete the reconstruction.

  At present, various ideas have been presented for scaffold materials used when there is an abnormality in articular cartilage such as a hip joint and a knee joint and the cartilage needs to be repaired, regenerated and reconstructed. However, what is sufficient to serve as a scaffold for treating and reconstructing the necrotic part of the joint bone head and strengthening the bone-joint attachment part of the ligament has not been developed due to material difficulties. The reason for this is that the site where it is used is a scaffold that should be applied to the interface, i.e. the location of the joint, which is a discontinuous osteosynthesis site where the cartilage and bone contact with movement, consisting of different functions and materials. Because there is.

  As one of the development measures for such a scaffold, a prosthetic material is produced by combining a cartilage substitute and a bone substitute, and a bone substitute is used for the joint skull and a cartilage substitute for the articular cartilage. It is conceivable to insert and fix objects. However, if both of these alternatives are not monolithic and consist of a combination of separate parts, a continuous connective transition form of cartilage and bone tissue cannot be obtained, and when the joint is in operation, There arises a problem that the two peel off. Therefore, the scaffold material worthy of being used for the joint part has a good affinity for bone in the bone and biohistologically and mechanically, and the part in the cartilage has a good affinity for the cartilage and biohistologically and mechanically. It must be stable in the bone joint, which is a movable interface, so that it does not fall out.

  In this case, if the target prosthetic material is non-absorbable in the living body such as metal, ceramic, polymer, etc., it will not be replaced with living tissue over time, and infection or mechanical failure may occur during long-term implantation. Continuing to worry about the occurrence of new problems. Therefore, it is necessary to have both the bioactivity and the biodegradability that can be decomposed and absorbed in the living body and disappear in the living body while being replaced with the living tissue and reconstructing the shape. In addition, the porous part that shares both the dense and porous parts at the same time, and the porous part that substitutes for the cartilage side has a higher open rate as it is closer to the cartilage surface, and the dense part that substitutes for the bone. It is desirable from a mechanical and physiological viewpoint that the portion of the portion that is densely embedded has a lower open rate.

  That is, scaffolds for the treatment and reconstruction of articular osteochondral disorders, etc., in the porous part, cells rapidly invade, the cartilage tissue is induced and formed in the surface layer part with the degradation of the scaffold, and exchanges with the biological tissue, the dense layer For a certain period until it is decomposed, the bone is conducted and closely adhered to maintain a sufficient strength, but finally, development of a material that is completely decomposed and completely replaces the bone tissue is required.

  By the way, the present inventor, as an implant material for repairing and reconstructing a defect portion of a living bone having cortical bone on the surface layer (outside) of the cancellous bone, has a continuous pore inside and is a bioactive bioceramic powder. A dense skin layer made of biodegradable absorbable polymer containing bioactive bioceramic powder is laminated on a part of the surface of a three-dimensional porous material made of biodegradable absorbable polymer containing An artificial bone has already been proposed (Patent Document 1).

This implant material is applied to the cancellous bone defect portion of the inner layer of the living bone to embed a three-dimensional porous body, and is applied to the cortical bone defect portion of the surface layer to embed a dense epidermis layer. Is. This is an artificial bone preferably used as a substitute material for autograft bone fragments and allograft bone fragments. However, it is not suitable as a scaffold to be adapted to the boundary surface, which is a discontinuous osteosynthesis site where the cartilage and the bone come into contact with each other with movement, which is composed of different functions and materials, that is, the position of the joint.
JP 2004-121301 A

  The present invention has been made under the above circumstances, and when there is an abnormality in the articular bone cartilage such as the hip joint and the knee joint, it is necessary to repair, regenerate and reconstruct the cartilage, that is, treatment and reconstruction of the necrotic part of the joint bone head. As a temporary prosthesis / scaffold material used to strengthen the bone joint attachment part of the ligament, it can be stably embedded and fixed in the bone joint with the above-mentioned physical properties and functions that are desired in the medical field. The problem to be solved is to provide an implant gradient material.

In order to solve the above problems, the first implant gradient material according to the present invention is a bioresorbable and bioactive bioceramic powder-containing biodegradable absorbable polymer continuous porous composite. In the range of 10 to 90%, the porosity is successively changed so as to increase from the surface layer portion on one side to the surface layer portion on the opposite side. .
And the 2nd implant inclination material which concerns on this invention consists of a continuous porous composite body of the biodegradable absorptive polymer containing the bioresorbable and bioactive bioceramics powder, and the porosity is 10 Within the range of ˜90%, it is successively changed so as to become higher as it approaches the surface layer part on both sides from the intermediate part of the complex or from the center part of the complex to the surrounding surface layer part. It is characterized by this.

