KR20230074009A - Manufacturing method of biocompatible magnesium mesh - Google Patents

Abstract

The present invention comprises a protective film forming step of forming a protective film layer by treating the magnesium mesh with hydrogen fluoride or sodium hydroxide; A pre-calcification treatment step of pre-calcifying the magnesium mesh surface-treated through the protective film forming step; and a heat treatment step of heat-treating the magnesium mesh pretreated through the precalcification treatment step; and a biocompatible magnesium mesh manufactured by the method.
The biocompatible magnesium mesh according to the present invention has a fluorine film layer or an alkaline protective layer to suppress dissolution and improve bioactivity, and has excellent bone regeneration effect as calcium phosphate is precipitated through precalcification treatment. shows an excellent effect to provide.

Description

Manufacturing method of biocompatible magnesium mesh {MANUFACTURING METHOD OF BIOCOMPATIBLE MAGNESIUM MESH}

The present invention relates to a method for manufacturing a biocompatible magnesium mesh, and more specifically, a fluorine film layer or an alkali protective layer is formed to suppress rapid dissolution of the magnesium mesh, improve biocompatibility, and contain phosphate and calcium ions. It relates to a method for manufacturing a biocompatible magnesium mesh with excellent bone regeneration effect by performing precalcification treatment in a solution or by applying a low voltage to a phosphate-containing solution during calcification cycle treatment to promote calcium phosphate precipitation.

In order to obtain long-term predictive results for implants, alveolar bone showing a sufficient amount and size must exist at the site of implant placement. Acquisition of esthetics and functionality of implants cannot be guaranteed only with residual alveolar bone showing serious defects. In this case, as one of the methods to increase the height and width of the bone, particulate grafts are being performed. However, one of the disadvantages of this method is that, because of the lack of structural integrity, the shape of the soft tissue collapses, resulting in compression or displacement of the bone graft material, making it impossible to obtain desirable results. To solve these problems and to reconstruct the alveolar ridge, a mesh (shielding film) that covers the defect together with bone graft material to prevent soft tissue penetration as well as external deformation is applied.

Titanium is a metal that exhibits excellent corrosion resistance and biocompatibility and is used for various purposes in the surgical field. Titanium mesh not only has sufficient strength to prevent soft tissue from collapsing, but also provides a stable space for a bone graft material. However, the titanium mesh requires secondary surgical treatment for removal after bone healing is complete. On the other hand, since magnesium and some alloys thereof are biodegraded during bone regeneration, secondary surgery to remove them after bone regeneration is not required, thereby reducing the burden on patients and doctors. However, since the biodegradation rate of magnesium is too fast, the part where clinical application is limited is pointed out as the biggest problem. Although there is some variation depending on the patient's condition, it is usually maintained for 12 weeks or longer to induce bone regeneration in the bone defect. In this regard, many studies have been conducted on pure magnesium and its alloys as biomaterials, but the rapid decomposition of magnesium in the high chloride environment of the living body has become a major obstacle in clinical application. Various methods have been tried to control the biodegradation rate of magnesium and improve osteoconductivity, such as adding alloying elements, forming a stable protective coating layer, or forming a bioactive ceramic coating layer. Although it is possible to slow down the decomposition rate of alloys, it has many limitations in meeting various clinical needs.

On the other hand, forming a dense coating layer of a biodegradable polymer material or ceramic material can greatly contribute to improving the corrosion resistance of magnesium. Attempts to improve the corrosion resistance of magnesium-based materials by micro arc oxidation (MAO), sol-gel coating, physical conversion coating and chemical conversion coating have been reported in several literatures.

Among these techniques, chemical conversion coating is easy to apply and can effectively form a uniform coating even when the shape of the substrate is irregular. Phosphate coatings such as magnesium phosphate and calcium phosphate by chemical conversion have been investigated for corrosion inhibition of magnesium-based biomaterials. However, the corrosion behavior and biocompatibility of these phosphate conversion coatings have not been sufficiently studied.

On the other hand, hydrogel is a hydrophilic material in which water-soluble polymers form a three-dimensional network structure by physical or chemical bonding, and absorbs a large amount of water to swell, but maintains its shape without dissolving in water. Hydrogels are used in biomedical fields such as drug delivery systems, tissue engineering scaffolds, and biosensors due to their high water content, porous structure, relatively soft physical properties, excellent biocompatibility, and physical similarity with the extracellular matrix. It has been widely developed and applied. In addition, since the porous structure of the hydrogel allows the drug to be released slowly, it is also applied in the field of drug delivery. Some hydrogels change their shape depending on temperature, acidity, light or environmental factors.

Hydrogels can exhibit various properties depending on the polymer constituting the main chain and the crosslinking method. Even when the same polymer is used for the main chain, the resulting hydrogel exhibits different properties when the crosslinking method is different. Crosslinking methods of hydrogels can be largely divided into physical methods and chemical methods. Physical cross-linking is obtained in a reversible manner by ionic interaction, hydrogen bond, and molecular structure entanglement, and they can obtain a three-dimensional network structure without separate chemical additives or complicated processes. there is. On the other hand, chemical crosslinking is an irreversible method generally obtained by covalent bonding and is superior in stability to physical crosslinking.

Since the hydrogel of the hydrophilic polymer network structure is not easy to dissolve and deliver poorly soluble drugs, a method using an amphiphilic block copolymer having both hydrophilic and hydrophobic properties is being considered. The best-known amphiphilic block copolymer is the PEO-PPO-PEO triblock copolymer composed of hydrophilic polyethylene oxide (PEO) and hydrophobic polypropylene oxide (PPO). Pluronic F-127 is a PEO-PPO-PEO triblock copolymer. A high-concentration aqueous solution of 20% or more exhibits a sol-gel transition when the temperature is raised from 4°C to 37°C, and its gelation behavior is is reversible for This hydrogel is a representative model for the development of an injectable gel system and is being considered for bio-application in various fields including drug delivery and tissue engineering.

