阅读说明：本技术 一种抗菌壳聚糖基止血贴 (Antibacterial chitosan-based hemostatic patch ) 是由 张正男 段书霞 邵蕊娜 闫钧 付迎坤 常聪 周静 储旭 韩颖 柳小军 田林奇 于 2020-12-30 设计创作，主要内容包括：本发明公开了一种抗菌壳聚糖基止血贴,包括从下到上依次设置的背衬层、止血层和保护层；所述背衬层为聚丙烯或聚对苯二甲酸乙二酯制备的基材,其上涂有粘合剂；所述止血层包括下侧的无纺布和上侧的复合止血材料,所述复合止血材料为改性壳聚糖、聚乙二醇2000、明胶、黄原胶、茶多糖-纳米硒复合物、多巴胺修饰纳米二氧化硅、油酸酰胺制备得到的复合水凝胶；所述保护层为PET薄膜。本发明提供的抗菌壳聚糖基止血贴,方便储存、携带,使用方便,不会对伤口产生刺激,具有良好的抗菌抗感染功效,能够通过粘附密封及激活凝血系统实现迅速凝血,且能够避免血管栓塞副作用的发生。(The invention discloses an antibacterial chitosan-based hemostatic patch, which comprises a back lining layer, a hemostatic layer and a protective layer which are sequentially arranged from bottom to top; the back lining layer is a base material prepared from polypropylene or polyethylene terephthalate, and is coated with an adhesive; the hemostatic layer comprises a non-woven fabric on the lower side and a composite hemostatic material on the upper side, and the composite hemostatic material is composite hydrogel prepared from modified chitosan, polyethylene glycol 2000, gelatin, xanthan gum, a tea polysaccharide-nano selenium compound, dopamine-modified nano silicon dioxide and oleamide; the protective layer is a PET film. The antibacterial chitosan-based hemostatic patch provided by the invention is convenient to store and carry, is convenient to use, does not stimulate wounds, has good antibacterial and anti-infection effects, can realize rapid blood coagulation by adhering and sealing and activating a blood coagulation system, and can avoid the side effect of vascular embolism.)

1. An antibacterial chitosan-based hemostatic patch is characterized by comprising a back lining layer, a hemostatic layer and a protective layer which are sequentially arranged from bottom to top; the back lining layer is a base material prepared from polypropylene or polyethylene terephthalate, and is coated with an adhesive; the hemostatic layer comprises a non-woven fabric on the lower side and a composite hemostatic material on the upper side, and the composite hemostatic material is composite hydrogel prepared from modified chitosan, polyethylene glycol 2000, gelatin, xanthan gum, a tea polysaccharide-nano selenium compound, dopamine-modified nano silicon dioxide and oleamide; the protective layer is a PET film.

2. The antimicrobial chitosan-based hemostatic patch according to claim 1, wherein the binder is urethane ethyl methacrylate dextran.

3. The antibacterial chitosan-based hemostatic patch according to claim 1, wherein the preparation method of the modified chitosan comprises the following steps: dissolving chitosan powder in 1wt% acetic acid to prepare 1wt% chitosan-acetic acid solution, adding alkyl aldehyde, stirring at room temperature for 12h, adjusting pH to 5 with NaOH solution, slowly adding sodium borohydride, then continuously stirring for 2h, adjusting pH to 7 with NaOH solution again, filtering and washing to neutrality after precipitation, repeatedly washing with ethanol, removing redundant aldehyde, freeze-drying and grinding to obtain the modified chitosan.

4. The antibacterial chitosan-based hemostatic patch according to claim 1, wherein the preparation method of the tea polysaccharide-nano selenium compound comprises: adding deionized water into tea polysaccharide freeze-dried powder to prepare a solution, adding a Vc solution, uniformly mixing, then dropwise adding a sodium selenite solution, oscillating for 20-30 s, reacting for 0.5-1 h under the condition of water bath at 40 ℃, centrifuging, adding deionized water into a precipitate for resuspension, and standing to obtain dispersed spherical tea polysaccharide-nano selenium; wherein the molar ratio of Vc to sodium selenite is 8: 1.

5. The antibacterial chitosan-based hemostatic patch according to claim 1, wherein the preparation method of the dopamine-modified nano-silica comprises the following steps: ultrasonically dispersing nano silicon dioxide and dopamine hydrochloride in a mass ratio of 20:1 in a weak base solution with the pH =8.0, stirring and reacting for 12-24 h, centrifugally separating, discarding a supernatant, washing a precipitate with deionized water for more than 5 times, and freeze-drying to obtain the nano-silicon dioxide/dopamine hydrochloride composite material.

6. The antibacterial chitosan-based hemostatic patch according to claim 1, wherein the composite hemostatic material is prepared from the following raw materials in parts by weight: 60-120 parts of modified chitosan, 20002-4 parts of polyethylene glycol, 16-32 parts of gelatin, 8-16 parts of xanthan gum, 5-11 parts of tea polysaccharide-nano selenium compound, 4-13 parts of dopamine modified nano silicon dioxide and 0.05-0.1 part of oleamide.

7. The antibacterial chitosan-based hemostatic patch according to claim 1, wherein the weight part ratio of the gelatin to the xanthan gum is 2: 1.

8. The antibacterial chitosan-based hemostatic patch according to claim 1, wherein the weight part ratio of the modified chitosan, the polyvinyl alcohol 2000, the gelatin and the xanthan gum is 30:1:8: 4.

