Dressing compositions, absorbable hemostatic dressings and methods of making the same

Abstract

This application belongs to the field of medical dressing technology, specifically relating to dressing compositions, absorbable hemostatic dressings, and their preparation methods. This application provides a dressing composition that, by compounding modified chitosan with modified ergothioneine, forms a dressing composition with non-swelling properties upon contact with water. The chitosan in this application is esterified to introduce hydrophilic carboxyl groups, improving its solubility. Simultaneously, aspartic acid itself promotes cell proliferation and wound healing. Therefore, the dressing prepared from this composition can maintain a stable shape and volume in a body fluid environment, effectively reducing mechanical pressure on surrounding tissues, thereby effectively avoiding various complications caused by material expansion and effectively avoiding the risk of traditional hemostatic materials swelling upon contact with water and compressing nerve tissue. Furthermore, the compounding of modified ergothioneine and modified chitosan in this application not only provides non-swelling and absorbable properties upon contact with water but also exhibits high adhesion and high antioxidant properties.

Description

Technical Field

[0001] This application belongs to the field of medical dressing technology, specifically relating to dressing compositions, absorbable hemostatic dressings and their preparation methods. Background Technology

[0002] Throughout the continuous advancement of medicine, the innovation and development of hemostasis techniques have always been crucial for ensuring patient safety and improving surgical outcomes. Currently, the medical field has developed various hemostasis techniques, including pressure hemostasis (using hemostatic sponges, gauze, etc., for local pressure to achieve hemostasis); powder-based hemostasis (using powdered substances such as starch and polysaccharide polymers to pack bleeding sites); and tissue adhesive hemostasis (using tissue adhesives such as fibrin glue and collagen to achieve hemostasis by bonding tissues).

[0003] However, existing hemostasis techniques still have many limitations and shortcomings in practical applications. Currently widely used hemostatic materials generally suffer from swelling upon contact with water. In most surgical scenarios, while this problem may not directly endanger the patient's life, it can still affect the surgical procedure and postoperative recovery. For surgeries requiring extremely high precision and safety, such as spinal surgery, the drawbacks of hemostatic material swelling upon contact with water are significantly amplified. In spinal surgery, if traditional hemostatic materials are used, the swelling upon contact with water could potentially compress surrounding nerve tissue, leading to serious neurological complications such as paralysis.

[0004] Therefore, developing an absorbable hemostatic dressing that does not swell when exposed to water is key to solving the problems of current hemostatic materials and is of great significance for improving surgical safety and reducing the incidence of postoperative complications. Summary of the Invention

[0005] Based on this, one embodiment of this application provides a dressing composition, an absorbable hemostatic dressing, and a method for preparing the same.

[0006] This application provides a dressing composition comprising: modified chitosan and modified ergothioneine;

[0007] The modified chitosan is the reaction product of chitosan and aspartic acid under the action of an esterification agent;

[0008] The modified ergothionein is a reaction product of ergothionein and quercetin under the action of a crosslinking agent;

[0009] The raw materials for preparing the modified chitosan include the following components in parts by weight: 0.8-1.2 parts chitosan, 0.5-2 parts aspartic acid, and 0.2-0.5 parts esterification reagent.

[0010] In some embodiments, the raw materials for preparing the modified chitosan also include DMSO.

[0011] In some embodiments, the number of DMSO parts is 5 to 8.

[0012] In some embodiments, the esterification agent includes concentrated sulfuric acid.

[0013] In some embodiments, the mass ratio of the modified chitosan to the modified ergothioneine is (0.8-1.2):(3-5.5).

[0014] In some embodiments, the raw materials for preparing the modified ergothioneine include ergothioneine, quercetin, extracellular matrix, and crosslinking agent;

[0015] In some embodiments, the raw materials for preparing the modified ergothioneine include the following components in parts by weight: 0.8-1.2 parts ergothioneine, 0.3-0.6 parts quercetin, 6-10 parts extracellular matrix, 0.2-0.5 parts crosslinking agent, and 46-50 parts anhydrous ethanol.

[0016] In some embodiments, the crosslinking agent includes genipin.