Bisphosphonate drugs, one of the osteoporosis treatments, have high affinity for calcium and hydroxyapatite, so they are easily attached to bone, and in the process of bone resorption, they are introduced into osteoclasts and function. It is known to not only strongly inhibit bone resorption, but also eventually induce apoptosis. In the field of dentistry, when alendronate, a bisphosphonate drug, was administered to a test animal model with increased alveolar bone resorption, it showed a positive effect of reducing bone loss and increasing bone density. In an in vivo study, when the implant was topically loaded with bisphosphonate, more bone was formed earlier and higher bone-to-implant contact was observed than when the implant was not loaded. . Considering this, it is thought that rapid osseointegration can be obtained because the activity of osteoclasts is suppressed when bisphosphonate is released from the implant placement site immediately after implantation of the dental implant.

Korean Patent Registration No. 10-1289122 (2013.07.17.) Korean Patent Registration No. 10-1888091 (2018.08.07.)

One object of the present invention is to suppress dissolution of magnesium and improve biocompatibility by forming a fluorine film layer or alkali protective layer, as well as bone regeneration by performing precalcification treatment or precipitating calcium phosphate by applying a low voltage in a calcium phosphate-containing solution. It is to provide a method for manufacturing a biocompatible magnesium mesh with excellent effects.

Another object of the present invention is to provide a biocompatible magnesium mesh manufactured by the above manufacturing method.

As one aspect, the present invention provides a protective film forming step of forming a protective film layer by treating the magnesium mesh with hydrogen fluoride or sodium hydroxide; A pre-calcification treatment step of pre-calcifying the magnesium mesh surface-treated through the protective film forming step; and a heat treatment step of heat-treating the magnesium mesh pretreated through the calcification pretreatment step.

The magnesium mesh of the present invention is characterized in that it is a pure magnesium mesh consisting of 99.0% by weight or more of magnesium and residual impurities, or a magnesium alloy containing 95.0% by weight or more of magnesium. The magnesium alloy preferably has properties that do not change mechanical properties at high temperatures, for example, 300 ° C. or higher, preferably 400 ° C. or higher, more preferably 500 ° C. or higher, and examples thereof are not necessarily limited thereto. However, it may contain 95.0% by weight or more of magnesium, and the remaining components may consist of 1.5 to 2.5% by weight of aluminum, 0.5 to 0.8% by weight of zinc, and other impurities.

In addition, the magnesium mesh may have a circular or polygonal shape having a thickness of 0.05 to 0.15 mm, and a plurality of circular holes having a diameter of 0.4 to 0.6 mm, for example, 10 to 100 may be formed. The shape of the magnesium mesh can be appropriately adjusted according to the part of the body to be applied, and the circular hole applied to the magnesium mesh is for smooth movement of body fluid in the part of the body to which the magnesium mesh is applied. It can be appropriately adjusted according to conditions such as moving speed and quantity. For example, the number of circular holes of the magnesium mesh may be 65 to 75, preferably 65 to 70, and more preferably 66 to 68.

As an example, as shown in FIGS. 1 and 2 , the magnesium mesh has a plurality of circular holes having a thickness of 0.05 to 0.15 mm and a diameter of 0.4 to 0.6 mm.

As another example, the magnesium mesh may have a disk shape having a thickness of 0.05 to 0.15 mm and a diameter of 9 to 11 mm, and 65 to 75 circular holes having a diameter of 0.4 to 0.6 mm within a diameter of 8 mm.

Hereinafter, a method for manufacturing a biocompatible magnesium mesh according to the present invention will be described in detail.

First, the protective film forming step (S100) is a step of forming a protective film layer by surface treatment of the magnesium mesh with hydrogen fluoride or sodium hydroxide.

More specifically, the protective film forming step (S100) is a step of immersing the magnesium mesh in a hydrogen fluoride or sodium hydroxide solution, washing it, and then drying it to form a protective film layer.

The hydrogen fluoride solution preferably has a mass concentration of hydrogen fluoride of 35 to 45%, preferably 40%. The sodium hydroxide aqueous solution has a molar concentration of sodium hydroxide of 1 to 2M, preferably 1.5M. Formation of a protective film layer can be smoothly performed in a solution having the concentrations of hydrogen fluoride and sodium hydroxide.

The immersion may be performed for 90 to 150 minutes, preferably 100 to 140 minutes, more preferably 110 to 130 minutes in the case of hydrogen fluoride solution, and 25 to 35 minutes, preferably 28 minutes in the case of sodium hydroxide solution. to 32 minutes, most preferably 30 minutes. When the immersion is made for less than 90 minutes or 25 minutes, the protective film layer by hydrogen fluoride or the alkali protective layer by sodium hydroxide is not sufficiently formed, and even if the immersion is made for more than 150 minutes or 35 minutes, the formation of the protective film layer no more increase

The washing may be performed by a conventional method, and primary, secondary or tertiary distilled water, sterilized water, and the like may be used.

The drying may be performed in a drying process at 35 to 45° C. for 24 to 30 hours.

Through the protective film forming step (S100) consisting of the above process, a protective film layer is formed on the surface of the magnesium mesh to suppress dissolution of magnesium and improve bioactivity.

Next, the precalcification treatment step (S200) is a step of subjecting the magnesium mesh surface-treated through the protective film formation step (S100) to a cyclic pre-calcification treatment.

More specifically, the pre-calcification treatment step (S103) is a step of pre-calcification treatment by alternately and repeatedly immersing the magnesium mesh surface-treated through the protective film forming step (S101) in an aqueous solution of ammonium phosphate and an aqueous solution of calcium hydroxide, respectively.

The aqueous ammonium phosphate solution may be a sodium hydrogen phosphate aqueous solution or an ammonium hydrogen phosphate aqueous solution, and is preferably 0.03 to 0.07 mole.

The aqueous calcium hydroxide solution is 0.01 to 0.015 mol, preferably 0.01 to 0.013 mol, most preferably 0.011 mol.

The repeated immersion is alternately 50 to 70 seconds, preferably 55 to 65 seconds, more preferably 10 to 22 times, preferably 15 to 22 times, more preferably 60 seconds, respectively, in the aqueous solution of ammonium phosphate and the aqueous solution of calcium hydroxide, respectively. Is made by repeating 18 to 22 times, most preferably 20 times.