9. A method for preparing an antibacterial chitosan-based hemostatic patch according to any one of claims 1 to 8, comprising the following steps:

step one, non-woven fabric surface modification: preparing a Tris-HCl buffer solution containing hyaluronic acid and dopamine, respectively adding EDC and NHS, immersing the non-woven fabric in the buffer solution, reacting for 2 hours at room temperature, taking out, washing with deionized water for multiple times, immersing in the deionized water for 6 hours, and carrying out vacuum freeze drying to obtain the surface-modified non-woven fabric;

step two, preparing the composite hemostatic material: dissolving modified chitosan in 3wt% acetic acid to prepare a solution; dissolving gelatin and xanthan gum in deionized water at 40 deg.C to obtain solutions, standing and swelling for 8 hr to obtain gelatin solution and xanthan gum solution; adding a modified chitosan solution and oleamide into a gelatin solution, quickly stirring for 30s, adding polyethylene glycol 2000, a tea polysaccharide-nano selenium compound and dopamine-modified nano silicon dioxide, carrying out ultrasonic treatment for 40-60 s, then dropwise adding a xanthan gum solution, standing at room temperature for reaction for 12-24 h after dropwise adding, fully washing with deionized water, and carrying out freeze drying to obtain a composite hemostatic material;

combining the non-woven fabric with the composite hemostatic material: superposing and cold-pressing the non-woven fabric and the composite hemostatic material to obtain a hemostatic layer;

step four, preparing the antibacterial chitosan-based hemostatic plaster: and cutting the backing layer coated with the adhesive on the surface according to the size requirement, adhering the backing layer with the cut hemostatic layer, wherein the hemostatic layer is positioned in the middle of the backing layer, then attaching the protective layer on the adhesive surface of the adhesive backing layer, independently sealing, and performing irradiation sterilization to obtain the antibacterial chitosan-based hemostatic patch.

10. The preparation method of the antibacterial chitosan-based hemostatic patch according to claim 9, wherein the pressure adopted in the cold pressing in the third step is 2-4 MPa, and the time is 10-20 min.

Technical Field

The invention relates to the technical field of biomedical materials, in particular to an antibacterial chitosan-based hemostatic patch.

Background

The existing research shows that chitosan can adhere and aggregate red blood cells and blood platelets, activate a blood coagulation path through the activation of the blood platelets, accelerate the synthesis of fibrin glue, stimulate the vasoconstriction and finally seal wounds. Meanwhile, chitosan also has certain functions of resisting bacteria, relieving pain, promoting wound healing and reducing scars, and is an ideal hemostatic material. However, pure chitosan materials, including gels and fibers, tend to be mechanically weak. Therefore, the development of a chitosan-based composite hemostatic material with stable properties, safety, no toxicity and good mechanical strength is a hotspot. In the prior art, in order to improve the mechanical strength of the material when the chitosan composite material is prepared, a cross-linking agent such as terephthalaldehyde, adipic dialdehyde or glutaraldehyde is mostly needed, and the residual cross-linking agent can cause stimulation to wounds and is not beneficial to wound healing.

The hemostatic plaster has the advantages of convenient storage and use, difficult pollution and wide application. The nano-selenium has good antibacterial activity, but is easy to aggregate and inactivate; the nano silicon dioxide has good hemostasis and water absorption performances, can activate a blood coagulation system, is a common component for preparing the composite hemostasis material, is unstable in powder, is easy to gather to cause the reduction of the hemostasis effect, has the risk of causing vascular embolism due to the fact that the powder falls off and enters blood vessels, can be immobilized to ensure the activity of the powder, fully exerts the hemostasis and blood coagulation effects, and can avoid leakage, which is a difficult problem facing the research and development of the composite hemostasis material. In order to improve the adhesion and adhesiveness of the composite hemostatic material and avoid leakage of powdery minerals, researchers and researchers often adopt methods of increasing the viscosity of the material or improving the compactness of the material, which causes the problems that the hemostatic material is difficult to separate from a wound, and secondary damage or poor comfort of the material is caused when the hemostatic material is removed.

In order to solve the problems, the nano particles are modified to reduce aggregation, and the modified chitosan, the polyvinyl alcohol, the gelatin and the xanthan gum are reasonably proportioned to form a double-network structure to fix the particle components, so that the leakage of the particle components is avoided under the condition of not using a cross-linking agent.

Disclosure of Invention

The invention provides an antibacterial chitosan-based hemostatic patch which can be directly used on a wound surface, cannot be bonded with the wound, has good mechanical property, is safe and nontoxic and resists infection and a preparation method thereof.

The purpose of the invention is realized by the following technical scheme:

an antibacterial chitosan-based hemostatic patch comprises a back lining layer, a hemostatic layer and a protective layer which are arranged from bottom to top in sequence; the back lining layer is a base material prepared from polypropylene or polyethylene terephthalate, and is coated with an adhesive; the hemostatic layer comprises a non-woven fabric on the lower side and a composite hemostatic material on the upper side, and the composite hemostatic material is composite hydrogel prepared from modified chitosan, polyethylene glycol 2000, gelatin, xanthan gum, a tea polysaccharide-nano selenium compound, dopamine-modified nano silicon dioxide and oleamide; the protective layer is a PET film.

Further, the binder is urethane ethyl methacrylate dextran.

Further, the non-woven fabric is prepared from one or more of polylactic acid fiber, polycarbonate fiber, polyglycolic acid fiber, polycaprolactone fiber and polybutylene succinate fiber.

