KR101340044B1 - Hyaluronic acid catechol conjugate and use thereof - Google Patents

Abstract

The present invention relates to a hyaluronic acid catechol conjugate and its use, and more particularly, to a method for manufacturing a medical implant, including a method of modifying the surface of a medical implant after hyaluronic acid catechol preparation and a method of immobilizing a bioactive material. to provide. Hyaluronic acid catechol conjugates prepared according to the method of the present invention can be developed into a better material by immobilizing on the surface of medical implants or medical materials such as implants, dental implants, stents, screws, bone substitutes, etc. It provides a very useful coating method.

Description

Hyaluronic acid catechol conjugates and use thereof

The present invention relates to a hyaluronic acid catechol conjugate and its use, and more particularly, to a method for manufacturing a medical implant, including a method of modifying the surface of a medical implant after hyaluronic acid catechol preparation and a method of immobilizing a bioactive material. to provide.

Medical implants such as implants, dental implants, stents, screws, bone substitutes, etc., are inserted in the lost area to treat wounds, damaged teeth, joints, or tissue. However, when the medical implant is inserted into the body, the surface of the medical implant is recognized as an external surface in the body, and the precoagulation is activated to prevent bleeding and blood loss. In addition, medical implants must come into contact with biological tissues permanently, so they must have both surface suitability and in vivo affinity.

In the coating of medical implants using the conventional hyaluronic acid solution, there is a problem that a stable immobilization technology for hyaluronic acid has not been applied and its effectiveness has not been verified.

Therefore, there has been a need for a technique for modifying the surface of a medical implant and an effective method for immobilizing a bioactive material.

Many prior art methods of modifying the surface to provide a successful implant are well known. For example, 10-2009-0117807 describes a method for producing hypotonic implants using salts to modify superhydrophilic surfaces. However, this does not have a simple process, unlike the present patent, and does not have the result of whether the implant loaded with bone growth factor has bio-activation.

On the other hand, there have been several attempts to modify the surface of the stent to prevent anticoagulation. Among them, the process of technology to immobilize using heparin was complicated.

The inventors of the present invention, while searching for a medical implant having both surface suitability and in vivo affinity, fix the hyaluronic acid catechol conjugate on the surface of the medical implant or medical material and develop a better material. It confirmed and completed this invention.

Accordingly, an object of the present invention is to provide a hyaluronic acid catechol conjugate formed by combining a carboxy group of hyaluronic acid with an amide bond of an amine group of dopamine.

Another object of the present invention is to (a) adding EDC (1-Ethyl-3- [3-dimethyl aminopropyl] carbodiimide Hydrochloride) and NHS (N-hydroxysuccinimide) to the mixture of hyaluronic acid and dopamine in the same amount as the dopamine equivalent, respectively. ; (b) reacting the composite at a pH of 2 to 7 for 1 to 18 hours; And (c) to provide a method for producing a hyaluronic acid catechol conjugate comprising the step of purifying the composite at pH 2 to 7.

Still another object of the present invention is to provide a composition for surface modification of medical equipment comprising the hyaluronic acid catechol conjugate of the present invention as an active ingredient.

Another object of the present invention is to prepare a solution of (a) 1 mg / mL to 200 mg / mL of the hyaluronic acid catechol conjugates; It provides a method for producing a hyaluronic acid catechol conjugated hydrogel containing (b) reacting for 2 to 24 hours by adding an oxidizing agent at a pH of 2 to 10 conditions.

Another object of the present invention is to prepare a solution of (a) 1 mg / mL to 200 mg / mL of the hyaluronic acid catechol conjugates; It provides a method for producing a hyaluronic acid catechol conjugated hydrogel containing (b) reacting for 2 to 24 hours by adjusting the pH to 2 to 10.

Another object of the present invention is to provide a hyaluronic acid catechol hydrogel prepared by the production method of the present invention.

Still another object of the present invention is to provide a cell culture support comprising the hydrogel of the present invention as an active ingredient.

In order to achieve the above object of the present invention, the present invention provides a hyaluronic acid catechol conjugate formed by combining a carboxyl group of hyaluronic acid with an amide bond of an amine group of dopamine.

