Preparation method and application of a metal ion-modified PVA / NC / PLL / drug ink composite film

Abstract

Preparation method and application of a metal ion-modified PVA / NC / PLL / medicinal ink composite film, which relates to the field of biomedical technology. First, the traditional Chinese medicine medicinal ink is prepared into medicinal ink nanoparticles. By using the negative charge of the medicinal ink nanoparticles and the positively charged polycationic polymer polylysine through ionic interactions, a nanofiber composite material is prepared by applying the high-voltage electrospinning technology. While ensuring the effects of the medicinal ink in stopping bleeding, cooling blood, clearing heat, and detumescence, a new method - near-infrared photothermal conversion effect is utilized, and at the same time, combined with the good antibacterial effect of the cationic polymer, the synergistic effect is achieved to promote diabetic wound healing, skin regeneration, eliminate the existence of bacterial biofilms, and avoid the potential safety hazards of antibacterial agents in the body. The metal ion-modified PVA / NC / PLL / medicinal ink composite film of the present invention is applied in the preparation of drugs or reagents for treating chronic diabetic infected wounds.

Description

Technical Field

[0001] The present invention relates to the field of biomedical technology. Background Art

[0002] It is reported that 25% of diabetic patients suffer from diabetic foot ulcers (DFUs). More seriously, the wound is infected for a long time and even eventually leads to amputation or osteomyelitis. Up to 90% of amputations are due to bacterial infections. Therefore, various antibacterial drugs are usually used clinically to treat diabetic wounds, but the effect is not ideal.

[0003] At present, the clinical response plan for diabetic foot is mainly prevention-based and treatment-assisted. The main treatment purpose is to improve symptoms and signs and prevent the further aggravation of the lesion. The specific plans mainly include anticoagulation, thrombolysis, anti-infection, etc. If conditions permit, vascular surgery can also be performed. However, any trauma wound of existing diabetic patients, especially diabetic foot, is very difficult to heal.

[0004] Therefore, with the increase in the number of diabetic patients and the threat to health, many strategies for treating diabetic wounds have received wide attention.

[0005] Antibacterial materials generally adopt the form of adding antibiotics, inorganic nano-materials or cationic antibacterial agents. However, the release of antibiotics may further increase the risk of generating bacterial drug resistance. The potential cytotoxicity and environmental hazards of metal nano-antibacterial agents have hindered their clinical applications. Although the materials prepared by covalent cross-linking based on cationic polymers have hemostatic and antibacterial properties, they are difficult to adapt to various irregularly shaped wounds, especially deep or penetrating wounds. Therefore, there is a great need to prepare multifunctional materials with inherent anti-infection ability, low incidence of bacterial drug resistance, excellent biocompatibility and shape adaptability. The present invention aims to develop a multifunctional material with hemostatic, skin regeneration-promoting, scar-reducing, antibacterial and infectious wound healing-promoting properties.

[0006] Poly-L-lysine (PLL) is a polymer with multiple lysine units (abbreviated as Lys). Lysine is a natural amino acid, and its molecular structure contains an amino group (-NH2) and a carboxyl group (-COOH). These functional groups endow it with special affinity in biological systems. Due to the positively charged amino groups of polylysine, it often undergoes electrostatic interactions with negatively charged biomolecules (such as DNA, RNA, cell membranes, etc.) in biological systems, so it is widely used in the biomedical field. Cationic PLL can electrostatically attract anionic bacteria, completely remove bacteria and effectively reduce the emergence of drug-resistant bacteria and the risk of bacterial spread. In addition, PLL has the ability to isolate planktonic bacteria in solution through interactions, thereby preventing bacteria from adhering to skin tissues and reducing the formation of biofilms. However, due to the complications of diabetic wounds, excessive use of PLL may lead to many side effects and little effect. Therefore, it is of great practical significance to develop a simple, efficient, and biocompatible method for preparing a nano-drug carrier dressing for the treatment of chronic diabetic wounds.

[0007] As is well known, there are many complex reasons that hinder the healing of diabetic wounds. These include low immunity, microenvironment disorders, metabolic disorders, hypoxia, hyperglycemia, and increased susceptibility to bacterial infections. Classical methods for skin wound healing include removing necrotic tissue and using topical antibacterial agents and wound dressings (such as films, scaffolds, foams, sponges, and hydrogels). Electrospun fibers have sustained drug release / loading, good mechanical properties, a high surface area-to-volume ratio, high porosity, high swelling ability, and strong wound-exudate absorption ability. They are easy to combine with various incorporations and can be applied to different types of wounds for the treatment of acute or chronic wounds. Most nanofiber membranes can be used for site-specific delivery systems. However, the strong adsorption of porous materials in turn leads to a slow drug release rate of the loaded drugs, limiting their application scope. Summary of the Invention

[0008] The purpose of the present invention is to solve the above technical problems and provide a preparation method and application of a metal ion-modified PVA / NC / PLL / medicated ink composite membrane.

