WO2007074896A1

WO2007074896A1 - Composite scaffold for tissue regeneration

Info

Publication number: WO2007074896A1
Application number: PCT/JP2006/326212
Authority: WO
Inventors: Masaki Hojo; Taiji Adachi; Chiaki Hiwa; Shunsuke Baba; Takeomi Inoue; Toshiyuki Imoto
Original assignee: Japan Science And Technology Agency; National University Corporation Kyoto University; National University Corporation Kobe University; Arblast Co., Ltd.; Imoto Machinery Co., Ltd.; The New Industry Research Organization
Priority date: 2005-12-28
Filing date: 2006-12-28
Publication date: 2007-07-05
Also published as: JPWO2007074896A1; JP2009039139A

Abstract

It is intended to provide a composite scaffold for tissue regeneration which has a high rigidity and strength in the radial direction as well as in the longitudinal direction of a tubular fabric structure, and in which in the case of therapeutic surgery such as implanting, it is difficult to be deformed in the radial direction and inside cells are not destroyed. At crossing parts of a structure comprising polylactic acid resin (PLA) fiber, PLA fiber is hung and interwoven spirally (in a coil-like shape). Here, it is preferable to use a polycaprolactone resin (PCL) or a copolymer of lactic acid and glycolic acid (PLGA) as a binder. By interweaving the coil-shaped PLA fiber while hanging it at the crossing parts of the structure, it becomes possible to control a coil pitch easily and to significantly improve the rigidity and strength in the radial direction by 2- to 10-fold.

Description

Specification

Combined Scaffold for tissue regeneration

Technical field

[0001] The present invention relates to a scaffold for tissue regeneration for medical use, and more particularly, to a scaffold made of a composite material composed of biodegradable greaves. Bone tissue and nerve tissue are regenerated by injecting stem cells, osteoblasts, etc. into the scaffold structure, and performing treatment on the tissue defect.

Background art

[0002] When a defect occurs in the human body, it is often healed naturally! However, when the defect becomes large, there are cases where it cannot be repaired by natural healing power. Regenerative medicine technology that regenerates tissue with stem cells that are undifferentiated cells at such times is expanding its application to all parts of the human body. In this case, what is required is a scaffold for inducing tissue regeneration, and biodegradable fat that is degraded in the body according to tissue regeneration is used for this scaffold.

[0003] Since biodegradable coagulation degrades itself in the living body or in a normal environment, it has recently been in the limelight! / Occupies an important position in regenerative medicine! The Examples of biodegradable resin used for medical purposes include polylactic acid (PLA) resin and polycaprolacton (PCL) resin. Among biodegradable plastics, PLA resin is excellent in biodegradability and bioabsorbability, and is expected to be a new medical material that combines high strength, biocompatibility, and self-degradability.

[0004] By the way, when a large defect space is generated in a living body, the site is generally compensated by scar-like collagen tissue. In the tissue defect occupied by scar tissue, it is impossible to expect the regeneration of the actual living tissue. One way to regenerate an organization

It is to remove the scar tissue that occupies the regeneration site, and another method is to secure the space for regeneration in the defect portion so that the defect portion is not occupied by the scar tissue. It is necessary to create a space in the defect area to support the cell division and proliferation. In order to make this place, it is necessary to have a scaffold as a scaffold for cells. is there.

[0005] Scafold has moderate rigidity and sufficient strength, which can prevent the invasion of neighboring tissues such as granulation, etc., in which cells and so on can be easily seeded while its application range is widened. Therefore, functions such as biodegradability control are required, and new materials having these functions are demanded.

[0006] Conventionally, tissue regeneration scaffolds include porous hydroxyapatite for bone regeneration, collagen gel for cartilage regeneration (Non-patent Document 1), or a structure made of poly-force prolataton fibers (Non-patent Document) 2) etc. are being studied, and clinical trials are being conducted for each.

[0007] Further, as a scaffold for biomaterials, a noble hybrid type apatite-collagen composite has been proposed. This is because carbonate apatite has a composition close to that of living bone tissue and crystallinity, and is a material having an excellent affinity for living tissue. By making the sponge into a sponge, high porosity and porous biopatient apatite 'collagen complex is to be used for regenerative medical materials (Patent Document 1).

[0008] For example, stainless steel, titanium alloy, ceramics, and the like have conventionally been used as auxiliary aggregates for fractures of the human body, such as when bone defects are caused by bone diseases or trauma. In order to repair the function of the defective hard tissue, such as artificial bones or artificial roots, what is transplanted to the defect is a metal that is difficult to break down and does not rust. Although there is no adverse effect on the skin, it is better to remove it if the bones heal. However, it may not be removed if the risk of surgery is high, such as the elderly. There is a demand for materials that have sufficient strength and rigidity, and that self-decompose and bioabsorbable as the defect is healed.

[0009] At present, the Ministry of Health, Labor and Welfare and the Japan Dental Association have been advocating the “80 Ni O Movement” since 2000 for the purpose of improving the quality of life (QOL) of the elderly. So keep your teeth at least 20 ". However, the current situation is 11.5 at 60, 7.8 at 70, 5.5 at 75, and 4.0 at 80. Loss of teeth is caused by tooth decay, gum problems, and periodontal disease. And 80% for 35-45 years old, 88 for 45-55 years old It is said that% is strong in periodontal disease. When it is effective against periodontal disease, the gingiva swells, the gap between the gingiva and the tooth deepens, the inflammation spreads deeper and bones are lost, resulting in loss of the tooth. It is said that if the alveolar bone can be regenerated, teeth can be prevented from falling off.

[0010] The only method that has already been widely applied clinically as a method for regenerating alveolar bone tissue by tissue engineering techniques is a periodontal tissue regeneration method called GTR (Guided Tissue Regeneration). In this method, when the inflammatory lesions present in the alveolar part absorbed by periodontitis are removed and the periodontal tissue is regenerated, connective tissue and epithelium enter quickly from the surroundings, and the periodontal ligament tissue and alveolar bone are sufficient. It is not played back. Thus, what is important is to provide a field for the regenerated cells suitable for the tissue and block the desired sputum cell invasion.

Specifically, after removing the inflamed tissue by deploying the gingival flap by surgery, a shielding membrane (GTR membrane) is inserted between the root surface and the gingival flap. However, the GTR method has a limited ability to regenerate large alveolar bone defects, and the defect is large and cannot be repaired with natural healing power. There is regenerative medical technology to regenerate In this case, a tissue regeneration scaffold (scaffold) for inducing tissue regeneration is first required.