In order to achieve another object of the present invention (a) dopamine equivalent weight of EDC (1-Ethyl-3- [3-dimethyl aminopropyl] carbodiimide Hydrochloride) and NHS (N-hydroxysuccinimide) in a mixture of hyaluronic acid and dopamine Putting in an equivalent equivalent; (b) reacting the composite at a pH of 2 to 7 for 2 to 18 hours; And (c) provides a method for producing a hyaluronic acid catechol conjugates comprising the step of purifying the composite at pH 2 to 7.

In order to achieve another object of the present invention, the present invention provides a composition for surface modification of medical equipment comprising the hyaluronic acid catechol conjugates of the present invention as an active ingredient.

In order to achieve another object of the present invention, the present invention comprises the steps of (a) preparing a solution of 1 mg / mL to 200 mg / mL of the hyaluronic acid catechol conjugates; It provides a method for producing a hyaluronic acid catechol conjugated hydrogel, and (b) reacting for 2 to 24 hours by adding an oxidizing agent at a pH of 2 to 10 conditions.

In order to achieve another object of the present invention, the present invention comprises the steps of (a) preparing a solution of 1 mg / mL to 200 mg / mL of the hyaluronic acid catechol conjugates; It provides a method for producing a hyaluronic acid catechol conjugated hydrogel containing (b) reacting for 2 to 24 hours by adjusting the pH to 2 to 10.

In order to achieve another object of the present invention, the present invention provides a hyaluronic acid catechol hydrogel prepared by the production method of the present invention.

In order to achieve another object of the present invention, the present invention provides a cell culture support comprising a hydrogel of the present invention as an active ingredient.

The present invention is described in detail below.

The present invention relates to a novel method for preparing hyaluronic acid catechol conjugates and coating the surface of artificial material used for medical purposes as a surface modification method.

More specifically, the present invention provides a hyaluronic acid catechol conjugate formed by combining a carboxy group of hyaluronic acid with an amide bond of an amine group of dopamine.

In the present invention, hyaluronic acid (hyaluronate, hyaluronic acid: HA) is a straight chain natural acidity of β-DN-acetylglucosamine and β-D-glucuronic acid alternately bonded by β-1,3 and β-1,4 bonds. It is a mucopolysaccharide. The molecular weight ranges from 50,000 to 8 million by the adjustment method. In addition to being widely distributed in connective tissues of mammals, it has been found in placenta, eye vitreous body, articular bone fluid, group A and C hemolytic streptococci and the like. The glucuronide bond and the N-acetylglucosamide bond are decomposed by hyaluronidase (general name of mutinase, namely, an enzyme that degrades the polymerization of hyaluronic acid).

In addition, dopamine has a chemical formula of C ₈ H ₁₁ NO ₂ , molecular weight of 153.18. It is the first catecholamine produced in the reaction of L-dopa with aromatic-L-amino acid decarboxylase. In addition to acting as a neurotransmitter, they are also precursors of noradrenaline and adrenaline of catecholamines. The aqueous solution is extremely unstable and easily oxidized but relatively stable in acid. Dopamine is also present in peripheral tissues and is excreted in the urinary tract. Dopamine receptors can be distinguished as D2 receptors, which are not conjugated with the D1 receptor, which is conjugated with adenylate cyclase.

More specifically, the hyaluronic acid catechol conjugate of the present invention may be a compound represented by the following Chemical Formula 1.

[Formula 1]

이고 K는 1 내지 10의 정수이며, X 는 각각 독립적으로 H 또는 OH 이고, n 은 2 내지 700의 정수이고, m 은 n 보다 작으며 1내지 300의 정수이다.
Where L is

And K is an integer from 1 to 10, X is each independently H or OH, n is an integer from 2 to 700, m is less than n and an integer from 1 to 300.

On the other hand, the hyaluronic acid catechol conjugate of the present invention

(a) adding EDC (1-Ethyl-3- [3-dimethyl aminopropyl] carbodiimide Hydrochloride) and NHS (N-hydroxysuccinimide) to the mixed solution of hyaluronic acid and dopamine as a dopamine equivalent, respectively;

(b) reacting the composite at a pH of 2 to 7 for 2 to 18 hours; And

(c) may be prepared by a method comprising the step of purifying the composite at pH 2-7.

The manufacturing method of the present invention will be described in detail for each step as follows.

Step (a) is a step of adding EDC and NHS in the same amount as the dopamine equivalent, respectively, in the mixed solution of hyaluronic acid and dopamine.