[0009] A preparation method of a metal ion-modified PVA / NC / PLL / medicated ink composite membrane is specifically completed according to the following steps:

[0010] I. Preparation of PLL / medicated ink nanoparticles:

[0011] ①. Dissolve polylysine in deionized water to obtain a polylysine solution with a concentration of 1 mg / mL to 50 mg / mL;

[0012] ②. Add the medicinal ink nanoparticles to the polylysine solution, stir and react at 40 °C to 50 °C for a period of time, then centrifuge and separate. Use deionized water as a cleaning agent to ultrasonically clean the precipitate obtained after centrifugation and separation to remove the unreacted substances, and finally dry to obtain PLL / medicinal ink nanoparticles;

[0013] II. Prepare the PVA / NC sol;

[0014] ①. Dissolve polyvinyl alcohol in deionized water to obtain a polyvinyl alcohol solution with a mass fraction of 5% to 15%;

[0015] ②. Add a certain amount of cellulose nanocrystals to the polyvinyl alcohol solution with a mass fraction of 5% to 15%, then stir and react at 50 °C to 55 °C for a period of time, and then let it stand to exhaust bubbles to obtain the PVA / NC sol;

[0016] III. Prepare the PVA / NC / PLL / medicinal ink sol:

[0017] Add the PLL / medicinal ink nanoparticles to the PVA / NC sol, then stir and react at 35 °C to 40 °C for a period of time, and let it stand to exhaust bubbles to obtain the PVA / NC / PLL / medicinal ink sol;

[0018] IV. Metal ion modification:

[0019] Place the PVA / NC / PLL / medicinal ink sol in a solution containing metal ions, stir and react for a period of time, take it out and wash it with deionized water to obtain the metal ion-modified PVA / NC / PLL / medicinal ink sol;

[0020] V. High-voltage electrospinning:

[0021] Place the conductive paper on the receiving screen, perform high-voltage electrospinning on the metal ion-modified PVA / NC / PLL / medicinal ink sol. After the electrospinning is completed, remove the fiber membrane from the conductive paper and vacuum dry it to obtain the metal ion-modified PVA / NC / PLL / medicinal ink composite membrane.

[0022] Use of a metal ion-modified PVA / NC / PLL / medicinal ink composite membrane in the preparation of drugs or reagents for treating chronic diabetic infected wounds.

[0023] Principle of the present invention:

[0024] Traditional Chinese medicine ink is made from pine soot, glue solution and natural spice herbs, and has the effects of hemostasis, cooling blood, clearing heat and detumescence. The main component of the medicine ink is carbon, and its physical and chemical properties are similar to those of carbon-based materials such as graphene and carbon nanotubes. With the development of technology, Chinese medicine ink has been proven to be applicable to new fields, such as strain sensors, solar steam, photothermal therapy, etc. The selection of a photothermal agent is very important. First of all, it is non-toxic and can effectively perform photothermal conversion. As a potential photothermal agent, traditional Chinese medicine ink in China is non-toxic in the body and has a relatively high photothermal conversion efficiency under near-infrared irradiation. Thus, traditional Chinese medicine ink in China has good thermal activity and can be combined with polylysine (PLL) to have a synergistic effect in chronic wound healing, and the nanofiber can be remotely controlled by heating with near-infrared light irradiation to achieve the purpose of controlling drug release.

[0025] The present invention has the following beneficial effects:

[0026] First, the present invention first prepares traditional Chinese medicine ink into medicine ink nanoparticles, and uses the negative charge of the medicine ink nanoparticles and the positively charged polycationic polymer (polylysine) to interact through ions, and applies the high-voltage electrospinning technology to prepare a nanofiber composite material. While ensuring the effects of hemostasis, cooling blood, clearing heat and detumescence of the medicine ink, the photothermal conversion effect of near-infrared light is utilized by a new method, and at the same time, combined with the good antibacterial effect of the cationic polymer, the synergistic effect is achieved to promote the healing of diabetic wounds, skin regeneration, eliminate the existence of bacterial biofilms, and avoid the potential safety hazards of antibacterial agents in the body.

[0027] Second, polylysine (PLL) is negatively charged, and polylysine adsorbs to the medicine ink nanoparticles, preventing the aggregation of the medicine ink nanoparticles and significantly improving the stability of the medicine ink nanoparticles. The metal ion-modified PVA / NC / PLL / medicine ink sol prepared by the present invention is used to prepare a metal ion-modified PVA / NC / PLL / medicine ink composite membrane through the high-voltage electrospinning technology. Under the action of photothermal, it has a strong inhibitory effect on both Gram-positive bacteria and Gram-negative bacteria and has no cytotoxicity to human dermal fibroblasts.