  In the first implant gradient material, the content of the bioceramic powder is higher in the range of 30 to 80% by mass as it approaches the surface layer on the opposite side from the surface layer on one side of the continuous porous composite. It is preferable to change continuously so that it may become. Moreover, in the second implant gradient material, the content of the bioceramic powder is within the range of 30 to 80% by mass, and the closer to the surface layer parts on both sides from the middle part of the continuous porous composite, or It is preferable that the thickness of the composite is continuously changed so as to increase from the central portion toward the surrounding surface layer portion. All of these implant gradient materials are formed into a continuous pore composite, BMP (Bone Morphogenic Protein), TGF-β (Transforming Growth Factor-b), EP4 (Prostanoid Receptor), biological bone growth factors, It is preferable to be impregnated with at least one of b-FGF (basic fibroblast growth factor), PRP (platelet-rich plasma) and / or living osteoblasts.

  Such an implant gradient material of the present invention is used for treatment, regeneration, or reconstruction or reinforcement of a bone-joint attachment portion of a ligament, and the joint head and the joint cartilage are in contact with the knee, crotch, foot, and shoulder. It is applied to joints such as elbows and spine (cervical vertebrae, lumbar vertebrae) as temporary prosthetic materials, scaffolds and carriers for the release of biological osteogenic factors.

  In the implant gradient material of the present invention, the body fluid easily penetrates into the continuous pores of the surface layer portion having a high porosity of the continuous porous composite, so that the body fluid contacting the surface of the surface layer portion and the body fluid penetrating the continuous pores are Is rapidly hydrolyzed. And since the surface part with high porosity is easy for osteoblasts to invade, the (soft) bone tissue is triggered by bio-ceramics powder that is bioactive during hydrolysis, and the inside of the surface part with high porosity is In a short period of time, the surface layer portion and the inner layer portion having a relatively high porosity connected thereto are replaced with (soft) bone tissue in a short period of time. On the other hand, the surface part, middle part and central part on one side with low porosity of the continuous porous composite are strong, hydrolysis is much slower than the surface part with high porosity, and hydrolysis proceeds to some extent. The strength is maintained for a period of time, and finally, everything is decomposed, and the living bone is formed by conduction with the bioactive bioceramic powder to replace the bone tissue. And since the bioceramics powder contained in this continuous porous composite is in vivo absorbable, it does not remain or deposit in the replaced and regenerated (soft) bone tissue. Moreover, it does not leach into soft tissues or blood vessels. Thus, since the implant gradient material of the present invention has physical properties or functions required as a scaffold material used for the treatment of osteoarticular cartilage disorders, for example, the first implant gradient material is used as the joint material. If the surface layer part with high porosity is embedded and fixed in the part where the necrotic part of the bone head is excised, the surface layer part with high porosity and the inner layer part with relatively high porosity connected thereto are fixed. Disappears by replacing the cartilage tissue that was induced and formed early, and disappearing by replacing the bone part with the low porosity, which has strength, with the total replacement with the bone tissue formed by conduction. The body is also completely absorbed and the necrotic bone and cartilage parts of the joint head are regenerated. Moreover, when the second implant gradient material is embedded in the excised portion of the joint bone head, in addition to the above-described effects, the bone tissue is rapidly induced and formed in the surface layer portion having a high porosity in contact with the bone of the excised portion. The tilted material is fixed in combination with the excised part of the articular head in a short period of time.

