Human tissue adhesive and preparation method thereof

Abstract

The invention relates to the technical field of biological adhesives, in particular to a human tissue adhesive and a preparation method thereof, and the human tissue adhesive comprises the following raw materials: modified polydopamine nanoparticles, sulfonated carbon nanotubes, selenium-calcium phosphate composite nanoparticles (Se-HAp NPs), growth factors, curcumin, quercetin, poly (N-isopropylacrylamide) and polylactic acid. According to the modified polydopamine nano-particles, the wet adhesion strength of the adhesive is remarkably improved, the adhesion and flexibility of the adhesive are synergistically enhanced by combining the flexible nano-supporting effect of the sulfonated carbon nano-tubes, and the modified polydopamine nano-particles and the sulfonated carbon nano-tubes form a stable nano-network structure to support uniform distribution of Se-HAp NPs; the functional integrity of the Se-HAp NPs in a dynamic environment is ensured by the sulfonated carbon nanotubes, and the Se-HAp NPs and the modified polydopamine nanoparticles jointly improve the biological activity and stability of the adhesive and promote tissue repair, so that the adhesive can adapt to a dynamic tissue environment.

Description

Technical Field

[0001] The present invention relates to the technical field of biological adhesives, and particularly to a human tissue adhesive and a preparation method thereof. Background Art

[0002] In modern medicine, tissue adhesives have become an important part of wound repair, surgical suture replacement, and biomedical materials. However, the current tissue adhesives on the market are mainly for static tissues, and there are significant limitations in the repair of dynamic tissues such as the heart, lungs, and blood vessels. Moreover, dynamic tissues are in a humid environment for a long time, which will further reduce the adhesion of the adhesive. Therefore, the continuous mechanical movement characteristics such as the continuous beating of the heart, the periodic expansion and contraction of the lungs, and the pulsation of blood vessels pose higher requirements for the adhesion, flexibility, and stability of the adhesive. At the same time, inflammatory reactions and oxidative stress will occur during tissue repair. If the adhesive cannot provide good biocompatibility and promote repair and regeneration ability, it will lead to slow or failed tissue healing. Therefore, it is very meaningful to develop a tissue adhesive that can stably adhere in a dynamic environment and simultaneously has high flexibility and promotes repair and regeneration functions. Summary of the Invention

[0003] (1) Technical Problems to be Solved

[0004] The purpose of the present invention is to provide a human tissue adhesive and a preparation method thereof. By optimizing the formula of the adhesive and combining modern nanotechnology, the technical problems such as insufficient adhesion of dynamic tissues and poor mechanical flexibility are effectively solved, so that it can stably play a role in a dynamic physiological environment.

[0005] (2) Technical Solutions

[0006] To achieve the above purpose, on the one hand, the present invention provides a human tissue adhesive, which comprises the following raw materials in parts by weight: 5-10 parts of modified polydopamine nanoparticles, 1-5 parts of sulfonated carbon nanotubes, 0.2-1 part of growth factor, 1-2 parts of curcumin, 0.4-2 parts of quercetin, 10-20 parts of poly(N-isopropylacrylamide), and 40-60 parts of polylactic acid.

[0007] Further, the human tissue adhesive further comprises selenium-hydroxyapatite composite nanoparticles (Se-HAp NPs). The weight ratio of Se-HAp NPs to modified polydopamine nanoparticles is 15:(5-10). The particle size of Se-HAp NPs is 30-50 nm, and the specific surface area is 140-150 m 2 / g.

[0008] Further, the preparation method of the Se-HAp NPs comprises:

[0009] S11. Dissolve calcium nitrate in purified water under stirring, control the concentration to be 0.2 M, stir for 0.5 - 1 h, then slowly add polyvinylpyrrolidone dropwise, and continue to stir for 0.5 - 1 h to obtain the first mixed solution;

[0010] S12. Dissolve ammonium dihydrogen phosphate and sodium selenite in purified water respectively under stirring, and obtain the ammonium dihydrogen phosphate solution and sodium selenite solution after stirring for 0.5 - 1 h respectively. Control the concentrations of the ammonium dihydrogen phosphate solution and sodium selenite solution to be 0.12 M and 0.03 M respectively;

[0011] S13. Slowly add ammonia water to the first mixed solution under stirring in a water bath at 105 - 125 °C, adjust the pH value to 9 - 10, continue to stir for 1 - 2 h, then simultaneously drop in the ammonium dihydrogen phosphate solution and sodium selenite solution, control the dropping rate to be 1 mL / min, and then continue to stir and react for 20 - 24 h to obtain the second mixed solution;

[0012] S14. Centrifuge the second mixed solution at a high speed, with the rotation speed of 8000 - 10000 rpm and centrifuge for 10 - 15 min. Wash the obtained solid alternately with purified water and absolute ethanol for 3 times, then carry out vacuum drying. The drying temperature is 60 - 70 °C, dry for 12 - 14 h, then place it in a muffle furnace and calcine at 400 - 600 °C for 2 - 4 h to obtain Se-HAp NPs and grind them into powder for standby.

[0013] Furthermore, the preparation method of the modified polydopamine nanoparticles includes:

[0014] S21. Dissolve dopamine hydrochloride in phosphate buffered saline under stirring, and stir and react at room temperature for 4 - 6 h to obtain the third mixed solution;

[0015] S22. Centrifuge the third mixed solution at a high speed, with the rotation speed of 10000 - 12000 rpm and centrifuge for 10 - 15 min. Wash the separated solid with purified water for 3 times, then carry out vacuum drying. The drying temperature is 45 - 55 °C, dry for 20 - 24 h to obtain polydopamine particles and grind them into powder for standby;

[0016] S23. Add polydopamine powder into purified water and carry out ultrasonic treatment, set the pulse mode, the ultrasonic frequency is 40 - 50 kHz, and carry out ultrasonic treatment for 1 - 2 h to obtain the polydopamine nanoparticle dispersion;

[0017] S24. Dissolve N-acetylcysteine in purified water under stirring, and adjust the pH value to 8.5 - 9.0 with 0.1 M sodium hydroxide solution, stir for 1 - 2 h to obtain the N-acetylcysteine solution;

[0018] S25. Slowly add the polydopamine nanoparticle dispersion into the N-acetylcysteine solution under stirring, and stir and react at room temperature for 12 - 14 h to obtain a fourth mixed solution;

[0019] S26. Centrifuge the fourth mixed solution at a high speed, with a rotation speed of 10000 - 12000 rpm, centrifuge for 10 - 15 min. Wash the separated solid alternately with purified water and phosphate buffered saline 3 times, then perform freeze-drying. The drying temperature is -40 - -60 °C, and after drying for 20 - 24 h, obtain modified polydopamine nanoparticles and grind them into powder for standby.

