CN115317660A

CN115317660A - Near-infrared response antibacterial nano composite hydrogel dressing

Info

Publication number: CN115317660A
Application number: CN202210908559.9A
Authority: CN
Inventors: 张鹏; 周蓉
Original assignee: Shenyang Pharmaceutical University
Current assignee: Shenyang Pharmaceutical University
Priority date: 2022-07-29
Filing date: 2022-07-29
Publication date: 2022-11-11

Abstract

The invention relates to a near-infrared response antibacterial nano composite hydrogel dressing, belonging to the technical field of biomedical materials. A near-infrared response antibacterial nano-composite hydrogel dressing is composed of acrylamide-alginate hydrogel and a bismuth sulfide nano-crystal particle-protein composite loaded in the hydrogel in situ; the dressing has photothermal antibacterial property. The bismuth sulfide nanocrystal particle-protein composite is subjected to photo-thermal conversion under near-infrared light with the wavelength of 808 nm. The preparation method disclosed by the invention takes albumin as a sulfur source, and the bismuth sulfide nanocrystal particle-protein compound prepared by means of a biomineralization method has good biocompatibility and water dispersibility; sodium alginate is mixed into an acrylamide gel system, so that the sodium alginate has excellent mechanical property and elasticity; the bismuth sulfide nanocrystal particle-protein compound is introduced into a gel system, so that the bismuth sulfide nanocrystal particle-protein compound has excellent photo-thermal performance.

Description

Near-infrared response antibacterial nano composite hydrogel dressing

Technical Field

The invention relates to a near-infrared response antibacterial nano composite hydrogel dressing, belonging to the technical field of biomedical materials.

Background

The skin is an important organ for protecting tissues such as capillaries, nerves and organs of a body from being easily stimulated and damaged by external environmental changes, and plays an important role in lubrication, body temperature regulation, external stimulation sensing and the like. Regeneration of damaged skin is the most fundamental requirement to reestablish tissue integrity and restore normal function to the skin. It is well known that bacterial infections are one of the major obstacles to wound healing and cause other complications, and severe wound dehydration interferes with the ideal moist healing environment and delays wound healing, and in severe cases can even be life threatening. Traditional wound dressings such as cotton, gauze, etc. tend to adhere to wounds when dressing wounds due to their own dryness, and cause secondary injury after removal, so more and more researchers have turned their attention to the development of wet dressings. The hydrogel has the characteristics of capability of storing a large amount of water, capability of adjusting strength and toughness and the like due to the hydrophilic three-dimensional network, and is concerned. The wound dressing has the characteristics of high water absorption and high water retention while allowing gas exchange, has good biocompatibility, plays a barrier role with the outside, removes wound exudates at the same time, ensures the wound environment to be moist, and has no harm after secondary removal.

At present, antibiotics are generally used for treating broken skin infection clinically, but the antibiotics have long treatment period, can cause bacterial drug resistance and can also cause a plurality of adverse reactions. The photo-thermal antibacterial method converts light energy into heat energy through substances which absorb near-infrared light with a certain wavelength, and destroys proteins of bacteria at high temperature while the near-infrared light reaches the deep layer, so that the antibacterial effect is achieved. The method can greatly shorten the treatment time, and has the advantages of avoiding the generation of drug resistance by bacteria, safety, high efficiency and the like. At present, the main application fields of the photothermal agent are anti-tumor, anti-thrombus and the like, and the application of the photothermal agent in the antibacterial field needs to be further developed.

Conventional hydrogels are formed by physical or chemical crosslinking and generally have poor mechanical properties and a small equilibrium-to-swelling ratio, which greatly limits their practical application as dressings. Based on the current situation of medical dressings, a hydrogel dressing with good mechanical property, photo-thermal antibacterial property, water absorption and moisture retention and biocompatibility is urgently needed, and the treatment and management of wounds which are easy to infect are realized while necessary mechanical support is provided for the wounds.

Disclosure of Invention

The dressing is a near-infrared response antibacterial nano composite hydrogel dressing, has excellent elasticity and tensile property, and can be well attached to a wound while the body moves synchronously; under the irradiation of near infrared light, the antibacterial agent shows good photo-thermal antibacterial effect and prevents bacterial infection of wounds. The invention adopts heat crosslinking glue, has simple process, easy operation, large and stable yield, excellent mechanical property and obvious photo-thermal antibacterial effect, and solves the defects in the prior art.