Calcium phosphate is sufficiently adsorbed to the magnesium mesh by the concentration, immersion conditions and number of these aqueous solutions, and then the calcium phosphate is precipitated in vivo, resulting in an excellent bone regeneration effect.

In the pre-calcification treatment step (S200), surface treatment through the protective film formation step (S100) before repeatedly immersing the magnesium mesh surface-treated through the protective film forming step (S100) in an aqueous solution of ammonium phosphate and an aqueous solution of calcium hydroxide, respectively. A step of impregnating the magnesium mesh into an aqueous silica solution may be further included. This process has an effect of facilitating the adsorption of calcium phosphate to the surface-treated magnesium mesh.

The impregnation of the aqueous silica solution may be performed by immersing in an aqueous silica solution having a mass concentration of 0.4 to 0.6%, preferably 0.5% for 4 to 6 minutes, preferably 4.5 to 5.5 minutes, and more preferably 5 minutes. .

In addition, in the precalcification treatment step (S200), when the magnesium mesh surface-treated through the protective film forming step (S100) is repeatedly immersed in each of the aqueous ammonium phosphate solution and the aqueous solution of calcium hydroxide, each of the aqueous solutions is subjected to low voltage, preferably 1 It is preferable to apply a low voltage of from 1 to 20V, more preferably from 1 to 10V, more preferably from 1 to 5V. Dissociation of phosphoric acid and calcium is increased by the low voltage state, so that they can be well adsorbed on the magnesium mesh.

Next, the heat treatment step (S300) is a step of heat-treating the magnesium mesh pretreated through the calcification pretreatment step (S200).

More specifically, the heat treatment step (S300) is a step of fixing the adsorbed calcium phosphate by heat-treating the magnesium mesh pretreated through the calcification pretreatment step (S200).

The heat treatment is performed in an electric furnace at 90 to 600°C, preferably 90°C to 500°C, more preferably 100 to 400°C for 1.5 to 2.5 hours, preferably 1.8 to 2.2 hours, most preferably 2 hours. It can be done by processing.

When the heat treatment is performed under the above conditions (ie, a temperature of less than 90 ° C or a time of less than 30 minutes), fixation of calcium phosphate adsorbed to the magnesium mesh pretreated through the precalcification treatment step (S200) is not sufficient, and thus the magnesium mesh When is implanted in vivo, there is a problem in that sufficient HA precipitation of calcium phosphate is not achieved, so that the bioactivity is not sufficiently improved. On the other hand, when the heat treatment exceeds the above conditions (ie, a temperature of more than 500 ° C. or a time of more than 2.5 hours), there is a problem in that the biocompatibility of the magnesium mesh is reduced due to a decrease in physical properties of the magnesium mesh.

The biocompatible magnesium mesh manufactured by the above method has an effect of maintaining the mesh during the new bone formation period by suppressing rapid dissolution of magnesium due to the formation of a fluorine coating layer or an alkali protective layer.

In addition, the biocompatible magnesium mesh prepared by the above method is precipitated in a dense structure with protrusions observed in the initial stage of HA precipitation, and has an effect of increasing the amount of Ca and P precipitated by showing a Ca/P atomic ratio of 1.51 or more. there is.

In addition, the biocompatible magnesium mesh prepared by the above method is useful for improving bioactivity by increasing the amount of Ca and P precipitated, thereby increasing bone density and increasing the volume of new bone.

Therefore, as another aspect of the present invention, a biocompatible magnesium mesh manufactured by the method according to the present invention is provided.

Meanwhile, in the method for manufacturing the biocompatible magnesium mesh of the present invention, after the heat treatment step (S300), a hydrogel containing a drug for treating osteoporosis is applied to one or both sides of the magnesium mesh heat treated through the heat treatment step (S300). A drug application step (S400) of applying may be further included.

The osteoporosis treatment drug is preferably a bisphosphonate-based drug, and examples thereof include pamidronate, alendronate, risedronate, ibandronate, and zoledronate. Since the drug has a high affinity for calcium and HA (Hydroxyapatite), it is easily attached to bone and is introduced into osteoclasts in the process of bone resorption to reduce the function of osteoclasts. It has the effect of increasing bone density and new bone formation.

The hydrogel is a hydrophilic material having a three-dimensional network structure by physical or chemical bonding of water-soluble polymers, and a drug is loaded on the network structure to slowly release the drug.

As one specific example, the hydrogel is 2-hydroxyethyl methacrylate, methacrylic anhydride, PEO-PPO-PEO triblock copolymer (eg, (PEO) 99 (PPO ) 67 (PEO)99), and 2,2-dimethoxy-2-phenylacetophenone.

As another specific example, the hydrogel is 87% by weight of 2-hydroxyethyl methacrylate, 2% by weight of methacrylic anhydride, a PEO-PPO-PEO triblock copolymer (eg , (PEO) 99 (PPO) 67 (PEO) 99) 2% by weight, 2,2-dimethoxy-2-phenylacetophenone 1% by weight, and residual solvent (water ) may be a mixture of

The biocompatible magnesium mesh according to the present invention has a fluorine film layer or an alkaline protective layer to suppress dissolution and improve bioactivity, and has excellent bone regeneration effect as calcium phosphate is precipitated through precalcification treatment. shows an excellent effect to provide.