[0020] Further, the modified polydopamine nanoparticles are obtained by grafting N-acetylcysteine on the surface of polydopamine nanoparticles. The particle size of the modified polydopamine nanoparticles is 95 - 105 nm, and the specific surface area is 130 - 150 m 2 / g.

[0021] Further, the mass ratio of the polydopamine nanoparticles to N-acetylcysteine is 1:(0.1 - 0.3).

[0022] Further, the preparation method of the sulfonated carbon nanotubes includes:

[0023] S31. Prepare a mixed acid solution with a volume ratio of concentrated sulfuric acid to concentrated nitric acid of 3:1, and disperse the carbon nanotubes in the mixed acid solution for ultrasonic treatment. The ultrasonic frequency is 40 - 50 kHz, the ultrasonic temperature is 80 - 90 °C, and after ultrasonic treatment for 4 - 6 h, obtain a fifth mixed solution;

[0024] S32. Centrifuge the fifth mixed solution at a high speed, with a rotation speed of 10000 - 12000 rpm, centrifuge for 10 - 15 min. Wash the separated solid with purified water 3 times, then perform vacuum drying. The drying temperature is 65 - 75 °C, and after drying for 20 - 24 h, obtain oxidized carbon nanotubes and grind them into powder for standby;

[0025] S33. Add 100 mg of oxidized carbon nanotube powder into 50 mL of concentrated sulfuric acid and perform ultrasonic treatment. The ultrasonic frequency is 40 - 50 kHz, the ultrasonic temperature is 80 - 90 °C, and after ultrasonic treatment for 1 - 2 h, obtain a sixth mixed solution;

[0026] S34. After the sixth mixed solution is cooled, slowly pour it into purified water at 0 - 4 °C for high-speed centrifugation. The rotation speed is 10000 - 12000 rpm, centrifuge for 10 - 15 min. Wash the separated solid with purified water 3 times, then perform vacuum drying. The drying temperature is 60 - 70 °C, and after drying for 12 - 14 h, obtain sulfonated carbon nanotubes and grind them into powder for standby.

[0027] Further, the sulfonated carbon nanotubes are prepared by introducing sulfonic acid groups (-SO3H) on the surface of carbon nanotubes. The sulfonated carbon nanotubes have a diameter of 10 - 50 nm, a length of 1 - 10 μm, and a specific surface area of 360 - 400 m 2 / g.

[0028] On the other hand, based on the same inventive concept, the present invention also provides a preparation method of a human tissue adhesive, which is applied to the human tissue adhesive described above and includes the following steps:

[0029] S41. Prepare a seventh mixed solution with a volume ratio of dichloromethane to absolute ethanol of 1:1. Disperse the modified polydopamine nanoparticle powder, sulfonated carbon nanotube powder, and selenium-calcium phosphate composite nanoparticle powder in the seventh mixed solution and perform ultrasonic treatment. The ultrasonic frequency is 40 - 50 kHz. After ultrasonic treatment for 1 - 2 h, an eighth mixed solution is obtained;

[0030] S42. Dissolve polylactic acid in dichloromethane under stirring for 1 - 2 h to obtain a polylactic acid solution. Add the polylactic acid solution, poly(N-isopropylacrylamide), curcumin, and quercetin to the eighth mixed solution in sequence, continue stirring for 2 - 4 h, then place it in an ice bath at 0 - 4 °C, add a growth factor, and continue stirring for 0.5 - 1 h to obtain a ninth mixed solution;

[0031] S43. Pour the ninth mixed solution into a corresponding silicone mold for vacuum drying. The drying temperature is 35 - 40 °C. After drying for 20 - 24 h, the human tissue adhesive is obtained.

[0032] The mechanism of action of the above raw material components is as follows:

[0033] Growth factors are cell signaling molecules that can regulate cell behavior through signal pathways and promote tissue repair. During tissue repair and regeneration, growth factors can promote cell proliferation and differentiation, enhance angiogenesis, regulate the inflammatory response, and improve the adhesion and repair effect of dynamic tissues by promoting collagen synthesis.

[0034] Curcumin is a natural polyphenol with anti-inflammatory, antioxidant, antibacterial, and angiogenesis-promoting properties. In dynamic tissues, curcumin can reduce the inflammatory response, reduce tissue damage, improve the biocompatibility of the adhesive, provide antioxidant protection, reduce oxidative stress damage, protect surrounding tissue cells, and is particularly suitable for dynamic tissues such as cardiovascular and lung tissues that are vulnerable to oxidative damage. It can also prevent tissue fibrosis, reduce excessive scar formation, and improve the elastic matching of the adhesive in a high-stretch environment.

[0035] Quercetin is a flavonoid compound that has anti-inflammatory, antibacterial, antioxidant, and cell environment stabilizing effects. It can inhibit inflammatory responses, improve the physiological stability of dynamic tissues, destroy bacterial DNA, enhance the persistence of adhesives in the bloodstream and wet environments, reduce matrix degradation induced by oxidative stress, and improve the support and flexibility of adhesives for tissues.

