Micron-sized gelatin-hydroxyapatite composite fiber material and preparation method thereof

Abstract

The invention discloses a micron-sized gelatin-hydroxyapatite composite fiber material and a preparation method thereof. The preparation method comprises the following steps: (a) dissolving or dispersing gelatin in a volatile acid solution to obtain a gelatin solution; adding a cross-linking agent into the gelatin solution for in-situ cross-linking, and then adding hydroxyapatite nanoparticles for dispersion to obtain a mixed solution; the mass ratio of the hydroxyapatite nano particles to the gelatin is 0.30 to 1.50; (b) performing centrifugal spinning on the mixed solution, and drying to obtain a gelatin-hydroxyapatite composite fiber precursor; and (c) carrying out secondary crosslinking treatment on the gelatin-hydroxyapatite composite fiber precursor to obtain the gelatin-hydroxyapatite composite fiber material. The interference of HA particles on an electric field can be avoided, the uniformity of fibers is ensured, the production efficiency is higher, and the method is suitable for large-scale industrial production; by optimizing the formula of the mixed solution, the bone conduction performance of the composite fiber is effectively enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomaterials, relates to a composite fiber, and particularly relates to a micron-scale gelatin-hydroxyapatite composite fiber material and a preparation method thereof. Background Art

[0002] The repair of bone tissue has always been a research hotspot in the medical field. The components of bone include organic matter (mainly collagen) and inorganic matter (mainly hydroxyapatite). As a denatured product of collagen, gelatin inherits some excellent properties of collagen, has excellent biocompatibility, can be well compatible with human tissues, and reduces the immune rejection reaction; at the same time, it has biodegradability and can be gradually decomposed and metabolized in the human body, avoiding the potential risks brought by long-term implantation; its low immunogenicity further ensures its safety in the human body; its bioadhesiveness enables it to better combine with bone tissue and surrounding tissues, promoting the repair process; in addition, gelatin also has significant cost-effectiveness and has more economic advantages in large-scale production applications, and is widely used in the biomedical field. Hydroxyapatite (HA) has attracted much attention in the field of bone repair materials due to its unique biological properties. It has excellent biocompatibility and can form a good interfacial bond with bone tissue; its slow degradation property enables it to continuously play a role in the bone repair process and provide stable support for the growth of new bone tissue; its osteoconductivity can guide the growth and migration of bone cells and promote the regeneration of bone tissue; its bone integration ability helps the new bone to tightly combine with the implant material and improve the repair effect; therefore, it is widely used in the preparation of bone repair materials.

[0003] However, when gelatin or hydroxyapatite is used alone as a bone repair material, there are certain limitations. The mechanical properties of gelatin are relatively weak and it is difficult to bear the mechanical load alone during the bone repair process; while hydroxyapatite has good biological activity, but its processing performance is poor and it is difficult to be prepared into an ideal implant shape. Therefore, it is of great research significance and application value to composite the two to prepare a new type of bone repair material.

[0004] At present, there are two main methods for combining gelatin fibers with hydroxyapatite: (1) Mineralization deposition on gelatin fibers; (2) Adding hydroxyapatite to the spinning solution in advance for co - spinning. Although the method of mineralization deposition can achieve the combination of gelatin fibers and hydroxyapatite, there are many problems in practical applications: the mineralized layer may be discontinuous, which will affect the uniformity and overall performance of the material; in addition, the process cycle of this method is relatively long, increasing the production cost and time cost; more critically, the mineralization deposition process may have an adverse impact on the overall structural stability of the fibers, thus reducing the mechanical properties and biological properties of the material, restricting its application in the field of bone repair and other fields. The co - spinning of gelatin and hydroxyapatite is mainly achieved through electrospinning technology, and electrospinning relies on a high - voltage electric field to stretch the solution to form fine filaments. However, when the mass percentage content of hydroxyapatite nanoparticles is too high, the presence of hydroxyapatite nanoparticles will interfere with the uniform action of the electric field, resulting in uneven charge distribution during the spinning process. This uneven charge distribution will further affect the fiber forming effect, making the fiber diameter distribution uneven, and even causing problems such as fiber breakage, thus reducing the quality and performance of the material.