The invention aims to solve the problems of the traditional wound dressing and the antibacterial dressing and provides a preparation method of a near-infrared response antibacterial nano composite hydrogel dressing. The prepared hydrogel has a good photo-thermal effect, realizes antibiotic-free photo-thermal antibiosis and promotes wound healing while ensuring the wound environment to be moist.

The invention also aims to provide the hydrogel antibacterial dressing with the near infrared response performance, which is prepared by the method. The hydrogel disclosed by the invention has good elasticity and tensile property, can be well attached to a wound and synchronously move, shows a good photo-thermal antibacterial effect under the irradiation of near infrared light, and prevents bacterial infection of the wound. The near-infrared response antibacterial hydrogel dressing can be applied to prevention of postoperative infection of wounds and treatment of infected wounds.

A near-infrared response antibacterial nano-composite hydrogel dressing is composed of acrylamide-alginate hydrogel and a bismuth sulfide nanocrystal particle-protein composite loaded in the hydrogel in situ; the dressing has photothermal antibacterial property.

In the bismuth sulfide nanocrystal particle-protein composite, bismuth sulfide is in a particle state and is uniformly distributed in acrylamide-alginate hydrogel.

In the near-infrared response antibacterial nano-composite hydrogel dressing, the bismuth sulfide nano-crystal particle-protein composite is subjected to photo-thermal conversion under near-infrared light with the wavelength of 808 nm.

The near-infrared response nano-composite hydrogel prepared by the invention can be applied to the repair of the infected skin tissue injury, such as the aspect of wound dressing.

Preferably, the bismuth sulfide in the bismuth sulfide nanocrystal particle-protein compound is crystal particles, the average particle size is 100 nm-200nm, and zeta potential measurement shows that the bismuth sulfide nanocrystal particle-protein compound is negatively charged.

In the near-infrared response antibacterial nano-composite hydrogel dressing, the load capacity of the hydrogel of the bismuth sulfide nanocrystal particle-protein composite is 35-500 mug/mL, preferably 197-500 mug/mL, and more preferably 197-395 mug/mL in terms of bismuth sulfide.

In the near-infrared response antibacterial nano-composite hydrogel dressing, the load capacity of the bismuth sulfide nano-crystal particle-protein composite in the hydrogel is 35-500 mu g of bismuth sulfide in terms of the mass of the bismuth sulfide and the volume of the hydrogel: 1mL of hydrogel.

Preferably, the acrylamide-alginate hydrogel is an acrylamide-sodium alginate hydrogel or an acrylamide-potassium alginate hydrogel.

Preferably, the bismuth sulfide nanocrystal particle-protein complex is prepared by the following method: uniformly mixing 25.31-37.25% of bovine serum albumin aqueous solution and 1.93-2.84% of bismuth nitrate solution to obtain mixed solution; adding 2mol/L sodium hydroxide solution into the mixed solution, and adjusting the pH of the solution to 10-14 at room temperature to obtain reaction solution; the obtained reaction solution is continuously stirred and reacted for 12 to 24 hours at the temperature of between 20 and 37 ℃, and freeze-dried after dialysis to obtain the bismuth sulfide nanocrystal particle-protein compound.

Preferably, the dressing is made by the following method: fully stirring the aqueous dispersion of the bismuth sulfide nanocrystal particle-protein complex, acrylamide, alginate, a cross-linking agent, an initiator and a catalyst, and then ultrasonically mixing uniformly to obtain a pre-polymerization solution; and (4) gelling the pre-polymerized solution to obtain the near-infrared response antibacterial nano composite hydrogel dressing.