[0036] Poly(N-isopropylacrylamide) is a smart thermosensitive hydrogel that can shrink at human body temperature (37°C) and swell at low temperatures, endowing the adhesive with temperature-responsive properties. The lower critical solution temperature of poly(N-isopropylacrylamide) is approximately 32°C. Above this temperature, the poly(N-isopropylacrylamide) molecules undergo hydrophobic contraction, enhancing the adhesive strength. At lower temperatures, it is in a swollen state, which helps to enhance the plasticity of the adhesive, enabling it to adapt to the dynamic environments of different tissues. The hydrogel structure of poly(N-isopropylacrylamide) can disperse external tensile and compressive forces, improve tissue flexibility, prevent the adhesive from rupturing during heart pulsation or lung expansion, and reduce mechanical friction by forming a soft layer, making it particularly suitable for highly dynamic load tissues such as the heart, lungs, and blood vessels.

[0037] Polylactic acid is a biodegradable polymer material. The high strength and durability of polylactic acid ensure that the adhesive remains stable in a high-dynamic tissue environment and is not easily broken or detached. As polylactic acid slowly degrades and releases lactic acid, the lactic acid can further promote tissue repair without causing a foreign body reaction, thereby improving the long-term adaptability of the adhesive.

[0038] In the human tissue adhesive of the present invention, modified polydopamine nanoparticles and sulfonated carbon nanotubes synergistically enhance the adhesiveness and flexibility of the adhesive. The two form a stable nano-network structure to support the uniform distribution of Se-HAp NPs. The introduction of Se-HAp NPs significantly improves the bioactivity and stability of the adhesive, and promotes tissue repair, enabling it to adapt to dynamic tissue environments such as the heart, lungs, and blood vessels. Polydopamine is rich in dopamine structural units. Modified polydopamine nanoparticles are obtained by grafting N-acetylcysteine onto the surface of polydopamine nanoparticles, which can enhance the adhesion force through covalent and non-covalent interactions in a wet environment and provide a dynamic cross-linking mechanism. The sulfhydryl group (-SH) on the surface of N-acetylcysteine forms a disulfide bond (-S-S-) with the free cysteine on the surface of tissue proteins, greatly enhancing the wet adhesion strength. The high aspect ratio and nano-enhancement effect of sulfonated carbon nanotubes can form a nano-network structure inside the adhesive to evenly disperse stress and provide excellent tensile and bending strength, enabling the adhesive to adapt to the continuous movement of tissues, further improving the tensile strength and flexibility of the adhesive. The presence of surface sulfonic acid groups (-SO3H) significantly enhances the water solubility of sulfonated carbon nanotubes and can interact with the positively charged groups on the surface of biological tissue proteins, improving the adhesion stability of dynamic tissues. Modified polydopamine nanoparticles ensure that the adhesive is not easily detached in a high-shear environment and enhance the overall adhesion strength and flexibility through the flexible nano-support provided by sulfonated carbon nanotubes. The stable nano-network structure formed by modified polydopamine nanoparticles and sulfonated carbon nanotubes further supports the uniform distribution of Se-HAp NPs, and ensures the functional integrity of Se-HAp NPs in a dynamic environment through ionic bridge connection with sulfonated carbon nanotubes and the wrapping of the flexible carbon nano-skeleton of sulfonated carbon nanotubes. Se-HAp NPs significantly improve the bioactivity of the adhesive, jointly enhance the stability of the adhesive in a wet environment with modified polydopamine nanoparticles, and promote tissue repair at the same time. Modified polydopamine nanoparticles have good hydrophilicity and a biomimetic interface, can effectively scavenge reactive oxygen species, reduce the degradation of the adhesive, and improve biocompatibility. Se-HAp NPs slowly release Ca 2+ , Se 2+ and PO4 3- at the adhesion interface. The released Ca 2+ and Se 2+ undergo charge adsorption with protein and phospholipid molecules, further enhancing the interface stability. And Ca 2+ can induce cell adhesion and bone tissue regeneration. Se 2+ has antioxidant and antibacterial properties, destroying bacterial DNA. PO4 3-By forming calcium phosphate deposits on the tissue surface, the biointegration ability of the adhesive is improved, and the self-healing ability of the calcium phosphate structure enables the adhesive to adapt to dynamic physiological environments such as the heart, lungs, and blood vessels, thereby enhancing the durability of the adhesive. Combining with the bioactive sites provided by the modified polydopamine nanoparticles' cell-friendly interface promotes cell adhesion, proliferation, and differentiation, significantly improving the repair and regeneration ability of dynamic tissues. In addition, Se-HAp NPs further stabilize the internal nanostructure of the adhesive through electrostatic adsorption and coordination with modified polydopamine nanoparticles and sulfonated carbon nanotubes, preventing peeling and damage caused by external forces. In summary, the synergistic effect of modified polydopamine nanoparticles, sulfonated carbon nanotubes, and Se-HAp NPs enables the adhesive to not only adhere firmly to the surface of dynamic tissues but also exist stably in the physiological environment for a long time.

[0039] (3) Beneficial effects

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] 1. The dynamic cross-linking mechanism of modified polydopamine nanoparticles greatly enhances the wet adhesion strength, ensuring that the adhesive is not easily detached in a high-shear environment, and through the flexible nano-supporting effect provided by sulfonated carbon nanotubes, the overall adhesion strength and flexibility are enhanced;

[0042] 2. Sulfonated carbon nanotubes form a nano-network structure inside the adhesive, evenly dispersing stress, providing excellent tensile and bending strength, and improving the tensile strength and flexibility of the adhesive;

[0043] 3. Modified polydopamine nanoparticles and sulfonated carbon nanotubes form a stable nano-network structure to support the uniform distribution of Se-HAp NPs, and together with the modified polydopamine nanoparticles, enhance the stability of the adhesive and promote tissue repair;

[0044] 4. Se-HAp NPs undergo electrostatic adsorption and coordination with modified polydopamine nanoparticles and sulfonated carbon nanotubes, further stabilizing the internal nanostructure of the adhesive and preventing peeling and damage caused by external forces. Description of the drawings

