KR100500534B1 - Multifunctional hydroxyapatite/chitosan composite fiber and preparation thereof - Google Patents

Abstract

 The present invention relates to a biocompatible apatite hydroxide / chitosan composite fiber and a method for producing the same, characterized in that prepared by spinning of the apatite hydroxide / chitosan complex, the method is a mixture of polycarboxylic acid in combination with the apatite hydroxide / chitosan complex In this method, biocompatible apatite hydroxide / chitosan composite fibers are prepared using a wet spinning method. According to the method, the toughness, flexibility, and moldability of the apatite / chitosan composite fibers, which have not been spun by conventional methods, can be achieved. It can be used as a textile product such as non-woven fabrics, fabrics, knitted fabrics with excellent biocompatibility and antimicrobial ability because it can produce fibers with excellent specific surface area per unit weight.

Apatite / chitosan composite fiber implants have no side effects on the human body and have excellent mechanical properties such as strength, hardness, elastic modulus, and toughness, so that they can be used as implant composite materials for bone reconstruction in various forms. Due to its excellent heavy metal adsorption capacity and excellent protein adsorption capacity, the apatite hydroxide / chitosan composite fiber can be used as a filter material.

Description

Multifunctional hydroxyapatite / chitosan composite fiber and preparation method thereof

The present invention relates to a biocompatible apatite hydroxide / chitosan composite fiber and a method for producing the same, which are prepared by spinning the hydroxide apatite / chitosan complex.

Apatite hydroxide is a calcium phosphate-based ceramic, which is a major component of human bone, and has excellent bone conductivity, bioactivity, biocompatibility, protein adsorption, heavy metal adsorption, and antibacterial properties. Although it has been used as a filter material, the apatite hydroxide is too hard and brittle, and has a problem in that a molding process is difficult in a specific shape.

Chitosan can be obtained by deacetylating chitin obtained from the shells of shellfish inhabiting the ocean, and its production is 100 billion tons of infinite biological resources per year. It is a natural polymer that is harmless to human body. It is antibacterial, antifungal, biodegradable, It has many functions such as biocompatibility, coagulation, and heavy metal adsorption. Chitosan is mainly used as a heavy metal adsorbent because of one amino group and two hydroxy groups per glucosamine pyranose ring.

Therefore, interest in the development of apatite hydroxide / chitosan composite materials that can compensate for the physical disadvantages of apatite hydroxide is increasing. However, as a conventional manufacturing method, calcium hydroxide, phosphoric acid, chitosan, acetic acid, etc. are added to add apatite hydroxide / chitosan composites. Although the ratio of the apatite hydroxide and chitosan determined in the preparation step was not changed, and the composite prepared once was impossible to be transformed into another form, acetic acid was added to the thus prepared apatite hydroxide / chitosan complex, and it was opaque when dried again. One film could be produced, but the apatite hydroxide particles were not evenly dispersed and were agglomerated so that the spinneret was blocked by the particles in the spinning process, so that spinning was impossible and could not be made into fibers.

Accordingly, the present invention provides a multifunctional apatite hydroxide / chitosan composite fiber and a method for producing the same, which are manufactured by spinning a hydroxide apatite / chitosan composite which can solve all the problems of the prior art as described above. It is a task.

In order to solve the above problems, the present inventors in the prior patent application No. 2002-0041541 dissolves the existing apatite hydroxide / chitosan complex containing the existing apatite hydroxide nanoparticles in polycarboxylic acid to prevent the crystal growth of the hydroxide apatite nanoparticles on the chitosan support As a result, the nanoparticles were not aggregated to maintain an even dispersion state, thereby preparing a biocompatible film using chitosan and apatite having excellent transparency, antibacterial properties, biocompatibility, and physical properties. Furthermore, the present inventors found that the mixture of the chitosan composite and the polycarboxylic acid was wet-sprayed to form a fiber, thereby preparing a hydroxide / chitosan composite fiber having excellent toughness, flexibility, and moldability, and having a specific surface area per unit weight. The present invention has been completed. In addition, the present inventors can manufacture nonwoven fabrics, textiles, knitted fabrics using the apatite hydroxide / chitosan composite fibers, and then produce implants into the fiber products, and also by using the excellent heavy metal adsorption function of apatite hydroxide and chitosan It was found that the filter material for heavy metal and protein removal can be prepared to complete the present invention.

Therefore, according to the present invention, in the preparation of the apatite hydroxide / chitosan composite fiber, a polycarboxylic acid is added to the chitosan composite containing the apatite hydroxide nanoparticles, mixed, and the resulting mixture is wet-spun. A method for producing a composite fiber is provided.