Further, the alginate is sodium alginate or potassium alginate; the cross-linking agent is N, N-methylene bisacrylamide or N-hydroxymethyl acrylamide, the initiator is ammonium persulfate or potassium persulfate, and the catalyst is trimethyl ethylenediamine;

the dosage of the acrylamide is 6 to 25 percent of the total mass of the aqueous dispersion of the bismuth sulfide nanocrystal particle-protein composite and the acrylamide; the dosage of the alginate is 1.5 to 4 percent of the total mass of the aqueous dispersion of the bismuth sulfide nanocrystal particle-protein composite and the alginate; the dosage of the cross-linking agent is 0.05-1.5% of the mass of acrylamide; the dosage of the initiator is 0.04-0.22 percent of the mass of the acrylamide; the dosage of the catalyst is 3.25-8% of the mass of the acrylamide.

Further, the ultrasonic condition is 80-800W, 20-100 Hz, and the ultrasonic time is 0.5-50 h; the gelling temperature is 20-80 ℃, and the gelling time is 1-12 hours.

Further, the aqueous dispersion of the bismuth sulfide nanocrystal particle-protein complex is prepared by the following method: the aqueous dispersion of the bismuth sulfide nanocrystal particle-protein complex is prepared by the following method: and dispersing the freeze-dried bismuth sulfide nanocrystal particle-protein composite in water, wherein the content of bismuth sulfide in the dispersion liquid is 35-395 mu g/mL calculated by bismuth sulfide, and the bismuth sulfide is uniformly dispersed by means of ultrasound, wherein the ultrasound conditions are 80-800W, 20-100 Hz, and the ultrasound time is 0.5-4 h.

The invention has the beneficial effects that: the preparation method disclosed by the invention takes albumin as a sulfur source, and the bismuth sulfide nanocrystal particle-protein compound prepared by means of a biomineralization method has good biocompatibility and water dispersibility; sodium alginate is mixed into an acrylamide gel system, so that the sodium alginate has excellent mechanical property and elasticity; the bismuth sulfide nanocrystal particle-protein compound is introduced into a gel system, so that the bismuth sulfide nanocrystal particle-protein compound has excellent photo-thermal performance.

The hydrogel prepared by the method has the following advantages: the hydrogel dressing has excellent photo-thermal antibacterial effect, and can realize rapid antibacterial on the surface of a wound. The photo-thermal material bismuth sulfide nanoparticles used in the hydrogel dressing have good biocompatibility and low toxicity. The hydrogel dressing prepared by the invention has the advantages of stable components, quick sterilization, safe method, large and stable yield, excellent mechanical property, obvious photo-thermal effect and lasting antibacterial effect. The hydrogel dressing prepared by the invention has good water retention and ventilation effects, can well move along with the skin and has no residue. The method is simple, has low cost and is suitable for large-scale preparation and commercial production.

The experimental results show that: the photo-thermal effect of the hydrogel dressing prepared by the invention can be adjusted by changing the content of the bismuth sulfide nanocrystal particle-protein compound in the hydrogel; the porosity, swelling property, water retention property and the like of the hydrogel prepared by the method can be adjusted by changing the using amounts of sodium alginate, acrylamide, a cross-linking agent, an initiator and a catalyst in the hydrogel; the crosslinking degree, porosity, swelling property, wound exudate absorption and the like of the hydrogel can be adjusted by changing the crosslinking time of the hydrogel. Experimental results prove that the bismuth sulfide nanocrystal particle-protein compound endows the hydrogel dressing with broad-spectrum photothermal antibacterial activity, and the sodium alginate endows the hydrogel dressing with the properties of elasticity, tissue adhesion, hemostasis and the like. In addition, bacteriostatic experiments show that the hydrogel has good antibacterial performance. The hemolysis experiment proves that the chitosan derivative has good in vitro biocompatibility. The whole blood coagulation experiment proves that the compound has good procoagulant effect. Water vapor transmission rate experiments prove that the air-permeable fabric has good air permeability. The wound exudate experiment proves that the wound exudate has good absorption capacity of wound exudate. Therefore, the series of nano-composite hydrogel dressings have good application prospect in the field of healing of wounds of skin infected by bacteria.

Drawings

Fig. 1 (a) is a solution diagram and a transmission electron microscope diagram of the prepared bismuth sulfide nanocrystal particle-protein complex, and the scale bar: 200nm; FIG. 1 (b) is a graph of the swelling curve of a hydrogel; FIG. 1 (c) is a graph of the water retention profile of a hydrogel; fig. 1 (d) is an SEM image of the hydrogel, scale bar: 50 μm.