1 is a design diagram of a biocompatible magnesium mesh used in the present invention.
2 is a photograph showing a biocompatible magnesium mesh used in the present invention taken with a scanning electron microscope.
Figure 3 is a photograph showing the application of the biocompatible magnesium mesh prepared by the present invention to the test rat (a: preparation for calvarial defect by Trepinvir, b: calvarial damage (diameter = 8 mm), c: Mg membrane placement on magnesium mesh and periosteal covering).
4 is a photograph showing a magnesium mesh (HT-H1) of Comparative Example 2 and a magnesium mesh (HT-H4) of Comparative Example 3 of the present invention taken with a scanning electron microscope. (a) and (b) are photographs of the magnesium mesh (HT-H1) of Comparative Example 2 taken at 10 and 50 magnifications, respectively, and (c) and (d) are the magnesium mesh (HT-H4 of Comparative Example 3). ) are photographs taken at 10x magnification and 50x magnification, respectively.
5 is a photograph showing a magnesium mesh (CP-H1) of Example 1 and a magnesium mesh (CP-H4) of Example 2 of the present invention taken with a scanning electron microscope. (a) and (b) are photographs of the magnesium mesh (CP-H1) of Comparative Example 2 taken at 10 and 50 magnifications, respectively, and (c) and (d) are the magnesium mesh of Comparative Example 3 (CP-H4 ) are photographs taken at 10x magnification and 50x magnification, respectively.
6 is an X-ray diffraction analysis result of magnesium meshes of Examples 1 and 2 and Comparative Examples 1 to 3 of the present invention ((a) is the magnesium mesh (UT) of Comparative Example 1, (b) is Comparative Example 2 Magnesium mesh (HT-H1) heat-treated at 100 ° C after 90 ° C hydrothermal treatment of Comparative Example 3 (HT-H4), (d) Magnesium mesh (CP-H1) heat-treated at 100 ° C after 90 ° C cycle calcification pre-treatment of Example 1, (e) is magnesium mesh (CP-H4) heat-treated at 400 ° C after 90 ° C cycle calcification pre-treatment of Example 2) .
7 is an untreated magnesium mesh (UT) (a) of Comparative Example 1, a magnesium mesh (HT-H1) (b) heat-treated at 100 ° C after 90 ° C hydrothermal treatment of Comparative Example 2, and 90 ° C cycling of Example 1 This is the result of examining the pH change over 7 days after immersing the magnesium mesh (CP-H1) (c) heat-treated at 100 ° C after calcification pre-treatment in 10 ml of 37 ° C SBF.
8 is a magnesium mesh (HT-H1) heat-treated at 100 ° C. for 2 hours after hydrothermal treatment at 90 ° C. of Comparative Example 2 (a is 10 magnification, b is 50 magnification) and 90 ° C of Comparative Example 3 HR FE-SEM photograph observed after immersing a magnesium mesh (HT-H1) heat-treated at 400°C for 2 hours after hydrothermal treatment (c is 10x magnification, d is 50x magnification) in SBF for 3 days HR FE-SEM It is an image.
9 is a magnesium mesh (CP-H1) heat-treated at 100° C. for 2 hours after 90° C. calcination pre-treatment of Example 1 (a is 10 times magnification, b is 50 times magnification) and 90° C calcination cycle calcification of Example 2 HR FE-SEM image observed after immersing a magnesium mesh (CP-H4) (c is 10 magnification, d is 50 magnification) heat-treated at 400 ° C. for 2 hours after pretreatment in SBF for 3 days.
10 is a sample (CP-H1) and a hybrid gel specimen (HG) heat-treated at 100 ° C after 90 ° C cycle calcification pre-treatment in Example 1, after loading treatment with ibandronate, and then in 1 mL distilled water for 24 hours. This is a picture showing the result of examining the amount of emission over 7 days by immersion method.
11 is a non-treatment group (UT) after forming a critical defect with a diameter of 8 mm on the head of a test animal (rat), a group (HT-H1) heat-treated at 100 ° C after 90 ° C hydrothermal treatment, and 400 ° C After 4 weeks of planting and examining the magnesium mesh of the group (HT-H4) heat treated at 90 ° C, the group heat treated at 100 ° C (CP-H1) and the group heat treated at 400 ° C (CP-H4) after calcination pretreatment at 90 ° C. A picture showing bone density.
12 is a non-treatment group (UT) after forming a critical defect with a diameter of 8 mm on the head of a test animal (rat), a group (HT-H1) treated at 100 ° C after 90 ° C hydrothermal treatment, and 400 ° C After 4 weeks of planting and examining the magnesium mesh of the group (HT-H4) heat treated at 90 ° C, the group heat treated at 100 ° C (CP-H1) and the group heat treated at 400 ° C (CP-H4) after calcination pretreatment at 90 ° C. This is a picture showing the bone volume.
13 shows an untreated group (UT), a group subjected to heat treatment at 100 ° C after hydrothermal treatment at 90 ° C (HT-H1 and a group treated with heat treatment at 400 ° C (HT-H4), and a group subjected to heat treatment at 100 ° C after 90 ° C cycle calcification pre-treatment). (CP-H1) and 400 ℃ heat treatment group (CP-H4) are a picture showing the analysis results of the inflammatory cytokine IL-1β in the blood.
14 shows an untreated group (UT), a group subjected to heat treatment at 100 ° C after hydrothermal treatment at 90 ° C (HT-H1 and a group treated with heat treatment at 400 ° C (HT-H4), and a group subjected to heat treatment at 100 ° C after 90 ° C cycle calcification pre-treatment). (CP-H1) and 400 ℃ heat treatment group (CP-H4) are a picture showing the analysis results of the inflammatory cytokine IL-6 in the blood.

Hereinafter, a preferred embodiment of the present invention and the physical properties of each component will be described in detail, but this is to be explained in detail so that a person having ordinary knowledge in the art to which the present invention belongs can easily practice the invention, This is not meant to limit the technical spirit and scope of the present invention.

Preparation Example 1: Preparation of Magnesium Mesh Specimen

The magnesium mesh for animal testing was designed with a diameter of 10 mm including the retaining part in consideration of the fact that the critical defect size for the head of the test animal (rat) was 8 mm in diameter. In addition, the mesh for testing was designed so that 67 circular holes with a diameter of 0.5 mm were formed in a circular part with a diameter of 8 mm to enable movement of bodily fluid. Magnesium foil (99.9% Mg, as rolled, Goodfellow, England) with a thickness of 0.1 mm was used as a material for manufacturing magnesium mesh, and a circular hole in the mesh was formed using a laser processing machine (LF-30, Legens, Incheon, Korea). ) was processed (see FIGS. 1 and 2).