In addition, a multifunctional apatite hydroxide / chitosan composite fiber can be obtained by the above production method.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The apatite hydroxide / chitosan composite fiber of the present invention is composed mainly of apatite hydroxide (Ca ₁₀ (PO ₄ ) ₆ (OH) ₂ ) nanoparticles and chitosan, and the preferred method for preparing the fiber is as follows.

In the present invention, the chitosan solution is prepared by dissolving chitosan in acetic acid solution, and the chitosan solution is mixed with the phosphoric acid solution. When the mixed solution is added dropwise to the calcium hydroxide (Ca (OH) ₂ ) suspension, phosphoric acid and calcium hydroxide react to synthesize apatite. Finally, the obtained apatite hydroxide / chitosan complex was stirred and matured, filtered, washed several times, and concentrated. The weight ratio of apatite hydroxide and chitosan may be adjusted by mixing a chitosan solution in which only chitosan is dissolved in acetic acid solution without drying the apatite hydroxide / chitosan complex.

In the present invention, polycarboxylic acid is added to the apatite hydroxide / chitosan composite prepared as described above with respect to the weight of apatite hydroxide to prepare a spinning stock solution. The spinning stock solution is filtered and degassed and wet-spun under aqueous sodium hydroxide solution through a nozzle. The fiber may be dried to prepare a fiber, and citric acid, butanetetracarboxylic acid, malic acid, and the like may be used as the polycarboxylic acid. The added polycarboxylic acid is ionized on the hydroxide apatite / chitosan complex and the carboxyl group can form an ionic bond with the ionized amino group of chitosan, while at the same time ion exchange of carboxylic acid ions having a higher affinity than phosphate ions for calcium ions on the surface of the apatite hydroxide To maintain the evenly dispersed state of the apatite hydroxide by preventing the crystal growth of the apatite hydroxide nanoparticles in the chitosan solution by combining in at least one of the monodentate or the bidentate method. As the spinning solution is released through the spinneret, the spinneret is not blocked when the fiber is formed, and thus the fiber can be smoothly manufactured. In addition, when the hydroxyapatite / chitosan complex is lyophilized in a slurry state without drying in a general manner, it may be prepared in a fine powder form, so that the complex is more easily dissolved in an aqueous polycarboxylic acid solution, thereby facilitating the manufacturing process of the spinning solution. The fineness and physical properties of the fiber produced can be excellent and the fiber can be produced under good spinning conditions.

In the present invention, it is possible to spun yarn with the prepared fiber and to manufacture a woven or knitted fabric, and to make a non-woven fabric by making the web using the fiber as it is. In addition, implants made of textile products such as woven or non-woven fabrics made of the hydroxide apatite / chitosan composite fibers are Na ⁺ , Cl ^-, HCO ₃ ^-, K ^+, When a bottle containing a simulated body fluid having a composition and ion concentration such as Mg ²⁺ , Ca ²⁺ , and HPO 4 ^2- is treated at about 37 ° C. for a certain time, the apatite hydroxide is apatite hydroxide / chitosan composite fiber. Implants coated on the surface can be prepared.

When implants made of textile products such as knitted fabrics or non-woven fabrics made of the apatite hydroxide / chitosan composite fiber are implanted into the patient's body, chitosan is dissolved in body fluids in the human body, and eventually, such as bones of the human body. Only the hydroxyapatite fibrous tissue, which is a component, remains, and these tissues have numerous pores, which have the effect of improving the speed and efficiency of bone regeneration in the human body, and the chitosan decomposed in the body also has the function of promoting bone regeneration. Has the effect of increasing the treatment recovery rate and treatment rate.

In addition, the apatite hydroxide / chitosan composite fiber obtained by the present invention has an excellent heavy metal adsorption function, which is capable of adsorbing heavy metals such as Fe ³⁺ , Pb ²⁺ and Cd ²⁺ onto the surface of the composite fiber as well as adsorbing protein components. do. By using these properties, it is possible to prepare a filter material for removing heavy metals and proteins using apatite hydroxide / chitosan composite fibers or yarns, textiles, knitted fabrics, and nonwoven fabrics made of the composite fibers.

As shown in FIG. 1, when the weight ratio of apatite hydroxide and chitosan is 30/70, it can be seen that a large amount of apatite hydroxide particles are uniformly applied to the fiber surface. In FIG. 4, the apatite hydroxide particles are spread over the fiber surface. It can be seen that it is evenly distributed and has a large amount of fine pores.