Further, the preparation method of the modified chitosan comprises the following steps: dissolving chitosan powder in 1wt% acetic acid to prepare 1wt% chitosan-acetic acid solution, adding alkyl aldehyde, stirring at room temperature for 12h, adjusting pH to 5 with NaOH solution, slowly adding sodium borohydride, then continuously stirring for 2h, adjusting pH to 7 with NaOH solution again, filtering and washing to neutrality after precipitation, repeatedly washing with ethanol, removing redundant aldehyde, freeze-drying and grinding to obtain the modified chitosan.

Further, the alkyl aldehyde is one or more of hexanal, dodecanal and octadecanal.

Further, the preparation method of the tea polysaccharide-nano selenium compound comprises the following steps: adding deionized water into the tea polysaccharide freeze-dried powder to prepare a solution, adding the Vc solution, uniformly mixing, then dropwise adding the sodium selenite solution, oscillating for 20-30 s, reacting for 0.5-1 h under the condition of water bath at 40 ℃, centrifuging, adding deionized water into the precipitate for resuspension, and standing to obtain the dispersed spherical tea polysaccharide-nano selenium.

Further, the molar ratio of Vc to sodium selenite is 8: 1.

Further, the preparation method of the dopamine modified nano-silica comprises the following steps: ultrasonically dispersing nano silicon dioxide and dopamine hydrochloride in a mass ratio of 20:1 in a weak base solution with the pH value of 8.0, stirring and reacting for 12-24 h, centrifugally separating, removing a supernatant, washing a precipitate with deionized water for more than 5 times, and freeze-drying to obtain the nano-silicon dioxide/dopamine hydrochloride composite material.

Further, the composite hemostatic material comprises the following raw materials in parts by weight: 60-120 parts of modified chitosan, 20002-4 parts of polyethylene glycol, 16-32 parts of gelatin, 8-16 parts of xanthan gum, 5-11 parts of tea polysaccharide-nano selenium compound, 4-13 parts of dopamine modified nano silicon dioxide and 0.05-0.1 part of oleamide.

Further, the weight part ratio of the gelatin to the xanthan gum is 2: 1.

Further, the weight part ratio of the modified chitosan, the polyvinyl alcohol 2000, the gelatin and the xanthan gum is 30:1:8: 4.

A preparation method of the antibacterial chitosan-based hemostatic patch comprises the following steps:

step one, non-woven fabric surface modification: preparing a Tris-HCl buffer solution containing hyaluronic acid and dopamine, respectively adding EDC and NHS, immersing the non-woven fabric in the buffer solution, reacting for 2 hours at room temperature, taking out, washing with deionized water for multiple times, immersing in the deionized water for 6 hours, and carrying out vacuum freeze drying to obtain the surface-modified non-woven fabric;

step two, preparing the composite hemostatic material: dissolving modified chitosan in 3wt% acetic acid to prepare a solution; dissolving gelatin and xanthan gum in deionized water at 40 deg.C to obtain solutions, standing and swelling for 8 hr to obtain gelatin solution and xanthan gum solution; adding a modified chitosan solution and oleamide into a gelatin solution, quickly stirring for 30s, adding polyethylene glycol 2000, a tea polysaccharide-nano selenium compound and dopamine-modified nano silicon dioxide, carrying out ultrasonic treatment for 40-60 s, then dropwise adding a xanthan gum solution, standing at room temperature for reaction for 12-24 h after dropwise adding, fully washing with deionized water, and carrying out freeze drying to obtain a composite hemostatic material;

combining the non-woven fabric with the composite hemostatic material: superposing and cold-pressing the non-woven fabric and the composite hemostatic material to obtain a hemostatic layer;

step four, preparing the antibacterial chitosan-based hemostatic plaster: and cutting the backing layer coated with the adhesive on the surface according to the size requirement, adhering the backing layer with the cut hemostatic layer, wherein the hemostatic layer is positioned in the middle of the backing layer, then attaching the protective layer on the adhesive surface of the adhesive backing layer, independently sealing, and performing irradiation sterilization to obtain the antibacterial chitosan-based hemostatic patch.

Further, the pressure adopted by cold pressing in the third step is 2-4 MPa, and the time is 10-20 min.

The surface of the non-woven fabric can be grafted with hyaluronic acid, so that on one hand, the mechanical property of the non-woven fabric is improved due to the strong hydrogen bond effect among hyaluronic acid molecules, and on the other hand, the hyaluronic acid has a very excellent water retention effect and further improves the water absorption and water retention properties of the non-woven fabric. In addition, dopamine molecules can be self-assembled on the surface of the non-woven fabric, and the surface of the base material is modified through self-polymerization and amino reaction with hyaluronic acid, so that the modified surface of the non-woven fabric has good adhesion and hydrophilic water retention. After the surface of the non-woven fabric is modified, the non-woven fabric can be combined with the composite hemostatic material under the conditions of normal temperature and small pressure without using a binder, and the combination is firm, so that the stimulation of the binder to the wound is effectively avoided.

The chitosan, the gelatin and the xanthan gum used in the functional layer of the invention are natural biological macromolecules, have good biocompatibility and no toxic or side effect, the hemostatic function and the antibacterial property of the chitosan are improved through alkylation modification, the chitosan has positive charge in an acidic aqueous solution and can generate a crosslinking effect with the gelatin, so that the chitosan, the tea polysaccharide-nano selenium compound and the dopamine modified nano silicon dioxide are primarily crosslinked and fixed together with polyethylene glycol to avoid the aggregation of the chitosan and the tea polysaccharide-nano selenium compound and the dopamine modified nano silicon dioxide, when anionic polysaccharide xanthan gum with negative charge is dripped, the xanthan gum and the chitosan generate a cogel through the complexing effect to carry out secondary fixation on the tea polysaccharide-nano selenium nanosphere and the dopamine modified nano silicon dioxide, the side effect of vascular embolism possibly caused by the leakage of the chitosan and the xanthan gum is avoided, and simultaneously, as the three-dimensional spiral structure, the hydrogel can penetrate through a gel system, so that the porous structure of the composite gel can be ensured, and the mechanical property of the hydrogel can be improved.