[0045] Figure 1 SEM image of modified polydopamine nanoparticles in Example 1 of the present invention;

[0046] Figure 2 SEM image of sulfonated carbon nanotubes in Example 1 of the present invention;

[0047] Figure 3 SEM image of Se-HAp NPs in Example 1 of the present invention. Detailed implementation manners

[0048] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0049] The test equipment and preparations in the following embodiments are as follows: electronic balance (Sartorius, Germany), electrothermal constant temperature water bath (Kedao, Jiangsu), magnetic stirrer (Meiyingpu, Shanghai), ultrasonic instrument (Yixin, Shanghai), high-speed centrifuge (Jidi, Guangzhou), vacuum drying oven (Jiecheng, Shanghai), muffle furnace (Lantian Instrument, Hangzhou), electrothermal blast drying oven (Geruida, Suzhou), scanning electron microscope (Zeiss, Germany), specific surface area analyzer (Beijing Beishide Instrument Technology), freeze dryer (Pudong Freeze Drying, Shanghai), pH meter (Yidian, Shanghai), universal material testing machine (Jianzhuo, Suzhou); chemical drugs and reagents are purchased from Sigma-Aldrich.

[0050] Example 1: This example discloses a human tissue adhesive, which includes the following raw materials in parts by weight: modified polydopamine nanoparticles 7.5 parts, sulfonated carbon nanotubes 3 parts, growth factor 0.6 part, curcumin 1.5 parts, quercetin 1.2 parts, poly(N-isopropylacrylamide) 15 parts, polylactic acid 50 parts. The human tissue adhesive also includes selenium-hydroxyapatite composite nanoparticles (Se-HAp NPs). The weight ratio of Se-HAp NPs to modified polydopamine nanoparticles is 15:7.5. The particle size of Se-HAp NPs is 30-50 nm, and the specific surface area is 140-150 m 2 / g.

[0051] In the human tissue adhesive of the present invention, the modified polydopamine nanoparticles and the sulfonated carbon nanotubes synergistically enhance the adhesion and flexibility of the adhesive. The two form a stable nano-network structure to support the uniform distribution of Se-HAp NPs. The introduction of Se-HAp NPs significantly improves the biological activity and stability of the adhesive and promotes tissue repair, enabling it to adapt to dynamic tissue environments such as the heart, lungs, and blood vessels. Polydopamine is rich in dopamine structural units. N-acetylcysteine is grafted onto the surface of the polydopamine nanoparticles to obtain modified polydopamine nanoparticles. Figure 1This is the SEM image of the modified polydopamine nanoparticles. It can be seen that the modified polydopamine nanoparticles have obvious network and pore structures. Grafting N-acetylcysteine reduces the aggregation tendency of the modified polydopamine nanoparticles, improves the stability of the nanoparticles while further enhancing the biocompatibility of the adhesive. The surface of the modified polydopamine nanoparticles contains a large number of phenolic hydroxyl groups (-OH) and amino groups (-NH2), which can enhance the adhesion force with tissue proteins through covalent bond formation and non-covalent interactions in a humid environment, and provide a dynamic cross-linking mechanism. The sulfhydryl group (-SH) on the surface of N-acetylcysteine forms a disulfide bond (-S-S-) through disulfide cross-linking with the free cysteine on the surface of tissue proteins, greatly enhancing the wet adhesion strength. The disulfide bond (-S-S-) can also break and recombine under different physiological conditions, enabling the adhesive to adapt to the continuously deformed physiological environments such as the heart and lungs, thus providing a lasting dynamic adhesion ability. Figure 2 This is the SEM image of the sulfonated carbon nanotubes. It can be seen that there are obvious tubular structures. The high aspect ratio and nano-enhancement effect of the sulfonated carbon nanotubes can form a nano-network structure inside the adhesive. In dynamic tissues, the high strength and flexibility of the sulfonated carbon nanotubes help to disperse the mechanical stress in the adhesive, reduce local stress concentration, and provide excellent tensile and bending strengths, enabling the adhesive to adapt to the continuous movement of tissues, further improving the tensile strength and flexibility of the adhesive, and preventing cracking or delamination of the dynamic tissues caused by movement. The presence of sulfonic acid groups (-SO3H) on its surface significantly enhances the water solubility of the sulfonated carbon nanotubes. And the sulfonic acid group (-SO3H), as a strong anionic group, can interact with the positively charged groups on the surface of biological tissue proteins to enhance the binding force, thereby improving the adhesion stability of dynamic tissues. The modified polydopamine nanoparticles ensure that the adhesive is not easily detached in a high-shear environment, and through the flexible nano-supporting effect provided by the sulfonated carbon nanotubes, enhance the overall adhesion strength and flexibility. The stable nano-network structure formed by the modified polydopamine nanoparticles and the sulfonated carbon nanotubes further supports the uniform distribution of Se-HAp NPs. Figure 3 This is the SEM image of Se-HAp NPs. It can be seen that the particle size of Se-HAp NPs is uniform and the morphology is spherical. The sulfonic acid group (-SO3H) on the surface of the sulfonated carbon nanotubes reacts with Ca on the surface of Se-HAp NPs 2+Ionic bridging occurs, and the flexible carbon nanotube framework of sulfonated carbon nanotubes prevents their aggregation, ensuring the functional integrity of Se-HAp NPs in a dynamic environment. Se-HAp NPs significantly enhance the bioactivity of the adhesive, improve the stability of the adhesive in a humid environment together with modified polydopamine nanoparticles, and promote tissue repair. Modified polydopamine nanoparticles have good hydrophilicity and a biomimetic interface. N-acetylcysteine grafted on their surface can effectively scavenge reactive oxygen species, reduce adhesive degradation, and improve biocompatibility. Se-HAp NPs slowly release Ca 2+ , Se 2+ and PO4 3- at the adhesion interface. The released Ca 2+ and Se 2+ undergo charge adsorption with protein and phospholipid molecules, further enhancing the interface stability. Moreover, Ca 2+ can induce cell adhesion and bone tissue regeneration, while Se 2+ has antioxidant and antibacterial properties, destroying bacterial DNA and reducing oxidative stress. PO4 3- forms calcium phosphate deposits on the tissue surface, improving the biointegration ability of the adhesive. The self-healing ability of the calcium phosphate structure enables the adhesive to adapt to dynamic physiological environments such as the heart, lungs, and blood vessels, thereby improving the durability of the adhesive. Combining with the bioactive sites provided by the cell-friendly interface of modified polydopamine nanoparticles, it promotes cell adhesion, proliferation, and differentiation, significantly enhancing the repair and regeneration ability of dynamic tissues. In addition, Se-HAp NPs further stabilize the internal nanostructure of the adhesive through electrostatic adsorption and coordination with modified polydopamine nanoparticles and sulfonated carbon nanotubes, preventing peeling and damage caused by external forces. In summary, the synergistic effect of modified polydopamine nanoparticles, sulfonated carbon nanotubes, and Se-HAp NPs enables the adhesive to not only adhere firmly to the surface of dynamic tissues but also exist stably in the physiological environment for a long time.