FIG. 2 (a) is the water vapor transmission rate of a hydrogel; FIG. 2 (b) is a graph showing a light intensity of 2.0W/cm ² Temperature change profile of the hydrogel; FIG. 2 (c) is a graph of hemolysis of a hydrogel; figure 2 (d) is the wound simulated exudate absorption rate of the hydrogel.

FIG. 3 (a) is a graph showing the growth of E.coli; FIG. 3 (b) is a graph showing the growth of E.coli; FIG. 3 (c) is a graph showing the growth of Staphylococcus aureus, and FIG. 3 (d) is a graph showing the growth of Staphylococcus aureus.

FIG. 4 (a) is the in vitro antimicrobial activity of NIR light-enhanced hydrogels against Staphylococcus aureus; FIG. 4 (b) is the in vitro antibacterial activity against E.coli.

Detailed Description

The following non-limiting examples will allow one of ordinary skill in the art to more fully understand the present invention, but will not limit the invention in any way.

The test methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials are commercially available, unless otherwise specified.

One of the specific implementation modes is as follows:

the preparation steps of the bismuth sulfide nanocrystal particle-protein composite comprise:

(1A) Dissolving albumin in purified water, and fully stirring at room temperature to dissolve the albumin, wherein the mass concentration of the albumin is 25.31-37.25%;

(1B) Adding bismuth Nitrate (NO) pentahydrate ₃ ) ₃ ·5H ₂ Dissolving O in nitric acid, and fully stirring at room temperature to dissolve the O, wherein the mass concentration of the bismuth nitrate pentahydrate is 1.93-2.84%;

(1C) Slowly dripping the mixed solution obtained in the step (1B) into the mixed solution obtained in the step (1A), and fully stirring at room temperature to make the mixed solution uniform;

(1D) Adding sodium hydroxide into the mixed solution obtained in the step (1C), and adjusting the solution to be alkaline pH =12 at room temperature to obtain a reaction solution, wherein the concentration of the sodium hydroxide is 2mol/L;

(1E) And (3) continuously stirring the reaction solution obtained in the step (1D) at the temperature of between 20 and 37 ℃ for reaction for 12 to 24 hours, dialyzing and freeze-drying to obtain the bismuth sulfide nanocrystal particle-protein compound.

Preferably, in step (1A), the albumin is bovine serum albumin; in the step (1B), the volume of the nitric acid is 1ml, the concentration of the nitric acid is 90-98%, and the mass ratio of the nitric acid to the bismuth nitrate pentahydrate is 1000-5000%; the alkalinity in the step (1D) is that the pH value is 10-14; in the step (1E), deionized water is adopted for dialysis for 12-24 hours.

A preparation method of a near-infrared light response antibacterial nano-composite hydrogel dressing comprises the following steps:

(1) Synthesizing a bismuth sulfide nanocrystal particle-protein complex;

(2) Uniformly dispersing the bismuth sulfide nanocrystal particle-protein compound in water, wherein the bismuth sulfide is 35-500 mu g/mL in terms of bismuth sulfide nanoparticles to obtain a bismuth sulfide nanocrystal particle-protein compound dispersion liquid;

(3) Ultrasonically and uniformly mixing a bismuth sulfide nanocrystal particle-protein compound solution with acrylamide, alginate, a cross-linking agent, an initiator and a catalyst to obtain a pre-polymerization solution;

(4) And (4) gelling the pre-polymerized solution to obtain the near-infrared response antibacterial nano composite hydrogel dressing.

Preferably, in the step (2), the preparation step of the bismuth sulfide nanocrystal particle-protein complex solution comprises:

dispersing the freeze-dried bismuth sulfide nanocrystal particle-protein compound in water, and uniformly dispersing the compound by means of ultrasound; the ultrasonic condition is 80-800W, 20-100 Hz, and the ultrasonic time is 0.5-4 hours.