  The content of the bioceramic powder may be constant throughout the continuous porous composite, but the content of the bioceramic powder is within the range of 30 to 80% by mass of the continuous porous composite. Within the range of the content of the implant gradient material or bioceramics powder that is successively changed so as to increase from the surface layer portion on one side to the surface layer portion on the opposite side, the continuous pores The implant gradient material which is successively changed so as to increase from the middle part of the porous composite to the surface layer part on both sides or from the center part of the composite to the surrounding surface part part is bioceramics. Since the bioactivity of the surface layer portion with a high powder content increases, the induction formation of osteoblasts and (soft) bone tissue in the surface layer portion becomes particularly active, and the replacement with (soft) bone tissue is further promoted. The

  In addition, an implant gradient in which a continuous pore complex is impregnated with at least one of biological bone growth factors BMP, TGF-β, EP4, b-FGF, and PRP and / or living osteoblasts Since the material greatly promotes the proliferation and growth of osteoblasts, the formation of (soft) bone tissue is vigorous and is regenerated more rapidly.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

  1A is a perspective view of an implant gradient material according to an embodiment of the present invention, FIG. 1B is a cross-sectional view of the implant gradient material, and FIG. 2 is an explanatory diagram of an example of use of the implant gradient material. .

  This implant gradient material 10 is composed of a continuous porous composite 1 of a biodegradable and absorbable polymer containing a bioceramic powder that is bioabsorbable and bioactive, and has a porosity of 10 to 10. Within 90% of the range, the composite layer successively changes so as to increase from the surface layer portion 1a on the one side (surface layer portion on the lower surface side) toward the surface layer portion on the opposite side (surface layer portion on the upper surface side). . The implant gradient material made of the continuous porous composite 1 is formed in a columnar shape as shown in FIG. 1 (a), but is not limited to this, and depends on the joint site to be implanted. Various shapes such as a rectangular column shape, an elliptic column shape, a flat plate shape, and the like can be obtained, and the size may be set to an optimum size according to the joint site to be embedded.

  Crystalline poly-L-lactic acid, polyglycolic acid, or the like is also used as the biodegradable absorbable polymer that is a raw material of the continuous porous composite 1. The high surface layer portion 1a and the inner layer portion having a relatively high porosity are required to be as strong and flexible as cartilage, and are quickly decomposed so that they can be quickly combined with living (soft) bone or replaced completely. As a biodegradable absorbent polymer used as a raw material for the continuous porous composite 1, it is safe, decomposes quickly, is not very brittle, and is a mixture of amorphous or crystalline and amorphous. Poly-D, L-lactic acid, L-lactic acid and D, L-lactic acid copolymer, lactic acid and glycolic acid copolymer, lactic acid and caprolactone copolymer, lactic acid and ethylene glycol copolymer, lactic acid And para-dioxanone copolymer, etc. Suitable are, they alone or used by mixing two or more. These biodegradable and absorbable polymers are preferably those having a viscosity average molecular weight of about 50,000 to 600,000 in consideration of the strength required for the continuous porous composite 1 and the period of in vivo degradation and absorption. used.

  The continuous porous composite 1 constituting the implant gradient material 10 has continuous pores therein, and is contained in a state where a part of the bioceramic powder is exposed on the inner surface of the continuous pores or on the surface of the composite 1. It is what. And as above-mentioned, the porosity of this continuous porous composite 1 is within the range of 10 to 90%, preferably within the range of 20 to 80%, and the surface layer portion 1a (the surface layer portion on the lower surface side) on one side. To the surface layer portion 1b on the opposite side (surface layer portion on the upper surface side). The continuous pores preferably account for 50 to 90% of the total pores, especially 70 to 90%. In addition, the pore diameter of the continuous pores is adjusted in the range of 50 to 600 μm, preferably in the range of 100 to 400 μm, and the pore diameter increases as it approaches the surface layer portion 1b on one side having a higher porosity.

  When the porosity or the like is inclined as described above, the surface layer portion 1b (hereinafter referred to as a high porosity surface layer portion) having a high porosity of the continuous porous composite 1 can easily and quickly penetrate body fluid. Coupled with the fact that it is hydrolyzed and osteoblasts easily invade and the content of bioactive bioceramic powder is high as described later, (soft) bone tissue is induced and formed at an early stage. Combined and replaced with (soft) bone. If the porosity of the high-porosity surface layer portion 1b exceeds 90% and the pore diameter is larger than 600 μm, the physical strength of the high-porosity surface layer portion 1b is lowered and becomes brittle. In addition, if the continuous pores are less than 50% of the total pores and the pore diameter is smaller than 50 μm, it is difficult for the body fluid and osteoblasts to enter, and hydrolysis and induced formation of bone tissue are slowed down. (Soft) It is not preferable because it takes a long time to bond and replace bone. However, it has been found that osteoinductivity is expressed when there are continuous pores as fine as about 1 to 0.1 μm in combination with the above preferable pore diameter.

