Silk in vivo implant material for bone tissue repair and preparation method thereof
By preparing in vivo implantable materials from silkworm cocoons through degumming and concentration of silk fibroin solution, the problem of mismatch between mechanical strength and degradation rate of existing bone repair materials is solved, realizing the preparation of efficient and low-cost bone tissue repair materials with excellent mechanical properties and biocompatibility.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XI'AN POLYTECHNIC UNIVERSITY
- Filing Date
- 2026-04-03
- Publication Date
- 2026-06-26
AI Technical Summary
Existing bone repair materials, such as metal prostheses and ceramic materials, suffer from problems such as mismatched mechanical strength, insufficient brittleness, and inaccurate degradation rate of silk-based materials, leading to implant loosening, immune rejection, and degradation mismatch in the bone tissue regeneration process.
A process involving silkworm cocoon degumming, silk fibroin solution concentration, silk fabric sizing, sewing, and hot pressing was used to prepare a silk implant material. By adjusting the sewing density, the degradation rate was precisely controlled, thereby improving mechanical properties and biocompatibility.
The prepared silk implant material matches the bone density and toughness of the human body, promotes bone growth, has non-toxic and absorbable degradation products, reduces stress shielding effect, has a controllable degradation rate, and is low in material cost and can be mass-produced.
Smart Images
Figure CN122272905A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of biomedical textile materials, specifically to a silk implantable material for bone tissue repair and its preparation method. Background Technology
[0002] In the field of bone repair, traditional bone repair materials have many drawbacks. Metal prostheses such as titanium alloys and stainless steel, while possessing high mechanical strength, have a significantly different elastic modulus compared to human bone, easily leading to stress shielding effects, resulting in implant loosening and absorption by surrounding bone tissue. Furthermore, they are difficult to degrade in the body, requiring secondary surgery for removal, increasing patient suffering and medical costs. Ceramic materials such as alumina and hydroxyapatite are brittle and lack toughness, easily breaking under significant external forces, limiting their application in bone repair. While autologous bone grafting offers good biocompatibility and osteoconductivity, its availability is limited, its acquisition causes additional trauma to patients, and it carries the risk of immune rejection.
[0003] Silk, as a natural protein fiber, possesses excellent biocompatibility, controllable biodegradability, high drug permeability, low immunogenicity, and non-toxic degradation products, demonstrating immense application potential in the biomedical field. However, bone repair materials prepared using silk still face some challenges. On the one hand, the mechanical properties of silk composite materials need further improvement to meet the needs of bone repair in different sites; on the other hand, the in vivo degradation rate of existing silk-based materials is not precisely controlled enough, making it difficult to match the regeneration process of bone tissue. Summary of the Invention
[0004] The purpose of this invention is to provide a silk implant material for bone tissue repair and its preparation method, so as to solve the problems existing in the prior art.
[0005] To solve the above-mentioned technical problems, the present invention provides the following solution: A silk implant material for bone tissue repair is disclosed. The material is prepared by degumming silkworm cocoons with sodium carbonate solution to obtain degummed cocoons; dissolving the degummed cocoons in lithium bromide solution, dialysis in deionized water, and concentrating in polyethylene glycol solution to obtain a silk fibroin solution; using the silk fibroin solution as a sizing agent, sizing the degummed silk fabric and degummed silk yarn; layering the sized silk fabric; sewing with the sized silk yarn; cutting; and hot pressing. The degummed silk fabric is made by washing plain silk fabric with ethanol and then degumming it with sodium carbonate solution. The degummed silk yarn is made by washing silk yarn with medical ethanol and then degumming it with sodium carbonate solution.
[0006] A method for preparing a silk implantable material for bone tissue repair, the method comprising the following preparation steps: (1) Mix the regenerated silk fibroin solution with a polyethylene glycol aqueous solution of 35-45% by mass at a mass ratio of 1:(10-20), and stir and concentrate at room temperature for 3.5-4.5 hours to obtain a silk fibroin protein solution; (2) Immerse the plain silk fabric in 10 to 12 times its weight of 70 to 80 wt% ethanol aqueous solution, wash for 25 to 35 minutes to remove dirt and chemical residues, filter, degumme wash 2 to 4 times, and dry at 55 to 65℃ for 6 to 8 hours to obtain degummed silk fabric. (3) Immerse the silk yarn in 10-12 times its weight of 70-80 wt% ethanol aqueous solution, wash for 25-35 min to remove dirt and chemical residues, filter, add 10-20 times its weight of 0.04-0.06 wt% sodium carbonate aqueous solution, degumme for 20-40 min, wash 1-3 times with deionized water at 55-65°C, repeat the above degumming and washing steps 2-4 times, and dry at 55-65°C for 6-8 h to obtain degummed silk yarn; (4) Lay out 90-110 layers of sized silk fabric, use sized silk yarn as thread, sew them together, and cut them into 40×40mm pieces. 2 The materials are sized and placed in a hot press for hot pressing to obtain a silk implant material for bone tissue repair.