According to the invention, firstly, the chitosan solution is added into the gelatin solution, so that the gelatin three-dimensional structure and the chitosan skeleton are crosslinked to form a first network structure, the hydrogel has good toughness, the first network structure crosslinked skeleton can slide in the hydrogel under the action of external force, the integral displacement of the hemostatic composite material cannot be caused, and the hemostatic composite material can be always contacted with a wound; the oleamide is non-toxic, stable in property and good in biocompatibility, the oleamide is uniformly dispersed in a system, and then the tea polysaccharide-nano selenium compound and the dopamine modified nano silicon dioxide are added, so that the oleamide can promote the dispersion of mineral components in the system in the ultrasonic treatment process and avoid aggregation, and the dispersion and immobilization of the mineral components are realized; the polyethylene glycol 2000 used in the invention can improve the ductility and the tear resistance of the composite hydrogel, so that the composite hemostatic material can contain a high content of mineral components, and the composite hemostatic material cannot become hard and fragile due to the addition of the tea polysaccharide-nano selenium compound and the dopamine modified nano silicon dioxide. The xanthan gum is compounded with the gelatin and the modified chitosan to form a second network structure in a dripping mode, so that the prepared composite hemostatic material can be tightly attached to a wound, has high viscosity, can absorb seepage and promote wound healing, has low peel strength, can be easily removed, and cannot cause secondary damage to the wound when being peeled from the wound.

Compared with the prior art, the invention has the following beneficial effects:

(1) according to the antibacterial chitosan-based hemostatic patch provided by the invention, the back lining layer is coated with the adhesive with good biocompatibility, the base material of the back lining layer can meet the requirement of mechanical performance and has the characteristics of softness and breathability, and the non-woven fabric has strong water absorption and retention capacity by grafting hyaluronic acid on the surface, so that the tissue seepage absorbed by the hemostatic composite material can be absorbed, the composite hemostatic material can keep proper humidity, and the wound healing is promoted; the surface of the non-woven fabric is also provided with a polydopamine layer generated through self-assembly polymerization and reaction with hyaluronic acid, the polydopamine has adhesiveness, the non-woven fabric and the composite hemostatic material can be firmly bonded together, the leakage of the tea polysaccharide-nano selenium compound and the dopamine modified nano silicon dioxide can be further prevented, and vascular embolism can be avoided.

(2) The tea polysaccharide-nano selenium compound is prepared by loading nano selenium on tea polysaccharide in situ, has good stability and larger specific surface area, has higher activity and sterilization efficiency compared with the conventional nano selenium particles, has excellent anti-infection function, and can promote wound healing; the dopamine modified nano-silica can promote the composite hemostatic material to adhere to and seal wounds, and the nano-silica has the characteristic of activating a blood coagulation system, so that the nano-silica can rapidly activate the blood coagulation system and realize hemostasis by cooperating with the modified chitosan.

(3) The antibacterial chitosan-based hemostatic patch provided by the invention is convenient to store and carry, is convenient to use, does not stimulate wounds, forms a first network structure through the crosslinking of gelatin and chitosan, forms a second network structure through the gelation of xanthan gum and chitosan, prepares the double-network structure composite hydrogel, improves the ductility and the tear resistance of the composite hydrogel by adding a proper amount of polyvinyl alcohol 2000, and can effectively fix particle components, the porous structure of the composite hemostatic material can ensure the hemostasis and antibiosis of the particle components and the promotion of the healing efficacy of the wounds, and the crosslinking effect and the fixation of the polyvinyl alcohol 2000 can prevent the leakage of the particle components and avoid the occurrence of side effects.

Drawings

FIG. 1 shows the results of cytotoxicity test.

FIG. 2 shows the results of an in vitro whole blood coagulation test.

Detailed Description

To further illustrate the technical means and effects of the present invention, the following detailed description is given with reference to specific embodiments.

Example 1

An antibacterial chitosan-based hemostatic patch comprises a back lining layer, a hemostatic layer and a protective layer which are arranged from bottom to top in sequence; the back lining layer is a base material prepared from polypropylene, and a urethane ethyl methacrylate glucan adhesive is coated on the back lining layer; the hemostatic layer comprises polylactic acid fiber non-woven fabric on the lower side and a composite hemostatic material on the upper side, and the composite hemostatic material is prepared from the following raw materials in parts by weight: 60 parts of modified chitosan, 20002 parts of polyethylene glycol, 16 parts of gelatin, 8 parts of xanthan gum, 5 parts of tea polysaccharide-nano selenium compound, 4 parts of dopamine modified nano silicon dioxide and 0.05 part of oleamide; the protective layer is a PET film.

Further, the preparation method of the modified chitosan comprises the following steps: dissolving chitosan powder in 1wt% acetic acid to prepare 1wt% chitosan-acetic acid solution, adding hexanal, stirring at room temperature for 12h, adjusting pH to 5 with NaOH solution, slowly adding sodium borohydride, stirring for 2h, adjusting pH to 7 with NaOH solution again, filtering and washing to neutrality after precipitation, repeatedly washing with ethanol to remove excessive aldehyde, freeze-drying and grinding to obtain the modified chitosan.