[0005] The Chinese invention patent with the application number 202510257451.1 discloses a polymer nanofiber and its preparation method and application. The raw materials for preparing this polymer nanofiber include gelatin, a cross - linker, a nano - reinforcing phase (including nano - hydroxyapatite), and a solvent. However, in this application, the mass ratio of gelatin to the nano - reinforcing phase is preferably (10~60):1, which means that the content of the nano - reinforcing phase is relatively low. The low content of the nano - reinforcing phase results in poor osteoconductive properties of the material, making it difficult to meet the high requirements of bone repair materials for osteoconductivity and restricting its application effect in bone tissue engineering. Summary of the Invention

[0006] The purpose of the present invention is to provide a preparation method of a micron - scale gelatin - hydroxyapatite composite fiber material to overcome the deficiencies of the prior art.

[0007] To achieve the above - mentioned purpose, the technical solution adopted by the present invention is: A preparation method of a micron - scale gelatin - hydroxyapatite composite fiber material, comprising the following steps: (a) Dissolve or disperse gelatin in a volatile acid solution to obtain a gelatin solution; add a cross - linker to the gelatin solution for in - situ cross - linking, and then add hydroxyapatite nanoparticles for dispersion to obtain a mixed solution; the mass ratio of the hydroxyapatite nanoparticles to the gelatin is 0.30~1.50; (b) Centrifugally spin and dry the mixed solution to obtain a gelatin - hydroxyapatite composite fiber precursor; (c) Subject the gelatin-hydroxyapatite composite fiber precursor to a secondary cross-linking treatment to obtain a gelatin-hydroxyapatite composite fiber material.

[0008] Optimally, in step (a), the volatile acid solution is a mixed solution of a volatile acid and water, and the volatile acid is one or a mixed acid selected from formic acid and acetic acid; the mass or volume concentration of the volatile acid in the volatile acid solution is 30% - 80%.

[0009] Further, in step (a), the mass ratio of the gelatin to the volatile acid solution is 1:2 - 4, and the swelling temperature of the gelatin in the volatile acid solution is 40 - 60 °C and the swelling time is 1 - 3 h.

[0010] Furthermore, in step (a), the cross-linking agent is a mixture of one selected from 1-ethyl-(3-dimethylaminopropyl)carbodiimide, 1-cyclohexyl-3-(2-morpholinoethyl)carbodiimide, and N,N'-dicyclohexylcarbodiimide and N-hydroxysuccinimide in a mass ratio of 1:0.25 - 2, the mass ratio of the cross-linking agent to the gelatin is 0.2 - 2:100, and the in-situ cross-linking temperature is 20 - 40 °C and the time is 5 - 20 min.

[0011] Optimally, in step (b), the mixed solution is added to the spinning turntable of a centrifugal spinning machine through an injection pump, and is centrifugally spun onto a surrounding collection device to volatilize the volatile acid solution; the spinning turntable has a plurality of spinneret holes with a diameter of 200 - 1200 μm; the rotation speed of the spinning turntable is 6000 - 20000 rpm, and the collection distance between the spinning turntable and the receiving device is 10 - 30 cm.

[0012] Further, in step (b), the drying is carried out in an oven at 30 - 60 °C for a drying time of 6 - 48 h.

[0013] Optimally, in step (c), the secondary cross-linking treatment is dehydration thermal cross-linking, and the temperature of the dehydration thermal cross-linking is 100 - 160 °C and the cross-linking time is 1 - 8 h.

[0014] Another object of the present invention is to provide a micron-scale gelatin-hydroxyapatite composite fiber material, which is prepared by the above preparation method.

[0015] Optimally, the diameter of the gelatin-hydroxyapatite composite fiber material is 5 μm - 40 μm.

[0016] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: In the preparation method of the micron-scale gelatin-hydroxyapatite composite fiber material of the present invention, HA nanoparticles are directly added to obtain a mixed solution for centrifugal spinning, avoiding the complex post-mineralization process and simplifying the preparation process; at the same time, it can avoid the interference of HA particles on the electric field, ensure the uniformity of the fibers, have higher production efficiency, and is suitable for large-scale industrial production; by optimizing the formula of the mixed solution, a high HA mass percentage is successfully achieved, effectively enhancing the osteoconductive performance of the composite fibers; through subsequent physical cross-linking treatment, the mechanical strength, water stability and biodegradability of the composite fibers are enhanced, making them more suitable for long-term use in bone repair and tissue engineering scaffolds applications.