[0007] As an optimization, the preparation steps of the regenerated silk fibroin solution in step (1) are as follows: degummed silk and 9.3 mol / L lithium bromide aqueous solution are mixed evenly at a mass ratio of 1:(10~20), heated to 55~65℃, stirred for 3~5h, transferred into a dialysis bag, and dialyzed with 30~50 times the volume of lithium bromide aqueous solution in deionized water for 2~4 days, changing the deionized water 4~6 times to obtain the regenerated silk fibroin solution.
[0008] As an optimization, the preparation steps of the degummed silk are as follows: raw silk is mixed with 0.04~0.06 wt% sodium carbonate aqueous solution at a mass ratio of 1:(10~20), heated to 100~110℃, stirred for 25~35 min, washed with deionized water at 55~65℃ 1~3 times, the above degumming and washing steps are repeated 2~4 times, and dried at 55~65℃ for 6~8 h to obtain degummed silk.
[0009] As an optimization, the degumming and washing step (2) is as follows: the plain silk fabric and 0.04~0.06 wt% sodium carbonate aqueous solution are mixed evenly at a mass ratio of 1:(10~20), degummed for 20~40 min, and washed 1~3 times with deionized water at 55~65°C.
[0010] As an optimization, the preparation steps of the sized silk fabric in step (4) are as follows: the degummed silk fabric is immersed in a silk fibroin solution for sizing once, with a sizing rate of 45~55%, to obtain the sized silk fabric.
[0011] As an optimization, the preparation steps of the sized silk yarn in step (4) are as follows: the degummed silk yarn is immersed in a silk fibroin solution for sizing twice, with a sizing rate of 55-65%, to obtain sized silk yarn.
[0012] As an optimization, the stitch length in step (4) is 5×5mm.
[0013] As an optimization, the hot pressing process parameters in step (4) are: temperature 140~150℃, pressure 50~70MPa, and hot pressing time 4~6min.
[0014] Compared with the prior art, the beneficial effects achieved by the present invention are: First, the present invention employs a preparation process of sizing, suturing, and hot pressing, which is simple, efficient, and low-cost, and can be mass-produced and applied in the medical field.
[0015] Secondly, the silk implant material for bone tissue repair prepared in this invention exhibits excellent osteoconductivity and mechanical strength, with a material density of 1.45 g / cm³. 3 ) and toughness (0.99-12.80MJ / cm 3 ) and human cortical bone (1.80-2.00g / cm) 3 2-12 MJ / cm 3 It has a high degree of matching and is closer to the inorganic component characteristics of natural bone, which can effectively promote the growth of damaged bone and effectively reduce the stress shielding effect of metal implants.
[0016] Finally, the silk implant material prepared by this invention for bone tissue repair retains the biocompatibility and controllable degradation of silk fibroin, and the degradation rate can be precisely controlled by adjusting the suture density; silk fibroin itself has antibacterial properties, and the degradation products can provide nutrition to bone cells, promote cell proliferation and bone tissue regeneration; the degradation products are peptide chains and amino acids, which can be naturally absorbed by the human body and do not require secondary surgery for removal. Attached Figure Description
[0017] Figure 1 The tensile strength diagrams are for Example 2 and Comparative Examples 1-3; Figure 2 The bending strength diagrams are for Example 2 and Comparative Examples 1-3; Figure 3 The graph shows the in vitro degradation performance of Examples 2 and Comparative Examples 1-3 in PBS buffer. Figure 4 Three-view morphology images of Example 2 and Comparative Examples 1-3 after degradation in PBS buffer for 30 days; Figure 5 This is a photograph of the actual animal implanted in Example 2. Figure 6 This is a Micro-CT image of the animal after implantation in Example 2. Detailed Implementation