Further, the preparation method of the tea polysaccharide-nano selenium compound comprises the following steps: adding deionized water into tea polysaccharide lyophilized powder to prepare a solution, adding a Vc solution, uniformly mixing, then dropwise adding a sodium selenite solution, wherein the molar ratio of Vc to sodium selenite is 8:1, oscillating for 20s, reacting for 0.5h under the condition of 40 ℃ water bath, centrifuging, adding deionized water into precipitates for resuspension, and standing to obtain the dispersed spherical tea polysaccharide-nano selenium.

Further, the preparation method of the dopamine modified nano-silica comprises the following steps: ultrasonically dispersing nano silicon dioxide and dopamine hydrochloride in a mass ratio of 20:1 in a weak base solution with the pH value of 8.0, stirring and reacting for 12 hours, centrifugally separating, discarding a supernatant, washing a precipitate with deionized water for more than 5 times, and freeze-drying to obtain the nano-silicon dioxide/dopamine hydrochloride composite material.

A preparation method of the antibacterial chitosan-based hemostatic patch comprises the following steps:

step one, non-woven fabric surface modification: preparing a Tris-HCl buffer solution containing hyaluronic acid and dopamine, respectively adding EDC and NHS, immersing the non-woven fabric in the buffer solution, reacting for 2 hours at room temperature, taking out, washing with deionized water for multiple times, immersing in the deionized water for 6 hours, and carrying out vacuum freeze drying to obtain the surface-modified non-woven fabric;

step two, preparing the composite hemostatic material: dissolving modified chitosan in 3wt% acetic acid to prepare a solution; dissolving gelatin and xanthan gum in deionized water at 40 deg.C to obtain solutions, standing and swelling for 8 hr to obtain gelatin solution and xanthan gum solution; adding a modified chitosan solution and oleamide into a gelatin solution, quickly stirring for 30s, adding polyethylene glycol 2000, a tea polysaccharide-nano selenium compound and dopamine-modified nano silicon dioxide, carrying out ultrasonic treatment for 40s, then dropwise adding a xanthan gum solution, standing at room temperature for reaction for 12h after dropwise adding, fully washing with deionized water, and carrying out freeze drying to obtain a composite hemostatic material;

combining the non-woven fabric with the composite hemostatic material: superposing and cold-pressing the non-woven fabric and the composite hemostatic material to obtain a hemostatic layer; wherein the pressure adopted by cold pressing is 2MPa, and the time is 10 min.

Step four, preparing the antibacterial chitosan-based hemostatic plaster: and cutting the backing layer coated with the adhesive on the surface according to the size requirement, adhering the backing layer with the cut hemostatic layer, wherein the hemostatic layer is positioned in the middle of the backing layer, then attaching the protective layer on the adhesive surface of the adhesive backing layer, independently sealing, and performing irradiation sterilization to obtain the antibacterial chitosan-based hemostatic patch.

Example 2

An antibacterial chitosan-based hemostatic patch comprises a back lining layer, a hemostatic layer and a protective layer which are arranged from bottom to top in sequence; the back lining layer is a base material prepared from polyethylene terephthalate, and a urethane ethyl methacrylate glucan adhesive is coated on the base material; the hemostatic layer comprises a polycarbonate fiber non-woven fabric on the lower side and a composite hemostatic material on the upper side, and the composite hemostatic material is prepared from the following raw materials in parts by weight: 90 parts of modified chitosan, 20003 parts of polyethylene glycol, 24 parts of gelatin, 12 parts of xanthan gum, 8 parts of tea polysaccharide-nano selenium compound, 7 parts of dopamine modified nano silicon dioxide and 0.08 part of oleamide; the protective layer is a PET film.

Further, the preparation method of the modified chitosan comprises the following steps: dissolving chitosan powder in 1wt% acetic acid to prepare 1wt% chitosan-acetic acid solution, adding dodecanal, stirring at room temperature for 12h, adjusting pH to 5 with NaOH solution, slowly adding sodium borohydride, then stirring for 2h, adjusting pH to 7 with NaOH solution again, filtering and washing to neutrality after precipitation, repeatedly washing with ethanol to remove excessive aldehyde, freeze-drying and grinding to obtain the modified chitosan.

Further, the preparation method of the tea polysaccharide-nano selenium compound comprises the following steps: adding deionized water into tea polysaccharide lyophilized powder to prepare a solution, adding a Vc solution, uniformly mixing, then dropwise adding a sodium selenite solution, wherein the molar ratio of Vc to sodium selenite is 8:1, oscillating for 25s, reacting for 0.8h under the condition of 40 ℃ water bath, centrifuging, adding deionized water into precipitates for resuspension, and standing to obtain the dispersed spherical tea polysaccharide-nano selenium.

Further, the preparation method of the dopamine modified nano-silica comprises the following steps: ultrasonically dispersing nano silicon dioxide and dopamine hydrochloride in a mass ratio of 20:1 in a weak base solution with the pH value of 8.0, stirring and reacting for 12-24 h, centrifugally separating, removing a supernatant, washing a precipitate with deionized water for more than 5 times, and freeze-drying to obtain the nano-silicon dioxide/dopamine hydrochloride composite material.

