A human tissue adhesive and a method for its preparation

Abstract

The present application relates to the technical field of biological adhesives, and particularly relates to a human tissue adhesive and a preparation method thereof, which 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-isopropyl acrylamide) and polylactic acid. In the present application, the modified polydopamine nanoparticles significantly improve the wet-state adhesive strength of the adhesive, and the flexible nano-supporting effect of the sulfonated carbon nanotubes synergistically enhances the adhesion and flexibility thereof, and the two form a stable nano-network structure to support the uniform distribution of the Se-HAp NPs, the sulfonated carbon nanotubes ensure the functional integrity of the Se-HAp NPs in a dynamic environment, and the Se-HAp NPs together with the modified polydopamine nanoparticles 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, in particular to a human tissue adhesive and a preparation method thereof. Background Art

[0002] In modern medicine, tissue adhesives have become an important component of wound repair, surgical suture replacement, and biomedical materials. However, the tissue adhesives currently on the market are mainly targeted at static tissues, but have significant limitations in the repair of dynamic tissues such as the heart, lungs, and blood vessels. Moreover, dynamic tissues are in a moist environment for a long time, which further reduces the adhesion of the adhesive. Therefore, the continuous mechanical motion characteristics such as the continuous beating of the heart, the cyclical expansion and contraction of the lungs, and the pulsation of blood vessels place higher demands on the adhesion, flexibility, and stability of the adhesive. At the same time, inflammatory reactions and oxidative stress will occur during the tissue repair process. If the adhesive cannot provide good biocompatibility and the ability to promote repair and regeneration, it will lead to slow tissue healing or failure. Therefore, it is very meaningful to develop a tissue adhesive that can stably adhere in a dynamic environment and at the same time has high flexibility and the ability to promote repair and regeneration. 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 adhesive formula and combining it with modern nanotechnology, the technical problems such as insufficient dynamic tissue adhesion and poor mechanical flexibility are effectively solved, so that the adhesive can function stably under dynamic physiological environments.

[0005] (2) Technical solution

[0006] To achieve the above objectives, on the one hand, the present invention provides a human tissue adhesive comprising 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 parts 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] Furthermore, the human tissue adhesive further comprises selenium-calcium phosphate composite nanoparticles (Se-HAp NPs), wherein 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] Furthermore, the preparation method of the Se-HAp NPs comprises:

[0009] S11. Calcium nitrate was dissolved in purified water under stirring to a concentration of 0.2M. After stirring for 0.5 to 1h, polyvinyl pyrrolidone was slowly added dropwise, and stirring was continued for 0.5 to 1h to obtain a first mixed solution.

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

[0011] S13. Slowly add aqueous ammonia dropwise to the first mixed solution while stirring in a water bath at 105-125°C. Adjust the pH to 9-10. Continue stirring for 1-2 hours. Then, simultaneously add the ammonium dihydrogen phosphate solution and the sodium selenite solution dropwise at a rate of 1 mL / min. Continue stirring for 20-24 hours to obtain a second mixed solution.

[0012] S14. The second mixed solution is centrifuged at high speed at 8,000–10,000 rpm for 10–15 min. The resulting solid is washed three times with purified water and anhydrous ethanol, then vacuum-dried at 60–70°C for 12–14 h. The solid is then calcined in a muffle furnace at 400–600°C for 2–4 h to obtain Se-HAp NPs, which are then ground into a powder for later use.

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

[0014] S21 dopamine hydrochloride was dissolved in phosphate buffered saline under stirring, and the reaction was stirred at room temperature for 4 to 6 hours to obtain a third mixed solution;

[0015] S22. The third mixed solution was subjected to high-speed centrifugation at a speed of 10,000 to 12,000 rpm for 10 to 15 minutes. The separated solid was washed three times with purified water and then vacuum dried at a drying temperature of 45 to 55°C for 20 to 24 hours to obtain polydopamine particles which were ground into a powder for later use.

[0016] S23. Polydopamine powder was added to purified water and sonicated in pulse mode at a frequency of 40 to 50 kHz for 1 to 2 h to obtain a dispersion of polydopamine nanoparticles.

[0017] S24. N-acetylcysteine ​​was dissolved in purified water with stirring, and the pH was adjusted to 8.5~9.0 with 0.1M sodium hydroxide solution, and stirred for 1~2h to obtain an N-acetylcysteine ​​solution;

[0018] S25. The polydopamine nanoparticle dispersion was slowly added to the N-acetylcysteine ​​solution under stirring, and the reaction was stirred at room temperature for 12 to 14 hours to obtain a fourth mixed solution;

[0019] S26. The fourth mixed solution is subjected to high-speed centrifugation at a speed of 10,000-12,000 rpm for 10-15 minutes. The separated solid is washed three times with purified water and phosphate buffered saline, and then freeze-dried at a drying temperature of -40°C to -60°C for 20-24 hours to obtain modified polydopamine nanoparticles, which are ground into a powder for later use.