[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0019] Example 1: A method for preparing a silk implantable material for bone tissue repair, the method comprising the following steps: (1) Mix raw silk with 0.04wt% sodium carbonate aqueous solution at a mass ratio of 1:10, heat to 100℃, stir for 35 min, wash once with deionized water at 55℃, repeat the above degumming washing step twice, and dry at 55℃ for 8 h to obtain degummed silk; mix degummed silk with 9.3mol / L lithium bromide aqueous solution at a mass ratio of 1:10, heat to 55℃, stir for 5 h, transfer to dialysis bag, dialyze with 30 times the volume of lithium bromide aqueous solution with deionized water for 4 days, and change the deionized water 4 times to obtain regenerated silk fibroin solution; mix regenerated silk fibroin solution with 35% polyethylene glycol aqueous solution at a mass ratio of 1:10, stir and concentrate at room temperature for 4.5 h to obtain silk fibroin protein solution; (2) Immerse the plain silk fabric in 70wt% ethanol aqueous solution, 10 times its weight, wash for 35 min to remove dirt and chemical residues, filter, add 0.04wt% sodium carbonate aqueous solution, 10 times its weight, degumming for 40 min, wash once with deionized water at 55℃, repeat the above degumming washing steps twice, dry at 55℃ for 8 h to obtain degummed silk fabric; (3) Immerse the silk yarn in 70wt% ethanol aqueous solution, 10 times its weight, wash for 35 min to remove dirt and chemical residues, filter, add 0.04wt% sodium carbonate aqueous solution, 10 times the weight of the silk yarn, degumme for 40 min, wash once with deionized water at 55℃, repeat the above degumming and washing steps twice, dry at 55℃ for 8 h to obtain degummed silk yarn; (4) The degummed silk fabric is immersed in a silk fibroin solution and sized once, with a sizing rate of 45%, to obtain sized silk fabric; the degummed silk yarn is immersed in a silk fibroin solution and sized twice, with a sizing rate of 55%, to obtain sized silk yarn; the sized silk fabric is layered 90 times, and the sized silk yarn is used as sewing thread, with a stitch length of 5×5mm, and then cut into 40×40mm pieces. 2 The sample was sized and placed in a hot press for 6 minutes at a temperature of 140℃ and a pressure of 50MPa to obtain a silk implant material for bone tissue repair.
[0020] Example 2: A method for preparing a silk implantable material for bone tissue repair, the method comprising the following steps: (1) Mix raw silk with 0.05wt% sodium carbonate aqueous solution at a mass ratio of 1:15, heat to 105℃, stir for 30 min, wash twice with deionized water at 60℃, repeat the above degumming washing step 3 times, and dry at 60℃ for 7 h to obtain degummed silk; mix degummed silk with 9.3mol / L lithium bromide aqueous solution at a mass ratio of 1:15, heat to 60℃, stir for 4 h, transfer to dialysis bag, dialyze with 40 times the volume of lithium bromide aqueous solution with deionized water for 3 days, and change the deionized water 5 times to obtain regenerated silk fibroin solution; mix regenerated silk fibroin solution with 40% polyethylene glycol aqueous solution at a mass ratio of 1:15, stir and concentrate at room temperature for 4 h to obtain silk fibroin protein solution; (2) Immerse the plain silk fabric in 11 times its weight of 75wt% ethanol aqueous solution, wash for 30 min to remove dirt and chemical residues, filter, add 15 times its weight of 0.05wt% sodium carbonate aqueous solution, degumme for 30 min, wash twice with deionized water at 60℃, repeat the above degumming and washing steps 3 times, dry at 60℃ for 7 h to obtain degummed silk fabric; (3) Immerse the silk yarn in 11 times its weight of 75wt% ethanol aqueous solution, wash for 30 min to remove dirt and chemical residues, filter, add 15 times the weight of the silk yarn of 0.05wt% sodium carbonate aqueous solution, degumme for 30 min, wash twice with deionized water at 60℃, repeat the above degumming and washing steps 3 times, dry at 60℃ for 7 h to obtain degummed silk yarn; (4) The degummed silk fabric is immersed in a silk fibroin solution and sized once, with a sizing rate of 50%, to obtain sized silk fabric; the degummed silk yarn is immersed in a silk fibroin solution and sized twice, with a sizing rate of 60%, to obtain sized silk yarn; the sized silk fabric is layered 100 times, and the sized silk yarn is used as sewing thread, with a stitch length of 5×5mm, and then cut into 40×40mm pieces. 2The sample was sized and placed in a hot press for 5 minutes at a temperature of 145℃ and a pressure of 60MPa to obtain a silk implant material for bone tissue repair.