A preparation method of the antibacterial chitosan-based hemostatic patch comprises the following steps:

step one, non-woven fabric surface modification: preparing a Tris-HCl buffer solution containing hyaluronic acid and dopamine, respectively adding EDC and NHS, immersing the non-woven fabric in the buffer solution, reacting for 2 hours at room temperature, taking out, washing with deionized water for multiple times, immersing in the deionized water for 6 hours, and carrying out vacuum freeze drying to obtain the surface-modified non-woven fabric;

step two, preparing the composite hemostatic material: dissolving modified chitosan in 3wt% acetic acid to prepare a solution; dissolving gelatin and xanthan gum in deionized water at 40 deg.C to obtain solutions, standing and swelling for 8 hr to obtain gelatin solution and xanthan gum solution; adding a modified chitosan solution and oleamide into a gelatin solution, quickly stirring for 30s, adding polyethylene glycol 2000, a tea polysaccharide-nano selenium compound and dopamine-modified nano silicon dioxide, carrying out ultrasonic treatment for 40-60 s, then dropwise adding a xanthan gum solution, standing at room temperature for reaction for 12-24 h after dropwise adding, fully washing with deionized water, and carrying out freeze drying to obtain a composite hemostatic material;

combining the non-woven fabric with the composite hemostatic material: superposing and cold-pressing the non-woven fabric and the composite hemostatic material to obtain a hemostatic layer; wherein the pressure adopted by cold pressing is 3MPa, and the time is 15 min;

step four, preparing the antibacterial chitosan-based hemostatic plaster: and cutting the backing layer coated with the adhesive on the surface according to the size requirement, adhering the backing layer with the cut hemostatic layer, wherein the hemostatic layer is positioned in the middle of the backing layer, then attaching the protective layer on the adhesive surface of the adhesive backing layer, independently sealing, and performing irradiation sterilization to obtain the antibacterial chitosan-based hemostatic patch.

Example 3

An antibacterial chitosan-based hemostatic patch comprises a back lining layer, a hemostatic layer and a protective layer which are arranged from bottom to top in sequence; the back lining layer is a base material prepared from polyethylene terephthalate, and a urethane ethyl methacrylate glucan adhesive is coated on the base material; the hemostatic layer comprises polyglycolic acid fiber non-woven fabric on the lower side and a composite hemostatic material on the upper side, and the composite hemostatic material is prepared from the following raw materials in parts by weight: 120 parts of modified chitosan, 20004 parts of polyethylene glycol, 32 parts of gelatin, 16 parts of xanthan gum, 11 parts of tea polysaccharide-nano selenium compound, 13 parts of dopamine modified nano silicon dioxide and 0.1 part of oleamide; the protective layer is a PET film.

Further, the preparation method of the modified chitosan comprises the following steps: dissolving chitosan powder in 1wt% acetic acid to prepare 1wt% chitosan-acetic acid solution, adding octadecanal, stirring at room temperature for 12h, adjusting pH to 5 with NaOH solution, slowly adding sodium borohydride, then continuously stirring for 2h, adjusting pH to 7 with NaOH solution again, filtering and washing to neutrality after precipitation, repeatedly washing with ethanol, removing redundant aldehyde, freeze-drying and grinding to obtain the modified chitosan.

Further, the preparation method of the tea polysaccharide-nano selenium compound comprises the following steps: adding deionized water into tea polysaccharide freeze-dried powder to prepare a solution, adding a Vc solution, uniformly mixing, then dropwise adding a sodium selenite solution, wherein the molar ratio of Vc to sodium selenite is 8:1, oscillating for 20-30 s, reacting for 0.5-1 h under the condition of water bath at 40 ℃, centrifuging, adding deionized water into precipitates for resuspension, and standing to obtain the dispersed spherical tea polysaccharide-nano selenium.

Further, the preparation method of the dopamine modified nano-silica comprises the following steps: ultrasonically dispersing nano silicon dioxide and dopamine hydrochloride in a mass ratio of 20:1 in a weak base solution with the pH value of 8.0, stirring and reacting for 24 hours, centrifugally separating, discarding a supernatant, washing a precipitate with deionized water for more than 5 times, and freeze-drying to obtain the nano-silicon dioxide/dopamine hydrochloride composite material.

A preparation method of the antibacterial chitosan-based hemostatic patch comprises the following steps:

step one, non-woven fabric surface modification: preparing a Tris-HCl buffer solution containing hyaluronic acid and dopamine, respectively adding EDC and NHS, immersing the non-woven fabric in the buffer solution, reacting for 2 hours at room temperature, taking out, washing with deionized water for multiple times, immersing in the deionized water for 6 hours, and carrying out vacuum freeze drying to obtain the surface-modified non-woven fabric;

step two, preparing the composite hemostatic material: dissolving modified chitosan in 3wt% acetic acid to prepare a solution; dissolving gelatin and xanthan gum in deionized water at 40 deg.C to obtain solutions, standing and swelling for 8 hr to obtain gelatin solution and xanthan gum solution; adding a modified chitosan solution and oleamide into a gelatin solution, quickly stirring for 30s, adding polyethylene glycol 2000, a tea polysaccharide-nano selenium compound and dopamine-modified nano silicon dioxide, carrying out ultrasonic treatment for 60s, then dropwise adding a xanthan gum solution, standing at room temperature for reaction for 24h after dropwise adding, fully washing with deionized water, and carrying out freeze drying to obtain a composite hemostatic material;

combining the non-woven fabric with the composite hemostatic material: superposing and cold-pressing the non-woven fabric and the composite hemostatic material to obtain a hemostatic layer; wherein the pressure adopted by cold pressing is 4MPa, and the time is 20 min;

step four, preparing the antibacterial chitosan-based hemostatic plaster: and cutting the backing layer coated with the adhesive on the surface according to the size requirement, adhering the backing layer with the cut hemostatic layer, wherein the hemostatic layer is positioned in the middle of the backing layer, then attaching the protective layer on the adhesive surface of the adhesive backing layer, independently sealing, and performing irradiation sterilization to obtain the antibacterial chitosan-based hemostatic patch.