[0020] Furthermore, 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] Furthermore, the mass ratio of the polydopamine nanoparticles to N-acetylcysteine ​​is 1:(0.1-0.3).

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

[0023] S31. A mixed acid solution of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1 was prepared, and the carbon nanotubes were dispersed in the mixed acid solution and subjected to ultrasonic treatment at an ultrasonic frequency of 40 to 50 kHz and an ultrasonic temperature of 80 to 90 ° C. The fifth mixed solution was obtained after ultrasonic treatment for 4 to 6 hours.

[0024] S32. The fifth mixed solution was subjected to high-speed centrifugation at a speed of 10,000 to 12,000 rpm for 10 to 15 minutes. The separated solid was washed three times with purified water and then vacuum dried at a drying temperature of 65 to 75°C for 20 to 24 hours to obtain oxidized carbon nanotubes and ground into a powder for later use.

[0025] S33. 100 mg of oxidized carbon nanotube powder was added to 50 mL of concentrated sulfuric acid and subjected to ultrasonic treatment at an ultrasonic frequency of 40 to 50 kHz and an ultrasonic temperature of 80 to 90 ° C for 1 to 2 h to obtain a sixth mixed solution;

[0026] S34. After cooling, the sixth mixed solution is slowly poured into purified water at 0-4°C and centrifuged at high speed at 10,000-12,000 rpm for 10-15 minutes. The separated solid is washed three times with purified water and then vacuum dried at 60-70°C for 12-14 hours to obtain sulfonated carbon nanotubes, which are ground into a powder for later use.

[0027] Furthermore, the sulfonated carbon nanotubes are prepared by introducing sulfonic acid groups (-SO3H) on the surface of 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.

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

[0029] S41 configuration of dichloromethane and anhydrous ethanol volume ratio of 1: 1 seventh mixed solution, the modified polydopamine nanoparticle powder, sulfonated carbon nanotube powder, selenium - calcium phosphate composite nanoparticle powder was dispersed in the seventh mixed solution and ultrasonic treatment, ultrasonic frequency 40 ~ 50 kHz, ultrasonic treatment 1 ~ 2h to obtain an eighth mixed solution;

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

[0031] S43. Pour the ninth mixed solution into the corresponding silicone mold and vacuum dry it at a temperature of 35-40° C. for 20-24 hours to obtain the human tissue adhesive.

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

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

[0034] Curcumin is a natural polyphenol with anti-inflammatory, antioxidant, antimicrobial, and angiogenic properties. In dynamic tissues, curcumin can reduce inflammation, minimize tissue damage, and improve the biocompatibility of adhesives. It also provides antioxidant protection, reduces oxidative stress, and protects surrounding tissue cells. It is particularly suitable for dynamic tissues susceptible to oxidative damage, such as cardiovascular and lung tissue. It can also prevent tissue fibrosis, reduce excessive scarring, and improve the elastic compatibility of adhesives under high-tension conditions.

[0035] Quercetin is a flavonoid compound with anti-inflammatory, antibacterial, antioxidant and cellular environment stabilizing effects. It can inhibit inflammatory responses, improve the physiological stability of dynamic tissues, destroy bacterial DNA, and increase the durability of adhesives in blood flow and moist environments. At the same time, it reduces oxidative stress-induced matrix degradation and enhances the adhesive's support and flexibility for tissues.