[0052] The preparation method of the Se-HAp NPs includes:

[0053] S11. Dissolve calcium nitrate in purified water under stirring, control the concentration to be 0.2 M, stir for 1 h, then slowly add polyvinylpyrrolidone, and continue stirring for 1 h to obtain the first mixed solution;

[0054] S12. Dissolve ammonium dihydrogen phosphate and sodium selenite in purified water under stirring respectively, and obtain the ammonium dihydrogen phosphate solution and sodium selenite solution after stirring for 1 h respectively. Control the concentrations of the ammonium dihydrogen phosphate solution and sodium selenite solution to be 0.12 M and 0.03 M respectively;

[0055] S13. Slowly add ammonia water to the first mixed solution under stirring in a water bath at 120 °C, adjust the pH value to 9.5, continue stirring for 2 h, then simultaneously drop in ammonium dihydrogen phosphate solution and sodium selenite solution, control the dropping rate at 1 mL / min, and then continue stirring and reacting for 22 h to obtain a second mixed solution;

[0056] S14. Centrifuge the second mixed solution at a high speed at 9000 rpm for 12 min. The obtained solid is washed alternately with purified water and absolute ethanol 3 times and then dried in vacuum. The drying temperature is 65 °C. After drying for 13 h, it is calcined in a muffle furnace at 500 °C for 3 h to obtain Se-HAp NPs and ground into a powder for standby.

[0057] The preparation method of the modified polydopamine nanoparticles includes:

[0058] S21. Dissolve dopamine hydrochloride in phosphate buffered saline under stirring, and stir and react at room temperature for 5 h to obtain a third mixed solution;

[0059] S22. Centrifuge the third mixed solution at a high speed at 11000 rpm for 12 min. The separated solid is washed with purified water 3 times and then dried in vacuum. The drying temperature is 50 °C. After drying for 22 h, polydopamine particles are obtained and ground into a powder for standby;

[0060] S23. Add polydopamine powder to purified water and perform ultrasonic treatment. Set the pulse mode, ultrasonic frequency 45 kHz, and ultrasonic treatment for 2 h to obtain a polydopamine nanoparticle dispersion;

[0061] S24. Dissolve N-acetylcysteine in purified water under stirring, and adjust the pH value to 8.8 with 0.1 M sodium hydroxide solution, and stir for 2 h to obtain an N-acetylcysteine solution;

[0062] S25. Slowly add the polydopamine nanoparticle dispersion to the N-acetylcysteine solution under stirring, and stir and react at room temperature for 13 h to obtain a fourth mixed solution;

[0063] S26. Centrifuge the fourth mixed solution at a high speed at 11000 rpm for 12 min. The separated solid is washed alternately with purified water and phosphate buffered saline 3 times and then freeze-dried. The drying temperature is -50 °C. After drying for 22 h, modified polydopamine nanoparticles are obtained and ground into a powder for standby.

[0064] The modified polydopamine nanoparticles are obtained by grafting N-acetylcysteine on the surface of polydopamine nanoparticles. The particle size of the modified polydopamine nanoparticles is 95 - 105 nm, and the specific surface area is 130 - 150 m2 / g.

[0065] The mass ratio of the polydopamine nanoparticles to N-acetylcysteine is 1:0.2.

[0066] The preparation method of the sulfonated carbon nanotubes includes:

[0067] S31. Prepare a mixed acid solution with a volume ratio of concentrated sulfuric acid to concentrated nitric acid of 3:1, and disperse the carbon nanotubes in the mixed acid solution for ultrasonic treatment. The ultrasonic frequency is 45 kHz, the ultrasonic temperature is 85 °C, and after ultrasonic treatment for 5 h, a fifth mixed solution is obtained;

[0068] S32. Perform high-speed centrifugal separation on the fifth mixed solution at a rotation speed of 11000 rpm for 12 min. The separated solid is washed 3 times with purified water and then vacuum-dried at a drying temperature of 70 °C. After drying for 22 h, oxidized carbon nanotubes are obtained and ground into a powder for standby;

[0069] S33. Add 100 mg of oxidized carbon nanotube powder to 50 mL of concentrated sulfuric acid and perform ultrasonic treatment. The ultrasonic frequency is 45 kHz, the ultrasonic temperature is 85 °C, and after ultrasonic treatment for 2 h, a sixth mixed solution is obtained;

[0070] S34. After the sixth mixed solution is cooled, it is slowly poured into purified water at 0 °C for high-speed centrifugal separation at a rotation speed of 11000 rpm for 12 min. The separated solid is washed 3 times with purified water and then vacuum-dried at a drying temperature of 65 °C. After drying for 13 h, sulfonated carbon nanotubes are obtained and ground into a powder for standby.