The peel strength and tack strength of the composite hemostatic material samples obtained in examples 1 to 3 and A, B, C, D obtained by separately adjusting the weight ratio of gelatin to xanthan gum to 1:2, 1:1, 3:1, and 4:1 and performing the other operations under the same conditions as in example 2 were measured, and the results are shown in table 1 below.

TABLE 1

As can be seen from table 1, the ratio of gelatin to xanthan gum has a large influence on the peel strength and the tack of the antibacterial chitosan-based hemostatic patch, and the antibacterial chitosan-based hemostatic patches prepared in examples 1 to 3 have a small peel strength and a good tack, that is, when the weight ratio of gelatin to xanthan gum is 2:1, the antibacterial chitosan-based hemostatic patch can be tightly attached to a wound to avoid displacement, and can be easily torn off, so that secondary damage to the wound is not caused during peeling.

Comparative example 1

The same procedure as in example 2 was repeated, except that the composite hemostatic material contained no xanthan gum.

Comparative example 2

The same procedure as in example 2 was repeated, except that the composite hemostatic material contained no gelatin.

Comparative example 3

The same procedure as in example 2 was repeated, except that the composite hemostatic material contained no polyethylene glycol 2000.

Comparative example 4

The same procedure as in example 2 was repeated, except that the composite hemostatic material contained no oleamide.

Comparative example 5

Except the weight portion ratio of the composite hemostatic material preparation raw materials are as follows: the rest is the same as the example 2 except for 130 parts of modified chitosan, 20003 parts of polyethylene glycol, 24 parts of gelatin, 12 parts of xanthan gum, 8 parts of tea polysaccharide-nano selenium compound, 7 parts of dopamine modified nano silicon dioxide and 0.08 part of oleamide.

Comparative example 6

Except the weight portion ratio of the composite hemostatic material preparation raw materials are as follows: the rest is the same as the example 2 except that 90 parts of modified chitosan, 20003 parts of polyethylene glycol, 16 parts of gelatin, 8 parts of xanthan gum, 8 parts of tea polysaccharide-nano selenium compound, 7 parts of dopamine modified nano silicon dioxide and 0.08 part of oleamide.

Tensile Property test

The samples were tested for tensile properties using a universal material tester according to the method of GB/T1040.3-2006. The test was divided into a dry sample and a swollen sample (swollen for 1h in 0.05M, pH7.4 PBS buffer), and 3 replicates of each sample were tested and the tensile strength and elongation at break were recorded. The mechanical property test results of the antibacterial chitosan-based hemostatic patches prepared in examples 1-3 and comparative examples 1-6 are shown in the following table 2:

TABLE 2

Determination of porosity

Adding a certain volume of absolute ethyl alcohol into the measuring cylinder, wherein the volume is marked as V₁Putting the sample into the sample, standing for 5min to make the sample completely soaked by absolute ethyl alcohol and have no obvious air bubbles on the surface, and recording the total volume at the moment as V₂(ii) a The sample was removed and the volume of absolute ethanol remaining in the cylinder was recorded as V₃. Sample (A)The porosity P of the article is calculated by the following formula: p ═ V₁－V₃)/(V₂－V₃) X 100%, each sample was tested in parallel 3 times and the average was taken.

Water absorption test

Cutting the sample into the same size, fully drying, and respectively weighing the initial weight of each sample by an electronic balance to be recorded as m₀Then, each sample was placed in a petri dish, redistilled water was added to the petri dish, the samples were taken out at different times with tweezers, surface moisture was wiped off with absorbent paper, weighed with an electronic balance, and recorded as m_t. The water absorption was calculated by the following formula

Bacterial inhibition test

Samples were tested for bacteriostatic properties using staphylococcus aureus (ATCC 25923) and escherichia coli (ATCC 25922). After two strains are respectively cultured for 24h, the two strains are diluted to 1 × 10⁶CFU/mL. The same weight of sample (test group) and sterile gauze for medical use (control group) were placed in 48-well plates in triplicate, and 1mL of the bacterial suspension was added to each well and incubated at 37 ℃. The absorbance values at 6h, 12h and 24h were determined using an MTT cell proliferation assay kit. Using gauze control group as reference standard, and making into gauze of the formula W_{Rate of inhibition of bacteria}＝(A_{Control group}－A_{Test group})/(A_{Test group}-0.04), wherein 0.04 is the absorbance of the sterile culture fluid at an OD of 600.