Example 1: Manufacturing of biocompatible magnesium mesh

The magnesium mesh specimen prepared through Preparation Example 1 was immersed in a hydrogen fluoride (HF) aqueous solution having a mass concentration of 40% at room temperature for 2 hours, washed with tertiary distilled water, and dried in a dryer at a temperature of 40 ° C. for 26 hours. A fluorine coating layer was formed. Then, it is immersed in a silica aqueous solution having a mass concentration of 0.5% at 37 ° C for 5 minutes, and immersed in 0.06M NH ₄ H ₂ PO ₄ aqueous solution and 0.011M Ca (OH) ₂ aqueous solution at 90 ° C for 1 minute. Cyclic pre-calcification treatment was performed by circulating 20 times. Then, after heating the precalcined magnesium mesh in an electric furnace at 100° C. at a heating rate of 10° C., the magnesium mesh was heat-treated while maintaining the magnesium mesh for 2 hours to prepare a biocompatible magnesium mesh (CP-H1).

Example 2: Manufacturing of biocompatible magnesium mesh

The magnesium mesh specimen prepared through Preparation Example 1 was immersed in a hydrogen fluoride (HF) aqueous solution having a mass concentration of 40% at room temperature for 2 hours, washed with tertiary distilled water, and dried in a dryer at a temperature of 40 ° C. for 26 hours. A fluorine coating layer was formed. Then, it is immersed in a silica aqueous solution having a mass concentration of 0.5% at 37 ° C for 5 minutes, and immersed in 0.06M NH ₄ H ₂ PO ₄ aqueous solution and 0.011M Ca (OH) ₂ aqueous solution at 90 ° C for 1 minute. Cyclic pre-calcification treatment was performed by circulating 20 times. Then, after heating the precalcined magnesium mesh in an electric furnace at 400° C. at a heating rate of 10° C., the magnesium mesh was heat-treated while maintaining the magnesium mesh for 2 hours to prepare a biocompatible magnesium mesh (CP-H4).

Example 3: Manufacturing of biocompatible magnesium mesh

The magnesium mesh prepared in Preparation Example 1 was immersed in a hydrogen fluoride (HF) aqueous solution having a mass concentration of 40% at room temperature for 2 hours, washed with tertiary distilled water, and dried in a dryer at a temperature of 40 ° C. for 26 hours to remove fluorine A coating layer was formed. Then, it is immersed in a silica aqueous solution having a mass concentration of 0.5% at 37 ° C for 5 minutes, and immersed in 0.06M NH ₄ H ₂ PO ₄ aqueous solution and 0.011M Ca (OH) ₂ aqueous solution at 90 ° C for 1 minute. Cyclic pre-calcification treatment was performed by circulating 20 times in the method, and in this process, calcification pre-treatment was performed in a state in which a DC voltage of 2V was applied using a magnesium mesh as a cathode. Thereafter, an electric furnace was heated at a heating rate of 10 °C to 100 °C, and heat treatment was performed while maintaining the magnesium mesh for 2 hours to prepare a biocompatible magnesium mesh.

Example 4: Manufacturing of biocompatible magnesium mesh

The magnesium mesh prepared in Preparation Example 1 was immersed in a 1.5 M NaOH aqueous solution at 90 ° C for 30 minutes, subjected to alkali treatment, washed with tertiary distilled water, and dried in a dryer at a temperature of 40 ° C for 26 hours to form an alkaline film layer. formed. Then, it is immersed in a silica aqueous solution having a mass concentration of 0.5% at 37 ° C for 5 minutes, and immersed in 0.06M NH ₄ H ₂ PO ₄ aqueous solution and 0.011M Ca (OH) ₂ aqueous solution at 90 ° C for 1 minute. Cyclic pre-calcification treatment was performed by circulating 20 times in the method. Next, after heating the electric furnace at 100 ° C. at a temperature increase rate of 10 ° C., the magnesium mesh was maintained for 2 hours and heat treated to prepare a biocompatible magnesium mesh.

Comparative Example 1:

Magnesium mesh (UT) prepared through Preparation Example 1.

Comparative Example 2: Manufacture of hydrothermal treated magnesium mesh

The magnesium mesh prepared in Preparation Example 1 was immersed in an aqueous solution of hydrogen fluoride (HF) having a mass concentration of 40% at room temperature for 2 hours, washed with tertiary distilled water, and dried in a dryer at a temperature of 40 ° C. for 26 hours to remove fluorine A coating layer was formed. Then, prepare 25 g/L of Ca(NO ₃ ) ₂ 4H ₂ O and 25 g/L of NH ₄ H ₂ PO ₄ in 50 ml of distilled water, and then drop the Na ₂ HPO ₄ solution into the Ca(NO ₃ ) ₂ 4H ₂ O solution. After mixing, the pH was adjusted to 4 with 1M HNO ₃ . Thereafter, after filling 70% of the total volume ratio in a 30 ml container, the magnesium mesh specimen having the fluorine film layer was immersed and maintained at 90 ° C. for 30 minutes to prepare a hydrothermally treated magnesium mesh, and the magnesium mesh was heated at a rate of 10 ° C. It was placed in an electric furnace heated to 100 ° C. and maintained for 2 hours to heat-treat (HT-H1).

Comparative Example 3: Preparation of hydrothermal treated magnesium mesh

The magnesium mesh prepared in Preparation Example 1 was immersed in a hydrogen fluoride (HF) aqueous solution having a mass concentration of 40% at room temperature for 2 hours, washed with tertiary distilled water, and dried in a dryer at 40 ° C. for 26 hours to form a fluorine film layer. formed. Then, prepare 25 g/L of Ca(NO ₃ ) ₂ 4H ₂ O and 25 g/L of NH ₄ H ₂ PO ₄ in 50 ml of distilled water, and then drop the Na ₂ HPO ₄ solution into the Ca(NO ₃ ) ₂ 4H ₂ O solution. After mixing, the pH was adjusted to 4 with 1M HNO ₃ . Thereafter, after filling 70% of the total volume ratio in a 30 ml container, the magnesium mesh specimen having the fluorine film layer was immersed and maintained at 90 ° C. for 30 minutes to prepare a hydrothermally treated magnesium mesh, and the magnesium mesh was heated at a rate of 10 ° C. It was placed in an electric furnace heated to 400 ° C. and maintained for 2 hours to heat-treat (HT-H4).