[0028] Third, a certain amount of cellulose nanocrystals is added to the polyvinyl alcohol solution in the present invention, which can improve the mechanical properties and water resistance of polyvinyl alcohol (PVA). Metal ions are modified on the PVA / NC / PLL / medicine ink composite membrane for antibacterial, promoting angiogenesis and hemostasis. Under near-infrared light irradiation, the antibacterial effect is significantly enhanced.

[0029] IV. The metal ion-modified PVA / NC / PLL / medicinal ink composite film prepared by the present invention has antibacterial and photothermal conversion effects, and has very important application value and broad application prospects in the preparation of drugs or reagents for treating chronic diabetic infected wounds, promoting skin regeneration, eliminating the existence of bacterial biofilms, and avoiding potential safety hazards of antibacterial agents in the body. Description of the Drawings

[0030] Figure 1 Infrared spectrum of the pure PVA fiber film prepared in Comparative Example 1;

[0031] Figure 2 Infrared spectrum of the PVA / NC / PLL / medicinal ink composite film prepared in Comparative Example 3;

[0032] Figure 3 Antibacterial effect diagram, where 1 in the figure is the pure PVA fiber film prepared in Comparative Example 1, 2 is the PLL / PVA fiber film prepared in Comparative Example 2, 3 is the PVA / NC / PLL / medicinal ink composite film prepared in Comparative Example 3, and 4 is the metal ion-modified PVA / NC / PLL / medicinal ink composite film prepared in Example 1;

[0033] Figure 4 Temperature change of the photothermal conversion of the metal ion-modified PVA / NC / PLL / medicinal ink composite film prepared in Example 1. Detailed Description of the Invention

[0034] Detailed Description of the Invention I: A method for preparing a metal ion-modified PVA / NC / PLL / medicinal ink composite film is specifically completed according to the following steps:

[0035] I. Preparation of PLL / medicinal ink nanoparticles:

[0036] ①. Dissolve polylysine in deionized water to obtain a polylysine solution with a concentration of 1 mg / mL to 50 mg / mL;

[0037] ②. Add medicinal ink nanoparticles to the polylysine solution, stir and react at 40°C to 50°C for a period of time, then centrifuge and separate, use deionized water as a cleaning agent to ultrasonically clean the precipitate obtained after centrifugation and separation to remove unreacted substances, and finally dry to obtain PLL / medicinal ink nanoparticles;

[0038] II. Preparation of PVA / NC sol;

[0039] ①. Dissolve polyvinyl alcohol in deionized water to obtain a polyvinyl alcohol solution with a mass fraction of 5% to 15%;

[0040] ②. Add a certain amount of cellulose nanocrystals to a polyvinyl alcohol solution with a mass fraction of 5% - 15%, then stir and react for a period of time under the condition of 50°C - 55°C, and then let it stand to exhaust bubbles to obtain a PVA / NC sol;

[0041] III. Preparation of PVA / NC / PLL / medicinal ink sol:

[0042] Add PLL / medicinal ink nanoparticles to the PVA / NC sol, then stir and react for a period of time at 35°C - 40°C, and let it stand to exhaust bubbles to obtain a PVA / NC / PLL / medicinal ink sol;

[0043] IV. Metal ion modification:

[0044] Place the PVA / NC / PLL / medicinal ink sol in a solution containing metal ions, stir and react for a period of time, take it out and wash it with deionized water to obtain a metal ion-modified PVA / NC / PLL / medicinal ink sol;

[0045] V. High-voltage electrospinning:

[0046] Place the conductive paper on the receiving screen, perform high-voltage electrospinning on the metal ion-modified PVA / NC / PLL / medicinal ink sol. After the electrospinning is completed, remove the fiber membrane from the conductive paper and dry it in vacuum to obtain a metal ion-modified PVA / NC / PLL / medicinal ink composite membrane.

[0047] Specific Embodiment 2: The difference between this embodiment and Specific Embodiment 1 is: The preparation method of the medicinal ink nanoparticles described in Step 1 is specifically completed according to the following steps:

[0048] I. First, grind the commercially available medicinal ink, and then add the ground medicinal ink to a shear tank filled with deionized water and soak for a period of time;

[0049] II. Pass cooling water into the jacket of the shear tank to control the working temperature at room temperature; turn on the high-shear dispersion crusher for shearing and crushing to obtain a suspension containing medicinal ink nanoparticles;

[0050] III. Vacuum-dry the suspension containing medicinal ink nanoparticles, and then disperse it to obtain medicinal ink nanoparticle particles. Other steps are the same as those in Specific Embodiment 1.