[0011] As described above, application of the scaffold for tissue regeneration has been tried on various parts of the human body. In this specification, the application of scaffolds for tissue regeneration in the dental field will be shown for the following reasons.

1) The mouth is said to be the place with the most bacteria, and if tissue regeneration is possible at this site, it can be said that it can be applied to other sites.

2) Evaluation is quick because the damaged part is relatively small and the tissue regeneration period is short.

[0012] It is important for a material to be a scaffold to have a so-called biodegradation (bioabsorption) property that becomes a scaffold for cell growth and differentiation for a certain period of time and decomposes and disappears over time.

Currently, collagen sponge scaffolds are in practical use, but their biodegradability is sufficient, but their rigidity and flexibility are small, so the scope of application is limited to cases where there is no stress load. Some of the ingredients are derived from cattle and have problems such as mad cow disease. More In addition, there are problems in the process of medical treatment (the doctor must be able to process the shape by adjusting the shape in the medical field according to the shape of the defect). To do.

[0013] In recent years, research on bone remodeling (tissue remodeling) has been actively conducted. From the outside of the load bearing part, that is, the scaffold, the bone formation by osteoblasts and the enzyme are It is said that the biodegradation of the composite material proceeds at the same time, and the bone formation is further promoted when the stress burden increases.

[0014] Thus, the role of the scaffold is to serve as a substrate for cell sorting and proliferation, to secure space for regeneration, to prevent the invasion of other tissues into the regeneration field, to provide patterns for regenerated tissues, The supply of oxygen and nutrients to the vesicles, storage of cell growth factors, and avoidance of immune defense reactions from the host.

The following points are mainly mentioned as the characteristics of the scaffold required for that purpose.

1) Having high porosity for cell growth

2) Excellent biocompatibility!

3) Biodegradation and absorption rate can be controlled to fit the living body

4) Having chemical properties suitable for cell implantation and growth!

5) Excellent mechanical properties such as rigidity!

[0015] The present inventors have already developed a scuffold made of a composite material composed of biodegradable rosin (Patent Document 2, Non-Patent Document 3). The powerful scaffold has a structural opening, so that it can be seeded by injection during clinical practice, and it has excellent rigidity due to the combination of high-strength PLA fibers and PCL resin used as a binder. It is possible to support the load by the activity of

In addition, a structure that prevents epithelial entry into the defect and accumulation of bacterial plaque is provided, or a structure that immediately biodegrades at the interface with the defect after the operation is provided to quickly circulate body fluid in the scaffold. It has many functions such as creating a better environment for organizational regeneration.

[0016] In the above-mentioned composite scaffold, there is a strength in the longitudinal direction (tensile strength) when the tubular structure is formed by the effect of the PCL resin used as a binder. Therapeutic surgery such as implantation by placing cells in the inside where the rigidity and strength in the radial direction are small In the case of the bending, there is a problem that bending occurs and deformation (buckling or the like) occurs so as to collapse in the radial direction, and the cells inside are destroyed.

In addition, depending on the shape of the defect site of the affected area, there is a need to form a bent shape that is often embedded around the teeth. In such a case, even when trying to mold the above-mentioned composite scaffold into a bent shape in accordance with the shape of the defect site of the affected area, it is difficult to maintain the shape because the rigidity and strength in the radial direction are small. It was very difficult to form into a shape.

On the other hand, the internal structure and external shape of bones are changed by remodeling, which is a force that looks like a static tissue, and that dynamically absorbs and forms. Osteoblasts responsible for bone formation are coupled with bone resorption by osteoclasts responsible for bone resorption and secrete bone matrix components such as collagen to form osteoids. The bone matrix is then formed by calcification of the osteoid. In addition, early studies on bone remodeling mainly focused on in vivo experiments using animals. However, due to advances in cell culture technology, in vitro ( Experiments in vitro have been actively conducted. A bioabsorbable material is indispensable for designing an in vivo environment in which the surrounding environment of cells and tissues is designed to reconstruct a function that has been lost in the living body. Establishing a technology that can control the speed of the biomaterial absorbed in the body so as to match the speed of regeneration of the living tissue is an important issue in this field.

As shown in Fig. 18, the relationship between the regenerated new bone and the resorbed scaffold function is representative of the stress of the entire bone. As a typical function, when the scaffold is inserted into the defect, the scaffold is initially stressed. Over time, the scaffold will decompose, and the stress will decrease as the rigidity decreases. However, since bone regeneration proceeds simultaneously, the stress burden on the bone increases. The ideal regeneration process is to keep the bone and scuffold combined stresses until they are completely cured.

The application of scaffolds for tissue regeneration is expected to expand in the future, and since the tissue regeneration rate varies depending on the application site, it is necessary to adjust the biodegradation rate and stiffness accordingly. To overcome this problem, the biodegradable resin can be optimized. It is important to build scaffold variations, such as optimizing the cuffold geometry.

Patent Document 1: Japanese Patent Application Laid-Open No. 2003-169845

Patent Document 2: International Publication Gazette WO2005Z089828

(Non-patent literature l: S. Wakitani, T. Goto, R. G. Young, J. M. Mansour, V. M. Goldberg and A. I. C apian, Tissue Engineering, 4, 429 (1998))

Non-Patent Document 2: Hutmacher DW, Schantz T, Zein I, Ng KW, Teoh SH, Tan KC. J Bio med Mater Res. 2001 May; 55 (2): 203-16

Non-Patent Document 3: Development of biodegradable sallow composite scaffold for alveolar bone regeneration, Chiaki Niwa, Yasumasa Okizoe, Taiji Adachi, Zenichi Nakai, Biomedical Engineering Symposium 2005 2005.9.27-28

Disclosure of the invention

Problems to be solved by the invention

[0019] The problem to be solved by the present invention is that the biodegradation speed and rigidity need to be adjusted depending on the application site of the scaffold. Therefore, the optimization of the biodegradable resin is optimized the shape structure of the scaffold It is to build a scuff old noriage. As described above, a technology is established that can control the speed of biological material absorbed into the body so as to match the speed of regeneration of living tissue. With this technology, we aim to keep the vital functions such as strength necessary for the regeneration part almost constant during the tissue regeneration process. This makes it possible for the patient to have a normal life from surgery to complete cure.