[0017] The micron-scale gelatin-hydroxyapatite composite fiber material of the present invention has the following remarkable advantages: Unique fiber structure: The fiber structure endows the material with excellent compression and shaping properties. During actual use, doctors can easily compress and shape the material according to the specific shape and size of the bone defect of the patient, making it perfectly fit the bone defect site, greatly improving the applicability and operation convenience of the material. Compared with traditional block or granular bone repair materials, this fiber structure has stronger plasticity and can better adapt to complex bone defect morphologies, reducing the situation of poor repair effects caused by mismatched material shapes.

[0018] Excellent mixing performance: The fiber material can be conveniently mixed with bone fragments, blood, etc. before use. Bone fragments can provide induction signals of autologous bone tissue for bone repair and promote the regeneration of bone tissue; blood contains rich growth factors and nutrients, which helps to accelerate the bone repair process. Moreover, the fiber structure enables the fiber material to be mixed with these components more evenly and fully, and can better play a synergistic role, creating a more ideal microenvironment for bone tissue repair.

[0019] Controllable pore structure: By appropriately compressing the fiber material, its pore structure can be precisely controlled. The pore structure is crucial for bone repair materials. Appropriate porosity and pore connectivity can promote cell adhesion, proliferation and migration, providing channels for the growth of new bone tissue. The fiber material of the present invention can flexibly adjust the pore structure according to different bone repair requirements, thus better meeting the requirements of bone tissue regeneration and improving the bone repair effect.

[0020] Comprehensive performance improvement: The combination of gelatin and hydroxyapatite not only retains the respective excellent properties of both, but also produces a synergistic effect. The biocompatibility, biodegradability, low immunogenicity, and bioadhesion of gelatin provide a better biological environment for hydroxyapatite, enabling it to better exert its osteoconductivity and bone integration ability. Hydroxyapatite, on the other hand, enhances the mechanical properties of gelatin, improving the compressive strength and stability of the material. This combination enables the material to better withstand physiological loads during the bone repair process, while promoting the regeneration and repair of bone tissue, achieving a perfect balance between biological properties and mechanical properties. Brief Description of the Drawings

[0021] Figure 1 Scanning electron microscope image of the micron-scale gelatin-hydroxyapatite composite fiber material of the present invention (Example 1); Figure 2 EDS scanning image of the micron-scale gelatin-hydroxyapatite composite fiber material of the present invention (Example 1); Figure 3 Scanning electron microscope image of the micron-scale gelatin-hydroxyapatite composite fiber material of the present invention (Example 2); Figure 4 EDS scanning image of the micron-scale gelatin-hydroxyapatite composite fiber material of the present invention (Example 2); Figure 5 Scanning electron microscope image of the micron-scale gelatin-hydroxyapatite composite fiber material of the present invention (Example 3); Figure 6 EDS scanning image of the micron-scale gelatin-hydroxyapatite composite fiber material of the present invention (Example 3); Figure 7 Combined graph of the tensile modulus and elongation at break of the micron-scale gelatin-hydroxyapatite composite fiber material of the present invention; Figure 8 Column graph of the water absorption rate of the micron-scale gelatin-hydroxyapatite composite fiber material of the present invention. Detailed Description of the Invention

[0022] The preparation method of the micro-scale gelatin-hydroxyapatite composite fiber material of the present invention comprises the following steps: (a) dissolving or dispersing gelatin in a volatile acid solution to obtain a gelatin solution; adding a cross-linking agent to the gelatin solution for in-situ cross-linking, and then adding hydroxyapatite (HA) nanoparticles for dispersion to obtain a mixed solution; the mass ratio of the hydroxyapatite nanoparticles to the gelatin is 0.30 to 1.50 (this mass ratio can be any value within the aforementioned range, such as 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 1.0, 1.1, 1.2, 1.3, 1.4, and 1.5, etc.; the same applies to all numerical ranges mentioned below, preferably 0.5 to 1.0, more preferably 0.6 to 1.0); (b) subjecting the mixed solution to centrifugal spinning and drying to obtain a gelatin-hydroxyapatite composite fiber precursor; (c) subjecting the gelatin-hydroxyapatite composite fiber precursor to secondary cross-linking treatment to obtain a gelatin-hydroxyapatite composite fiber material. Directly adding HA nanoparticles to obtain a mixed solution for centrifugal spinning avoids the complex later mineralization process and simplifies the preparation process; at the same time, it can avoid the interference of HA particles on the electric field, ensure the uniformity of the fibers, has higher production efficiency, and is suitable for large-scale industrial production; by optimizing the formulation of the mixed solution, a high HA mass percentage is successfully achieved, effectively enhancing the osteoconduction performance of the composite fibers; through subsequent physical cross-linking treatment, the mechanical strength, water stability, and biodegradability of the composite fibers are enhanced, making them more suitable for long-term use in bone repair and tissue engineering scaffold applications.