[0051] Specific Embodiment 3: The difference between this embodiment and one of Specific Embodiments 1 or 2 is as follows: In Step 1, the mass ratio of the ground medicinal ink to deionized water is 1:(10 - 20); the soaking time in Step 1 is 3h - 8h; the rotation speed of shearing in Step 2 is 13000r / min - 25000r / min, and the shearing time is 20min - 60min; the temperature of vacuum drying in Step 3 is 40°C - 50°C. Other steps are the same as those in Specific Embodiment 1 or 2.

[0052] Specific Embodiment 4: The difference between this embodiment and one of Specific Embodiments 1 to 3 is as follows: In Step 1②, the mass ratio of the medicinal ink nanoparticles to polylysine in the PLL / medicinal ink nanoparticles is (2 - 5):(0.1 - 5); the stirring reaction time at 40°C - 50°C in Step 1② is 10h - 12h. Other steps are the same as those in Specific Embodiments 1 to 3.

[0053] Specific Embodiment 5: The difference between this embodiment and one of Specific Embodiments 1 to 4 is as follows: In Step 2②, the mass ratio of polyvinyl alcohol to cellulose nanocrystals in the PVA / NC sol is (5 - 9):1; the stirring reaction time under the condition of 50°C - 55°C in Step 2② is 4h - 6h; the standing time in Step 2② is 8h - 10h. Other steps are the same as those in Specific Embodiments 1 to 4.

[0054] Specific Embodiment 6: The difference between this embodiment and one of Specific Embodiments 1 to 5 is as follows: The stirring reaction time at 35°C - 40°C in Step 3 is 7h - 9h; the mass fraction of the medicinal ink nanoparticles in the PVA / NC / PLL / medicinal ink sol in Step 3 is 2% - 5%, and the mass fraction of polylysine is 0.1% - 5%.

[0055] Other steps are the same as those in Specific Embodiments 1 to 5.

[0056] Specific Embodiment 7: The difference between this embodiment and one of Specific Embodiments 1 to 6 is as follows: The solution containing metal ions in Step 4 is one or a mixture of copper sulfate solution, zinc nitrate solution, and magnesium nitrate solution; the concentration of metal ions in the solution containing metal ions in Step 4 is 5g / L - 15g / L; the stirring reaction time for placing the PVA / NC / PLL / medicinal ink sol in the solution containing metal ions in Step 4 is 4h - 6h. Other steps are the same as those in Specific Embodiments 1 to 6.

[0057] Embodiment 8: The difference between this embodiment and any one of Embodiments 1 to 7 is as follows: The process parameters of the high-voltage electrospinning in Step 5 are as follows: the voltage is 20 - 35 kV, the distance between the positive and negative electrode plates is 15 - 25 cm, the liquid flow rate is 1.0 - 2.0 mL / h, the environmental humidity is 30 - 50%, the environmental temperature is 20 - 30 °C, and the distance from the needle tip to the receiving screen is 12 cm - 15 cm; the temperature of the vacuum drying in Step 5 is 60 °C - 80 °C, and the time of the vacuum drying is 10 h - 15 h. Other steps are the same as those in Embodiments 1 to 7.

[0058] Embodiment 9: The difference between this embodiment and any one of Embodiments 1 to 8 is as follows: The metal ion-modified PVA / NC / PLL / medical ink composite film has good heating performance under near-infrared light irradiation, and the antibacterial effect is significantly enhanced; the wavelength of the near-infrared light is 808 nm. Other steps are the same as those in Embodiments 1 to 8.

[0059] Embodiment 10: This embodiment is an application of a metal ion-modified PVA / NC / PLL / medical ink composite film in the preparation of drugs or reagents for treating chronic diabetic infected wounds.

[0060] The following examples are used to verify the beneficial effects of the present invention:

[0061] Example 1: A preparation method of a metal ion-modified PVA / NC / PLL / medical ink composite film is specifically completed according to the following steps:

[0062] I. Preparation of medical ink nanoparticles:

[0063] ①. First, grind the commercially available medical ink for 3 h, and then add the ground medical ink into a shear tank filled with deionized water and soak for a period of time;

[0064] In Step ① of Step I, the mass ratio of the ground medical ink to deionized water is 1:20;

[0065] In Step ① of Step I, the soaking time is 6 h;

[0066] ②. Pass cooling water into the jacket of the shear tank to control the working temperature at room temperature; turn on the high-shear dispersion crusher for shear breaking to obtain a suspension containing medical ink nanoparticles;

[0067] In Step ② of Step I, the shear speed is 25000 r / min, and the shear time is 30 min;

[0068] ③. Vacuum-dry the suspension containing medical ink nanoparticles, and then disperse it to obtain medical ink nanoparticles;

[0069] The temperature of the vacuum drying described in Step 1③ is 45°C;

[0070] II. Preparation of PLL / medicinal ink nanoparticles:

[0071] ① Dissolve polylysine in deionized water to obtain a polylysine solution with a concentration of 10 mg / mL;