For optimization of biodegradable resin, the biodegradation speed is controlled by selecting biodegradable resin in the composite scaffold, and the structure is optimized so that it can be received from external scaffolds even during biodegradation. It is possible to maintain rigidity that can withstand load support.

[0020] Specifically, in the case of using a resin having a high biodegradability rate or applied to a site where bending strength is required, not only in the longitudinal direction of the scaffold structure but also in the radial direction. The cells inside are not deformed to collapse in the radial direction due to their large rigidity and strength. The objective is to provide a composite scaffold for tissue regeneration without destroying the tissue. It is another object of the present invention to provide a scaffold with excellent bending formability, which can be easily molded according to the shape of the affected area.

Means for solving the problem

[0021] The present inventors have abundant knowledge of biodegradable materials, technology for producing actual prototypes, and knowledge of dentists with abundant clinical experience. The composite scaffold for tissue regeneration according to the present invention has been completed by repeatedly examining the conformity to the defect.

[0022] In order to achieve the above object, the first aspect of the composite scaffold for tissue regeneration according to the present invention is a tubular woven structure having a space inside and made of biodegradable resin fibers. And a spiral structure composed of biodegradable resin fibers arranged in a spiral shape in the longitudinal direction of the woven structure and entangled with an intersection of the woven structure; and an intersection of fibers of the woven structure A scaffold comprising biodegradable resin that joins the parts and a scaffold composed of; is provided.

[0023] The inventors of the present invention are directed to the bone defect portion of the composite scaffold comprising the biodegradable resin previously invented (a structure composed of PLA resin fibers and a scaffold using PCL resin as a binder). As a result of studying the conformity condition, it was found that it was necessary to increase the rigidity and strength in the radial direction of the scaffold structure.

This is because the tissue regeneration speed differs depending on the application site of the scaffold, and it is necessary to adjust the biodegradation speed and rigidity accordingly. In some cases, the scaffold structure is less rigid. In this case, in order to prevent the defect part from being occupied by the scar tissue, the space for regeneration at the defect part is secured (space 'making), and the place for supporting cell proliferation is lost. The original function of Scaffolding that is made in the department cannot be secured. For this reason, a mechanism that can control the rigidity is incorporated into the scaffold, facilitating the control of the biodegradation rate of the biodegradable resin, and expanding the application area of the scaffold.

[0024] When the composite scaffold is actually inserted into the affected part of the bone defect, an instrument such as tweezers is used. However, when it is grasped by the instrument, it is deformed so as to be crushed in the radial direction. To improve the radial rigidity and strength of the veg scaffold structure, which avoids problems such as bending and bending when conforming to the shape of the defect site and destroying the cells inside. .

In addition, depending on the shape of the defect site in the affected area, there is a need to form a bent shape that is often embedded around the teeth. In accordance with the shape, the rigidity and strength in the radial direction of the structure of the sliding scaffold that is formed by bending the above-described composite scaffold into a bent shape is further increased.

[0025] On the other hand, the original function of Scaffold is to secure a space for regeneration in the defective part in advance (space 'making), and to create a place for supporting cell proliferation in the defective part. The porosity inside the scaffold structure should be kept high so that it does not interfere.

Therefore, the biodegradable resin fibers are arranged in a spiral shape in the longitudinal direction in a tubular woven structure having a space inside the biodegradable resin fibers so that they are intertwined with the intersections of the structures. A woven spiral structure was provided, and the intersections of the woven structure were joined using a binder made of biodegradable resin.

[0026] Here, the biodegradable rosin fiber constituting the woven fabric structure and the spiral structure is a fiber composed of any one selected from the group consisting of polylactic acid resin, polydalicolic acid, and copolymer power of lactic acid and glycolic acid. It is preferable that the biodegradable resin constituting the binder is any one selected from a copolymer of lactic acid and glycolic acid, poly-force prolatatone resin, and polyglycol-acid power.

In addition, the biodegradable resin fiber constituting the structure and the biodegradable resin fiber woven so as to be intertwined with the intersection of the structure may be the same type or different types. Alternatively, a biocompatible resin such as polyvinyl alcohol, polyethersulfone, or polycyanate acrylate may be applied.

[0027] All the binder materials that can be produced are biodegradable. Since this biodegradation rate varies depending on the material, it is necessary to select a material with a decomposition rate and strength suitable for the target of the defect site. For example, polylactic acid coagulation has a biodegradation rate (half-life) of 24 months or longer and is used for sites with long bone regeneration times. Polyglycolic acid has a biodegradation rate (half-life) power of up to 12 months.

In the case of a copolymer of lactic acid and glycolic acid, the biodegradation rate (half-life) is as short as 1 to 6 months, and it is a suitable material as a binder for sites where the bone regeneration rate is fast.

[0028] While investigating the state of adaptation of the composite scaffold made of the biodegradable resin previously invented to the bone defect, the present inventors have a bone regeneration rate of alveolar bone of about 8 weeks. The knowledge that In this case, a suitable binder for the scaffold structure is a copolymer of lactic acid and dallicolic acid, and the copolymerization ratio of lactic acid in the copolymer is preferably 10 to 90%. 15-25% or 75-85%.

The aim is to match the biodegradation rate (half-life) characteristics of the copolymer of lactic acid and glycolic acid with the bone regeneration speed characteristics of the alveolar bone.

[0029] In addition, in the binder using polyglycolic acid compared with polystrength prolatatone rosin, although the longitudinal extension of the scaffold is small, the adhesive performance and biodegradation performance as a binder can withstand practical use. Therefore, it is considered useful for bone defects where strength is particularly required.

[0030] However, it is preferable that the biodegradable coconut resin constituting the binder that has a slow biodegradability of the biodegradable cocoon fiber constituting the woven structure and the spiral structure is faster in biodegradability. As a specific example, the biodegradable resin fibers constituting the woven structure and the spiral structure are fibers made of polylactic acid resin, and the biodegradable resin constituting the binder is composed of lactic acid and glycolic acid. It is a combination of these copolymers.

[0031] Further, as another combination, the biodegradable resin fiber constituting the woven structure and the spiral structure is a fiber having the first copolymer power of lactic acid and glycolic acid, and the raw material constituting the binder. The degradable resin is a second copolymer of lactic acid and glycolic acid, and the copolymerization power of lactic acid of the first copolymer is smaller than the copolymerization ratio of lactic acid of the second copolymer Is mentioned.