[0023] In step (a), the volatile acid solution is a mixed solution of a volatile acid and water. The volatile acid is one or a mixed acid selected from formic acid and acetic acid, preferably acetic acid. The mass or volume concentration of the volatile acid in the volatile acid solution is 30% - 80% (preferably 50% - 60%). In step (a), the mass ratio of the gelatin to the volatile acid solution is 1:2 - 4, preferably 1:2.5 - 3. The swelling temperature of the gelatin in the volatile acid solution is 40 - 60°C (preferably 45 - 55°C), and the swelling is by stirring swelling for 1 - 3 hours. In step (a), the crosslinking agent is a mixture of one selected from 1-ethyl-(3-dimethylaminopropyl)carbodiimide, 1-cyclohexyl-3-(2-morpholinoethyl)carbodiimide, and N,N'-dicyclohexylcarbodiimide and N-hydroxysuccinimide in a mass ratio of 1:0.25 - 2, that is, the crosslinking agent is one of the following combinations: 1-ethyl-(3-dimethylaminopropyl)carbodiimide / N-hydroxysuccinimide (EDC / NHS), 1-cyclohexyl-3-(2-morpholinoethyl)carbodiimide (CMC / NHS), N,N'-dicyclohexylcarbodiimide (DCC / NHS), or a mixed acid, preferably the EDC / NHS combination. The mass ratio of the crosslinking agent to the gelatin is 0.2 - 2:100, and the temperature of the in-situ crosslinking is 20 - 40°C and the time is 5 - 20 minutes.

[0024] In step (b), the mixed solution is added to the spinning turntable of a centrifugal spinning machine through an injection pump, and is centrifugally spun onto a surrounding collecting device to volatilize the volatile acid solution. The spinning turntable has a plurality of spinneret holes with a diameter of 200 - 1200 μm (preferably 600 - 800 μm). The rotation speed of the spinning turntable is 6000 - 20000 rpm (preferably 12000 - 15000 rpm), and the collecting distance between the spinning turntable and the receiving device is 10 - 30 cm (preferably 12 - 20 cm). In step (b), the drying is carried out in an oven at 30 - 60°C for a drying time of 6 - 48 hours, preferably at 40 - 50°C and drying for 12 - 24 hours.

[0025] In step (c), the secondary crosslinking treatment is dehydration thermal crosslinking. The temperature of the dehydration thermal crosslinking is 100 - 160°C and the crosslinking time is 1 - 8 hours; preferably, the dehydration thermal crosslinking temperature is 120 - 140°C and the crosslinking time is 2 - 6 hours.

[0026] The micron-sized gelatin-hydroxyapatite composite fiber material of the present invention is prepared by the above preparation method. The diameter of the micron-sized gelatin-hydroxyapatite composite fiber material is 5 μm - 40 μm.

[0027] The preferred embodiments of the present invention will be described in detail below.

[0028] The foregoing and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front or rear, etc., are only with reference to the directions of the accompanying drawings. Therefore, the directional terms used are for illustration and not for limiting the present invention.

[0029] The following will detail the embodiments of the present invention and use the accompanying drawings as examples. In addition to these detailed descriptions, the present invention can also be widely implemented in other embodiments. Any easy substitution, modification, and equivalent change of any of the described embodiments are included in the scope of the present invention and are subject to the scope of the patent application. In the description of the specification, in order to enable readers to have a more complete understanding of the present invention, many specific details are provided; however, the present invention may still be implemented on the premise of omitting some or all of the specific details. In addition, well-known steps or components are not described in detail to avoid unnecessary limitations on the present invention. The same or similar components in the drawings will be represented by the same or similar symbols. It should be particularly noted that the drawings are only for illustration and do not represent the actual size or quantity of the components. Some details may not be fully drawn to make the drawings concise.