Preferably, in the step (3), the dosage of the acrylamide is 6-25% of the total mass of the bismuth sulfide nanoparticle dispersion liquid and the acrylamide;

preferably, in the step (3), the alginate is sodium alginate or potassium alginate;

preferably, the amount of the alginate in the step (3) is 1.5-4% of the total mass of the bismuth sulfide nanocrystal particle-protein composite solution and the alginate;

preferably, the crosslinking agent in the step (3) is N, N-methylene bisacrylamide or N-methylol acrylamide, and the initiator is ammonium persulfate or potassium persulfate;

preferably, the amount of the cross-linking agent in the step (3) is 0.05-1.5% of the mass of the acrylamide; the dosage of the initiator is 0.04 to 0.22 percent of the mass of the acrylamide;

preferably, the catalyst in the step (3) is trimethylethylenediamine;

preferably, the amount of the catalyst used in the step (3) is 3.25-8% of the mass of the acrylamide;

preferably, the ultrasonic conditions in the step (3) are 80-800W, 20-100 Hz, and the ultrasonic time is 0.5-50 hours;

preferably, the gelling temperature in the step (4) is 20-80 ℃; the gelling time is 1 to 12 hours;

preferably, the hydrogel in the step (4) is formed in a mold, and the gel thickness after demolding is 1-3 mm.

Example 1

(1) Synthesizing a bismuth sulfide nanocrystal particle-protein complex;

(1A) Dissolving bovine serum albumin in purified water (bovine serum albumin accounts for 3.15% of the solution mass), and stirring at room temperature for 10 min to dissolve the bovine serum albumin;

(1B) Adding bismuth nitrate (Bi (NO)) pentahydrate ₃ ) ₃ ·5H ₂ Dissolving O (0.024 g, alatin) in 1ml of nitric acid with the concentration of 90-98 percent, wherein the mass ratio of the O to the bismuth nitrate pentahydrate is 4000 percent, and fully stirring for 10 minutes at room temperature to dissolve the O;

(1C) Slowly dripping the mixed solution obtained in the step (1B) into the mixed solution obtained in the step (1A), and fully stirring for 30 minutes at room temperature to make the mixed solution uniform;

(1D) Adding sodium hydroxide into the mixed solution obtained in the step (1C), and adjusting the solution to be alkaline at room temperature (pH = 12) to obtain a reaction solution, wherein the concentration of the sodium hydroxide is 2mol/L;

(1E) And (3) continuously stirring the reaction solution obtained in the step (1D) at 37 ℃ for reaction for 12 hours, dialyzing the reaction solution with deionized water for 12 hours, and freeze-drying to obtain the bismuth sulfide nanocrystal particle-protein compound.

(2) Uniformly dispersing the bismuth sulfide nanocrystal particle-protein compound in water to enable the concentration of bismuth sulfide to be 25 mug/mL, and performing ultrasonic treatment for 20 minutes to obtain a uniformly dispersed bismuth sulfide nanocrystal particle-protein compound dispersion liquid;

(3) Uniformly mixing bismuth sulfide nanocrystal particle-protein compound dispersion liquid with the concentration of 39.45 mu g/mL of bismuth sulfide, acrylamide (acrylamide accounts for 16.67 percent of the total mass of the mixed solution and the acrylamide), sodium alginate (sodium alginate accounts for 2.74 percent of the total mass of the mixed solution and the sodium alginate), N-methylene bisacrylamide (1 percent of the mass of the N, N-methylene bisacrylamide relative to the mass of the acrylamide), ammonium persulfate (0.815 percent of the mass of the ammonium persulfate relative to the mass of the acrylamide), and tetramethylethylenediamine (6.25 percent of the mass of the tetramethylethylenediamine relative to the mass of the acrylamide) by ultrasonic treatment for 60 minutes after fully stirring to obtain pre-polymerization liquid;

(4) Pouring the prepolymerization solution into a mold with the length of 5 cm, the width of 5 cm and the thickness of 3 mm, standing the mold with the prepolymerization solution for 12 hours, reacting for 12 hours at room temperature to form gel, demolding to obtain the hydrogel dressing with good mechanical properties and photo-thermal antibacterial properties, and naming the hydrogel dressing as Bi ₂ S ₃ 25 hydrogel。

Example 2

In contrast to example 1, the bismuth sulfide nanocrystal particle-protein complex dispersion in step (3) was replaced with 0. Mu.g/mL of bismuth sulfide at a concentration of 25. Mu.g/mL (i.e., hydrogel alone without addition of the bismuth sulfide nanocrystal particle-protein complex), and the hydrogel obtained was named Bi ₂ S ₃ 0 hydrogel。