Experimental Example 1: Surface analysis of magnesium mesh specimen

Changes in the morphological microstructure of the prepared magnesium mesh specimens after immersion in SBF were observed with a high-resolution field emission scanning electron microscope (HR FESEM, S800, Hitachi, Tokyo, Japan), and changes in the concentration of elements were observed in an X-ray spectrum (EDS). , Bruker, Billerica, MA, USA). In addition, the crystal structure of elements present in the film layer of the prepared magnesium mesh specimen was investigated with an X-ray diffractometer (Dmax III-A type, Rigaku, Tokyo, Japan).

4 (a) and (b) are high-resolution scanning electron micrographs of the magnesium mesh (HT-H1) heat-treated at 100 ° C. for 2 hours after hydrothermal treatment at 90 ° C. of Comparative Example 2, and FIG. 4 (c) and (d) is a high-resolution scanning electron micrograph of the magnesium mesh (HT-H4) heat-treated at 400° C. for 2 hours in Comparative Example 3. As can be seen in FIG. 4, on the surface subjected to hydrothermal treatment, needle-shaped calcium phosphate precipitates were precipitated in a dense structure.

5 (a) and (b) are high-resolution scanning electron micrographs of the magnesium mesh (CP-H1) heat-treated at 100 ° C. for 2 hours after 90 ° C cycle calcification pre-treatment of Example 1, and FIG. 5 (c) and (d) is a high-resolution scanning electron micrograph of the magnesium mesh (CP-H4) heat-treated at 400 °C for 2 hours after 90 °C cyclic calcification pretreatment of Example 2. As can be seen in FIG. 5, unlike FIG. 4, calcium phosphate precipitates having a fine grain structure were precipitated in clusters on the surface subjected to cyclic calcification treatment.

6 is a magnesium mesh (UT) of Comparative Example 1, a magnesium mesh (HT-H1) heat-treated at 100 ° C after 90 ° C hydrothermal treatment of Comparative Example 2, and a magnesium mesh heat-treated at 400 ° C after 90 ° C hydrothermal treatment of Comparative Example 3 Mesh (HT-H4), magnesium mesh heat-treated at 100 ° C after 90 ° C cycle calcination pre-treatment of Example 1 (CP-H1), and magnesium mesh heat-treated at 400 ° C after 90 ° C cycle calcification pre-treatment of Example 2 (CP This is the result of X-ray diffraction analysis of -H4). As can be seen in FIG. 6, only magnesium peaks were observed in the untreated magnesium mesh (UT) of Comparative Example 1 (a), but in the hydrothermal treated surfaces of Comparative Examples 2 and 3 ((b) and (c)) In addition to the magnesium peak, CaH ₂ , CaPO ₃ and calcium phosphate hydrate peaks were observed together. In addition, in addition to the magnesium (Mg) peak, an octa calcium phosphate peak was also observed on the surfaces subjected to the cycle calcification treatment of Examples 1 and 2.

On the other hand, in the biocompatible magnesium meshes of Examples 3 and 4, octa calcium phosphate peaks were observed in addition to magnesium (Mg) peaks on the surface treated with circular calcification as in Examples 1 and 2, although not shown herein.

Experimental Example 2: Immersion Test of Similar Body Fluids of Magnesium Mesh Specimens

Specimens prepared to investigate the corrosion behavior of the magnesium mesh specimens prepared according to the present invention were immersed in 10 ml of 37 ° C. SBF solution (simulated body fluid), maintained for 7 days in an incubator with a 5% CO ₂ atmosphere, and pH change was investigated. did In addition, to investigate the bioactivity, it was immersed in 37 ℃ SBF solution for 1 day and 3 days, and the precipitation pattern of CaP was investigated. SBF was prepared by adding 0.185 g/L of calcium chloride dihydrate, 0.09767 g/L of magnesium sulfate, and 0.350 g/L of sodium hydrogen carbonate to Hanks' solution (H2387, Sigma Chemical Co, USA), and the pH was adjusted using 1N HCl aqueous solution. was adjusted to 7.4. During the bioactivity test, the prepared specimens were sterilized at 120 ° C for 20 minutes and used for the test, and the SBF solution was exchanged every day to reduce the effect of ion concentration and pH change.

7 is an untreated magnesium mesh (UT) (a) of Comparative Example 1, a magnesium mesh (HT-H1) (b) heat-treated at 100 ° C after 90 ° C hydrothermal treatment of Comparative Example 2, and 90 ° C cycling of Example 1 This is the result of examining the pH change over 7 days after immersing the magnesium mesh (CP-H1) (c) heat-treated at 100 ° C after calcification pre-treatment in 10 ml of 37 ° C SBF. The pH of the untreated magnesium mesh (UT) rose faster than that of the surface-treated magnesium mesh over time, and it was similar in the case of surface-treated magnesium meshes, but compared to the hydrothermal treatment group (HT-H1) (b), the circulating pre-calcification group (CP-H1) (c) showed a tendency to rise more slowly.

8 is a magnesium mesh (HT-H1) heat-treated at 100° C. for 2 hours after hydrothermal treatment at 90° C. in Comparative Example 2 (a is 10 magnification and b is 50 magnification) and after hydrothermal treatment at 90° C. in Comparative Example 3 HR FE-SEM photograph observed after immersing a magnesium mesh (HT-H1) (c is 10 magnification, d is 50 magnification) heat-treated at 400 ° C for 2 hours in SBF for 3 days HR FE-SEM image showing Figure, and Table 1 is their EDS analysis results. On the surface of HT-H1, the protruding calcium phosphate observed in the early stage of HA precipitation was deposited in a dense structure and showed a Ca/P atomic ratio of 1.07, but only Mg was detected on the surface of HT-H4, and Ca and P were not detected. .

Group/Element Mg (wt%) Ca(wt%) P(wt%) Ca/P ratio (at%) HT-H1 4.56 19.33 13.93 1.07 HT-H4 44.35 - - -

9 is a magnesium mesh (CP-H1) heat-treated at 100° C. for 2 hours after 90° C. calcination pre-treatment of Example 1 (a is 10 times magnification, b is 50 times magnification) and 90° C calcination cycle calcification of Example 2 A magnesium mesh (CP-H4) (c is a magnification of 10, d is a magnification of 50) after pretreatment at 400 ° C. for 2 hours is immersed in SBF for 3 days. HR FE-SEM photograph, Table 2 is These are the results of EDS analysis.