[0030] Example 1 This example provides a preparation method and the preparation method of a micron-scale gelatin-hydroxyapatite composite fiber material, which are as follows: (a) Weigh 20 g of gelatin and add it to a beaker containing a mixed solution of 30 mL of acetic acid and 20 mL of water (about 50 g). Magnetically stir (300 r / min) in a water bath at 50 °C for 2 h to obtain a gelatin solution; add 0.2 g of EDC and 0.1 g of NHS to the gelatin solution, and stir at a speed of 300 r / min in a water bath at 30 °C for 10 min; then add 12.5 g of hydroxyapatite (needle-shaped, purity 96%, particle size 60 nm, Adamas), and magnetically stir (300 r / min) in a water bath at 30 °C for 10 min and ultrasonically disperse (ultrasonic frequency is 35 kHz) to obtain a mixed solution (i.e., mineralized gelatin spinning stock solution); (b) Add the mineralized gelatin spinning stock solution to the spinning turntable of a centrifugal spinning machine at a speed of 40 mL / h through an injection pump (there are 6 evenly distributed 800-μm spinneret holes around the spinning turntable, and the diameter of the spinning turntable is 8 cm). Start the rotating motor to make the spinning turntable rotate at a speed of 15000 r / min. The mineralized gelatin spinning stock solution is thrown out through the spinneret holes by the centrifugal force of high-speed rotation onto a collecting device with a distance of 15 cm from the spinning turntable, and the solvent is volatilized by the high-speed flowing air in the centrifugal spinning machine; Take the product off the collecting device and put it into a blast drying oven with a temperature set at 40 °C and dry for 18 h to obtain a gelatin-hydroxyapatite composite fiber precursor; (c) Place the gelatin-hydroxyapatite composite fiber precursor in a vacuum drying oven, evacuate the air and heat it to 140 °C, and perform dehydration and thermal cross-linking for 4 h to obtain the final micron-sized gelatin-hydroxyapatite composite fiber material (denoted as Group 1). The scanning electron microscope scan and EDS scan of the finally obtained micron-sized gelatin-hydroxyapatite composite fiber material are shown in Figure 1 and Figure 2 as shown.

[0031] Example 2 This example provides a method for preparing a micron-sized gelatin-hydroxyapatite composite fiber material, which is basically the same as that in Example 1, except that: 17.5 g of gelatin is added in step (a), and the test results are shown in Figure 3 and Figure 4 , and it is denoted as Group 2.

[0032] Example 3 This example provides a method for preparing a micron-sized gelatin-hydroxyapatite composite fiber material, which is basically the same as that in Example 2, except that: 17.5 g of hydroxyapatite is added in step (a), and the test results are shown in Figure 5 and Figure 6 , and it is denoted as Group 3.

[0033] Comparative Example 1 This example provides a gelatin-hydroxyapatite composite fiber material and its preparation method, which is basically the same as that in Example 1, except that: 6 g of hydroxyapatite is added in step (a).

[0034] Comparative Example 2 This example provides a gelatin-hydroxyapatite composite fiber material and its preparation method, which is basically the same as that in Example 1, except that: 35 g of hydroxyapatite is added in step (a). At this time, the viscosity of the mixed solution is too high, and it is impossible to extrude and spin smoothly.

[0035] Comparative Example 3 This example provides a method for preparing a gelatin-hydroxyapatite composite fiber material, which is basically the same as that in Example 1, except that: 12.5 g of gelatin is weighed and added to a beaker containing a mixed solution of 20 mL of acetic acid and 30 mL of water; 12.5 g of hydroxyapatite is added to the gelatin solution. At this time, the gelatin concentration is too low, and the spun fibers cannot be effectively entangled and cannot be effectively collected.

[0036] Comparative Example 4 This example provides a gelatin-hydroxyapatite composite fiber material and its preparation method, which is basically the same as that in Example 1, except that: step (c) is not carried out, resulting in poor water resistance of the obtained gelatin-hydroxyapatite composite fiber material, and dissolution occurs during the water absorption test, and the structural integrity cannot be maintained.

[0037] Comparative Example 5 This example provides a gelatin-hydroxyapatite composite fiber material and its preparation method, which is basically the same as that in Example 1, except that: in step (a), a non-volatile acid (citric acid) is used instead of acetic acid, resulting in a higher solution viscosity and poorer volatility, and it is difficult for the solution to be ejected from the spinning disc during the spinning process, and the ejected part of the solution cannot be volatilized in time to form fibers.

[0038] Mechanical property test: Cut the gelatin-hydroxyapatite composite fiber materials prepared by centrifugal spinning in Examples 1-3 into samples of 25×15×1 mm 3 and then use a universal testing machine to conduct a tensile modulus test at a tensile rate of 20 mm / min. The test results of the tensile modulus and elongation at break are as Figure 7 shown.