In this case, the lactic acid copolymerization ratio of the first copolymer is preferably 10 to 20%, and the lactic acid copolymerization ratio of the second copolymer is preferably 50 to 70%. 1st copolymer and 2nd This is because it is necessary to provide a difference in the copolymerization ratio of lactic acid in these copolymers, and if the ratios are similar, they will dissolve each other and no longer function as a binder.

[0032] In addition, the structure woven with biodegradable resin fibers was woven so as to be intertwined with the intersections of the structures so that the biodegradable resin fibers are spirally arranged in the longitudinal direction. For example, a tubular woven fabric structure made by using Lilac knitting with polylactic acid resin fiber is hooked at the intersection of the surface fibers and fibers forming the structure shape, and the tubular structure This refers to weaving polylactic acid resin fibers spirally at a predetermined pitch interval along the longitudinal direction.

In addition, by adopting a configuration in which both ends of the tubular woven structure can be closed, even if a culture solution or the like is injected into the woven structure, it can be held inside the woven structure. Here, the structure which can close both ends is realizable by binding both ends with a biodegradable resin fiber, for example.

[0033] By hooking polylactic acid resin fibers in a spiral manner by hooking the fibers in the tubular woven fabric structure described above, the rigidity and strength in the radial direction of the tubular woven fabric structure of the scaffold are increased. We succeeded in improving to about 10 times.

As a result, when a surgical operation such as implantation is performed using a scaffold of a tubular woven structure with cells inside the scaffold, the tubular woven structure is not deformed so as to be crushed in the radial direction. , It does not occur that the cells inside are destroyed. In addition, since the rigidity and strength in the radial direction of the tubular woven fabric structure are improved, it is excellent in moldability of the bent shape and can be easily molded in accordance with the shape of the defect affected part.

[0034] Next, from a second aspect of the composite scaffold for tissue regeneration according to the present invention, a tubular woven structure having a space inside and made of biodegradable cocoon fiber; and the woven structure A spiral structure composed of biodegradable resin fibers arranged in a spiral shape in the longitudinal direction of the fabric structure and bonded to the intersection of the inner surface or the outer surface of the fabric structure; and joining the intersection of the fabric structure There is provided a scaffold comprising a biodegradable resin and a scaffold comprising;

[0035] Veg biodegradable rosin fiber that enhances the productivity of the composite scaffold for tissue regeneration of the present invention is arranged in a spiral shape in the longitudinal direction and woven so as to be entangled with the intersecting portion of the structure. Pre-degradable biodegradable resin fibers spiral in the longitudinal direction outside or inside the structure And attached to the intersection of the structures by heat treatment or the like. And it is made to adhere to the crossing part of a structure with a binder. Others are the same as in the first viewpoint, and the explanation is omitted.

[0036] The scaffold structure is preferably a braided braid formed by Lilian knitting or a tubular structure having a saddle shape. By using a tubular structure, it is possible to freely bend and deform the tubular shape while maintaining the strength and rigidity required for the scaffold.

[0037] Further, the composite scaffold for tissue regeneration according to the present invention controls the tubular structure by controlling the pitch interval of the polylactic acid resin fibers spirally arranged in the longitudinal direction of the tubular structure. Can control the stiffness and strength of the body in the radial direction.

Here, the pitch interval of the helical polylactic acid resin fibers hooked and woven at the intersection of the scaffold structure is 0.5 to 2 mm, and the diameter of the polylactic acid resin fibers used is 0.05. It is preferably ~ 0.5 mm.

[0038] When the scaffold of the present invention is inserted into a bone defect using an instrument (for example, tweezers), if the spiral interval inside the scaffold is wide, the scaffold in the longitudinal direction of the scaffold It is difficult to grip the scuffold with the instrument so that the rigidity is uneven and the extreme deformation does not occur (for example, it is bent). On the other hand, if the spiral interval is too narrow, the rigidity becomes too high and the bending property is deteriorated, so that it is inappropriate for adapting to a bone defect portion. Thus, there is an optimal helical spacing in the scaffold of the present invention.

[0039] These scuffolds of the present invention described above are used as a scaffold for regenerating alveolar bone inserted or embedded in an alveolar bone defect.

By injecting cultured cells into the scaffold structure of the present invention and inserting or embedding them in the alveolar bone defect, alveolar bone formation and periodontal tissue regeneration can be achieved. is there.

[0040] The method for producing a composite scaffold for tissue regeneration according to the present invention includes the following steps (1) to (4).

(1) Insert a rod into a woven fabric structure with a space inside woven with biodegradable resin fiber Process

(2) A step of fixing one end of the biodegradable resin fiber to the rod, sandwiching the other end, hooking from the end portion to the intersection of the fabric structure, and knitting.

(3) A step of knitting the biodegradable resin fiber while being hooked to the woven structure at a predetermined interval every 1Z4 to 1Z2

(4) Step of applying biodegradable resin as a binder to the intersection of the woven structure [0041] As another method for producing the composite scaffold for tissue regeneration according to the present invention, It includes the steps 1) to (5).

(1) A process of spirally winding biodegradable rosin fiber around a rod

(2) A step of inserting the rod into a woven structure having a space inside which is woven with biodegradable resin fiber.

(3) Heating the woven structure

(4) Step of extracting the rod from the woven structure

(5) Step of applying biodegradable resin as a binder to the intersection of the woven structure [0042] Here, for example, a fluorine resin coding rod is used as the rod in the above production method! / I can.

Note that a specific manufacturing procedure will be described in Examples described later. The invention's effect

[0043] According to the composite scaffold for tissue regeneration of the present invention, the tissue regeneration speed varies depending on the application site of the scaffold. Therefore, it is necessary to adjust the biodegradation speed and rigidity according to this! / ヽぅIt has the effect of being able to provide a scaffold that can satisfy the requirements and can select a biodegradable resin having an optimized biodegradation rate.

[0044] Specifically, the rigidity and strength in the radial direction perpendicular to the longitudinal direction of the scaffold structure can be increased independently of the longitudinal direction, and grasped with an instrument during a therapeutic operation such as implantation. In this case, even when the load of the external tissue force is large, the cell is deformed so as to be crushed in the radial direction, and the cells inside the scaffold are not destroyed.