[0071] The sulfonated carbon nanotubes are prepared by introducing sulfonic acid groups (-SO3H) on the surface of the carbon nanotubes. The diameter of the sulfonated carbon nanotubes is 10 - 50 nm, the length is 1 - 10 μm, and the specific surface area is 360 - 400 m 2 / g.

[0072] A preparation method of a human tissue adhesive, applied to the described human tissue adhesive, includes the following steps:

[0073] S41. Prepare a seventh mixed solution with a volume ratio of dichloromethane to absolute ethanol of 1:1, and disperse the modified polydopamine nanoparticle powder, sulfonated carbon nanotube powder, and selenium-calcium phosphate composite nanoparticle powder in the seventh mixed solution for ultrasonic treatment. The ultrasonic frequency is 45 kHz, and after ultrasonic treatment for 2 h, an eighth mixed solution is obtained;

[0074] S42. Dissolve polylactic acid in dichloromethane under stirring. After stirring for 2 h, a polylactic acid solution is obtained. Then, add the polylactic acid solution, poly(N-isopropylacrylamide), curcumin, and quercetin to the eighth mixed solution in sequence, continue stirring for 3 h, then place it in an ice bath at 0 °C, add the growth factor and continue stirring for 1 h to obtain the ninth mixed solution;

[0075] S43. Pour the ninth mixed solution into the corresponding silicone mold for vacuum drying. The drying temperature is 40 °C. After drying for 22 h, the human tissue adhesive is obtained.

[0076] Example 2: This example discloses a human tissue adhesive, which includes the following raw materials in parts by weight: 5 parts of modified polydopamine nanoparticles, 1 part of sulfonated carbon nanotubes, 0.2 part of growth factor, 1 part of curcumin, 0.4 part of quercetin, 10 parts of poly(N-isopropylacrylamide), and 40 parts of polylactic acid. The human tissue adhesive also includes selenium-hydroxyapatite composite nanoparticles (Se-HAp NPs). The weight ratio of Se-HAp NPs to modified polydopamine nanoparticles is 15:5. The particle size of Se-HAp NPs is 30 - 50 nm, and the specific surface area is 140 - 150 m 2 / g. The preparation methods of Se-HAp NPs, modified polydopamine nanoparticles, and sulfonated carbon nanotubes in this example are the same as those in Example 1. The preparation method of the human tissue adhesive in this example is the same as that in Example 1.

[0077] Example 3: This example discloses a human tissue adhesive, which includes the following raw materials in parts by weight: 10 parts of modified polydopamine nanoparticles, 5 parts of sulfonated carbon nanotubes, 1 part of growth factor, 2 parts of curcumin, 2 parts of quercetin, 20 parts of poly(N-isopropylacrylamide), and 60 parts of polylactic acid. The human tissue adhesive also includes selenium-hydroxyapatite composite nanoparticles (Se-HAp NPs). The weight ratio of Se-HAp NPs to modified polydopamine nanoparticles is 15:10. The particle size of Se-HAp NPs is 30 - 50 nm, and the specific surface area is 140 - 150 m 2 / g. The preparation methods of Se-HAp NPs, modified polydopamine nanoparticles, and sulfonated carbon nanotubes in this example are the same as those in Example 1. The preparation method of the human tissue adhesive in this example is the same as that in Example 1.

[0078] Control Group 1: The difference between this example and Example 1 is that it does not contain modified polydopamine nanoparticles. This example discloses a human tissue adhesive, which comprises the following raw materials in parts by weight: 3 parts of sulfonated carbon nanotubes, 0.6 part of growth factor, 1.5 parts of curcumin, 1.2 parts of quercetin, 15 parts of poly(N-isopropylacrylamide), 50 parts of polylactic acid. The human tissue adhesive further comprises selenium-hydroxyapatite composite nanoparticles (Se-HAp NPs), with 15 parts of Se-HAp NPs, the particle size of Se-HAp NPs being 30 - 50 nm, and the specific surface area being 140 - 150 m 2 / g. The preparation methods of Se-HAp NPs and sulfonated carbon nanotubes in this example are the same as those in Example 1. The preparation method of a human tissue adhesive in this example is the same as that in Example 1.

[0079] Control Group 2: The difference between this example and Example 1 is that it does not contain sulfonated carbon nanotubes. This example discloses a human tissue adhesive, which comprises the following raw materials in parts by weight: 7.5 parts of modified polydopamine nanoparticles, 0.6 part of growth factor, 1.5 parts of curcumin, 1.2 parts of quercetin, 15 parts of poly(N-isopropylacrylamide), 50 parts of polylactic acid. The human tissue adhesive further comprises selenium-hydroxyapatite composite nanoparticles (Se-HAp NPs), with the weight ratio of Se-HAp NPs to modified polydopamine nanoparticles being 15:7.5, the particle size of Se-HAp NPs being 30 - 50 nm, and the specific surface area being 140 - 150 m 2 / g. The preparation methods of Se-HAp NPs and modified polydopamine nanoparticles in this example are the same as those in Example 1. The preparation method of a human tissue adhesive in this example is the same as that in Example 1.

[0080] Control Group 3: The difference between this example and Example 1 is that it does not contain modified polydopamine nanoparticles and sulfonated carbon nanotubes. This example discloses a human tissue adhesive, which comprises the following raw materials in parts by weight: 0.6 part of growth factor, 1.5 parts of curcumin, 1.2 parts of quercetin, 15 parts of poly(N-isopropylacrylamide), 50 parts of polylactic acid. The human tissue adhesive further comprises selenium-hydroxyapatite composite nanoparticles (Se-HAp NPs), with the weight ratio of Se-HAp NPs to modified polydopamine nanoparticles being 15:7.5, the particle size of Se-HAp NPs being 30 - 50 nm, and the specific surface area being 140 - 150 m 2 / g. The preparation method of Se-HAp NPs in this example is the same as that in Example 1. The preparation method of a human tissue adhesive in this example is the same as that in Example 1.