[0021] Example 3: A method for preparing a silk implantable material for bone tissue repair, the method comprising the following steps: (1) Mix raw silk with 0.06 wt% sodium carbonate aqueous solution at a mass ratio of 1:20, heat to 110℃, stir for 25 min, wash with 65℃ deionized water 3 times, repeat the above degumming washing step 4 times, dry at 65℃ for 6 h to obtain degummed silk; mix degummed silk with 9.3 mol / L lithium bromide aqueous solution at a mass ratio of 1:20, heat to 65℃, stir for 3 h, transfer to dialysis bag, dialyze with 50 times the volume of lithium bromide aqueous solution with deionized water for 2 days, change the deionized water 6 times to obtain regenerated silk fibroin solution; mix regenerated silk fibroin solution with 45% polyethylene glycol aqueous solution at a mass ratio of 1:20, stir and concentrate at room temperature for 3.5 h to obtain silk fibroin protein solution; (2) Immerse the plain silk fabric in 12 times its weight of 80 wt% ethanol aqueous solution, wash for 25 min to remove dirt and chemical residues, filter, add 20 times its weight of 0.06 wt% sodium carbonate aqueous solution, degumme for 20 min, wash 3 times with deionized water at 65℃, repeat the above degumming and washing steps 4 times, dry at 65℃ for 6 h to obtain degummed silk fabric; (3) Immerse the silk yarn in 12 times its weight of 80 wt% ethanol aqueous solution, wash for 25 min to remove dirt and chemical residues, filter, add 20 times its weight of 0.06 wt% sodium carbonate aqueous solution, degumme for 20 min, wash 3 times with deionized water at 65℃, repeat the above degumming and washing steps 4 times, dry at 65℃ for 6 h to obtain degummed silk yarn; (4) The degummed silk fabric is immersed in a silk fibroin solution and sized once, with a sizing rate of 55%, to obtain sized silk fabric; the degummed silk yarn is immersed in a silk fibroin solution and sized twice, with a sizing rate of 65%, to obtain sized silk yarn; the sized silk fabric is layered 110 times, and the sized silk yarn is used as sewing thread, with a stitch length of 5×5mm, and then cut into 40×40mm pieces. 2 The sample was sized and placed in a hot press for 4 minutes at a temperature of 150°C and a pressure of 70 MPa to obtain a silk implant material for bone tissue repair.
[0022] Comparative Example 1: The preparation method of the silk implant material for bone tissue repair in Comparative Example 1 differs from that in Example 2 only in that "using a stitch spacing of 5×5mm for suturing" in step (4) is changed to "using a stitch spacing of 5×10mm for suturing". The remaining steps are the same as in Example 2.
[0023] Comparative Example 2: The preparation method of the silk implant material for bone tissue repair in Comparative Example 2 differs from that in Example 2 only in that "using a stitch spacing of 5×5mm for suturing" in step (4) is changed to "using a stitch spacing of 5×15mm for suturing". The remaining steps are the same as in Example 2.
[0024] Comparative Example 3: The preparation method of the silk implant material for bone tissue repair in Comparative Example 3 differs from that in Example 2 only in that "using a stitch spacing of 5×5mm for suturing" in step (4) is changed to "using a stitch spacing of 5×20mm for suturing". The remaining steps are the same as in Example 2.
[0025] Test Example 1 Mechanical property testing Test methods: According to GB / T 1040.1-2025 and GB / T 1449-2005, the tensile strength, flexural strength, and shear stress of the silk implant materials used for bone tissue repair in the examples and comparative examples were tested using a universal electronic testing machine. The results are shown in Table 1.
[0026] Table 1
[0027] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-3 in Table 1 reveals that the silk implant material for bone tissue repair prepared in this invention has good mechanical properties.
[0028] By comparison, the tensile strength, flexural strength, and shear stress of Examples 1-3 are greater than those of Comparative Examples 1-3. This indicates that by using silk fibroin solution as a sizing agent, sizing degummed silk fabric and degummed silk yarn, layering the sized silk fabric, sewing with sized silk yarn, cutting, and hot pressing, a silk implant material for bone tissue repair can be obtained. By controlling the suture stitch length, the silk implant material for bone tissue repair can exhibit excellent mechanical strength.
[0029] Test Example 2 Degradation performance test Test method: The silk implant materials used for bone tissue repair in the examples and comparative examples were placed in PBS buffer at pH 7.4 and degraded in vitro at 37°C for 30 days. The samples were then removed, washed, and lyophilized to constant weight, and the remaining mass ratio was calculated. The results are shown in Table 2.
[0030] Table 2
[0031] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-3 in Table 2 reveals that the silk implant material for bone tissue repair prepared in this invention has good biodegradability.
[0032] By comparison, the residual mass ratio of Examples 1-3 is less than that of Comparative Examples 1-3, indicating that the silk fibroin protein solution is used as a sizing agent. The degummed silk fabric and degummed silk yarn are sized, the sized silk fabric is layered and laid out, and then sewn, cut, and hot-pressed with the sized silk yarn. The resulting silk implant material for bone tissue repair retains the biocompatibility and controllable degradation of silk fibroin protein. The degradation rate can be precisely controlled by adjusting the suture density.