[0072] ② Add the medicinal ink nanoparticles to the polylysine solution, stir and react at 40°C for 12 h, then perform centrifugal separation, ultrasonically clean the precipitate obtained after centrifugal separation 3 times with deionized water as the cleaning agent to remove unreacted substances, and finally perform vacuum drying at 80°C to obtain PLL / medicinal ink nanoparticles;

[0073] In the PLL / medicinal ink nanoparticles described in Step 2②, the mass ratio of the medicinal ink nanoparticles to polylysine is 3:2;

[0074] III. Preparation of PVA / NC sol;

[0075] ① Dissolve polyvinyl alcohol in deionized water to obtain a polyvinyl alcohol solution with a mass fraction of 10%;

[0076] ② Add a certain amount of cellulose nanocrystals to the polyvinyl alcohol solution with a mass fraction of 10%, then stir and react at 50°C for 5 h, and then let it stand to remove air bubbles for 10 h to obtain PVA / NC sol;

[0077] In the PVA / NC sol described in Step 3②, the mass ratio of polyvinyl alcohol to cellulose nanocrystals is 7:1;

[0078] IV. Preparation of PVA / NC / PLL / medicinal ink sol:

[0079] Add the PLL / medicinal ink nanoparticles to the PVA / NC sol, then stir and react at 37°C for 8 h, and let it stand to remove air bubbles for 10 h to obtain PVA / NC / PLL / medicinal ink sol;

[0080] In the PVA / NC / PLL / medicinal ink sol described in Step 4, the mass fraction of the medicinal ink nanoparticles is 3%;

[0081] V. Metal ion modification:

[0082] Place the PVA / NC / PLL / medicinal ink sol in a solution containing metal ions, stir and react for 5 h, take it out and wash it 3 times with deionized water to obtain the metal ion-modified PVA / NC / PLL / medicinal ink sol;

[0083] The solution containing metal ions described in Step 5 is a mixed solution of copper sulfate solution and zinc nitrate solution, wherein the concentration of the copper sulfate solution is 5 g / L and the concentration of the zinc nitrate solution is 2 g / L;

[0084] VI. High-voltage electrospinning:

[0085] Place the conductive paper on the receiving screen, perform high-voltage electrospinning on the PVA / NC / PLL / drug ink sol modified with metal ions. After electrospinning is completed, remove the fiber membrane from the conductive paper and vacuum dry it at 80 °C for 12 h to obtain a metal ion-modified PVA / NC / PLL / drug ink composite membrane;

[0086] The process parameters of the high-voltage electrospinning described in step VI are as follows: the voltage is 25 kV, the distance between the positive and negative plates is 20 cm, the liquid flow rate is 2.0 mL / h, the environmental humidity is 40%, the environmental temperature is 25 °C, and the distance from the needle tip to the receiving screen is 13 cm.

[0087] Control Example 1: The preparation method of a pure PVA fiber membrane is completed according to the following steps:

[0088] I. Prepare a PVA sol;

[0089] Dissolve polyvinyl alcohol (PVA) in deionized water to obtain a 10% (by mass) polyvinyl alcohol solution; stir and react the 10% (by mass) polyvinyl alcohol solution at 50 °C for 5 h, and then let it stand to exhaust air bubbles for 10 h to obtain a PVA sol;

[0090] II. High-voltage electrospinning:

[0091] Place the conductive paper on the receiving screen, perform high-voltage electrospinning on the PVA sol. After electrospinning is completed, remove the fiber membrane from the conductive paper and vacuum dry it at 80 °C for 12 h to obtain a pure PVA fiber membrane;

[0092] The process parameters of the high-voltage electrospinning described in step II are as follows: the voltage is 25 kV, the distance between the positive and negative plates is 20 cm, the liquid flow rate is 2.0 mL / h, the environmental humidity is 40%, the environmental temperature is 25 °C, and the distance from the needle tip to the receiving screen is 13 cm.

[0093] Control Example 2: The preparation method of a PLL / PVA fiber membrane is completed according to the following steps:

[0094] I. Prepare a PLL / PVA sol;

[0095] Dissolve polyvinyl alcohol (PVA) in deionized water to obtain a 10% (by mass) polyvinyl alcohol solution; stir and react the 10% (by mass) polyvinyl alcohol solution at 50 °C for 5 h, and then let it stand to exhaust air bubbles for 10 h to obtain a PVA sol;

[0096] II. Add polylysine (PLL) to the PVA sol, then stir and react at 40°C for 12 h, and let it stand to remove air bubbles for 10 h to obtain the PVA / PLL sol;

[0097] III. High-voltage electrospinning:

[0098] Place the conductive paper on the receiving screen, perform high-voltage electrospinning on the PVA / PLL sol, after the electrospinning is completed, remove the fiber membrane from the conductive paper, and vacuum dry it at 80°C for 12 h to obtain the PLL / PVA fiber membrane;

[0099] The process parameters of the high-voltage electrospinning described in step II are: voltage is 25 kV, the distance between the positive and negative plates is 20 cm, the liquid flow rate is 2.0 mL / h, the environmental humidity is 40%, the environmental temperature is 25°C, and the distance from the needle tip to the receiving screen is 13 cm.