[0036] Poly(N-isopropylacrylamide) is a smart, thermosensitive hydrogel that contracts at human body temperature (37°C) and expands at lower temperatures, endowing the adhesive with temperature-responsive properties. The lower critical solution temperature (LCST) of poly(N-isopropylacrylamide) is approximately 32°C. Above this temperature, the poly(N-isopropylacrylamide) molecules undergo hydrophobic contraction, enhancing bond strength. At lower temperatures, they swell, which helps enhance the adhesive's plasticity and adapt to the dynamic environments of different tissues. The hydrogel structure of poly(N-isopropylacrylamide) disperses external tensile and contractile forces, improving tissue flexibility and preventing adhesive rupture during heartbeat or lung expansion. By forming a soft layer, it reduces mechanical friction, making it particularly suitable for tissues subject to high dynamic loads, 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 highly dynamic tissue environments and is not easy to break or fall off. As polylactic acid slowly degrades and releases lactic acid, lactic acid can further promote tissue repair without causing foreign body reactions, 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 adhesive's adhesion and flexibility. The two form a stable nanonetwork structure that supports the uniform distribution of Se-HAp NPs. The introduction of Se-HAp NPs significantly improves the adhesive's bioactivity and stability, promotes tissue repair, and enables it to adapt to dynamic tissue environments such as the heart, lungs, and blood vessels. Polydopamine, rich in dopamine structural units, is grafted onto the surface of polydopamine nanoparticles to produce modified polydopamine nanoparticles. These nanoparticles enhance adhesion in wet environments through covalent and non-covalent interactions and provide a dynamic crosslinking mechanism. The sulfhydryl groups (-SH) on the surface of N-acetylcysteine ​​form disulfide bonds (-SS-) with free cysteines on the surface of tissue proteins, significantly enhancing wet adhesion strength. The high aspect ratio and nanoreinforcement effect of the sulfonated carbon nanotubes (SCNTs) enable the formation of a nanostructured network within the adhesive, uniformly distributing stress and providing exceptional tensile and flexural strength. This allows the adhesive to adapt to continuous tissue movement, further enhancing its tensile strength and flexibility. The presence of surface sulfonic acid groups (-SO3H) significantly enhances the water solubility of the SCNTs and allows them to interact with positively charged groups on the surface of biological tissue proteins, improving the adhesive stability in dynamic tissues. The modified polydopamine nanoparticles (PDNPs) prevent the adhesive from detaching under high shear conditions, and the SDNTs provide flexible nanostructured support, enhancing overall adhesive strength and flexibility. The stable nanostructure formed by the modified PDNPs and SCNTs further supports the uniform distribution of Se-HAp NPs. Ionic bridging with the SCNTs and encapsulation within the SCNTs' flexible carbon nanostructure ensure the functional integrity of the Se-HAp NPs under dynamic conditions. The Se-HAp NPs significantly enhance the bioactivity of the adhesive and, together with the modified PDNPs, improve the adhesive's stability in wet environments while promoting tissue repair. Modified polydopamine nanoparticles have good hydrophilicity and biomimetic interface, can effectively remove reactive oxygen species, reduce adhesive degradation, and improve biocompatibility, while Se-HAp NPs slowly release Ca at the adhesive interface. 2+ 、Se 2+ and PO4 3- , released Ca 2+ and Se 2+ Charge adsorption occurs with proteins and phospholipid molecules, further enhancing interfacial stability, and Ca 2+ Can induce cell adhesion and bone tissue regeneration, Se 2+ It has antioxidant and antibacterial properties, destroys bacterial DNA, PO4 3-By forming calcium phosphate deposits on the tissue surface, the adhesive's biointegration ability is improved, and the self-healing ability of the calcium phosphate structure enables the adhesive to adapt to the dynamic physiological environments of the heart, lungs, and blood vessels, thereby improving the adhesive's durability. Combined with the bioactive sites provided by the cell-friendly interface of modified polydopamine nanoparticles, it promotes cell adhesion, proliferation, and differentiation, significantly improving the repair and regeneration capacity 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 maintain strong adhesion on dynamic tissue surfaces, but also to exist stably in physiological environments for a long time.

[0039] (3) Beneficial effects

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1. The dynamic cross-linking mechanism of modified polydopamine nanoparticles significantly enhances wet adhesion strength, ensuring the adhesive resists detachment under high shear conditions. The flexible nanostructured support provided by sulfonated carbon nanotubes enhances overall bond strength and flexibility.

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

[0043] 3. Modified polydopamine nanoparticles and sulfonated carbon nanotubes form a stable nanonetwork structure that supports the uniform distribution of Se-HAp NPs. Together with the modified polydopamine nanoparticles, they 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a SEM image of the sulfonated carbon nanotubes of Example 1 of the present invention;

[0046] Figure 2 This is the SEM image of Se-HAp NPs in Example 1 of the present invention. DETAILED DESCRIPTION

[0047] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0048] The experimental equipment and preparations of the embodiments described below are as follows: electronic balance (Sartorius, Germany), electric constant temperature water bath (Jiangsu Kedao), magnetic stirrer (Shanghai Meiyingpu), ultrasonic analyzer (Shanghai Yixin), high-speed centrifuge (Guangzhou Jidi), vacuum drying oven (Shanghai Jiecheng), muffle furnace (Hangzhou Lantian Instrument), electric blast drying oven (Suzhou Greida), scanning electron microscope (Zeiss, Germany), specific surface area analyzer (Beijing Best Instrument Technology), freeze dryer (Shanghai Pudong Freeze Drying), pH meter (Shanghai Yidian), universal material testing machine (Suzhou Jianzhuo); chemicals and reagents were purchased from Sigma-Aldrich.