[0081] Control Group 4: The difference between this example and Example 1 is that it does not contain Se-HAp NPs. This example discloses a human tissue adhesive, which comprises the following raw materials in parts by weight: 7.5 parts of modified polydopamine nanoparticles, 3 parts of sulfonated carbon nanotubes, 0.6 part of growth factor, 1.5 parts of curcumin, 1.2 parts of quercetin, 15 parts of poly(N-isopropylacrylamide), and 50 parts of polylactic acid. The preparation methods of the modified polydopamine nanoparticles and sulfonated carbon nanotubes in this example are the same as those in Example 1. The preparation method of a human tissue adhesive in this example is the same as that in Example 1.

[0082] Effect evaluation: (1) Adhesion performance test: After a 6-mm-diameter pigskin was prepared and soaked in phosphate buffered saline for 24 h, it was taken out and fixed to a cylindrical fixture of a universal material testing machine. The adhesives prepared in each experimental group were applied between two pieces of pigskin, a pressure of 50 kPa was applied and kept for 5 minutes for curing, and then it was pulled apart at a tensile speed of 1 mm / min. The adhesive force and adhesive strength of the adhesive were measured at a constant peeling speed of 50 mm / min, and the peeling strength of the adhesive was measured according to the 180° peeling method. Each experimental group was repeated 3 times and the average value was taken; (2) Tensile performance test: After the adhesives prepared in each experimental group were soaked in phosphate buffered saline at 37 °C for 24 h, a tensile experiment was carried out using a universal material testing machine at a constant peeling speed of 50 mm / min, and the tensile strength and elastic modulus of the materials in each experimental group were recorded. Each experimental group was repeated 3 times and the average value was taken.

[0083] Table 1 Performance determination results of adhesives prepared in each experimental group

[0084] Group Adhesion force / N Adhesion strength / MPa Wet state peel strength / N / m Tensile strength / MPa Elastic modulus / MPa Example 1 7.5±0.4 2.8±0.2 68±2 2.6±0.2 0.5±0.05 Example 2 6.8±0.2 2.4±0.1 64±3 2.2±0.1 0.6±0.05 Example 3 7.2±0.1 2.7±0.1 67±2 2.5±0.1 0.5±0.08 Control group 1 5.4±0.6 1.6±0.3 39±5 1.9±0.2 0.6±0.06 Control group 2 5.7±0.4 1.5±0.2 35±4 1.3±0.1 0.6±0.08 Control group 3 2.4±0.5 0.9±0.1 29±4 0.8±0.1 0.5±0.1 Control group 4 5.6±0.4 1.8±0.1 42±2 1.7±0.2 0.6±0.08

[0085] Table 1 shows the statistical results of the performance measurements of the adhesives obtained in each experimental group. It can be seen from Table 1 that there are significant differences in the performance of the adhesives prepared in each experimental group. Higher adhesive force, adhesive strength, and peel strength can ensure that the adhesive is not easily detached in a dynamic physiological environment, guaranteeing the reliability of long-term use; higher tensile strength ensures that the adhesive will not break easily in a high-stress environment, and an appropriate elastic modulus ensures a good match between the adhesive and biological tissues, ensuring safety. By comparing the performance of the adhesives prepared in Examples 1-3 with those in Control Groups 1-4, it can be found that, generally speaking, the adhesives prepared in Examples 1-3 have better performance. Among them, the adhesive prepared in Example 1 has the best adhesion performance, with the highest adhesive force of 7.5 N, the highest adhesive strength of 2.8 MPa, and the highest peel strength of 68 N / m, showing excellent adhesion performance. At the same time, it has the highest tensile strength and an appropriate elastic modulus, showing good flexibility, being able to adapt to the movement state of dynamic tissues without affecting the normal function of tissues. By comparing Example 1 with Control Groups 1-3, it can be found that when modified polydopamine nanoparticles and sulfonated carbon nanotubes are added simultaneously during the preparation of the adhesive, the adhesion and flexibility of the adhesive can be significantly enhanced.

[0086] Through the above limited experiments, the application effect of the human tissue adhesive in Example 1 of the present invention is remarkable. By optimizing the formula of the adhesive and combining modern nanotechnology, the adhesion and flexibility of the adhesive can be significantly improved, ensuring that it can firmly adhere to the surface of dynamic tissues and adapt to the dynamic tissue environment, maintaining long-term stability.

[0087] Finally, it should be noted that although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A human tissue adhesive, characterized in that, It includes the following raw materials in parts by weight: 5-10 parts of modified polydopamine nanoparticles, 1-5 parts of sulfonated carbon nanotubes, 0.2-1 part of growth factor, 1-2 parts of curcumin, 0.4-2 parts of quercetin, 10-20 parts of poly(N-isopropylacrylamide), and 40-60 parts of polylactic acid.

2. The human tissue adhesive according to claim 1, characterized in that, The human tissue adhesive further includes selenium-hydroxyapatite composite nanoparticles (Se-HAp NPs). The weight ratio of Se-HAp NPs to the modified polydopamine nanoparticles is 15:(5-10). The particle size of Se-HAp NPs is 30-50 nm, and the specific surface area is 140-150 m 2 / g.

3. The human tissue adhesive according to claim 2, characterized in that, The preparation method of the Se-HAp NPs includes: S11. Dissolve calcium nitrate in purified water under stirring, control the concentration to be 0.2 M, stir for 0.5-1 h, then slowly add polyvinylpyrrolidone dropwise, and continue to stir for 0.5-1 h to obtain a first mixed solution; S12. Dissolve ammonium dihydrogen phosphate and sodium selenite in purified water under stirring respectively, stir for 0.5-1 h to obtain an ammonium dihydrogen phosphate solution and a sodium selenite solution respectively, and control the concentrations of the ammonium dihydrogen phosphate solution and the sodium selenite solution to be 0.12 M and 0.03 M respectively; S13. Slowly add ammonia water to the first mixed solution under stirring in a water bath at 105-125 °C, adjust the pH value to 9-10, continue to stir for 1-2 h, then simultaneously drop in the ammonium dihydrogen phosphate solution and the sodium selenite solution, control the dropping rate to be 1 mL / min, and then continue to stir and react for 20-24 h to obtain a second mixed solution; S14. Centrifuge the second mixed solution at a high speed, with a rotation speed of 8000-10000 rpm, centrifuge for 10-15 min, wash the obtained solid alternately with purified water and absolute ethanol 3 times, then carry out vacuum drying, with a drying temperature of 60-70 °C, dry for 12-14 h, then place it in a muffle furnace and calcine at 400-600 °C for 2-4 h to obtain Se-HAp NPs and grind them into a powder form for standby.