EDC (1-Ethyl-3- [3-dimethyl aminopropyl] carbodiimide Hydrochloride) is a representative compound having the formula C ₈ H ₁₇ N ₃ -HCl and developed as a water-soluble carbodiimide. It is a compound that mainly promotes dehydration reaction between carboxyl group and amino, but unlike other general dehydration reactions, it can be used in aqueous solution. It is used for peptide formation reaction and amidation of protein carboxyl groups from amino compounds.

NHS (N-hydroxysuccinimide) has a chemical formula of C ₄ H ₄ NNaO ₆ and is mainly used as an activating reagent to promote carboxyl acid in organic or biochemistry. It is also mainly used with EDC to improve reaction efficiency and stability.

Hyaluronic acid and dopamine are not limited thereto, but the reaction may be smoothly performed and mixed in a ratio of 1 to 20: 1.

In the above, each amount of EDC and NHS may be equivalent to a dopamine equivalent, that is, equivalent to the dopamine equivalent, for the efficiency of the reaction. Substantially the same equivalent weight as above refers to a range of equivalents that can be recognized as equal within an experimentally possible error range in the range of 95% to 105% relative to the dopamine equivalent. More preferably equivalent to the dopamine equivalents.

In one embodiment of the present invention, hyaluronic acid catechol conjugates were prepared according to the preparation method of the present invention. UV conjugate spectroscopy was used to prepare the conjugates and confirmed that the catechol group is bound to hyaluronic acid was confirmed that the binding of about 2 to 3%.

In one embodiment of the present invention, the glass and ITO (Indium Tin Oxide) coated on the ceramic, the surface of the synthetic polymer material coated with PU (polyurethane) and PTFE (polytetrafluorofluoroethylene) respectively, and the metal and metal oxide SiO ₂ , PT and St are coated on the coated surface, respectively, to confirm the coating ability of the hyaluronic acid catechol conjugate. As a result, it was found that the surface of the ceramic, synthetic polymer material, metal, and metal oxide surface was changed to very hydrophilic after the coating of hyaluronic acid catechol, and thus the coating was very well regardless of the type of material.

In one embodiment of the present invention, the coating effect of hyaluronic acid catechol was confirmed by coating on the dental implant fixture and stent, respectively. As a result, the dental implant fixture coated with the hyaluronic acid catechol conjugate was well implanted without inflammation, and the stent was well coated according to the surface treatment.

Therefore, the hyaluronic acid catechol conjugates of the present invention are well coated with metals, ceramics, synthetic resins, etc., which are used as materials for medical devices, and thus enhance affinity so that they can stably exist in vivo without causing unnecessary immunity and inflammatory reactions. Can be. Accordingly, the present invention provides a composition for surface modification of medical equipment comprising a hyaluronic acid catechol conjugate as an active ingredient.

Surface modification means changing the chemical and physical structure of the particle surface. Among these, chemical surface modification mainly collides with metal, glass, or plastic surface due to collision of high-energy electrons or ions in a material having low bonding energy such as plastic. The collision generates radicals and ions, and oxygen, water and moisture around them react with carbon and hydrogen on the surface to generate highly polar functional groups such as carbonyl, carboxyl, hydroxy, and cyan groups to chemically surface. This is modified with hydrophilicity. When the surface is modified, the hydrophilicity is improved, the adhesion is improved, the surface roughness is changed, and the surface oil is removed. The effect of improving printability, coating, and printing characteristics can be obtained.

In the present invention, by modifying the surface of the hyaluronic acid catechol conjugates improves biocompatibility with the main material for medical devices, such as implants used as titanium or titanium alloys with low bioactivity.

In the present invention, the medical device is a mechanical machine, a medical product, a dental material, a hygiene product, etc., which is intended to affect a disease, diagnosis, treatment, or prevention of a person or an animal, or to affect a body structure and a function of a person or an animal. Say the tool. Specific examples of such medical devices include, for example, implants, stents, blood bags, urine bags, transfusion sets, suture chambers, drain tubes, various catheters, blood accessors, blood circuits, artificial blood vessels, artificial kidneys, artificial cardiopulmonary, artificial Valves, plasma exchange membranes, various adsorbents, continuous portable peritoneal perfusion dialysis device (CAPD), intra-aortic balloon pump (IABP), face makers, artificial joints, artificial heads, dental materials, eye lenses, soft contact lenses, etc. It is not limited to. Preferably the medical device of the present invention is a composition, characterized in that selected from the group consisting of implants, stents, artificial joints, artificial heads, dental materials, cell culture apparatus.