[0049] Example 1: This example discloses a human tissue adhesive, comprising the following raw materials in parts by weight: 7.5 parts of modified polydopamine nanoparticles, 3 parts of sulfonated carbon nanotubes, 0.6 parts 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 human tissue adhesive also includes selenium-calcium phosphate composite nanoparticles (Se-HAp NPs), wherein 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.

[0050] In the human tissue adhesive of the present invention, modified polydopamine nanoparticles and sulfonated carbon nanotubes synergistically enhance the adhesive's adhesion and flexibility. The two form a stable nanonetwork structure that supports the uniform distribution of Se-HAp NPs. The introduction of Se-HAp NPs significantly improves the adhesive's bioactivity and stability, 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 polydopamine nanoparticles to obtain modified polydopamine nanoparticles. The modified polydopamine nanoparticles have a distinct network and pore structure. Grafting N-acetylcysteine ​​reduces the aggregation tendency of the modified polydopamine nanoparticles, improving 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 adhesion by forming covalent bonds and non-covalent interactions with tissue proteins in a wet environment and provide a dynamic cross-linking mechanism. The sulfhydryl groups (-SH) on the surface of N-acetylcysteine ​​form disulfide bonds (-SS-) by disulfide cross-linking with free cysteine ​​on the surface of tissue proteins, greatly enhancing the wet adhesion strength. The disulfide bonds (-SS-) can also break and recombine under different physiological conditions, allowing the adhesive to adapt to the physiological environment of continuous deformation such as the heart and lungs, thereby providing long-lasting dynamic adhesion ability. Figure 1 The SEM image of sulfonated carbon nanotubes shows a distinct tubular structure. The high aspect ratio and nano-reinforcement effect of sulfonated carbon nanotubes can form a nano-network structure inside the adhesive. In dynamic tissues, the high strength and flexibility of sulfonated carbon nanotubes help disperse the mechanical stress in the adhesive, reduce local stress concentration, and provide excellent tensile and bending strength, allowing the adhesive to adapt to the continuous movement of the tissue, further improving the tensile strength and flexibility of the adhesive, and preventing dynamic tissue from cracking or delamination due to movement. The presence of sulfonic acid groups (-SO3H) on its surface significantly enhances the water solubility of sulfonated carbon nanotubes, and the sulfonic acid groups (-SO3H) as strong anionic groups can interact with the positively charged groups on the surface of biological tissue proteins to enhance the bonding force, thereby improving the bonding stability of dynamic tissues. The modified polydopamine nanoparticles ensure that the adhesive is not easy to fall off under high shear conditions, and the flexible nano-support provided by the sulfonated carbon nanotubes enhances the overall bonding strength and flexibility. The stable nano-network structure formed by the modified polydopamine nanoparticles and sulfonated carbon nanotubes further supports the uniform distribution of Se-HAp NPs. Figure 2 The SEM image of Se-HAp NPs shows that the particle size of Se-HAp NPs is uniform and the morphology is spherical. The sulfonic acid groups (-SO3H) on the surface of sulfonated carbon nanotubes interact with the Ca 2+Ionic bridge connection occurs and is wrapped by the flexible carbon nanoskeleton of sulfonated carbon nanotubes to prevent their agglomeration and ensure the functional integrity of Se-HAp NPs in dynamic environments. Se-HApNPs significantly improve the bioactivity of the adhesive and, together with modified polydopamine nanoparticles, improve the stability of the adhesive in a wet environment while promoting tissue repair. Modified polydopamine nanoparticles have good hydrophilicity and biomimetic interface. The N-acetylcysteine ​​grafted on its surface can effectively remove reactive oxygen species, reduce adhesive degradation, and improve biocompatibility. Se-HApNPs slowly release Ca at the bonding interface. 2+ 、Se 2+ and PO4 3- , released Ca 2+ and Se 2+ Charge adsorption occurs with proteins and phospholipid molecules, further enhancing interfacial stability, and Ca 2+ Can induce cell adhesion and bone tissue regeneration, Se 2+ It has antioxidant and antibacterial properties, destroys bacterial DNA, reduces oxidative stress, PO4 3- By forming calcium phosphate deposits on the tissue surface, the adhesive's biointegration ability is improved, and the self-healing ability of the calcium phosphate structure enables the adhesive to adapt to the dynamic physiological environments of the heart, lungs, and blood vessels, thereby improving the adhesive's durability. Combined with the bioactive sites provided by the cell-friendly interface of modified polydopamine nanoparticles, it promotes cell adhesion, proliferation, and differentiation, significantly improving the repair and regeneration capacity 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 maintain strong adhesion on dynamic tissue surfaces, but also to exist stably in physiological environments for a long time.