Example 3

In contrast to example 1, the bismuth sulfide concentration of the bismuth sulfide nanocrystal particle-protein complex dispersion in step (3) was replaced with 78.9. Mu.g/mL to prepare a hydrogel named Bi ₂ S ₃ 50 hydrogel。

Example 4

Different from the example 1, the bismuth sulfide nano-crystal particle-protein complex dispersion liquid with the bismuth sulfide concentration of 25 mug/mL in the step (3) is replaced by 197.29 mug/mL, and the prepared hydrogel is named as Bi ₂ S ₃ 125 hydrogel。

Example 5

Different from the example 1, the bismuth ion concentration of 25 mug/mL in the step (3) of the bismuth sulfide nanocrystal particle-protein complex dispersion liquid is replaced by 394.58 mug/mL, and the prepared hydrogel is named as Bi ₂ S ₃ 250 hydrogel。

The antibacterial hydrogel dressing with adhesion, hemostasis and near infrared response has stable performance, the antibacterial performance of the dressing is good in-vivo and in-vitro antibacterial tests, the mechanical performance of the dressing is excellent in the tests, the hydrogel prepared by the method shows good biocompatibility, and the dressing is analyzed in detail by combining the attached drawings and experimental data:

the bismuth sulfide nanocrystal particle-protein composite dispersion liquid shown in fig. 1 (a) has good dispersibility and stability, no layering phenomenon occurs after the bismuth sulfide nanocrystal particle-protein composite dispersion liquid is placed for a period of time, and the morphology and the particle size of the nanoparticles can be clearly seen in a transmission electron microscope image, and are about 100 nanometers.

The swelling behavior test result of the hydrogel shown in fig. 1 (b) shows that the swelling rate of the hydrogel gradually decreases with the increase of the content of the bismuth sulfide nanoparticles in the hydrogel, which indicates that the amount of pores in the hydrogel decreases.

The water retention behavior test result of the hydrogel in fig. 1 (c) shows that the hydrogel loses water faster with the increase of the content of the bismuth sulfide nanoparticles in the hydrogel, and the content of water in the hydrogel gradually decreases with the increase of time.

FIG. 1 (d) shows Bi ₂ S ₃ 0 hydrogel (a) and Bi ₂ S ₃ 250 SEM image of hydrogel lyophilized (b) showing interconnected uniform pore size microstructure.

FIG. 2 (a) the test results of water vapor transmission rate of hydrogel show that the water vapor transmission rate of the hydrogel dressing prepared by the invention is within the standard range (3E to E)300g/m ² H) has good gas permeability, allowing normal gas exchange.

The photo-thermal performance test result of the hydrogel shown in FIG. 2 (b) shows that the hydrogel with different bismuth ion concentrations prepared by the experiment has light intensity of 2.0W/cm ² The temperature rise condition of irradiating for 10 minutes under 808nm near infrared light is that the higher the concentration of bismuth ions is, the faster the temperature rise is, the higher the finally reached temperature is, and Bi ₂ S ₃ 250 The hydrogel temperature can reach 56 ℃.

Fig. 2 (c) is an in vitro hemolysis test result of the hydrogel dressing prepared according to the present invention, and when the hemolysis ratio of the positive group (water) is set as 100%, the hemolysis ratio of all hydrogel groups is less than 3%, which shows good blood compatibility.

Fig. 2 (d) shows the experimental results of wound simulated exudate of the hydrogel dressing, which indicates that the hydrogel dressing prepared by the invention has good absorption capacity for wound exudate.

FIGS. 3 (a), 3 (b), 3 (c) and 3 (d) are graphs showing the photothermal antibacterial effect test of the hydrogel dressings prepared according to the present invention against Escherichia coli and Staphylococcus aureus in vitro, and the results show that Bi ₂ S ₃ 250 OD values of escherichia coli and staphylococcus aureus in the hydrogel treatment group are close to 0, and experimental results show that the hydrogel has good in-vitro photothermal antibacterial performance.