In addition, the medical device of the present invention is a precious metal material including gold (Au), silver (Ag), platinum (Pt), palladium (Pd), and copper (Cu), steel (steel), tantalum (Ta), magnesium ( Mg), metallic materials including nickel (Ni), chromium (Cr), iron (Fe), nitinol alloy (NiTi), cobalt-chromium alloy (CoCr) gallium arsenide (GaAs), and titanium (Ti), polytetra Fluoroethylene, polycarbonate, polyurethane, nitrocellulose, polystyrene, polyethylene, polyethylene terephthalate (PET), polydimethylsiloxane (PDMS), and poly High molecular materials, including ether ether ketones (PEEK), metal oxides including silicon oxide (SiO ₂ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), and niobium oxide (Nb ₂ O ₅ ) Or materials of the same kind as those of nonmetals, including silicone, silicone rubber, and glass, or .

On the other hand, in one embodiment of the present invention it was confirmed whether the hyaluronic acid catechol conjugates of the present invention to form a hydrogel (hydrogel) and its physical properties. After dissolving the hyaluronic acid catechol solution in PBS and adding sodium iodate (NaIO ₄ ) as an oxidizing agent, the hyaluronic acid catechol was cross-linked due to the acidity sensitive crosslinking property of the catechol to form a hydrogel. As a result of measuring the mechanical strength of the formed hydrogel by Rheology, it has a mechanical strength of 550 Pa of storage modulus (G ') and 200 Pa of loss modulus (G''). The pore size of the hydrogel was confirmed to be about 40um.

As a result of culturing the neural stem cells in the hydrogel of the present invention as described above in one embodiment of the present invention, the hyaluronic acid of the present invention in the HA-methacrylate (hyaluronic acid-methacrylate) hydrogel which is a commonly used material In catechol hydrogels, the survival rate of neural stem cells was more prevalent.

Therefore,

(a) preparing a solution of 1 mg / mL to 200 mg / mL of the hyaluronic acid catechol conjugate; And

(b) reacting for 2 to 24 hours by adding an oxidizing agent at a pH of 2 to 10;

It provides a method for producing a hyaluronic acid catechol conjugated hydrogel comprising a.

In addition,

(a) preparing a solution of 1 mg / mL to 200 mg / mL of the hyaluronic acid catechol conjugate; And

(b) adjusting the pH to 2 to 10 and reacting for 2 to 24 hours;

It provides a method for producing a hyaluronic acid catechol conjugated hydrogel comprising a.

Step (a) is a step of preparing a solution of 1 mg / mL to 200 mg / mL of the hyaluronic acid catechol conjugates. The solvent of the solution is PBS (phosphate beffer saline), among those used as a buffer solution can be used by using two or more of HCl, Sodium citrate, Citric acid, Acetic acid, Sodium acetate, Borax, Sodium hydroxide, Buffers such as TAPS, Bicine, Tris, Tricine, TAPSO, HEPES, TES, MOPS, PIPES, Cacodylate, SSC, and MES used in other biological experiments can be used.

Step (b) is a step of reacting for 2 to 24 hours by adding an oxidizing agent at a pH of 2 to 10 conditions. Under the pH conditions, hyaluronic acid catechol is crosslinked with each other by the acidity sensitive crosslinking property of catechol to form a hydrogel. The oxidizing agent in the above, NaIO ₄ , Na ₂ S ₂ O ₈ One or more metal salt compounds selected from the group consisting of Fe ^{3 +} , Cr ^{6 +} , Mn ^{7 +} , I ^{7 +} , inorganic peroxides such as Oxygen (O ₂ ), Ozone (O ₃ ) and Hydrogen peroxide (H ₂ O ₂ ); Halogenated compounds such as fluorine (F ₂ ), chlorine (Cl ₂ ), acidic compounds such as nitric acid (HNO ₃ ), sulfuric acid (H ₂ SO ₄ ), and persulfuric acids (H ₂ SO ₅ and H ₂ SO ₈ ), permanganates (MnO ₄ ^-) compound, manganese salts (MnO ₄ ^{2 -)} compound, a perborate _{compound, silver oxide (Ag 2 O)} , Osmium tetroxide (OsO 4), Tollens' reagent, 2,2'-Dipyridyldisulfide (DPS Oxidizing agents).