[0045] In addition, since the rigidity and strength in the radial direction are increased, the scaffolding is caused by human activity. In order to support the differentiation and proliferation of cells by securing a space for regeneration in the bone defect where the bone structure does not collapse and the bone defect is not occupied by scar tissue (space 'making') There is also an effect that the field can be surely made in the defect portion.

[0046] Compared to the case where the biodegradable resin fiber simply formed in a spiral shape is placed inside the scaffold, the biodegradable resin fiber is coiled inside the scaffold by being woven or bonded to the intersection. Can be fixed, has excellent flexibility and has excellent moldability, can construct a scaffold with an optimal shape at the bone defect site of the affected area, and can stably seed cells. .

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In particular, specific data on changes in stiffness when a biodegradable resin fiber is woven in a crossing portion of the scaffold so as to be spiral in the longitudinal direction compared to a conventional tubular structure scaffold. It will be explained while showing. In the following description, a tubular woven structure having a space inside and made of biodegradable resin fibers, and arranged in a spiral shape in the longitudinal direction of the woven structure, are intertwined at the intersection of the woven structure. In addition, a scaffold composed of a spiral structure made of biodegradable resin fibers is referred to as a coiled scaffold.

Further, a tubular woven structure having a space inside and made of biodegradable resin fibers is referred to as a coilless scaffold.

Example 1

[0048] Fig. 1 shows a photograph of the appearance of a coiled scaffold according to the present invention. The scaffold shown in Fig. 1 has a structure in which PLA fibers are spirally hooked at the intersection of structures woven with polylactic acid resin (PLA) fibers.

For comparison, Fig. 2 shows a conventional scaffold appearance photograph. The scaffold in Fig. 2 has a structure that is simply woven with polylactic acid resin fiber.

[0049] The scaffold structure shown in Fig. 1 and Fig. 2 is made by weaving with PLA fibers with a diameter of 0.1 mm, and has a cross-sectional area of about 2 mm in diameter and a length of 15 mm (adjustable) ) The porosity of this woven structure is over 90%. The coiled scuff old in Figure 1 Hooked at the intersection of structures, spirally (coiled) PLA fibers with a diameter of 0.1 mm are woven at a pitch of 1 mm. The intertwined portions 11 and 12 with the crossing portion of the structure in FIG. 1 schematically show a state of being hooked into the crossing portion of the structural body and woven in a spiral shape.

[0050] In this way, the rigidity and strength in the radial direction can be controlled by hooking the PLA fibers at a predetermined pitch by hooking them at the intersections of the structures.

The porosity is calculated by calculating the volume of the PLA structure used for the woven structure, assuming the woven structure as a circular tube with a constant cross-section, and determining the volume of the woven structure manufactured to a certain length. Calculated.

[0051] Fig. 3 shows the relationship between the displacement in the radial direction and the compressive force of the scaffold with coil (structure with PLA fibers hooked in a coil shape at the lmm pitch at the intersection) and the coiled scaffold. The graph which compared the result of having measured) is shown. Here, as shown in FIG. 8, the radial stiffness characteristic is a measurement of the compressive force required for the unit compression distance (displacement) in the radial direction perpendicular to the longitudinal axis direction of the scaffold structure.

[0052] The horizontal axis of the graph in FIG. 3 represents displacement, and the vertical axis of the graph represents the force required for compression. The dotted line is a scaffold without a coil, and is a scaffold with a solid line force S coil. As described above, the coiled scaffold used for the measurement was woven with PLA fiber having a diameter of 0.1 mm, and crossed into a structure with a cross-sectional area of about 2 mm in diameter and a length of about 15 mm. In this section, PLA fiber with a diameter of 0.1 mm is hooked at a pitch of 1 mm and woven in a coil shape.

[0053] For example, the compressive force required for lmm displacement in the radial direction is about 0.1N in the case of the coilless scaffold, whereas it is about 1N in the case of the coiled scaffold. From the measurement results in Fig. 3, it can be understood that the coiled scaffold has an approximately 10-fold improvement in compressive force (lateral stiffness characteristics) for the same radial displacement compared to the coilless scaffold.

Next, FIG. 4 shows a graph in which the lateral stiffness is measured when the diameter and pitch of the PLA fibers that are hooked and woven into the coil shape are changed in the coiled scaffold. In the graph of Fig. 4, the horizontal axis is woven by hooking PLA fibers to the intersection of the scaffold structures. The pitch of the coil is shown, and the vertical axis represents the lateral rigidity. Here, the vertical axis is the value obtained by dividing the lateral stiffness of the scaffold with coil (the load required to deform lmm in the direction of the arrow in Fig. 8) by the lateral stiffness of the scaffold without coil. The lateral stiffness on the vertical axis is expressed as the ratio of coiled and uncoiled.

[0055] Figure 4 shows two samples of three cases with a coil pitch of lmm, 2mm, and 3mm when the diameter of the PLA fiber woven into a coil is 0.1mm and 0.07mm. It was prepared and measured one by one. The solid line indicates the case where the PLA fiber diameter is 0.1 mm, and the dotted line indicates the case where the PLA fiber diameter is 0.07 mm. The measured data values of the two samples measured are second-order approximations. It is a curve.

[0056] From the graph of FIG. 4, it can be seen that the lateral stiffness increases as the coil pitch decreases and the coil fiber diameter increases. Scaffolding force with coil The strength of the lateral stiffness has been improved by 2 to 10 times, and it can be understood that the strength of this lateral stiffness can be controlled using the diameter and pitch of the PLA fiber that is hooked into the coil shape as a parameter.

Example 2

[0057] Next, Fig. 5 shows a graph in which the lateral stiffness of a scaffold using poly force prolataton (PCL) resin as a binder is measured in the structure of a scaffold without a coil and a scaffold with a coil. In the graph of Fig. 5, when the coil pitch is lmm, the compression force required for the displacement lmm is 0.3N when the coilless scaffold (PCL resin as binder) is used, and the coiled scuffold (diameter is 0.07mm). In the case of 0. lmm), it is 1.5N.

From the graph in Fig. 5, it can be seen that coiled scaffold (PCL resin as a binder) exhibits excellent lateral stiffness characteristics.

[0058] In addition, the scaffold using PCL resin as a binder does not use a binder! / ヽ When combined with a force coiled scaffold that was previously known to have improved rigidity, Furthermore, the strength of lateral rigidity can be improved by about 5 times.