[0051] The preparation method of the Se-HAp NPs comprises:

[0052] S11 calcium nitrate was dissolved in purified water with stirring to control the concentration of 0.2M, and after stirring for 1h, polyvinyl pyrrolidone was slowly added dropwise, and stirring was continued for 1h to obtain a first mixed solution;

[0053] S12. Ammonium dihydrogen phosphate and sodium selenite were dissolved in purified water under stirring, and stirred for 1 h to obtain ammonium dihydrogen phosphate solution and sodium selenite solution, respectively. The concentrations of the ammonium dihydrogen phosphate solution and sodium selenite solution were controlled to be 0.12 M and 0.03 M, respectively.

[0054] S13. Aqueous ammonia was slowly added dropwise to the first mixed solution while stirring in a water bath at 120°C. The pH was adjusted to 9.5. Stirring was continued for 2 h. Then, the ammonium dihydrogen phosphate solution and the sodium selenite solution were simultaneously added dropwise at a rate of 1 mL / min. The reaction was continued with stirring for 22 h to obtain a second mixed solution.

[0055] S14. The second mixed solution was centrifuged at 9000 rpm for 12 minutes. The resulting solid was washed three times with purified water and anhydrous ethanol, then vacuum-dried at 65°C for 13 hours. The solid was then calcined in a muffle furnace at 500°C for 3 hours to obtain Se-HAp NPs, which were then ground into a powder for later use.

[0056] The preparation method of the modified polydopamine nanoparticles comprises:

[0057] S21 dopamine hydrochloride was dissolved in phosphate buffered saline under stirring, and the reaction was stirred at room temperature for 5h to obtain a third mixed solution;

[0058] S22. The third mixed solution was subjected to high-speed centrifugation at 11,000 rpm for 12 min. The separated solid was washed three times with purified water and then vacuum dried at 50 ° C for 22 h to obtain polydopamine particles which were ground into a powder for later use.

[0059] S23. Polydopamine powder was added to purified water and sonicated, setting the pulse mode to an ultrasonic frequency of 45kHz, and sonicated for 2h to obtain a dispersion of polydopamine nanoparticles;

[0060] S24. N-acetylcysteine ​​was dissolved in purified water with stirring, and the pH value was adjusted to 8.8 with 0.1M sodium hydroxide solution, and stirred for 2h to obtain an N-acetylcysteine ​​solution;

[0061] S25. The polydopamine nanoparticle dispersion was slowly added to the N-acetylcysteine ​​solution under stirring, and the reaction was stirred at room temperature for 13h to obtain a fourth mixed solution;

[0062] S26. The fourth mixed solution was subjected to high-speed centrifugation at 11,000 rpm for 12 minutes. The separated solid was washed three times with purified water and phosphate buffered saline, and then freeze-dried at -50°C for 22 hours to obtain modified polydopamine nanoparticles, which were ground into a powder for later use.

[0063] 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.

[0064] The mass ratio of the polydopamine nanoparticles to N-acetylcysteine ​​is 1:0.2.

[0065] The preparation method of the sulfonated carbon nanotubes comprises:

[0066] S31 configuration of concentrated sulfuric acid and concentrated nitric acid volume ratio of 3: 1 mixed acid solution, and the carbon nanotubes were dispersed in the mixed acid solution and ultrasonic treatment, ultrasonic frequency 45 kHz, ultrasonic temperature 85 ℃, ultrasonic treatment for 5h to obtain a fifth mixed solution;

[0067] S32. The fifth mixed solution was subjected to high-speed centrifugation at a speed of 11000 rpm for 12 min. The separated solid was washed three times with purified water and then vacuum dried at a drying temperature of 70 ° C. After drying for 22 h, the oxidized carbon nanotubes were ground into a powder and set aside.

[0068] S33 was added to 50mL of concentrated sulfuric acid 100mg of oxidized carbon nanotube powder and subjected to ultrasonic treatment at an ultrasonic frequency of 45kHz and an ultrasonic temperature of 85°C for 2h to obtain a sixth mixed solution;

[0069] S34. After cooling, the sixth mixed solution was slowly poured into purified water at 0°C and centrifuged at 11,000 rpm for 12 minutes. The separated solid was washed three times with purified water and then vacuum dried at 65°C for 13 hours to obtain sulfonated carbon nanotubes, which were ground into a powder for later use.