In view of the reaction time and the physicochemical properties of the resultant hydrogel, the oxidant to be added is preferably added in an amount of 0.1 to 10 equivalents relative to the catechol equivalents.

In addition, step (b) may be a step of reacting for 2 to 24 hours by adjusting the pH to 2 to 10 without the addition of an oxidizing agent. Under the pH conditions, hyaluronic acid catechol is crosslinked with each other by the acidity sensitive crosslinking property of catechol to form a hydrogel.

On the other hand, the present invention provides a hyaluronic acid catechol hydrogel prepared by the method for producing a hydrogel of the present invention. In addition, the present invention provides a cell culture support (scaffold) comprising the hydrogel as an active ingredient. The cell culture support of the present invention is excellent in efficiency because cells are cultured with little cytotoxicity. The cell culture support of the present invention may serve as a support in culturing nerve cells or neural stem cells, and may be used in various ways such as cell culture for transplantation or general cell culture.

As described above, the hyaluronic acid catechol conjugates of the present invention can easily impart adhesion to the biocompatible hyaluronic acid, as well as to coat the biocompatible hyaluronic acid on various solid surfaces. In particular, according to the present invention has the advantage of providing an effect that can be applied to the culture plate for culturing cells, dental implant surface, stent surface, as well as the existing coating method. In addition, in relation to the development of implant materials such as gold, titanium, silicon, and ceramics, which are actually used for medical purposes, the present invention is a biocompatible material because dopamine bound to hyaluronic acid is well coated on various surfaces and hydrophilic in the present invention. It can be useful for development.

1 is a structural formula of hyaluronic acid catechol conjugates.
Figure 2 is a UV visible spectra of the hyaluronic acid catechol conjugates to determine the reaction rate of the hyaluronic acid catechol conjugates.
Figure 3 compares the surface hydrophilic change before and after coating, when the hyaluronic acid catechol is coated on various surfaces.
Figure 4 is a photograph comparing the hydrogel formed by the acid-sensitive cross-linked solution with the solution before cross-linking with the chemical oxidizing agent of hyaluronic acid catechol.
5 is a graph showing the formation time of the hyaluronic acid catechol hydrogel according to the sodium periodate equivalent.
6 is a result of measuring the mechanical strength of the hydrogel formed by the acid-sensitive crosslinking of hyaluronic acid catechol.
Figure 7 measures the pore size of the hydrogel formed by acid-sensitive crosslinking of hyaluronic acid catechol.
8 is a photograph in which the implant is placed in the micro-pig tibia.
9 is a surface composition analysis results before and after coating with hyaluronic acid catechol conjugates using XPS.
10 is an analysis result of the N peak before and after coating with hyaluronic acid catechol conjugates using XPS.
FIG. 11 compares the ability of neural stem cells to adhere to polystyrene coated with hyaluronic acid catechol and neural stem cells on the glass surface before and after coating.
12 graphically illustrates the results of FIG. 13.
FIG. 13 compares the degree of neural stem cell survival in a hydrogel using hyaluronic acid catechol with a conventional hyaluronic acid methacrylate (HA-methacrylate) hydrogel. FIG.
14 is a graph showing the survival rate of neural stem cells of FIG. 15.

Hereinafter, the present invention will be described in detail by way of examples.

However, the following examples are only for illustrating the present invention, and the content of the present invention is not limited to the following examples.

< Example  1>

Hyaluronic Acid Catechol Conjugate Preparation

Hereinafter, the present invention will be described in detail by way of examples.

However, the following examples are only for illustrating the present invention, and the content of the present invention is not limited to the following examples.

&Lt; Example 1 >

Hyaluronic Acid Catechol Conjugate Preparation

In order to prepare the hyaluronic acid catechol conjugate (Conjugate) of the present invention, the experiment was performed as follows. In the present invention, (a) preparing hyaluronic acid and dopamine for preparing a hyaluronic acid catechol conjugate, and then using EDC and NHS as a dopamine equivalent in order to make an amide bond by chemical bond using COOH group of hyaluronic acid and NH ₂ group of dopamine. Adding in the same equivalent weight; (b) reacting for 18 hours on 0.2M PBS with pH 5; (c) purifying the composite by dialysis using a membrane of MWCO: 3000 in 0.1M PBS at pH 2; (d) purifying the composite by dialysis with distilled water at pH 2 again using 5 M HCl; (d) Hyaluronic acid catechol was prepared by removing water using a freeze dryer to obtain hyaluronic acid catechol (HA-catechol).