[0059] Next, FIG. 6 shows a structure of a non-coiled scaffold and a coiled scaffold with a copolymer (PLGA) of polylactic acid resin (PLA) and polyglycolic acid (PGA) as a binder. The graph which measured the lateral rigidity of the used scaffold is shown.

In the graph of Fig. 6, when the coil pitch is lmm, the compression force required for the displacement lmm is 0.5N for the coilless scuffold (PLGA resin as the binder), and the coiled scuffold (diameter is 0.07mm). ) Is 1.8 N, and in the case of a coiled scaffold (diameter is 0.1 mm), it is 2.5 N.

From the graph in Fig. 6, it can be seen that coiled scaffold (PLGA resin as a binder) shows excellent lateral stiffness characteristics.

[0060] From the results shown in Fig. 6, it can be understood that the lateral rigidity is further improved compared to the case where a scafold force PCL resin using PLGA resin as a binder is used as a binder. Coiled scaffold woven with PLA fibers with a diameter of 0.1 mm (PLGA resin as a binder) can improve the strength of lateral rigidity by about 5 times compared to the coilless scaffold (PLGA resin as a binder). Can do it.

Here, 75/25 PLGA (75PLA + 25PGA) is used as PLGA resin. The binder used was 5% by weight of PLGA resin relative to the solvent (acetone).

[0062] Fig. 7 shows a graph in which the rigidity and strength in the longitudinal direction are compared and measured for the PLA fiber structure and the structure using PLGA as a binder.

Analysis of the graph in Fig. 7 shows that the structure with PLA fiber shows the maximum strength when the initial stiffness, strain and strain are about 70%, while the scaffold with PLGA is rigid. The maximum strength is exhibited when the strain is about 6%, and the breaking strain is about 10%. Therefore, it can be understood that the scaffold coated with PLGA has high rigidity and low stretchability.

Example 3

[0063] Next, the coil insertion process of the coiled scaffold will be described. Coil 揷 Obtaining Kawasaki is as follows (1) to (4).

(1) The process of inserting a fluorocoating coding rod into the structure knitted into a cage shape

(2) One end of the PLA fiber for the coil is fixed to the fluoro-resin coding rod, the opposite end of the PLA fiber for the coil is sandwiched with stainless tweezers, and the stitch crossing is from the end of the structure knitted into a cage shape The process of hooking and knitting (3) The process of knitting the PLA fiber for coil to the structure knitted into a cage shape every 1/2 turn (the process is controlled to a predetermined coil pitch (for example, lmm pitch)) )

(4) Application process of biodegradable resin as a binder to the intersection of the structure knitted into a cage shape

The coil insertion process of another method of the coiled scaffold will be described with reference to FIG. The coil insertion procedure is as follows (1) to (6).

(1) A process of spirally winding polylactic acid resin fiber around a fluorine resin coating rod (see (a) in Fig. 9)

First, a polylactic acid resin fiber is spirally wound around a fluorine resin coating rod. At this time, the coil pitch is controlled.

(2) The process of inserting a fluorocoating cord into a structure woven with polylactic acid resin fiber (see (b) in Fig. 9)

A fluorine-resin-coating rod in which the polylactic acid-resin fiber of (1) above is spirally wound inside a scaffold structure (for example, a Lilian knitted saddle-shaped tubular structure). insert.

(3) Heating process (See (c) in Fig. 9)

By heating at about 60 ° C using a hot plate, the spiral diameter of the polylactic acid resin fibers wound spirally around the surface of the fluorine resin coding rod is expanded, and the fluorine resin coding rod The surface force of can be peeled off.

(4) Step of extracting the structural force of the fluorocoating coding rod (see (d) in Fig. 9)

By pulling out the structural strength of the fluororesin coding rod, only the helical polylactic acid resin fiber can be left inside the tubular structure.

(5) Heating process (See (e) in Fig. 9)

By heating in this step, the diameter of the helical polylactic acid resin fiber further expands and comes into contact with the intersecting portion of the tubular structure. (See (f) in Figure 9)

(6) Binder application process at the intersection of the structure knitted into a cage shape On the surface of the tubular structure, poly force prolatatone rosin, polydaricholic acid, lactic acid and glycol

By applying the slip, the crossing part of the spiral polylactic acid resin fiber and the polylactic acid resin fiber forming the tubular structure is joined, and the rigidity in the longitudinal axis direction and the radial direction is dramatically improved. An improved scaffold can be made.

Example 4

[0065] In Example 3, a woven fabric structure and a spiral structure were prepared from PLA greave fiber (coated scaffold was produced), and the mechanical properties were determined using scafold using PCL greave as a binder. The result evaluated about the proliferation property of a cell is shown.

Scaffold fabrication method

Biodegradable polymers for pharmaceuticals (manufactured by API, USA) manufactured at cGMP (Current Good Manufacturing Practice) -compliant manufacturing facilities approved by Food and Drug Administration (FDA) are used as PLA and PCL resins.

First, PLA resin is made into a fiber having a diameter of 0.lm by heat drawing in a clean room melt extrusion apparatus, and then a tubular woven structure is produced by Lilian knitting.

Next, the PLA fibers are knitted in a spiral while being caught at the intersection of the woven structure. This corresponds to a spiral structure. By providing a spiral structure, the number of fiber intersections can be increased and the number of cell growth points can be increased, and the radial stiffness of the tubular woven structure can be increased to maintain biodegradation strength. become able to.

Then, after applying PCL resin to this woven structure, the solvent is removed by vacuum drying to produce a composite scaffold having a diameter of 2.8 mm as shown in FIG. Here, the pitch of the scaffold spiral shown in Fig. 10 is about 2 mm. In addition, the above work is performed in a clean bench, and sterilization with gamma rays (25KGy) is performed after preparation.

[0066] 2) Cell culture and analysis

Next, the results of cell culture experiments using the scaffold prepared by the above production method will be described. In the experiment, mouse osteoblast-like cells (MC3T3-E1, RIKEN BRC) were used. The culture was supplemented with α-MEM supplemented with 10% urine fetal serum, 2 mM L-glutamine, and 100 gZmL antibiotics. For differentiation induction, 50 gZmL of ascorbic acid and 10 mM of j8-glyceport phosphate were added. The culture period is 1, 2, 4, 6 and And 8 weeks. The number of cells was measured from the fluorescence using a DNA quantification method with Hoechst33258 solution. The ALP activity was obtained by dividing the same extraction solution from the cells of the scaffold or culture dish to obtain the ALP activity value per DNA. Absorbance was measured with an ALP activity measurement kit (Wako Lab Assay (registered trademark) ALP, manufactured by Wako Pure Chemical Industries, Ltd.), and calcium content was also measured with an assay kit (Force Lucium C-Test Saiko Co., manufactured by Wako Pure Chemical Industries, Ltd.). .