[0070] The sulfonated carbon nanotubes are prepared by introducing sulfonic acid groups (-SO3H) on the surface of 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.

[0071] A method for preparing a human tissue adhesive, applied to the aforementioned human tissue adhesive, comprises the following steps:

[0072] S41 configuration of dichloromethane and anhydrous ethanol volume ratio of 1: 1 seventh mixed solution, the modified polydopamine nanoparticle powder, sulfonated carbon nanotube powder, selenium - calcium phosphate composite nanoparticle powder was dispersed in the seventh mixed solution and ultrasonic treatment, ultrasonic frequency 45 kHz, ultrasonic treatment 2h to obtain an eighth mixed solution;

[0073] S42. Dissolve polylactic acid in dichloromethane under stirring for 2 hours to obtain a polylactic acid solution. The polylactic acid solution, poly(N-isopropylacrylamide), curcumin, and quercetin are sequentially added to the eighth mixed solution. Stirring is continued for 3 hours, and then placed in an ice bath at 0°C. Growth factors are added and stirring is continued for 1 hour to obtain a ninth mixed solution.

[0074] S43. The ninth mixed solution is poured into a corresponding silicone mold and vacuum dried at 40° C. for 22 hours to obtain the human tissue adhesive.

[0075] Example 2: This example discloses a human tissue adhesive, comprising the following raw materials in parts by weight: 5 parts of modified polydopamine nanoparticles, 1 part of sulfonated carbon nanotubes, 0.2 parts of growth factor, 1 part of curcumin, 0.4 parts of quercetin, 10 parts of poly(N-isopropylacrylamide), and 40 parts of polylactic acid. The human tissue adhesive also includes selenium-calcium phosphate composite nanoparticles (Se-HAp NPs), wherein 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 The preparation methods of Se-HAp NPs, modified polydopamine nanoparticles and sulfonated carbon nanotubes in this embodiment are the same as those in Example 1. The preparation method of a human tissue adhesive in this embodiment is the same as that in Example 1.

[0076] Example 3: This example discloses a human tissue adhesive, comprising 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-calcium phosphate composite nanoparticles (Se-HAp NPs), wherein 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 The preparation methods of Se-HAp NPs, modified polydopamine nanoparticles and sulfonated carbon nanotubes in this embodiment are the same as those in Example 1. The preparation method of a human tissue adhesive in this embodiment is the same as that in Example 1.

[0077] Control Group 1: This Example differs from Example 1 in that modified polydopamine nanoparticles are not included. This Example discloses a human tissue adhesive comprising the following raw materials in parts by weight: 3 parts sulfonated carbon nanotubes, 0.6 parts growth factor, 1.5 parts curcumin, 1.2 parts quercetin, 15 parts poly(N-isopropylacrylamide), and 50 parts polylactic acid. The human tissue adhesive further comprises 15 parts of selenium-calcium phosphate composite nanoparticles (Se-HAp NPs), with a particle size of 30-50 nm and a specific surface area of ​​140-150 m 2 The preparation methods of Se-HAp NPs and sulfonated carbon nanotubes in this embodiment are the same as those in Example 1. The preparation method of a human tissue adhesive in this embodiment is the same as that in Example 1.

[0078] Control group 2: This embodiment differs from embodiment 1 in that sulfonated carbon nanotubes are not included. This embodiment discloses a human tissue adhesive comprising the following raw materials in parts by weight: 7.5 parts of modified polydopamine nanoparticles, 0.6 parts 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 human tissue adhesive further comprises selenium-calcium phosphate composite nanoparticles (Se-HAp NPs), wherein the weight ratio of Se-HAp NPs to modified polydopamine nanoparticles is 15:7.5, and the particle size of Se-HAp NPs is 30-50 nm, and the specific surface area is 140-150 m 2 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.

[0079] Control group 3: This embodiment differs from embodiment 1 in that modified polydopamine nanoparticles and sulfonated carbon nanotubes are not included. This embodiment discloses a human tissue adhesive comprising the following raw materials in parts by weight: 0.6 parts 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 human tissue adhesive further comprises selenium-calcium phosphate composite nanoparticles (Se-HAp NPs), wherein 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 The preparation method of Se-HAp NPs in this embodiment is the same as that in Example 1. The preparation method of a human tissue adhesive in this embodiment is the same as that in Example 1.