[0039] Water absorption property test: Cut the gelatin-hydroxyapatite composite fiber materials prepared by centrifugal spinning in Examples 1-3 into several samples of 2×2 cm 2 and dry them to constant weight in a 40 °C forced-air oven. Weigh m1 and then put them into 100 mL of distilled water. After they are fully swollen, take them out and dry the water on the surface of the fibers with filter paper and then weigh m2. The determination of the water absorption rate is repeated 3 times and the average value is taken, where: water absorption rate / % = (m2 - m1) / m1. Calculate the water absorption rate of each group of gelatin-hydroxyapatite composite fiber materials and plot it in the Figure 8 bar chart.

[0040] The above examples are only for explaining the technical concept and characteristics of the present invention, and their purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly, and it cannot be used to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A preparation method of a micron-scale gelatin-hydroxyapatite composite fiber material, characterized in that, It includes the following steps: (a) Dissolve or disperse gelatin in a volatile acid solution to obtain a gelatin solution; Add a crosslinking agent to the gelatin solution for in-situ crosslinking, and then add hydroxyapatite nanoparticles for dispersion to obtain a mixed solution; the mass ratio of the hydroxyapatite nanoparticles to the gelatin is 0.30 - 1.50; (b) Subject the mixed solution to centrifugal spinning and drying to obtain a gelatin-hydroxyapatite composite fiber precursor; (c) Subject the gelatin-hydroxyapatite composite fiber precursor to a secondary crosslinking treatment to obtain a gelatin-hydroxyapatite composite fiber material.

2. The preparation method of the micron-scale gelatin-hydroxyapatite composite fiber material according to claim 1, characterized in that: In step (a), the volatile acid solution is a mixed solution of a volatile acid and water, and the volatile acid is one or a mixed acid selected from formic acid and acetic acid; the mass or volume concentration of the volatile acid in the volatile acid solution is 30% - 80%.

3. The preparation method of the micron-sized gelatin-hydroxyapatite composite fiber material according to claim 2, characterized in that: In step (a), the mass ratio of the gelatin to the volatile acid solution is 1:2 - 4, the swelling temperature of the gelatin in the volatile acid solution is 40 - 60°C, and the swelling time is 1 - 3 h.

4. The preparation method of the micron-scale gelatin-hydroxyapatite composite fiber material according to claim 3, characterized in that: In step (a), the crosslinking agent is a mixture of one selected from 1-ethyl-(3-dimethylaminopropyl)carbodiimide, 1-cyclohexyl-3-(2-morpholinoethyl)carbodiimide, and N,N'-dicyclohexylcarbodiimide and N-hydroxysuccinimide in a mass ratio of 1:0.25 - 2, the mass ratio of the crosslinking agent to the gelatin is 0.2 - 2:100, the temperature of the in-situ crosslinking is 20 - 40°C, and the time is 5 - 20 min.

5. The preparation method of the micron-scale gelatin-hydroxyapatite composite fiber material according to claim 1, wherein: In step (b), add the mixed solution to the spinning turntable of a centrifugal spinning machine through an injection pump, and carry out centrifugal spinning onto a surrounding collecting device to volatilize the volatile acid solution; The spinning turntable has a plurality of spinneret holes with a diameter of 200 - 1200 μm; the rotation speed of the spinning turntable is 6000 - 20000 rpm, and the collecting distance between the spinning turntable and the receiving device is 10 - 30 cm.

6. The preparation method of the micron-scale gelatin-hydroxyapatite composite fiber material according to claim 5, characterized in that: In step (b), the drying is carried out in an oven at 30 - 60°C for a drying time of 6 - 48 h.

7. The preparation method of the micron-sized gelatin-hydroxyapatite composite fiber material according to claim 1, characterized in that: In step (c), the secondary crosslinking treatment is dehydration thermal crosslinking, the temperature of the dehydration thermal crosslinking is 100 - 160°C, and the crosslinking time is 1 - 8 h.

8. A micron-scale gelatin-hydroxyapatite composite fiber material, characterized in that: It is prepared by the preparation method described in any one of claims 1 to 7.

9. The micron-sized gelatin-hydroxyapatite composite fiber material according to claim 8, characterized in that: The diameter of the micron-scale gelatin-hydroxyapatite composite fiber material is 5 μm - 40 μm.

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