The antibacterial chitosan-based hemostatic patches prepared in examples 1 to 3 and comparative examples 1 to 6 were subjected to porosity, water absorption and antibacterial tests, and the results are shown in table 3:

TABLE 3

As can be seen from Table 3, the antibacterial chitosan-based hemostatic patch samples prepared in the embodiments 1 to 3 of the present invention have high porosity and water absorption rate and strong antibacterial activity. Comparative examples 1 and 2 have low porosity and poor water absorption, probably due to the inability to form a double network structure, resulting in a composite hemostatic material with a small number of pores and a large pore diameter; comparative example 3 does not contain polyethylene glycol 2000, comparative example 4 does not contain oleamide, and both of them have poor antibacterial activity, which may be caused by that the antibacterial efficacy of the nanoparticles cannot be fully exerted due to uneven dispersion of the particle components in the composite hemostatic material; comparative example 5 the amount of the modified chitosan is more than 120 parts, the bacteriostatic rate is inferior to that of example 2, it is inferred that the amount of the modified chitosan has important influence on the double-network structure of the hemostatic composite material, and the double-network structure can influence the dispersion and fixation of the tea polysaccharide-nano selenium compound and the dopamine modified nano silicon dioxide, which indicates that the bactericidal property of the antibacterial chitosan-based hemostatic patch is not only related to the amount of the tea polysaccharide-nano selenium compound, but also related to the distribution of the compound in the composite hemostatic material; comparative example 6 the weight ratio of the modified chitosan, the polyvinyl alcohol 2000, the gelatin and the xanthan gum is not more than 30:1:8:4, the porosity of the antibacterial chitosan-based hemostatic patch is increased, the water absorption is reduced, and the antibacterial activity is reduced to a certain degree, which shows that the double-network structure of the composite hemostatic material has a specific structure, and the use amount of each component plays a key role in the formation of the structure.

Cytotoxicity assays

NIH3T3 fibroblasts were cultured in 96-well plates, divided into 11 groups of 5 duplicate wells. Replacing a normal culture medium with a sample leaching solution during experimental group change, wherein the numbers of examples 1-3 are T1, T2 and T3 in sequence, and the numbers of comparative examples 1-6 are D1, D2, D3, D4, D5 and D6 in sequence; the positive control group uses DMEM high-sugar complete medium containing 0.64% phenol, and is marked as PC; the negative control was normal DMEM high-glucose complete medium, noted NC. After 24 hours of culture, the detection was performed 3 times, and the average value was calculated. The detection method comprises the following steps: 0.02mL of 5mg/mL MTT solution was added to each well, incubated at 37 ℃ for 4 hours, aspirated, and 0.1mL of DMSO was added to each well and mixed well. The absorbance (wavelength 570nm) was measured and the cell viability was calculated according to the following formula:

cell survival rate (%) ═ a_{Sample (I)}-A_{Blank 1})/(A_{Negative of}-A_{Blank 2})×100％

In the formula, A_{Sample (I)}: adding the absorbance value of the hole of the sample leaching solution;

A_{blank 1}: absorbance values of the solution in wells with only the extract but no cells inoculated;

A_{negative of}: adding the absorbance value of the solution in the holes of the DMEM complete culture medium;

A_{blank 2}: absorbance values of the solution in wells with DMEM complete medium only and no cells inoculated.

The test results are shown in fig. 1, and it can be seen from fig. 1 that the antibacterial chitosan-based hemostatic patch leaching solution prepared in the examples and comparative examples of the present invention has a cell survival rate of over 90% in 24 hours, and has no cytotoxicity.

In vitro whole blood coagulation test

Taking healthy New Zealand white-ear rabbits, taking blood from heart, and mixing the blood and anticoagulant citric acid at a ratio of 9:1 to obtain anticoagulant whole blood. Numbering samples A-I in examples 1-3 and comparative examples 1-6, setting Blank (Blank) as control group, placing sample in test tube, pre-heating at 37 deg.C for 5min, adding 1mL anticoagulated rabbit blood, incubating at 37 deg.C for 3min, and adding 500 μ L CaCl₂Timing is started after the solution (with the concentration of 25mM) is added, the test tube is taken out every 10s and inclined, whether the blood flows or not is observed until the blood is completely coagulated, and when the blood is inclined at 90 ℃ without flowing, the time for blood coagulation is recorded, namely the whole blood coagulation time BCT.

The test results are shown in FIG. 2. As can be seen from FIG. 2, the blood coagulation time of the sample groups of the antibacterial chitosan-based hemostatic patch prepared in the embodiments 1 to 3 of the present invention is less than 100s, which is far lower than that of the blank group. The blood coagulation time of the sample groups of comparative examples 1-2 is obviously longer than that of the sample groups of examples 1-3, which is probably caused by the fact that the hydrophilicity of the sample groups of the comparative examples is poorer than that of the sample group of example 2 due to the single network structure of the two sample groups; comparative example 3, which contained no polyethylene glycol 2000, blood clotting times exceeded 130s, which may be due to uneven distribution of the particulate components; comparative example 4 contains no oleamide and the blood clotting time exceeds 110s, which is probably due to aggregation of dopamine-modified nanosilica, resulting in failure of some components to achieve hemostatic efficacy; the comparative example 5 has more modified chitosan, and the blood coagulation time is obviously longer than that of the examples 1-3, which shows that the promotion effect of the antibacterial chitosan-based hemostatic patch on blood coagulation is related to the components contained in the patch and the specific double-network structure of the composite hemostatic material; comparative example 6 the weight ratio of the modified chitosan to the polyvinyl alcohol 2000 to the gelatin to the xanthan gum is not more than 30:1:8:4, and the blood coagulation time is as long as 160s, which also shows that the specific double-network structure of the composite hemostatic material can be cooperated with the modified chitosan, the tea polysaccharide-nano selenium compound and the dopamine modified nano silicon dioxide to promote blood coagulation.

The above description is only for the specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and other modifications or equivalent substitutions made by the technical solution of the present invention by the ordinary skilled in the art should be covered within the scope of the claims of the present invention without departing from the spirit and scope of the technical solution of the present invention.