Group/Element Mg (wt%) Ca(wt%) P(wt%) Ca/P ratio (at%) CP-H1 7.07 28.73 14.69 1.51 CP-H4 43.29 - - -

As can be seen in Figure 9 and Table 2, on the surface of CP-H1 of Example 1, the protrusions observed in the initial stage of HA precipitation were precipitated in a dense structure and showed a Ca / P atomic ratio of 1.51, but HT-H4 of Example 2 On the surface, Mg increased greatly, and Ca and P were not detected.

In addition, when comparing HT-H1 in Table 1 and CP-H1 in Table 2, it can be seen that the precipitation of Ca and P increased in the circulating calcification pre-treatment group (CP-H1) compared to the hydrothermal treatment group (HT-H1). there was.

On the other hand, in the biocompatible magnesium meshes of Examples 3 and 4, although not shown in this specification, as in Example 1, the projections observed in the initial stage of HA precipitation are precipitated in a dense structure, and the Ca / P atomic ratio of Example 3 is 1.57, Example 4 gave 1.48.

Experimental Example 3: Preparation of Hybrid Gel Shielding Film Specimen and Ibandronate Mounting and Release Test

2-Hydroxyethyl methacrylate (HEMA, 97%, Aldrich) 87 wt%, methacrylic anhydride (MA, 94%, Aldrich) 2 wt%, (PEO) 99 (PPO) 67 (PEO) 99 ( Pluronic F127, Aldrich) 2 wt% and 2,2-dimethoxy-2-phenylacetophenone (DMPAP 99%, Aldrich) 1 wt% were mixed in distilled water (residual content) and photopolymerized to form a hybrid gel with a diameter of 10 mm × thickness of 0.2 mm ( hybrid gel) specimens were prepared. Pluronic F127 was mixed with water at 4 ° C in a ratio of 8: 2 and stirred for 30 minutes or more to confirm that the components were completely dissolved. The prepared sample was poured into a silicon mold using a micro pipette and irradiated with UV light at a wavelength of 365 nm for 10 minutes. Thereafter, in order to induce elution of the unreacted monomer in the shielding film, it was immersed in 100 ml of distilled water, stirred for 3 days, and distilled water was exchanged once a day. The hybrid gel shielding film specimen prepared in this way is referred to as HG.

For the loading treatment and release test of ibandronate, 3 ml of 1 vial Unibone (Unimed) provided for subcutaneous injection was divided into 3 parts, and ibandronate sodium hydrate was reduced to 1.125 mg/ml. A diluted solution was used for testing.

The disk-shaped hybrid gel specimen (HG) and the specimen (CP-H1) heat-treated at 100 ° C after 90 ° C cyclic calcification pre-treatment of Example 1 were immersed in 1 ml of prepared ibandronate solution for 24 hours, mounted, and then 3 The immersion in 1 ml of tea distilled water for 24 hours was repeated over 7 days, and the amount of ibandronate released was quantitatively measured over 7 days using an HPLC system (1260, Agilent Technologies, CA, USA).

As can be seen in FIG. 10, the CP-H1 of Example 1 showed a small amount but released over 6 days, whereas the hybrid gel specimen (HG) showed a short release over 2 days.

Experimental Example 4: Erosion test of magnesium mesh on test animals

Eating tests on test animals were performed in compliance with the principles of the Declaration of Helsinki, which stipulates the test animals.

A total of 20 8-week-old male rats (Sprague-Dawley rats) weighing (230±20) g were used as the test animals. The test animals were used in the test after basic breeding for one week in an animal breeding room where the temperature and humidity were kept constant.

Erosion tests on test animals were conducted in the untreated group (UT), the 100℃ heat treatment group after hydrothermal treatment (HT-H1), the 400℃ heat treatment group after hydrothermal treatment (HT-H4), and the 100℃ heat treatment group after cyclic calcification pretreatment (CP). -H1) and 400℃ heat treatment group after cyclic calcification pretreatment (CP-H4) were targeted.

As shown in FIG. 3 below, 0.7 ml/kg of ketamine and 0.2 ml/kg of xylazine HCl were intramuscularly injected into each test rat to induce general anesthesia, followed by epinephrine (1:100,000). ) was added to 2% lidocaine for additional local anesthesia of the surgical site. The hair of the corresponding skull region was shaved and removed, disinfected with a betadine scrub, and the region was vertically incised with a scalpel to separate the periosteum attached to the calvarial. Then, a trephine bur with an outer diameter of 8 mm was mounted on the endodontic motor (X-SMARTTM, Densply, Japan), and under the conditions of a rotational speed of 400 rpm and a rotational force of 5 Ncm, a critical defect size of 8 mm in diameter A circular defect of the size was formed. Then, the prepared magnesium mesh specimen and the hybrid gel specimen were covered, and then the periosteum and skin were sutured with an absorbable suture. Thereafter, 4 ml of an aminoglycoside antibiotic was intramuscularly injected for 3 days to prevent secondary infection.

As can be seen in FIG. 11, bone density was the highest at 0.294±0.039 g/mm ³ in the CP-H1 group and the lowest at 0.207±0.010 g/mm ³ in the CP-H4 group, and the CP-H1 group was found to be the lowest in the remaining tests. There was a statistically significant difference from the groups (P<0.05). In addition, as can be seen in FIG. 12, even in the case of new bone volume, the CP-H1 group was the highest at 6.251±1.481 mm ³ and the untreated UT group was the lowest at 3.048±0.212 mm ³ , with the CP-H1 group remaining the rest. There was a statistically significant difference from the test groups (P<0.05).

From these results, it was confirmed that precipitation of calcium phosphate through cyclic calcification pretreatment is useful for improving bioactivity.