[0067] 3) Mechanical property test of Scaforenored

Changes in the mechanical properties due to the biodegradation of the scaffolds were measured using a small tester (capacity 50N, Toei Sangyo, MT-101) with an axial tensile force (gauge length of 10 mm) at a strain rate of 3.5% Zs. In the radial direction, the compressive force was measured until the diameter decreased by lmm at a displacement speed of 0.35mmZs. The pitch of the used scaffold helix is about lmm.

Figure 11 (a) shows the relationship between tensile force and axial displacement. From Fig. 11 (a), the fabric structure without binder (Fabric in the figure) has a large yield until breakage after the yield point occurs in the fabric structure with binder (Composite in the figure). V indicates that the strength has increased, and it is awkward. This is presumably because the fiber structure was not easily deformed by bonding at the fiber intersection because the breaking elongation of the fabric structure (Fabric) was about 15 mm without using a binder.

[0068] On the other hand, the stiffness and yield stress of the woven fabric structure (coiled composite in the figure) to which the spiral structure was added increased about 4 times that of the woven fabric structure using the binder (Composite). Power.

Next, Fig. 11 (b) shows a graph of the relationship between radial compression force and displacement. From Fig. 11 (b), the woven structure with a spiral structure (Coiled composite) shows a compressive force 4.5 times that of the woven structure (Composite) using a binder when lmm deformation occurs. I can tell you. These results are thought to be due to the increase in the number of crossing points between the fibers due to the addition of the helical structure, that is, the addition of the helical fibers, and the increased number of adhesion points, and the rigidity in the radial direction increased due to the coil shape. It is done.

[0069] 4) About the cell proliferation of the scaffold!

When ALP activity was measured, there was no significant change in the activity value due to the addition of the spiral structure to the fabric structure. On the other hand, a comparison of the amount of DMA is shown in Figure 12. Thus, until 4 weeks, the value of Coiled scaffold with added spiral structure was large. In addition, when comparing the amount of calcium, as shown in FIG. 13, the value of the Soiled Scaffold with a spiral structure increased after 4 weeks! /.

FIG. 14 shows a micrograph of a Coiled scaffold to which a spiral structure in which cells are growing is added. In Fig. 14 (a), 5 days after seeding, it can be seen that many cells adhered to the fiber intersections. Observing the passage of 4 weeks in Fig. 14 (b), it can be seen that the cells are proliferating in vacancies between the fibers and are becoming opaque due to the deposition of calcium and the like. This is probably because the addition of a spiral structure to the scaffold fabric structure increased the amount of cells due to an increase in the number of crossing points between the fibers that became the starting point of growth, resulting in an increase in the amount of calcium.

[0070] 5) Biodegradation characteristics of scaffolds

As shown in Figure 15, both composite composites, which consist of a woven structure and a binder force, as well as a scaffolded composite with a spiral structure, the strength decreases over time. You can see that

However, as can be seen from FIG. 15, the strength increased conversely after 4 weeks, and the compressive strength exceeded that of the virgin material at 6 weeks. This is probably because calcium deposition started after 4 weeks, and the strength was increased because of the binding.

Figure 16 shows the stiffness change in the compression direction as a mechanical function of the regeneration process. In contrast to the composite scaffold, which is also composed of a woven fabric structure and a binder force, in a coiled composite with a spiral structure added, the rigidity increases more quickly due to the binding of calcium, which has a larger initial value. I understand that.

[0071] In this specification, the tissue regeneration rate differs depending on the application site of the scaffold, and it is necessary to adjust the biodegradation rate and rigidity accordingly. We introduced examples of biodegradable resin optimization and structure optimization that would build scaffold variations, such as optimizing the shape and structure of Nycafold. In the composite scaffold disclosed herein, the biodegradation rate is controlled by the selection of biodegradable coagulant, and even when the biodegradation rate is increased, the structure is optimized to improve the biodegradation rate. However, it must be rigid enough to withstand the support of the load applied to the external force of the Scaffold. It will be understood that characteristics that can be achieved are obtained.

[0072] Finally, FIG. 17 shows how doctors and others use the present scaffold in a medical field. FIG. 17 shows a state where gel-like cultured bone is injected using a syringe in the scaffold. The diameter of the scaffold is about 2mm and the length is about 10mm. The needle is about lmm in diameter. When the gel-like cultured bone is injected, the scaffold expands, and it can be seen that the gel protrudes from the surface gap.

After this, the scaffold is inserted or embedded in the bone defect. Industrial applicability

[0073] The present invention is expected to be used as a scaffold material for tissue regeneration used for medical and academic research experiments. In particular, with regard to alveolar bone and bone tissue regeneration scaffolds, stem cells and osteoblasts are injected into the structure according to the present invention, and the defect of the tissue is treated, so that bone tissue and nerve tissue can be treated. It can be used as a material that can be recycled.

Brief Description of Drawings

[0074] [Fig. 1] Photograph of the appearance of the scaffold according to the present invention (with a structure in which a polylactic acid resin fiber is hooked in a coil shape at the intersection of a structure body woven with a polylactic acid resin fiber; including a coil Scaffold)

[Fig.2] Photo of appearance of conventional scuffold (structure just woven with PLA fiber; no scuffold without coil)

[Fig.3] Graph comparing the results of measuring the radial stiffness characteristics (lateral stiffness) of a coiled scaffold (with a structure in which PLA fibers are hooked into a coil at lmm pitch) and a coilless scaffold

[Fig. 4] Graph of measured lateral stiffness when changing the diameter and pitch of PLA fibers that are hooked into a coil and woven into a coiled scaffold

[Fig.5] Graph showing the lateral stiffness of a scaffold using PCL as a binder in a PLA fiber structure

[Fig. 6] Graph showing the lateral stiffness of a scaffold using PLGA as a binder in a PLA fiber structure [Fig. 7] A graph comparing the rigidity (tensile strength) in the longitudinal direction between a PLA fiber structure and a structure using PLGA as a binder.