Figure 4 is a curve graph drawn using a thermogravimetric analysis (TGA, TA Instruments 2050) to determine the content ratio and thermal properties of the apatite hydroxide / chitosan composite fiber (a) general chitosan fiber (b) 10: The curve graph of 90-apatite hydroxide / chitosan fiber, (c) 20:80 hydroxide apatite / chitosan fiber, and (d) 30:70 hydroxide apatite / chitosan fiber is shown. Weight loss occurs due to evaporation of water to around 130 ℃, and rapid weight loss occurs due to pyrolysis of chitosan around 250 ℃ ~ 400 ℃. The temperature at which pyrolysis occurs rapidly is around 320 ℃, regardless of the apatite hydroxide content. As the temperature increases gradually, the apatite hydroxide / chitosan composite fiber continuously shows a moderate weight loss, but the chitosan fiber, which is an organic polymer, shows a rapid weight loss after 600 ° C. There was little residual amount of chitosan in the fiber after the final sintering process, and the residual amount of apatite hydroxide increased as the content of apatite hydroxide in the fiber increased. Apatite hydroxide is a ceramic made of inorganic material, and pyrolysis does not occur at high temperature above 1,000 ℃, whereas chitosan, an organic polymer, pyrolysis occurs at high temperature, so the result of pyrolysis by sintering of apatite hydroxide / chitosan composite fiber is applied to the inside of chitosan fiber. It can be confirmed that the apatite hydroxide particles are stably present.

5 is a graph of the X-ray diffractogram of the apatite hydroxide / chitosan composite fiber (a) general chitosan fiber (b) 10:90 apatite hydroxide / chitosan fiber, (c) 20:80 hydroxide apatite / chitosan (D) X-ray diffraction pattern of 30:70 hydroxide apatite / chitosan fiber, 10:90 apatite / chitosan composite fiber showed no characteristic peak of apatite hydroxide, but (020) It can be seen that the crystal surface peak was significantly decreased, and the (040) crystal surface peak near 20 ° was decreased. In addition, as the content of apatite hydroxide increases, the peak near 20 ° by the chitosan gradually decreases, but the (002) crystal surface peak near 26 ° due to the apatite hydroxide particles contained in the apatite hydroxide / chitosan composite fiber appears and near 32 °. It can be seen that the peaks of apatite hydroxide on the (300), (211) and (112) crystal surfaces are increased. Therefore, it can be seen that a material having a crystal structure such as apatite hydroxide exists.

Hereinafter, the present invention will be described in detail through Examples and Comparative Examples to be described below, but the present invention is not limited to the following Examples.

Example 1

 After dissolving 62.5 g of chitosan in 2263 ml of 2% acetic acid aqueous solution, 37.5 g of 80:20 apatite hydroxide / chitosan complex and 11 g of citric acid were added to the chitosan solution to prepare a spinning solution having a weight ratio of apatite hydroxide and chitosan of 30:70. It was. Chitosan content in the spinning stock was maintained at 3% (w / w). The prepared hydroxyapatite / chitosan composite spinning solution was filtered and degassed and spun in 10% aqueous sodium hydroxide solution at 0.1 mm × 300 nozzles. The wet-spun fibers were washed with water and dried to prepare apatite hydroxide / chitosan composite fibers.

Example 2

Apatite hydroxide / chitosan composite fibers were prepared in the same manner as in Example 1 except that the spinning stock solution was prepared using a weight ratio of apatite hydroxide to chitosan at 20:80.

Example 3

Apatite hydroxide / chitosan composite fibers were prepared in the same manner as in Example 1, except that a spinning stock solution was prepared using a weight ratio of apatite hydroxide to chitosan at 10:90.

Table 1 shows the physical properties of the apatite hydroxide / chitosan composite fibers prepared in Examples 1 to 3. In order to determine the content ratio and thermal properties of the apatite hydroxide / chitosan composite fiber, a thermogravimetric analysis (TGA, TA Instruments 2050) was used to measure the temperature from 20 ℃ / min to 30 ℃ to 1000 ℃ under a nitrogen stream. It is shown by the curve graph of FIG.

In addition, 0.1 g of apatite / chitosan composite fiber of 10:90, 20:80, and 30:70 of the weight ratios of Examples 1,2 and 3 and chitosan fiber of the comparative example were 50 ml of Pb ²⁺ and Cd ²⁺ aqueous solutions of 100 ppm ion concentration, respectively. After immersion for 1 hour in the inductive pair plasma analyzer (ICP-AES) to measure the residual metal ion concentration, the heavy metal removal rate of the apatite hydroxide / chitosan composite fiber was measured and shown in Table 2.

Example 4

After producing a nonwoven fabric as a hydroxide apatite / chitosan composite fiber and manufacture of implants of a type ^{Na + 142.0, Cl - 147.8,} HCO 3 - 4.2, K + 5.0, Mg 2+ 1.5, Ca 2+ 2.5, HPO 4 2- a surface of 1.0, SO ₄ ^2- 0.5 composition and ion concentration dipping physiological saline solution to a transparent polyethylene bottle containing the (simulated body fluid) having at 37 ℃ taken out after 14 days, such as molded articles were prepared by coating the implant with apatite hydroxide .