On the other hand, the advantage of pre-calcification cycle treatment is that bioactivity can be rapidly accelerated by precipitating HA with a fine grain structure by heat treatment after cycle treatment. In this test, the group (HT-H4, CP-H4) showed a decrease in the volume of new bone (see FIG. 12). This is thought to be caused by the increase in solubility due to the deterioration of the mechanical properties of the magnesium mesh during the heat treatment process. If the mechanical properties of the magnesium mesh do not change even at high temperatures (eg 400 ° C), the problem of reducing the volume of new bone will be solved. It is judged to be

Experimental Example 5: Blood analysis

When 4 weeks after the magnesium mesh was implanted in the test animal according to Experimental Example 4, 0.06 ml / 100 g of Zoretil and 0.04 ml / 100 g of Rompun were intramuscularly injected into each test animal, and the whole body Anesthesia was induced, the upper part of the heart was sterilized, and then cardiac puncture was performed, and about 2 ml of blood was collected in an EDTA-treated tube and stirred to mix the EDTA well. After centrifugation for 20 minutes, the plasma was transferred to an analysis tube and stored at -20°C until analysis.

In order to measure the secretion of pro-inflammatory cytokines in the separated plasma, the secretion of IL-1β (interluekin-1β) and IL-6 (interleukin-6) was measured by ELISA kit (Quantikine, R&D Systems, Minneapolis, USA). The degree of color development of the reaction solution was quantified by cytokine concentration by measuring absorbance at 450 nm with a microplate reader (FLUOsrar Omega).

As can be seen in FIG. 13, in the case of IL-1β, it was similarly low in all test groups except for the UT group, and showed a statistically significant difference between the UT group and the UT group (P<0.05). In addition, as can be seen in FIG. 14, in the case of IL-6, it was the highest in the heat treatment group (CP-H4) at 400 ° C after 90 ° C cycle calcification pretreatment, and in the heat treatment (CP-H1) at 100 ° C after 90 ° C cycle calcification pretreatment It came out the lowest, and the CP-H1 group and the HT-H4 group showed a statistically significant difference from the rest of the test groups (P<0.05).

As such, as a result of analyzing IL-1β and IL-6, it was the lowest in the group (CP-H1) heat-treated at 100 ° C after cyclic calcification pre-treatment, and the lowest in the untreated control group (UT) and heat-treated at 400 ° C after cyclic calcification pre-treatment. It was significantly higher in the group (CP-H4) (see FIGS. 13 and 14). The highest in the untreated control group is thought to be due to the fast dissolution rate of the Mg mesh. In addition, the reason why IL-6 was high in the CP-H4 group is thought to be due to the increase in solubility due to the decrease in mechanical properties of the rolled mesh during the heat treatment process. If this does not change, it is judged that the problem of decreasing the volume of new bone will be solved.

Therefore, in the method for manufacturing a biocompatible magnesium mesh according to the present invention, a fluorine film layer or an alkali protective layer is formed to suppress dissolution and improve bioactivity, and calcium phosphate is precipitated through precalcification treatment, resulting in an excellent bone regeneration effect. A biocompatible magnesium mesh is provided.

Claims (14)

A protective film forming step (S100) of immersing the magnesium mesh in a hydrogen fluoride or sodium hydroxide solution, washing it, and drying it to form a protective film layer; Preliminary treatment step (S200) by alternately and repeatedly immersing the magnesium mesh surface-treated through the protective film forming step (S100) in an aqueous solution of ammonium phosphate and an aqueous solution of calcium hydroxide, respectively; and a heat treatment step (S300) of heat-treating the magnesium mesh pretreated in the precalcification treatment step (S200) at 90 to 600° C. for 1.5 to 2.5 hours. The biocompatible according to claim 1, wherein the magnesium mesh in the protective film forming step (S100) is a pure magnesium mesh consisting of 99.0% by weight or more of magnesium and residual impurities or a magnesium alloy containing 95.0% by weight or more of magnesium. A method for manufacturing a molded magnesium mesh. The biocompatible type according to claim 1, wherein the magnesium mesh in the protective film forming step (S100) has a circular or polygonal shape with a thickness of 0.05 to 0.15 mm and a plurality of circular holes with a diameter of 0.4 to 0.6 mm. Manufacturing method of magnesium mesh. The method of claim 1, wherein the hydrogen fluoride solution in the protective film forming step (S100) has a mass concentration of hydrogen fluoride of 35 to 45%, and the aqueous sodium hydroxide solution has a molar concentration of sodium hydroxide of 1 to 2M. Manufacturing method of biocompatible magnesium mesh. The method of claim 1, wherein the immersion in the protective film forming step (S100) is 90 to 150 minutes in the case of hydrogen fluoride solution and 25 to 35 minutes in the case of sodium hydroxide solution. The method of claim 1, wherein the drying of the protective film forming step (S100) is performed in a dryer at 35 to 45° C. for 24 to 30 hours. The biocompatible magnesium mesh according to claim 1, characterized in that the repeated immersion in the precalcification step (S200) is repeated 10 to 22 times for 50 to 70 seconds, respectively, in an aqueous solution of ammonium phosphate and an aqueous solution of calcium hydroxide, respectively. manufacturing method. The method of claim 1, wherein the aqueous ammonium phosphate solution in the precalcification step (S200) is a sodium hydrogen phosphate aqueous solution or an ammonium hydrogen phosphate aqueous solution, and has an amount of 0.03 to 0.07 mole. The method of claim 1, wherein the amount of calcium hydroxide in the precalcification step (S200) is 0.01 to 0.015 mol. The manufacturing method of a biocompatible magnesium mesh according to claim 1, characterized in that it is immersed in an aqueous silica solution having a mass concentration of 0.4 to 0.6% for 4 to 6 minutes before repeated immersion in the precalcification treatment step (S200). The method of claim 1, wherein the repeated immersion in the precalcification treatment step (S200) is performed in a state in which a low voltage is applied to each aqueous solution. The method of claim 1, after the heat treatment step (S300), a drug application step (S400) of applying a hydrogel containing a drug for treating osteoporosis to one or both sides of the magnesium mesh heat-treated through the heat treatment step (S300) is added. Method for producing a biocompatible magnesium mesh comprising a. 13. The method of claim 12, wherein the osteoporosis treatment drug is at least one bisphosphonate-based drug selected from the group consisting of pamidronate, alendronate, risedronate, ibandronate, and zoledronate. Manufacturing method of biocompatible magnesium mesh. A body-friendly magnesium mesh manufactured by the method of any one of claims 1 to 13.

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