FIGS. 4 (a) and 4 (b) are graphs showing the photothermal antimicrobial efficacy of the hydrogel dressings of the present invention against Staphylococcus aureus and Escherichia coli in vitro, showing that near infrared irradiation for 10 minutes results in 100% killing of all bacteria (p < 0.001). The experimental result also shows that the hydrogel has good in-vitro photo-thermal antibacterial performance.

Claims

1. A near-infrared response antibacterial nano-composite hydrogel dressing is characterized in that: the dressing is composed of acrylamide-alginate hydrogel and a bismuth sulfide nanocrystal particle-protein compound loaded in the hydrogel in situ; the dressing has photothermal antibacterial property.

2. The dressing of claim 1, wherein: the bismuth sulfide nanocrystal particle-protein composite is subjected to photo-thermal conversion under near-infrared light with the wavelength of 808 nm.

3. The dressing of claim 1, wherein: the bismuth sulfide in the bismuth sulfide nano crystal particle-protein compound is crystal particles, the average particle size is 100 nm-200nm, and Zeta potential measurement shows that the bismuth sulfide nano crystal particle-protein compound is negatively charged.

4. The dressing of claim 1, wherein: the loading capacity of the bismuth sulfide nanocrystal particle-protein composite in the hydrogel is 35-500 mu g/mL, preferably 197-500 mu g/mL, and more preferably 197-395 mu g/mL in terms of bismuth sulfide.

5. The dressing of claim 1, wherein: the acrylamide-alginate hydrogel is acrylamide-sodium alginate hydrogel or acrylamide-potassium alginate hydrogel.

6. The dressing of claim 1, wherein: the bismuth sulfide nanocrystal particle-protein compound is prepared by the following method: uniformly mixing 25.31-37.25% bovine serum albumin aqueous solution and 1.93-2.84% bismuth nitrate solution to obtain mixed solution; adding 2mol/L sodium hydroxide solution into the mixed solution, and regulating the solution to be alkaline pH value of 10-14 at room temperature to obtain reaction solution; the obtained reaction solution is continuously stirred and reacted for 12 to 24 hours at the temperature of between 20 and 37 ℃, and freeze-dried after dialysis to obtain the bismuth sulfide nanocrystal particle-protein compound.

7. The dressing of claim 1, wherein: the dressing is prepared by the following method: fully stirring the aqueous dispersion of the bismuth sulfide nanocrystal particle-protein complex, acrylamide, alginate, a cross-linking agent, an initiator and a catalyst, and then ultrasonically mixing uniformly to obtain a pre-polymerization solution; and (3) gelling the prepolymerization solution to obtain the near-infrared response antibacterial nano composite hydrogel dressing.

8. The dressing of claim 7, wherein: the alginate is sodium alginate or potassium alginate; the cross-linking agent is N, N-methylene bisacrylamide or N-hydroxymethyl acrylamide, the initiator is ammonium persulfate or potassium persulfate, and the catalyst is trimethyl ethylenediamine;

the dosage of the acrylamide is 2-90% of the total mass of the bismuth sulfide nanocrystal particle-protein compound and the acrylamide; the dosage of the alginate is 1.5 to 4 percent of the total mass of the aqueous dispersion of the bismuth sulfide nanocrystal particle-protein compound and the alginate; the dosage of the cross-linking agent is 0.05-1.5% of the mass of acrylamide; the dosage of the initiator is 0.04-0.22 percent of the mass of the acrylamide; the dosage of the catalyst is 3.25-8% of the mass of the acrylamide.

9. The dressing of claim 7, wherein: the ultrasonic condition is 80-800W and 20-100 Hz, and the ultrasonic time is 0.5-50 h; the gelling temperature is 20-80 ℃, and the gelling time is 1-12 hours.

10. The dressing of claim 8, wherein: the aqueous dispersion of the bismuth sulfide nanocrystal particle-protein complex is prepared by the following method: and dispersing the freeze-dried bismuth sulfide nanocrystal particle-protein composite in water, wherein the content of bismuth sulfide in the dispersion is 35-395 mu g/mL calculated by bismuth sulfide, and the bismuth sulfide is uniformly dispersed by means of ultrasound, wherein the ultrasound condition is 80-800W, 20-100 Hz, and the ultrasound time is 0.5-4 h.