圆 8] Radial compression for radial stiffness measurement (arrow indicates compression direction) [Fig. 9] Flow diagram showing coil insertion process of a scaffold with coil

圆 10] External view of the scuff old produced in Example 3

[11] A graph showing the mechanical properties of the scaffold. (a) is a graph showing the relationship between tensile force and axial displacement, and (b) is a graph showing the relationship between compressive force and displacement in the radial direction.

[Fig. 12] A graph of DMA amount showing the proliferation of scaffold cells

[Fig. 13] Graph of calcium content showing the proliferation of scaffold cells

[14] Photomicrograph showing the proliferation of scaffold cells

[Fig.15] Time-intensity graph showing the biodegradation characteristics of the scaffold

[16] Graph of stiffness change in compression direction showing biodegradation characteristics of scaffold

[Fig. 17] Photograph showing the appearance of injecting cultured bone into the scaffold with a syringe

FIG. 18 is a graph showing the relationship between the function of regenerated new bone and resorbed scaffold.

1 Scaffold with a spiral structure

2 Tubular woven structure

3 Spiral structure

4 Intersection

5 Fluororesin coding rod

6 Polylactic acid resin fiber

11, 12 Intersections with the intersection of the fabric structure

20 needle

Claims

The scope of the claims

[1] a tubular woven structure having a space inside and made of biodegradable resin fibers;

A spiral structure composed of biodegradable resin fibers arranged in a spiral shape in the longitudinal direction of the woven structure and entangled with a fiber intersection of the woven structure;

A composite scaffold for tissue regeneration, comprising a binder made of biodegradable resin that joins the intersections of the fabric structure;

[2] a tubular woven structure having a space in the interior and made of biodegradable resin fibers;

A spiral structure composed of biodegradable resin fibers arranged in a spiral shape in the longitudinal direction of the woven structure and bonded to a fiber crossing portion on the inner surface or outer surface of the woven structure; A composite scaffold for tissue regeneration, comprising a binder composed of a biodegradable resin that joins the parts;

[3] The biodegradable coconut fiber constituting the woven fabric structure and the spiral structure is a fiber made of any one selected from polylactic acid resin, polydaricholic acid, and copolymer power of lactic acid and glycolic acid. The biodegradable resin constituting the binder is a copolymer selected from lactic acid and glycolic acid, poly-force prolatatone resin, and polyglycol-acid power. Or the composite scaffold for tissue regeneration as described in 2.

[4] The biodegradable resin fibers constituting the woven fabric structure and the spiral structure are fibers made of polylactic acid resin, and the biodegradable resin fibers constituting the binder are lactic acid and glycolic acid. 3. The composite tissue scaffold for tissue regeneration according to claim 1 or 2, which is a copolymer.

[5] The biodegradable resin fiber constituting the woven fabric structure and the spiral structure is a fiber having a first copolymer power of lactic acid and glycolic acid, and the biodegradable resin resin constituting the binder. Is a second copolymer of lactic acid and glycolic acid, and the copolymerization ratio of lactic acid in the first copolymer is smaller than the copolymerization ratio of lactic acid in the second copolymer The composite scaffold for tissue regeneration according to claim 1 or 2.

6. The composite scaffold for tissue regeneration according to claim 3 or 4, wherein the copolymer has a lactic acid copolymerization ratio of 10 to 90%.

[7] The lactic acid copolymerization ratio of the first copolymer is 10 to 20%, and the lactic acid copolymerization ratio of the second copolymer is 50 to 70%. Item 6. The composite scaffold for tissue regeneration according to Item 5.

8. The composite scaffold for tissue regeneration according to claim 1, wherein the woven structure is a woven structure formed by Lilian knitting and capable of closing both ends.

[9] The tissue regeneration device according to claim 1 or 2, wherein the tubular radial stiffness of the woven structure can be controlled independently by controlling the pitch interval of the spiral of the spiral structure. Combined Scaffold.

[10] The pitch interval is 0.5 to 2 mm, and the diameter of the biodegradable resin fiber is 0.

The composite scaffold for tissue regeneration according to claim 9, wherein the composite scaffold is 05-0. 5 mm.

[11] The composite scaffold for tissue regeneration according to any one of claims 1 to 10 may be used as a scaffold for regenerating alveolar bone inserted or embedded in an alveolar bone defect.

[12] A method for producing a composite scaffold for tissue regeneration, comprising the following steps.

(1) The process of inserting a rod into a woven fabric structure that has a space inside that is woven with biodegradable resin fiber

(4) Application process of biodegradable resin used as a binder for the intersection of the woven structure

[13] A method for producing a composite scaffold for tissue regeneration, comprising the following steps.

(1) A process of spirally winding biodegradable rosin fiber around a rod

(3) Heating the woven structure

(4) Step of extracting the rod from the woven structure (5) Application process of biodegradable resin used as a binder to the intersection of the woven structure

[14] The biodegradable coconut fiber is a fiber selected from polylactic acid coconut resin, polydaricholic acid, and a copolymer of lactic acid and glycolic acid, which has a certain strength, and serves as the binder. 14. The method for producing a composite scaffold for tissue regeneration according to claim 12 or 13, wherein the coconut resin is a copolymer of lactic acid and glycolic acid, poly-force prolatatone rosin, or polyglycolic acid.

[15] The biodegradable rosin fiber is a fiber made of polylactic acid resin, and the biodegradable rosin serving as the binder is a copolymer of lactic acid and glycolic acid. 12. A method for producing a composite scaffold for tissue regeneration according to 2 or 13.

[16] The biodegradable resin fiber is a fiber having a first copolymer power of lactic acid and glycolic acid, and the biodegradable resin resin constituting the binder is a second copolymer of lactic acid and glycolic acid. 14. The tissue according to claim 12 or 13, wherein the lactic acid copolymerization ratio of the first copolymer is smaller than the lactic acid copolymerization ratio of the second copolymer. A method for producing a composite scaffold for recycling.

[17] The method for producing a composite scaffold for tissue regeneration according to [14] or [15], wherein a copolymerization ratio of lactic acid in the copolymer is 10 to 90%.

[18] The copolymerization ratio of lactic acid of the first copolymer is 10 to 20%, and the copolymerization ratio of lactic acid of the second copolymer is 50 to 70%. Item 17. A method for producing a composite scaffold for tissue regeneration according to Item 16.