  On the other hand, the strength of the surface layer portion 1a on the opposite side (lower surface side) where the porosity of the continuous porous composite 1 is low (hereinafter referred to as a low porosity surface layer portion) is improved as the porosity decreases. Since an extremely high strength is not required for the implant gradient material adapted as a scaffold for the joint, it is not necessary to bring the porosity of the low-porosity surface layer portion 1a close to zero. Therefore, the lower limit of the porosity of the low-porosity surface layer portion 1a is set to 10%, preferably 20%, to give strength suitable for a scaffold and to shorten the time required for hydrolysis and total replacement with (soft) bone cells. I can do it.

  The bioceramic powder to be contained in the continuous porous composite 1 is bioactive, absorbs in vivo, is totally absorbed by the living body, and is completely replaced with bone tissue, and has good bone conduction (induction) ability. Non-calcined and uncalcined hydroxyapatite, dicalcium phosphate, tricalcium phosphate, tetracalcium phosphate, octacalcium phosphate, calcite, serabital, diopsite, smallpox, etc. having good biocompatibility are preferred used. Among them, uncalcined and uncalcined hydroxyapatite, tricalcium phosphate, and octacalcium phosphate are optimal because they have extremely high bioactivity, excellent osteoconductivity, low toxicity and are absorbed into the body in a short period of time. It is.

  These bioceramic powders have a particle size of about 30 μm or less, preferably about 10 μm or less, more preferably about 0.1 to 5 μm in consideration of dispersibility in the biodegradable absorbable polymer and absorbability to the living body. Things are used. In particular, the bioceramic powder having a particle size of about 0.1 to 5 μm has good absorbability to the living body, and sprays and the like when producing the continuous porous composite 1 by the method described later. It is preferably used because there is no fear of cutting the fiber formed by the above method.

  The content of the bioceramic powder of the continuous porous composite 1 may be constant throughout the continuous porous composite 1, but within the range of 30 to 80% by mass, the low porosity surface layer portion It is preferable that the ratio is successively changed so as to increase from 1a toward the high porosity surface layer portion 1b. That is, as the low porosity surface layer portion 1a approaches the high porosity surface layer portion 1b, the mass ratio of the bioceramic powder / biodegradable absorbent polymer is successively increased within a range of 30/70 to 80/20. It is preferable to change so that. When the content of the bioceramic powder is inclined as described above, the bioactivity of the high-porosity surface layer portion 1b is large, and the induction formation of osteoblasts and (soft) bone tissue is particularly active. Bonding and replacement with (soft) bone is further promoted.

  When the content ratio of the bioceramic powder in the high porosity surface layer portion 1b exceeds 80% by mass, there is a disadvantage in that the physical strength of the high porosity surface layer portion 1b is reduced, and the content ratio in the low porosity surface layer portion 1a. Is less than 30% by mass, the induction of formation of (soft) bone tissue by the bioceramic powder of the low-porosity surface layer 1a becomes inactive. The inconvenience of passing is caused. The upper limit of the more preferable content rate of bioceramics powder is 70 mass%.

  This continuous pore complex 1 includes biological bone growth factors BMP (Bone Morphogenic Protein), TGF-β (Transforming Growth Factor-b), EP4 (Prostanoid Receptor), b-FGF (basic Fibroblast Growth Factor). ) And / or PRP (platelet-rich plasma) and / or a living osteoblast is preferably impregnated. When impregnated with these biological bone growth factors and osteoblasts, the proliferation and growth of osteoblasts are greatly promoted, and the high porosity of the continuous pore complex 1 is extremely short (about 1 week). A (soft) bone tissue is formed in the surface layer portion 1b, and then the whole of the continuous porous composite 1 is completely replaced with the (soft) bone tissue, and the living body (soft) bone is repaired and reconstructed. Among the above factors, TGF-β and b-FGF are particularly effective for the growth of cartilage, and BMP and EP4 are particularly effective for the growth of bone. Therefore, when the living bone to be regenerated is cartilage, TGF-β And b-FGF are preferably impregnated with BMP or EP4 when the living bone to be regenerated is a hard bone. PRP is plasma rich in platelets, and the addition of this promotes the formation of new bone. In some cases, other growth factors such as IL-1, TNF-α, TNF-β, and IFN-γ may be impregnated.