[0100] Comparative Example 3: The preparation method of the PVA / NC / PLL / drug ink composite membrane is completed according to the following steps:

[0101] I. Prepare drug ink nanoparticles:

[0102] ①. First, grind the commercially available drug ink for 3 h, and then add the ground drug ink to a shear tank filled with deionized water and soak for a period of time;

[0103] The mass ratio of the ground drug ink to deionized water described in step I① is 1:20;

[0104] The soaking time described in step I① is 6 h;

[0105] ②. Pass cooling water into the jacket of the shear tank to control the working temperature at room temperature; turn on the high-shear dispersion crusher for shear fragmentation to obtain a suspension containing drug ink nanoparticles;

[0106] The shear speed described in step I② is 25000 r / min, and the shear time is 30 min;

[0107] ③. Vacuum dry the suspension containing drug ink nanoparticles, and then disperse it to obtain drug ink nanoparticles;

[0108] The temperature of the vacuum drying described in step I③ is 45°C;

[0109] II. Prepare PLL / drug ink nanoparticles:

[0110] ①. Dissolve polylysine in deionized water to obtain a polylysine solution with a concentration of 10 mg / mL;

[0111] ②. Add the medicinal ink nanoparticles into the polylysine solution, stir and react at 40 °C for 12 h, then perform centrifugal separation, ultrasonically clean the precipitate obtained after centrifugal separation 3 times with deionized water as the cleaning agent to remove the unreacted substances, and finally perform vacuum drying at 80 °C to obtain PLL / medicinal ink nanoparticles;

[0112] In the PLL / medicinal ink nanoparticles described in step ②, the mass ratio of the medicinal ink nanoparticles to polylysine is 3:2;

[0113] III. Prepare PVA / NC sol;

[0114] ①. Dissolve polyvinyl alcohol in deionized water to obtain a 10% (mass fraction) polyvinyl alcohol solution;

[0115] ②. Add a certain amount of cellulose nanocrystals to the 10% (mass fraction) polyvinyl alcohol solution, then stir and react at 50 °C for 5 h, and then let it stand to remove air bubbles for 10 h to obtain PVA / NC sol;

[0116] In the PVA / NC sol described in step III ②, the mass ratio of polyvinyl alcohol to cellulose nanocrystals is 7:1;

[0117] IV. Prepare PVA / NC / PLL / medicinal ink sol:

[0118] Add the PLL / medicinal ink nanoparticles into the PVA / NC sol, then stir and react at 37 °C for 8 h, and let it stand to remove air bubbles for 10 h to obtain PVA / NC / PLL / medicinal ink sol;

[0119] In the PVA / NC / PLL / medicinal ink sol described in step IV, the mass fraction of the medicinal ink nanoparticles is 3%;

[0120] V. High-voltage electrospinning:

[0121] Place the conductive paper on the receiving screen, perform high-voltage electrospinning on the PVA / NC / PLL / medicinal ink sol. After the electrospinning is completed, remove the fiber membrane from the conductive paper and perform vacuum drying at 80 °C for 12 h to obtain the PVA / NC / PLL / medicinal ink composite membrane;

[0122] The process parameters of the high-voltage electrospinning described in step V are: voltage is 25 kV, the distance between the positive and negative plates is 20 cm, the liquid flow rate is 2.0 mL / h, the environmental humidity is 40%, the environmental temperature is 25 °C, and the distance from the needle tip to the receiving screen is 13 cm.

[0123] The pure PVA fiber membrane prepared in Comparative Example 1 and the PVA / NC / PLL / ink composite membrane prepared in Comparative Example 3 were placed in a vacuum drying oven at 40 °C and dried for 3 h. After the infrared spectrometer was preheated, air was scanned as the background, and then the pure PVA fiber membrane prepared in Comparative Example 1 and the PVA / NC / PLL / ink composite membrane prepared in Comparative Example 3 were respectively placed for infrared scanning. The data were recorded and analyzed, as shown in Figures 1 to 2 shown;

[0124] Figure 1 is the infrared spectrogram of the pure PVA fiber membrane prepared in Comparative Example 1;

[0125] From Figure 1 it can be seen that: 853 cm -1 is the stretching vibration absorption peak of the C-C bond; 1147 cm -1 is the stretching vibration absorption peak of the C-O bond. 1710 - 1741 cm -1 is the stretching vibration absorption peak of the acetate group in PVA. 2870 - 2945 cm -1 is the stretching vibration absorption peak of C-H in -CH2, and the relatively wide absorption band at 3125 - 3570 cm -1 is attributed to the hydroxyl groups and water molecules in PVA.