[0080] Control Group 4: This example differs from Example 1 in that Se-HAp NPs are not present. This example discloses a human tissue adhesive comprising the following raw materials in parts by weight: 7.5 parts modified polydopamine nanoparticles, 3 parts sulfonated carbon nanotubes, 0.6 parts growth factor, 1.5 parts curcumin, 1.2 parts quercetin, 15 parts poly(N-isopropylacrylamide), and 50 parts polylactic acid. The preparation methods for the modified polydopamine nanoparticles and sulfonated carbon nanotubes in this example are the same as those in Example 1. The preparation method for a human tissue adhesive in this example is the same as that in Example 1.

[0081] Effect evaluation: (1) Adhesion performance test: Prepare pig skin with a diameter of 6 mm and soak it in phosphate buffered saline for 24 hours. Then take it out and fix it on the cylindrical fixture of the universal material testing machine. Take the adhesive prepared by each experimental group and apply it between two pieces of pig skin. Apply 50kPa pressure and keep it for 5 to 10 minutes to solidify. Then pull it apart at a tensile speed of 1mm / min. The adhesive force and adhesive strength of the adhesive are measured at a constant peeling speed of 50mm / min. The peeling strength of the adhesive is measured according to the 180° peeling method. Each experimental group is repeated 3 times and the average value is taken; (2) Tensile performance test: The adhesive prepared by each experimental group is soaked in phosphate buffered saline at 37℃ for 24 hours. After that, a tensile test is performed using a universal material testing machine at a constant peeling speed of 50mm / min. The tensile strength and elastic modulus of the material of each experimental group are recorded. Each experimental group is repeated 3 times and the average value is taken.

[0082]

[0083] Table 1 shows the statistical results of the adhesive performance measurements of the experimental groups. As can be seen from Table 1, there are significant differences in the performance of the adhesives prepared in the experimental groups. The higher adhesive force, bond strength, and peel strength ensure that the adhesives are not easily detached under dynamic physiological conditions, ensuring long-term reliability. The higher tensile strength ensures that the adhesives do not easily break under high stress conditions, and the appropriate elastic modulus ensures that the adhesives are compatible with biological tissues, ensuring safety. Comparing the adhesive performance of Examples 1-3 with Control Groups 1-4, it can be found that, overall, the adhesives prepared in Examples 1-3 have superior performance, and the adhesive prepared in Example 1 has the best adhesive performance, with a maximum bond force of 7.5 N, a maximum bond strength of 2.8 MPa, and a maximum peel strength of 68 N / m, demonstrating excellent adhesive performance. It also has the highest tensile strength and appropriate elastic modulus, exhibiting good flexibility, capable of adapting to the motion of dynamic tissues without affecting normal tissue function. Comparing Example 1 with Control Groups 1-4, it can be found that when modified polydopamine nanoparticles and sulfonated carbon nanotubes are added simultaneously during the preparation of the adhesive, the adhesive's adhesion and flexibility can be significantly enhanced.

[0084] Through the above limited experiments, the application effect of a human tissue adhesive in Example 1 of the present invention is significant. By optimizing the formula of the adhesive and combining it with modern nanotechnology, the adhesion and flexibility of the adhesive can be significantly improved, ensuring that it can maintain firm adhesion on the dynamic tissue surface, adapt to the dynamic tissue environment, and maintain long-term stability.

[0085] Finally, it should be noted that although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A human tissue adhesive, characterized in that: The invention 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 parts 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; The human tissue adhesive further comprises selenium-calcium phosphate composite nanoparticles (Se-HAp NPs), wherein 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; The preparation method of the modified polydopamine nanoparticles comprises: S21 dopamine hydrochloride was dissolved in phosphate buffered saline under stirring, and the reaction was stirred at room temperature for 4 to 6 hours to obtain a third mixed solution; S22. The third mixed solution was subjected to high-speed centrifugation at a speed of 10,000 to 12,000 rpm for 10 to 15 minutes. The separated solid was washed three times with purified water and then vacuum dried at a drying temperature of 45 to 55°C for 20 to 24 hours to obtain polydopamine particles which were ground into a powder for later use. S23. Polydopamine powder was added to purified water and sonicated, setting the pulse mode to an ultrasonic frequency of 40 to 50 kHz for 1 to 2 h to obtain a dispersion of polydopamine nanoparticles. S24. N-acetylcysteine ​​was dissolved in purified water with stirring, and the pH was adjusted to 8.5~9.0 with 0.1M sodium hydroxide solution, and stirred for 1~2h to obtain an N-acetylcysteine ​​solution; S25. The polydopamine nanoparticle dispersion was slowly added to the N-acetylcysteine ​​solution under stirring, and the reaction was stirred at room temperature for 12 to 14 hours to obtain a fourth mixed solution; S26. The fourth mixed solution is subjected to high-speed centrifugation at a speed of 10,000-12,000 rpm for 10-15 minutes. The separated solid is washed three times with purified water and phosphate buffered saline, and then freeze-dried at a drying temperature of -40°C to -60°C for 20-24 hours to obtain modified polydopamine nanoparticles, which are ground into a powder for later use.