[0033] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A silk implant material for bone tissue repair, characterized in that, The silk implant material used for bone tissue repair is prepared by degumming silkworm cocoons with sodium carbonate solution to obtain degummed silkworm cocoons; the degummed silkworm cocoons are dissolved in lithium bromide solution, dialyzed in deionized water, and concentrated in polyethylene glycol solution to obtain silk fibroin solution. Using silk fibroin solution as a sizing agent, degummed silk fabric and degummed silk yarn are sized, the sized silk fabric is layered and laid out, and then sewn, cut, and hot-pressed with the sized silk yarn. The degummed silk fabric is made by washing plain silk fabric with ethanol and then degumming it with sodium carbonate solution. The degummed silk yarn is made by washing silk yarn with medical ethanol and then degumming it with sodium carbonate solution.
2. A method for preparing a silk implantable material for bone tissue repair, characterized in that, The preparation method of the silk implant material for bone tissue repair includes the following preparation steps: (1) Mix the regenerated silk fibroin solution with a polyethylene glycol aqueous solution of 35-45% by mass at a mass ratio of 1:(10-20), and stir and concentrate at room temperature for 3.5-4.5 hours to obtain a silk fibroin protein solution; (2) Immerse the plain silk fabric in 10 to 12 times its weight of 70 to 80 wt% ethanol aqueous solution, wash for 25 to 35 minutes to remove dirt and chemical residues, filter, degumme wash 2 to 4 times, and dry at 55 to 65℃ for 6 to 8 hours to obtain degummed silk fabric. (3) Immerse the silk yarn in 10-12 times its weight of 70-80 wt% ethanol aqueous solution, wash for 25-35 min to remove dirt and chemical residues, filter, add 10-20 times its weight of 0.04-0.06 wt% sodium carbonate aqueous solution, degumme for 20-40 min, wash 1-3 times with deionized water at 55-65°C, repeat the above degumming and washing steps 2-4 times, and dry at 55-65°C for 6-8 h to obtain degummed silk yarn; (4) Lay out 90-110 layers of sized silk fabric, use sized silk yarn as thread, sew them together, and cut them into 40×40mm pieces. 2 The materials are sized and placed in a hot press for hot pressing to obtain a silk implant material for bone tissue repair.
3. The method for preparing the silk implant material for bone tissue repair according to claim 2, characterized in that, The preparation steps of the regenerated silk fibroin solution in step (1) are as follows: Degummed silk and 9.3 mol / L lithium bromide aqueous solution are mixed evenly at a mass ratio of 1:(10~20), heated to 55~65℃, stirred for 3~5h, transferred into a dialysis bag, and dialyzed with 30~50 times the volume of lithium bromide aqueous solution in deionized water for 2~4 days, changing the deionized water 4~6 times to obtain the regenerated silk fibroin solution.
4. The method for preparing the silk implant material for bone tissue repair according to claim 3, characterized in that, The preparation steps of the degummed silk are as follows: raw silk is mixed with 0.04~0.06 wt% sodium carbonate aqueous solution at a mass ratio of 1:(10~20), heated to 100~110℃, stirred for 25~35min, washed 1~3 times with deionized water at 55~65℃, the above degumming and washing steps are repeated 2~4 times, and dried at 55~65℃ for 6~8h to obtain degummed silk.
5. The method for preparing the silk implant material for bone tissue repair according to claim 2, characterized in that, The degumming and washing steps in step (2) are as follows: Mix the plain silk fabric and 0.04~0.06 wt% sodium carbonate aqueous solution at a mass ratio of 1:(10~20) evenly, degumme for 20~40 min, and wash 1~3 times with deionized water at 55~65°C.
6. The method for preparing the silk implant material for bone tissue repair according to claim 2, characterized in that, The preparation steps of the sized silk fabric in step (4) are as follows: the degummed silk fabric is immersed in a silk fibroin solution for sizing once, with a sizing rate of 45-55%, and the sized silk fabric is obtained.
7. The method for preparing the silk implant material for bone tissue repair according to claim 2, characterized in that, The preparation steps of the sized silk yarn in step (4) are as follows: the degummed silk yarn is immersed in a silk fibroin solution and sized twice, with a sizing rate of 55-65%, to obtain the sized silk yarn.
8. The method for preparing the silk implant material for bone tissue repair according to claim 2, characterized in that, The stitch length in step (4) is 5×5mm.
9. The method for preparing the silk implant material for bone tissue repair according to claim 2, characterized in that, The hot pressing process parameters in step (4) are: temperature 140~150℃, pressure 50~70MPa, and hot pressing time 4~6min.