4. The human tissue adhesive according to claim 1, wherein The preparation method of the modified polydopamine nanoparticles includes: S21. Dissolve dopamine hydrochloride in phosphate buffered saline under stirring, stir and react at room temperature for 4-6 h to obtain a third mixed solution; S22. Centrifuge the third mixed solution at a high speed, with a rotation speed of 10000-12000 rpm, centrifuge for 10-15 min, wash the separated solid with purified water 3 times, then carry out vacuum drying, with a drying temperature of 45-55 °C, dry for 20-24 h to obtain polydopamine particles and grind them into a powder form for standby; S23. Add polydopamine powder to purified water and carry out ultrasonic treatment, set the pulse mode, with an ultrasonic frequency of 40-50 kHz, ultrasonic treat for 1-2 h to obtain a polydopamine nanoparticle dispersion; S24. Dissolve N-acetylcysteine in purified water under stirring, and adjust the pH value to 8.5-9.0 with 0.1 M sodium hydroxide solution, stir for 1-2 h to obtain an N-acetylcysteine solution; S25. Slowly add the polydopamine nanoparticle dispersion to the N-acetylcysteine solution under stirring, stir and react at room temperature for 12-14 h to obtain a fourth mixed solution; S26. The fourth mixed solution is subjected to high-speed centrifugal separation at a rotational speed of 10,000 - 12,000 rpm for 10 - 15 minutes. The separated solid is washed alternately with purified water and phosphate buffered saline three times and then freeze-dried. The drying temperature is -40 - -60 °C. After drying for 20 - 24 hours, modified polydopamine nanoparticles are obtained and ground into a powder for standby.

5. The human tissue adhesive according to claim 4, wherein The modified polydopamine nanoparticles are obtained by grafting N-acetylcysteine on the surface of polydopamine nanoparticles. The particle size of the modified polydopamine nanoparticles is 95-105 nm, and the specific surface area is 130-150 m 2 / g.

6. The human tissue adhesive according to claim 4, wherein The mass ratio of the polydopamine nanoparticles to N-acetylcysteine is 1:(0.1 - 0.3).

7. A human tissue adhesive according to claim 1, characterized in that, The preparation method of the sulfonated carbon nanotubes includes: S31. Prepare a mixed acid solution with a volume ratio of concentrated sulfuric acid to concentrated nitric acid of 3:1, and disperse carbon nanotubes in the mixed acid solution for ultrasonic treatment. The ultrasonic frequency is 40 - 50 kHz, the ultrasonic temperature is 80 - 90 °C, and after ultrasonic treatment for 4 - 6 hours, a fifth mixed solution is obtained; S32. The fifth mixed solution is subjected to high-speed centrifugal separation at a rotational speed of 10,000 - 12,000 rpm for 10 - 15 minutes. The separated solid is washed three times with purified water and then vacuum-dried. The drying temperature is 65 - 75 °C. After drying for 20 - 24 hours, oxidized carbon nanotubes are obtained and ground into a powder for standby; S33. Add 100 mg of oxidized carbon nanotube powder to 50 mL of concentrated sulfuric acid and perform ultrasonic treatment. The ultrasonic frequency is 40 - 50 kHz, the ultrasonic temperature is 80 - 90 °C, and after ultrasonic treatment for 1 - 2 hours, a sixth mixed solution is obtained; S34. After the sixth mixed solution is cooled, it is slowly poured into purified water at 0 - 4 °C for high-speed centrifugal separation. The rotational speed is 10,000 - 12,000 rpm, and the centrifugation is carried out for 10 - 15 minutes. The separated solid is washed three times with purified water and then vacuum-dried. The drying temperature is 60 - 70 °C. After drying for 12 - 14 hours, sulfonated carbon nanotubes are obtained and ground into a powder for standby.

8. The human tissue adhesive according to claim 7, characterized in that The sulfonated carbon nanotubes are prepared by introducing sulfonic acid groups (-SO3H) on the surface of carbon nanotubes. The sulfonated carbon nanotubes have a diameter of 10 - 50 nm, a length of 1 - 10 μm, and a specific surface area of 360 - 400 m 2 / g.

9. A preparation method of a human tissue adhesive, which is applied to prepare a human tissue adhesive as described in any one of claims 1 to 8, characterized in that, The method includes the following steps: S41. Prepare a seventh mixed solution with a volume ratio of dichloromethane to absolute ethanol of 1:

1. Disperse the modified polydopamine nanoparticle powder, sulfonated carbon nanotube powder, and selenium-calcium phosphate composite nanoparticle powder in the seventh mixed solution for ultrasonic treatment. The ultrasonic frequency is 40 - 50 kHz, and after ultrasonic treatment for 1 - 2 hours, an eighth mixed solution is obtained; S42. Dissolve polylactic acid in dichloromethane under stirring for 1 - 2 hours to obtain a polylactic acid solution. The polylactic acid solution, poly(N-isopropylacrylamide), curcumin, and quercetin are successively added to the eighth mixed solution, and stirring is continued for 2 - 4 hours and then placed in an ice bath at 0 - 4 °C. Growth factors are added and stirring is continued for 0.5 - 1 hour to obtain a ninth mixed solution; S43. Pour the ninth mixed solution into a corresponding silicone mold for vacuum drying. The drying temperature is 35 - 40 °C. After drying for 20 - 24 hours, the human tissue adhesive is obtained.

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