< Example  2>

Confirmation of Hyaluronic Acid Catechol Conjugate Synthesis

In Example 1, UV visible spectroscopy was used to measure the synthesis and reaction rate of the hyaluronic acid catechol conjugates, and reference was made to the following documents (Chem. Mater. 2004, 16, 1202-1208 and J. AM). CHEM.SOC. 2007, 129, 2482-2487).

As shown in FIG. 2, since catechol, which is a dopamine absorbing material at 280 nm, it was confirmed that the catechol group was bound to hyaluronic acid by 2 to 3%.

< Example  3>

Confirmation of Coating Capability of Hyaluronic Acid Catechol Conjugate

The synthesized hyaluronic acid catechol was dissolved in 1x Phosphate Buffered Saline (PBS) at a concentration of 2% (w / v) and then sodium iodate (NaIO ₄ ), an oxidizing agent, was added in 1.5 equivalents of Catechol. After lowering the pH of the prepared solution to 2, the surface of glass and ITO (Indium Tin Oxide) coated on the ceramic of FIG. 3, the surface coated with PU (polyurethane) and PTFE (polytetrafluoroethylene) on the synthetic polymer material and the metal and metal oxide The surface coated with SiO ₂ , PT and St was shaken for 1 hour, and the solution was taken out and washed with distilled water. The contact angle measurement of water (Contact angle measurement) to compare the hydrophilicity before and after the surface coating.

As a result, as shown in Figure 3, it can be seen that the surface is very hydrophilic after the coating of hyaluronic acid catechol all on the ceramic, synthetic polymer material, metal and metal oxide surface. Meanwhile, the chemical functional group of hyaluronic acid catechol coated on the surface was confirmed by Fourier transform infrared spectroscopy (FT-IR), and the X-ray photoelectron spectrum (XPS) analysis was performed. The method confirmed the chemical state of the carbon atoms of hyaluronic acid catechol introduced to the surface (results not shown).

This result is the same as the result analyzed by XPS by coating a material similar to the hyaluronic acid catechol conjugates on gold nanoparticles (Vol. 19, Issue 12, pages 18841890, June 23, 2009 in Advanced Functional Materials).

< Example  4>

Hyaluronic Acid Catechol Conjugate Hydrogel  Formation and property check

Hyaluronic acid catechol was dissolved in 1x PBS at a concentration of 10% (w / v) and then adjusted to pH between 8-9. When sodium iodate (NaIO ₄ ), which is an oxidizing agent, is added to 1.5 equivalents of Catechol, hyaluronic acid catechol is cross-linked by the acid-sensitive crosslinking property of catechol to form a hydrogel.

In FIG. 4, the difference between the hyaluronic acid catechol solution before crosslinking and the reddish brown hydrogel formed after crosslinking can be confirmed. The formation time of the hydrogel varies depending on the NaIO ₄ concentration applied (adjusted between 1-2.3 equivalents), which can be controlled within 7 minutes at a fast time of 1 minute or less, as shown in the graph of FIG. The mechanical strength of the formed hydrogel was measured by the rheology method. As shown in FIG. 6, the mechanical modulus of the storage modulus (G ') 550 Pa and the loss modulus (G'') 200 Pa is shown. Has strength. The pore size of the formed hydrogel was about 40 μm, which can be seen from the results of scanning electron microscopy (SEM) measurement of FIG. 7.

< Example  5>

Confirmation of coating effect of hyaluronic acid catechol

Dental implant fixtures with a diameter of 3.5 mm and a length of 8.5 mm were prepared. The dental implant fixture, which was not treated as a control, and the hyaluronic acid catechol conjugate coating method described in Example 3, were used to prepare a dental implant fixture to which the hyaluronic acid catechol conjugate was immobilized. These were placed in the Tibia portion of each micro pig and aged for 16 days, and then the interfacial force of the implant-bone was confirmed. The stronger the force required to remove each implant fixture, the stronger the implant-bone interface force.

As a result, as shown in Figure 8 shows that the implant is well placed and after 16 days of aging, it shows that the bone has grown. Table 1 shows the result of measuring the force used to remove each implant.

According to the surface treatment, the interface force of the implant-bone changed, and in the case of the hyaluronic acid catechol conjugate, the result was higher than that of the control group. Implants coated with hyaluronic acid catechol conjugates show better results than controls, which means that dental implant fixtures coated with hyaluronic acid catechol conjugates are well implanted without inflammation and the interfacial force between bone and implant is very tight. do.