  Further, the surface of the continuous porous composite 1 may be subjected to oxidation treatment such as corona discharge, plasma treatment, hydrogen peroxide treatment, and the like. Since the wettability of the surface is improved and osteoblasts invade and grow more effectively into the continuous pores of the complex 2, there is an advantage that the binding to the living body (soft) bone and the total replacement are further promoted. is there.

  The implant gradient material made of the continuous porous composite 1 is manufactured by, for example, the following method. First, a biodegradable polymer is dissolved in a volatile solvent, and a bioceramic powder is mixed to prepare a suspension. The suspension is made into a fiber by means of spraying or the like, and the fibers are intertwined. Form an aggregate. Then, this fiber assembly is immersed in a volatile solvent such as methanol, ethanol, isopropanol, dichloroethane (methane), chloroform, etc. to be in a swollen or semi-molten state, and this is pressurized to form a cylindrical porous body as shown in FIG. The fiber fusion aggregate is formed into a matrix with the fiber-like form disappearing while the fibers of the fiber fusion aggregate are contracted and fused to form a matrix, and the inter-fiber voids become round pores. It is transformed into a continuous porous composite. In that case, when the fiber assembly is immersed in a volatile solvent to be in a swollen or semi-molten state as described above and pressed into a fiber fusion assembly, the amount of the fiber assembly is reduced to one side (lower surface side). ) From the surface layer portion 1a on one side to the surface layer portion 1b on the opposite side, the continuous porosity composite 1 can be obtained in which the porosity increases successively in sequence. Further, when producing a continuous porous composite in which the content of bioceramic powder increases from the low porosity surface layer portion 1a to the high porosity surface layer portion 1b, several kinds of bioceramic powders having different mixing amounts are produced. A suspension is prepared to form several types of fiber aggregates with different bioceramic powder content, and these fiber aggregates are swelled or stacked one after another in order from the one with the lowest bioceramic powder content. What is necessary is just to pressurize in a semi-molten state.

  In the case of treating an articular osteochondral disorder such as knee osteonecrosis using the implant gradient material 10 as described above, as shown in FIG. The implant gradient material 10 (preferably BMP, EP4 or PRP effective for bone growth is contained in the low-porosity surface layer portion 1a or the inner layer portion having a relatively low porosity, which is effective for cartilage growth. TGF-β and b-FGF, which are factors, are contained in the high-porosity surface layer portion 1b and the inner layer portion having a relatively high porosity connected thereto, so that the high-porosity surface layer portion 1b is on the cartilage 4 side. Immediately bury and fix. When the implant gradient material 10 is embedded in this manner, the high porosity surface layer portion 1b is rapidly hydrolyzed from the surface and inside by body fluid contacting the surface or body fluid penetrating the internal continuous pores, and bioactive bioceramics. By the powder, cartilage tissue is induced and formed on the peripheral side surface of the high-porosity surface layer portion 1b in contact with the cartilage 4 in a very short period of time, and the high-porosity surface layer portion 1b and the cartilage 4 are combined, and then the high-porosity surface layer The part 1b and the inner layer part having a relatively high porosity connected to the part 1b are immediately replaced with the cartilage tissue and disappear. On the other hand, although the low-porosity surface layer portion 1a of the continuous porous composite 1 and the inner layer portion having a relatively low porosity connected thereto are hydrolyzed to some extent, the high-porosity surface layer portion 1b is replaced with cartilage tissue. Sufficient strength is maintained until that time. As the hydrolysis proceeds further, the bone tissue of the knee joint head 2 is conductively formed in the low porosity surface layer portion 1a and the inner layer portion having a relatively low porosity connected thereto due to the osteoconductivity of the bioceramic powder. Finally, it is replaced with bone tissue and disappears. The bioceramic powder contained in the continuous porous composite 1 is also completely absorbed and disappears. As a result, the damaged part of the knee articular cartilage is completely repaired and reconstructed.

  FIG. 3 is a cross-sectional view of an implant gradient material according to another embodiment of the present invention.

  This implant gradient material 11 is, like the implant gradient material 10 described above, a columnar shape made of a continuous porous composite 1 of a biodegradable and absorbable polymer containing bioceramic powder that is bioabsorbable and bioactive. However, when the porosity is in the range of 10 to 90%, preferably in the range of 20 to 80%, the porosity increases from the central portion 1c of the continuous porous composite 1 to the surrounding surface layer portion 1d. In the range of 30 to 80% by mass, the bioceramic powder is gradually increased from the central portion 1c of the continuous porous composite to the surrounding surface layer portion 1d. It is different from the implant gradient material 10 described above in that it changes sequentially and continuously.