Comparative Example 1

Chitosan fibers were prepared in the same manner as in Example 1 except for preparing a spinning stock solution containing pure chitosan without mixing hydroxide apatite.

Hydroxyapatite Content (%) Intensity (g / d) % Elongation Island degree (denier) Example 1 30 0.86 19.1 3.76 Example 2 20 0.96 20.7 3.42 Example 3 10 1.48 20.8 2.62 Comparative example 0 1.72 17.4 2.14

* Table 1 shows the strength, elongation, and fineness of the hydroxide apatite / chitosan composite fiber containing 10, 20, and 30% of apatite hydroxide. As the amount of apatite hydroxide increased, the strength gradually decreased, and the change in elongation was not large, and the fineness gradually increased. Since the chitosan content of the spinning stock solution was fixed at 3% and the content of apatite hydroxide was increased, the thickness of the fiber increased as the content of apatite hydroxide was increased. Therefore, the decrease in strength due to the increase in the content of apatite hydroxide is because the relatively large amount of apatite hydroxide is present in the form of particles in the fiber state, the hydrogen bond between chitosan molecules is reduced and the apatite hydroxide particles are weak as the content of the apatite hydroxide is increased. It seems to work.

Pb ²⁺ Cd ²⁺ Example 1 99.9 99.7 Example 2 97.4 95.3 Example 3 94.2 92.9 Comparative example 47.0 22.2

* Table 2 shows the heavy metals Pb ²⁺ and Cd ²⁺ of the apatite hydroxide / chitosan composite fiber and chitosan fiber. The removal rate is shown. Compared to the fiber consisting of chitosan only, the hydroxide apatite / chitosan composite fiber shows a remarkably excellent heavy metal removal rate, and thus can be usefully used as a filter material for removing heavy metals and proteins.

As described above, according to the present invention, by dissolving the apatite hydroxide / chitosan complex, which could not be made into fibers due to the blockage of the spinneret, with polycarboxylic acid, it was possible to uniformly spin the fiber without the blockage of the spinneret. The hydroxide apatite / chitosan composite fiber produced according to the present invention has excellent toughness, flexibility, and moldability, and has a specific surface area per unit weight, and thus can be used as a textile product such as nonwoven fabric, woven fabric, and knitted fabric with excellent biocompatibility and heavy metal adsorption. The implant can be obtained with the nonwoven fabric, fabric, and knitted fabric. This implant has no side effects on the human body and can be used as an implant composite material for bone reconstruction having various mechanical properties such as strength, hardness, elastic modulus, and toughness. In addition, when the implant made of the nonwoven fabric, woven fabric, knitted fabric, etc. is treated in an ionic composition similar to the body fluid, it is possible to obtain a molded article coated with apatite hydroxide.

When the molded article made of the hydroxide apatite / chitosan composite fiber is made into a bone-like form and transplanted into the patient's body, chitosan is dissolved in the body fluids in the human body, and eventually only the hydroxide apatite fiber tissue, which is a component such as human bone, is left. Tissue has a number of fine pores, which has the effect of improving the bone regeneration rate and efficiency of the human body, and chitosan dissolved in the body also has the function of promoting bone regeneration, thereby improving the recovery rate and treatment rate of patients. Have In addition, it can be used as a filter material that can remove proteins, including heavy metals and microorganisms by industrially making the fiber with chitosan by using the excellent heavy metal adsorption capacity of apatite hydroxide.

1 is a scanning electron micrograph of a biocompatible fiber using the biocompatible apatite hydroxide / chitosan composite fiber (30/70).

Fig. 2 is a scanning electron micrograph of biocompatible fibers using biocompatible apatite hydroxide / chitosan composite fibers (10/90).

Fig. 3 is a scanning electron micrograph of biocompatible fibers using biocompatible apatite hydroxide / chitosan composite fibers (20/80).

4 is a curve graph drawn using a thermogravimetric analysis (TGA, TA Instruments 2050) to determine the content ratio and thermal properties of biocompatible apatite hydroxide / chitosan composite fibers.

5 is a graph of an X-ray diffractogram of a biocompatible apatite hydroxide / chitosan composite fiber.

Claims (5)

In preparing the apatite hydroxide / chitosan composite fiber, A method for producing a multifunctional apatite hydroxide / chitosan composite fiber, comprising adding polycarboxylic acid to a chitosan composite containing apatite hydroxide nanoparticles, mixing the mixture, and wet spinning the obtained mixture. The multifunctional apatite hydroxide / chitosan composite fiber manufactured by the manufacturing method of the multifunctional apatite hydroxide / chitosan composite fiber of Claim 1. 2. A textile product using the multifunctional apatite hydroxide / chitosan composite fiber of claim 2. An implant made from the fiber product of claim 3. A heavy metal and protein remover using the fiber product of claim 3.