[0126] Figure 2 is the infrared spectrogram of the PVA / NC / PLL / ink composite membrane prepared in Comparative Example 3;

[0127] In the infrared spectrum of the PVA / NC / PLL / ink composite membrane, in the range of 3300 - 3500 cm -1 , there is a medium-intensity broad peak, which is the stretching vibration peak of -NH2. Near 2950 cm -1 there is a sharp peak, which is the stretching vibration peak of -CH3. In the range of 1640 cm -1 -1500 cm -1 , there is an infrared characteristic peak of the C=O bond, which is the infrared stretching vibration peak of the carbonyl group. At 1500 - 1350 cm -1 there are two weak absorption peaks, which are the characteristic peaks caused by the in-plane bending vibrations of -CH3 and -CH2. From the above conclusions, it can be seen that since the surface of PLL is positively charged and the Zeta potential of the surface of the ink is negative, the two undergo electrostatic binding, and the PVA / NC / PLL / ink composite membrane is successfully prepared.

[0128] The pure PVA fiber membrane prepared in Comparative Example 1, the PLL / PVA fiber membrane prepared in Comparative Example 2, the PVA / NC / PLL / medicinal ink composite membrane prepared in Comparative Example 3, and the metal ion-modified PVA / NC / PLL / medicinal ink composite membrane prepared in Example 1 were respectively placed in 4 petri dishes and irradiated under ultraviolet light for 30 min; Escherichia coli was diluted to 1×10 4 CFU / mL. The diluted bacterial solution was added to a 2 mL centrifuge tube containing the fiber membrane sample after light irradiation. An 808 nm infrared laser emitter was selected, and its power was adjusted to 0.33 W / cm to irradiate the center of the fiber membrane in the centrifuge tube for 10 min. Then, 100 μL of the bacterial solution taken from each group of samples was evenly spread on the solid medium. The coated plate was placed in an incubator, and the results were observed and analyzed as shown in Figure 3 ;

[0129] Figure 3 The antibacterial effect diagram is shown. In the figure, 1 is the pure PVA fiber membrane prepared in Comparative Example 1, 2 is the PLL / PVA fiber membrane prepared in Comparative Example 2, 3 is the PVA / NC / PLL / medicinal ink composite membrane prepared in Comparative Example 3, and 4 is the metal ion-modified PVA / NC / PLL / medicinal ink composite membrane prepared in Example 1;

[0130] From Figure 3 it can be seen that: the pure PVA fiber membrane has basically no antibacterial effect, the PLL / PVA fiber membrane has an antibacterial effect, but it is not obvious, the PVA / NC / PLL / medicinal ink composite membrane has an obvious antibacterial effect, and the metal ion-modified PVA / NC / PLL / medicinal ink composite membrane can basically completely inhibit bacteria.

[0131] The metal ion-modified PVA / NC / PLL / medicinal ink composite membrane prepared in Example 1 was placed in a centrifuge tube, and 1 mL of water was added. An 808 nm infrared laser emitter was selected, and its power was adjusted to 0.33 W / cm to irradiate the center of the fiber membrane in the centrifuge tube. The temperature increase from 0 s to 600 s was recorded with an infrared imager and analyzed by plotting as shown in Figure 4 ;

[0132] From Figure 4 it can be seen that: the metal ion-modified PVA / NC / PLL / medicinal ink composite membrane prepared in Example 1 has very excellent photothermal performance and can be widely used in the preparation of drugs or reagents for treating chronic diabetic infected wounds.

Claims

1. A method for preparing a metal ion modified PVA / NC / PLL / medicine ink composite film, characterized in that The preparation method is specifically completed according to the following steps:

1. Preparation of PLL / drug ink nanoparticles: ①, dissolving polylysine in deionized water to obtain a polylysine solution with a concentration of 1 mg / mL to 50 mg / mL; ②, adding the drug ink nanoparticles to the polylysine solution, stirring and reacting at 40°C to 50°C for a period of time, and then centrifuging, and ultrasonically cleaning the precipitate obtained after centrifugation with deionized water as a cleaning agent to remove unreacted substances, and finally drying to obtain PLL / drug ink nanoparticles; 2. Preparation of PVA / NC sol; ① Dissolve polyvinyl alcohol in deionized water to obtain a polyvinyl alcohol solution with a mass fraction of 5% to 15%; ②, adding a certain amount of cellulose nanocrystals to a polyvinyl alcohol solution with a mass fraction of 5% to 15%, and then stirring and reacting at 50°C to 55°C for a period of time, and then standing to remove bubbles to obtain PVA / NC sol; 3. Preparation of PVA / NC / PLL / drug ink sol: Adding PLL / medicine ink nanoparticles into PVA / NC sol, stirring and reacting at 35°C to 40°C for a period of time, standing to remove bubbles, and obtaining PVA / NC / PLL / medicine ink sol; 4. Metal ion modification: The PVA / NC / PLL / medicine ink sol is placed in a solution containing metal ions and stirred for a period of time, and then taken out and washed with deionized water to obtain the metal ion-modified PVA / NC / PLL / medicine ink sol; 5. High voltage electrospinning: The conductive paper is placed on the receiving screen, and the metal ion-modified PVA / NC / PLL / drug ink sol is subjected to high-voltage electrospinning. After the spinning is completed, the fiber membrane is removed from the conductive paper and vacuum dried to obtain a metal ion-modified PVA / NC / PLL / drug ink composite membrane.

2. The method for preparing a metal ion modified PVA / NC / PLL / medicine ink composite membrane according to claim 1, characterized in that The preparation method of the medicinal ink nanoparticles described in step 1 is specifically completed according to the following steps:

1. First, grind the commercially available medicinal ink, then add the ground medicinal ink into a shear tank filled with deionized water and soak it for a period of time; 2. Pass cooling water into the jacket of the shear tank to control the working temperature at room temperature; turn on the high shear dispersing crusher to perform shear crushing to obtain a suspension containing drug ink nanoparticles; 3. The suspension containing the medicinal ink nanoparticles is vacuum dried, and then dispersed to obtain medicinal ink nanoparticle particles.

3. The method for preparing a metal ion modified PVA / NC / PLL / medicine ink composite membrane according to claim 2, characterized in that The mass ratio of the ground medicinal ink to deionized water described in step one is 1:(10-20); the soaking time described in step one is 3h-8h; the shearing speed described in step two is 13000r / min-25000r / min, and the shearing time is 20min-60min; the vacuum drying temperature described in step three is 40℃-50℃.

4. The method for preparing a metal ion modified PVA / NC / PLL / medicine ink composite membrane according to claim 1, characterized in that The mass ratio of the medicinal ink nanoparticles to polylysine in the PLL / medicinal ink nanoparticles described in step 1② is (2-5):(0.1-5); the stirring reaction time at 40°C-50°C in step 1② is 10h-12h.

5. The method for preparing a metal ion modified PVA / NC / PLL / medicine ink composite membrane according to claim 1, characterized in that The mass ratio of polyvinyl alcohol to cellulose nanocrystals in the PVA / NC sol described in step 2② is (5-9):1; the stirring reaction time at 50°C-55°C in step 2② is 4h-6h; the standing time described in step 2② is 8h-10h.

6. The method for preparing a metal ion modified PVA / NC / PLL / medicine ink composite membrane according to claim 1, characterized in that The stirring reaction time at 35° C. to 40° C. in step 3 is 7 to 9 hours; the mass fraction of the drug ink nanoparticles in the PVA / NC / PLL / drug ink sol described in step 3 is 2% to 5%, and the mass fraction of polylysine is 0.1% to 5%.

7. The method for preparing a metal ion modified PVA / NC / PLL / medicine ink composite membrane according to claim 1, characterized in that The solution containing metal ions described in step 4 is one of copper sulfate solution, zinc nitrate solution and magnesium nitrate solution or a mixture of several thereof; the concentration of metal ions in the solution containing metal ions described in step 4 is 5g / L to 15g / L; in step 4, the PVA / NC / PLL / drug ink sol is placed in the solution containing metal ions and stirred for reaction for 4h to 6h.

8. The method for preparing a metal ion modified PVA / NC / PLL / medicine ink composite membrane according to claim 1, characterized in that The process parameters of the high-voltage electrospinning described in step five are: voltage of 20-35 kV, distance between positive and negative plates of 15-25 cm, liquid flow rate of 1.0-2.0 mL / h, ambient humidity of 30-50%, ambient temperature of 20-30° C., and distance from needle tip to receiving screen of 12 cm-15 cm; the temperature of vacuum drying described in step five is 60° C.-80° C., and the time of vacuum drying is 10 h-15 h.

9. The method for preparing a metal ion modified PVA / NC / PLL / medicine ink composite membrane according to claim 1, characterized in that The metal ion-modified PVA / NC / PLL / medicine ink composite film has good temperature-raising performance and significantly enhanced antibacterial effect under near-infrared light; the wavelength of the near-infrared light is 808nm.

10. Use of a metal ion modified PVA / NC / PLL / medicine ink composite membrane according to any one of claims 1 to 9, characterized in that A metal ion-modified PVA / NC / PLL / medicine ink composite film is used in the preparation of medicines or reagents for treating chronic diabetic infected wounds.

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