  When such an implant gradient material 11 is embedded in the excised portion 3 of the joint bone, in addition to the effects of the implant gradient material 10 described above, the porosity and bioceramic powder content of the inner surface of the excised portion 3 are in contact. There is an advantage that the bone tissue is rapidly formed in the high surface layer 1d and is fixed in combination with the inner surface of the resection portion 3 of the joint bone in a short period of time.

  FIG. 4 is a cross-sectional view of an implant gradient material according to still another embodiment of the present invention.

  This implant gradient material 12 is also composed of a continuous porous composite 1 of a biodegradable absorbable polymer containing bioceramic powder that is bioabsorbable and bioactive in the same manner as the implant gradient material 10 described above. Are formed in a prismatic shape, and the porosity is in the range of 10 to 90%, preferably in the range of 20 to 80%, and the upper and lower surface layers from the middle portion 1e of the continuous porous composite 1 Within the range of 30 to 80% by mass of the bioceramic powder, the upper and lower sides from the intermediate portion 1e of the continuous porous composite 1 are successively changed so as to become higher toward the portions 1f and 1f. It is different from the implant gradient material 10 described above in that it gradually changes so as to become higher as it approaches the surface layer portions 1f, 1f on both sides.

  For example, as shown in FIG. 5, the implant gradient material 12 is inserted as a spacer between vertebrae 5, 5 of a joint such as a spine, a lumbar vertebra, and a cervical vertebra. When inserted in this manner, the surface layer portions 1f and 1f having a high porosity and bioceramics powder content in contact with the upper and lower vertebrae 5 and 5 are rapidly hydrolyzed, and the bone tissue is transferred from the upper and lower vertebrae 5 and 5 to the surface layer portion 1f. , 1f and formed in a short time, the implant gradient material 12 does not fall off from the joint. Then, the surface layer portions 1f and 1f are completely replaced with the bone tissue at an early stage and disappear, and the intermediate portion 1e maintains the strength for a certain period of time, but then the conduction formation of the bone tissue proceeds, and finally the bone Disappears with complete replacement of tissue.

  As described above, the implant gradient material 12 inserted as a spacer between the vertebrae is compressed from above and below when the thickness of the upper and lower surface layer portions 1f and 1f having a high porosity is increased. Therefore, the thickness of the upper and lower surface layer portions 1f and 1f is preferably as thin as about 0.1 to 2.0 mm. Further, in order to completely eliminate such fear, the implant gradient material 12 is rotated 90 degrees and the high porosity surface layer portions 1f and 1f are positioned on the left and right sides of the low porosity intermediate portion 1e. And then inserted between the vertebrae 5 and 5. In this way, the upper and lower vertebrae 5 are supported by the upper and lower end surfaces of the high-porosity surface layer portions 1f and 1f on both the left and right sides while the distance between the upper and lower vertebrae 5 and 5 is reliably maintained by the strong low-porosity intermediate portion 1e. , 5 in an early bridging state to prevent the implant composite material 12 from slipping out.

  FIG. 6 is a cross-sectional view of an implant gradient material according to still another embodiment of the present invention.

  This implant gradient material 13 is also composed of a continuous porous composite 1 of a biodegradable and absorbable polymer containing bioceramic powder that is bioabsorbable and bioactive in the same manner as the implant gradient material 10 described above. However, it is formed in a piece shape (small piece shape) so as to be suitable for reconstruction and reinforcement of the bone joint joint portion of the ligament, and the porosity is in the range of 10 to 90%, preferably 20 to 80%. Within the range, the point where the bioceramic powder is continuously changed from the middle portion 1e of the continuous porous composite 1 to the surface layer portions 1g, 1g on both the left and right sides so as to become higher, and the bioceramic powder is 30 to Within the range of 80% by mass, the implant gradient material described above is that the intermediate gradient portion 1e of the continuous porous composite 1 is successively changed so as to increase toward the surface layer portions 1g and 1g on the left and right sides. 0 and is different.