2. The human tissue adhesive according to claim 1, characterized in that: The preparation method of the Se-HAp NPs comprises: S11 calcium nitrate was dissolved in purified water under stirring to control the concentration of 0.2M, and polyvinyl pyrrolidone was slowly added dropwise after stirring for 0.5 to 1h, and stirring was continued for 0.5 to 1h to obtain a first mixed solution; S12. Dissolve ammonium dihydrogen phosphate and sodium selenite in purified water under stirring, and stir for 0.5 to 1 h to obtain ammonium dihydrogen phosphate solution and sodium selenite solution, respectively. The concentrations of the ammonium dihydrogen phosphate solution and sodium selenite solution are controlled to be 0.12 M and 0.03 M, respectively. S13. Slowly add aqueous ammonia dropwise to the first mixed solution while stirring in a water bath at 105-125°C. Adjust the pH to 9-10. Continue stirring for 1-2 hours. Then, simultaneously add the ammonium dihydrogen phosphate solution and the sodium selenite solution dropwise at a rate of 1 mL / min. Continue stirring for 20-24 hours to obtain a second mixed solution. S14. The second mixed solution is centrifuged at high speed at 8,000–10,000 rpm for 10–15 min. The resulting solid is washed three times with purified water and anhydrous ethanol, then vacuum-dried at 60–70°C for 12–14 h. The solid is then calcined in a muffle furnace at 400–600°C for 2–4 h to obtain Se-HAp NPs, which are then ground into a powder for later use.

3. The human tissue adhesive according to claim 1, characterized in that: 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.

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

5. The human tissue adhesive according to claim 1, characterized in that: The preparation method of the sulfonated carbon nanotubes comprises: S31. A mixed acid solution of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1 was prepared, and the carbon nanotubes were dispersed in the mixed acid solution and subjected to ultrasonic treatment at an ultrasonic frequency of 40 to 50 kHz and an ultrasonic temperature of 80 to 90 ° C. The fifth mixed solution was obtained after ultrasonic treatment for 4 to 6 hours. S32. The fifth mixed solution was subjected to high-speed centrifugation at a speed of 10,000 to 12,000 rpm for 10 to 15 minutes. The separated solid was washed three times with purified water and then vacuum dried at a drying temperature of 65 to 75°C for 20 to 24 hours to obtain oxidized carbon nanotubes and ground into a powder for later use. S33. 100 mg of oxidized carbon nanotube powder was added to 50 mL of concentrated sulfuric acid and subjected to ultrasonic treatment at an ultrasonic frequency of 40 to 50 kHz and an ultrasonic temperature of 80 to 90 ° C. After ultrasonic treatment for 1 to 2 h, a sixth mixed solution was obtained; S34. After cooling, the sixth mixed solution is slowly poured into purified water at 0-4°C and centrifuged at high speed at 10,000-12,000 rpm for 10-15 minutes. The separated solid is washed three times with purified water and then vacuum dried at 60-70°C for 12-14 hours to obtain sulfonated carbon nanotubes, which are ground into a powder for later use.

6. The human tissue adhesive according to claim 5, characterized in that: The sulfonated carbon nanotubes are prepared by introducing sulfonic acid groups (-SO3H) on the surface of 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.

7. A method for preparing a human tissue adhesive, which is used to prepare a human tissue adhesive according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: S41 configuration of dichloromethane and anhydrous ethanol volume ratio of 1: 1 seventh mixed solution, the modified polydopamine nanoparticle powder, sulfonated carbon nanotube powder, selenium - calcium phosphate composite nanoparticle powder was dispersed in the seventh mixed solution and ultrasonic treatment, ultrasonic frequency 40 ~ 50 kHz, ultrasonic treatment 1 ~ 2h to obtain an eighth mixed solution; S42. Dissolve polylactic acid in dichloromethane with stirring for 1-2 hours to obtain a polylactic acid solution. Add the polylactic acid solution, poly(N-isopropylacrylamide), curcumin, and quercetin sequentially to the eighth mixed solution. Continue stirring for 2-4 hours, then place in an ice bath at 0-4°C. Add the growth factor and continue stirring for 0.5-1 hour to obtain a ninth mixed solution. S43. Pour the ninth mixed solution into the corresponding silicone mold and vacuum dry it at a temperature of 35-40° C. for 20-24 hours to obtain the human tissue adhesive.

Images