Table 1 Necessary to remove implants aged for 16 days from the tibia of micro-pig

<Example 6>

Confirmation of stent coating effect of hyaluronic acid catechol conjugate

Hyaluronic acid catechol was dissolved in 0.04 mM in phosphate buffer salin (PBS). Thereafter, catechol and oxidizing agent equivalent 1: 1 are added to NaIO ₄ which is an oxidizing agent. Soak the stent for 18 hours in this coating solution. After a certain time, the stent is taken out, washed with distilled water and dried with nitrogen gas. Experiments were performed using XPS with stent surface analysis coated with hyaluronic acid catechol.

As a result, it was confirmed that the N peak, which was not seen on the untreated stent surface as shown in FIGS. 9 and 10, appeared in the stent coated with the hyaluronic acid catechol conjugate. This indicates that the coating with hyaluronic acid catechol is well done and that the conjugate of the present invention can modify the surface of a device or implant that is used for medical purposes.

&Lt; Example 7 >

Confirmation of Neural Stem Cell Culture Capacity of Hyaluronic Acid Catechol Conjugate

Surface adhesion of neural stem cells on polystyrene coated with hyaluronic acid catechol and glass surface was confirmed. After placing the cells on the surface of 5.0 X 10 ⁵ cells, the state of the cells attached to the surface after 15, 38, and 50 hours, respectively, was checked under a microscope and compared with the state of the cells on the uncoated surface.

As a result, as shown in Fig. 11, it can be observed that the cells that initially aggregated in the form of spheres over time stably adhered to the surface, and as a result of quantifying the number of cells attached to the surface, uncoated It can be seen that the adhesion of neural stem cells increased by five times after coating compared to the surface (see FIG. 12).

In addition to the surface coating in the hydrogel formed with hyaluronic acid catechol neural stem cells were cultured to confirm the survival of the cells. Neural stem cells were mixed with a hyaluronic acid catechol solution at a concentration of 4.0 X 10 ⁵ cells per 300 mL of gel solution, and sodium hydroiodate was added in the same manner as in Example 3 to form a hydrogel. The degree of cell culture in HA-methacrylate hydrogel, which is a commonly used control material, was compared.

As a result, it can be seen that the survival rate of neural stem cells is more prevalent in the hydrogel made of hyaluronic acid catechol as shown in FIG. 13. (Green: Live, Red: Dead) This was quantified and graphed in FIG. 14, but the survival rate was only 40% in HA-methacrylate, but almost all cultured cells were close to 100% in hyaluronic acid catechol. It was found that they survived.

Hyaluronic acid catechol conjugates of the present invention are provided with a technique for modifying the surface of a medical implant and a method for immobilizing a bioactive material. Therefore, the hyaluronic acid catechol conjugate of the present invention can be usefully used for the purpose of a successful medical implant preparation method.

Claims (12)

delete delete delete A composition for surface modification of a medical implant comprising a hyaluronic acid catechol conjugate formed by combining a carboxy group of hyaluronic acid with an amide group of a dopamine as an active ingredient.
The composition of claim 4, wherein the medical implant is selected from the group consisting of implants, stents, artificial joints, and artificial heads.
The method of claim 4, wherein the medical implant is gold (Au), silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), steel (steel), tantalum (Ta), magnesium (Mg) , Nickel (Ni), chromium (Cr), iron (Fe), nitinol alloy (NiTi), cobalt-chromium alloy (CoCr) gallium arsenide (GaAs), titanium (Ti), polytetrafluoroethylene, polycarbonate (polycarbonate), polyurethane, nitrocellulose, polystyrene, polyethylene, polyethylene terephthalate (PET), polydimethylsiloxane (PDMS), polyether ether ketone (PEEK), silicon oxide (SiO ₂ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), and niobium oxide (Nb ₂ O ₅ ) are made of any one material selected from the group consisting of silicon, silicon rubber, and glass. Composition characterized in that the.
The composition of claim 4, wherein the hyaluronic acid catechol conjugate is a compound represented by the following Chemical Formula 1;
[Chemical Formula 1]

Where L is

And K is an integer from 1 to 10, X is each independently H or OH, n is an integer from 2 to 700, m is less than n and is an integer from 1 to 300. delete delete delete delete delete

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