  As shown in FIG. 9, the implant gradient material 13 is used for reconstruction or reinforcement of the bone joint joint portion of the ligament. That is, as shown in FIG. 9, holes 6 and 6 are made in both bones of the bone joint, both ends 7 and 7 of the ligament 8 are passed through the holes 6 and 6, and both ends 7 and 7 of the ligament 8 and the hole 6 are formed. The implant gradient material 13 may be sandwiched between the inner surface of one side and the interference screw 9 may be screwed and fixed between the end portions 7 and 7 and the inner surface on the opposite side of the hole 6. In this way, the high-porosity surface layer portions 1g and 1g on both sides of the implant gradient material 14 are bonded to both end portions 7 and 7 of the ligament 8 and the inner surface of the hole 6 and then immediately replaced with bone tissue to disappear. At the same time, since the strong low-porosity intermediate portion 1e eventually disappears after being completely replaced with bone tissue, both end portions 7 and 7 of the ligament 8 are coupled to the hole 6 through the completely replaced bone tissue. In this case, if the interference screw 9 is made of a biodegradable and absorbable polymer containing bioactive bioceramic powder, the screw 9 is eventually replaced with bone tissue and the inner surface of the hole 6 and both ends of the ligament 8. Since it couple | bonds with the parts 7 and 7, the fixed strength of a ligament adhesion part will improve further.

  Needless to say, any of the implant gradient materials 11, 12, 13 is preferably impregnated with the aforementioned biological bone growth factor or living osteoblasts.

(A) is a perspective view of the implant gradient material which concerns on one Embodiment of this invention, (b) is a schematic sectional drawing of the implant gradient material. It is explanatory drawing of one example of use of the implant gradient material. It is a schematic sectional drawing of the implant gradient material which concerns on other embodiment of this invention. It is a schematic sectional drawing of the implant gradient material which concerns on other embodiment of this invention. It is explanatory drawing of one example of use of the implant gradient material. It is a schematic sectional drawing of the implant gradient material which concerns on other embodiment of this invention. It is explanatory drawing of one example of use of the implant gradient material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Continuous porous composite body 1a One surface layer part 1b Opposite surface layer part 1c Center part 1d Surrounding surface layer part 1e Middle part 1f Upper and lower both surface layer parts 1g Left and right both surface layer parts 2 Joint head 3 Joint bone head resection part 4 Cartilage 8 Ligament 10, 11, 12, 13 Implant gradient material

Claims (7)

  It is composed of a continuous porous composite of biodegradable and absorbent polymer containing bioabsorbable and bioactive bioceramic powder, and the surface layer on one side of the composite within a porosity of 10 to 90% A bioabsorbable and bioactive implant gradient material characterized by being successively and continuously changed so as to approach the surface layer portion on the opposite side from the portion.   It consists of a continuous porous composite of a biodegradable and absorbable polymer containing bioabsorbable and bioactive bioceramic powder, and the porosity is within the range of 10 to 90% from the middle part of the composite The in vivo absorbability and the living body characterized by being continuously changed so as to increase toward the surface layer part on both sides or from the center part of the complex toward the surrounding surface layer part. Active implant gradient material.   The content ratio of the bioceramic powder is successively changed within a range of 30 to 80% by mass so as to increase from the surface layer portion on one side of the continuous porous composite to the surface layer portion on the opposite side. The implant gradient material according to claim 1.   The content of the bioceramic powder is within a range of 30 to 80% by mass, from the middle part of the continuous porous composite to the surface layer part on both sides, or from the center part of the composite to the surrounding surface layer part. The implant gradient material according to claim 2, which is successively and continuously changed so as to become higher as approaching.   In addition to BMP (Bone Morphogenic Protein), TGF-β (Transforming Growth Factor-b), EP4 (Prostanoid Receptor), b-FGF (basic Fibroblast Growth Factor), PRP The implant gradient material according to any one of claims 1 to 4, which is impregnated with at least one kind of (platelet-rich plasma) and / or osteoblasts derived from a living body.   The implant material according to any one of claims 1 to 5, which is used for treatment of osteoarticular cartilage disorder, regeneration / reconstruction, or reconstruction or reinforcement of a bone joint joint portion of a ligament.   Prosthesis, scaffolding, and biological bone morphogenetic factors are removed from joints such as knees, hips, feet, shoulders, elbows, spines (cervical vertebrae, lumbar vertebrae) where joint head and articular cartilage are in contact The implant gradient material according to claim 1, which is adapted as a carrier for a carrier.

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