[0017] Another aspect of this application provides an absorbable hemostatic dressing, the absorbable hemostatic dressing comprising the aforementioned dressing composition.

[0018] In some embodiments, the absorbable hemostatic dressing comprises: 0.8-1.2 parts of modified chitosan, 3-5.5 parts of modified ergothioneine; and a solvent.

[0019] In some embodiments, the solvent includes one or more of sodium citrate solution, physiological saline, Ringer's solution, and heparin sodium salt solution;

[0020] In some embodiments, the concentration of the sodium citrate solution is 28 w / v%-32 w / v.

[0021] In some embodiments, the mass-to-volume ratio of the modified chitosan to the sodium citrate solution is 1:(5-10).

[0022] In some embodiments, the mass-to-volume ratio of the modified ergothioneine to the sodium citrate solution is (3-5):(5-10).

[0023] Another aspect of this application provides a method for preparing the absorbable hemostatic dressing, comprising: mixing the modified chitosan, modified ergothioneine and solvent to prepare the absorbable hemostatic dressing;

[0024] In some embodiments, the preparation method includes: preparing the modified ergothioneine and the modified chitosan respectively; and mixing the modified chitosan, the modified ergothioneine and the solvent evenly to prepare the absorbable hemostatic dressing.

[0025] In some embodiments, the method for preparing the modified ergothioneine includes:

[0026] The ergothioneine, quercetin, and alcohol solvent are mixed and dissolved, and the extracellular matrix and crosslinking agent are added to carry out a composite reaction. After the reaction, the mixture is freeze-dried and ground to prepare modified ergothioneine powder.

[0027] In some of these embodiments, the temperature of the composite reaction is 36°C-38°C and the time is 12h-48h.

[0028] In some embodiments, the alcohol solvent includes ethanol.

[0029] In some embodiments, the method for preparing modified chitosan includes: pretreating chitosan, mixing the pretreated chitosan, DMSO containing dissolved aspartic acid, and an esterification reagent, and then performing an esterification reaction; and performing post-treatment after the esterification reaction to prepare modified chitosan.

[0030] In some embodiments, the pretreatment of chitosan includes: adding chitosan to an acetic acid solution and stirring to swell; dropping the swollen mixture into a sodium hydroxide solution to precipitate; filtering, washing and drying.

[0031] In some embodiments, the concentration of the acetic acid solution is 1.5 w / v%-2.5 w / v; the concentration of the sodium hydroxide solution is 0.2 mol / L-0.3 mol / L.

[0032] In some embodiments, the post-processing includes one or more of the following: neutralization, filtration, drying, and grinding.

[0033] In some of these embodiments, the esterification reaction is carried out at a temperature of 30°C-40°C for 24-48 hours.

[0034] This application provides a dressing composition that combines modified chitosan and modified ergothioneine to form a dressing composition with non-swelling properties upon contact with water. The chitosan in this application is esterified to introduce hydrophilic carboxyl groups, improving its solubility. Simultaneously, aspartic acid itself promotes cell proliferation and wound healing. Therefore, the dressing prepared from this composition can maintain a stable shape and volume in a body fluid environment, effectively reducing mechanical pressure on surrounding tissues and thus effectively avoiding various complications caused by material expansion. This improves the safety and success rate of surgery and effectively avoids the risk of traditional hemostatic materials swelling and compressing nerve tissue upon contact with water. Furthermore, the combination of modified ergothioneine and modified chitosan in this application not only possesses non-swelling and absorbable properties upon contact with water but also exhibits high adhesion and high antioxidant properties. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application and to more completely understand this application and its beneficial effects, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is the state of an absorbable hemostatic dressing provided in one embodiment of this application;

[0037] Figure 2 This is a diagram of pigskin unfolded after T-peeling and stretching, provided in one embodiment of this application.

[0038] Figure 3 Cell morphology of a sample provided in one embodiment of this application under a microscope;

[0039] Figure 4 The image shows a sample provided in an embodiment of this application; from left to right, the sample consists of: DPPH stock solution, DPPH + ergothioneine powder, DPPH + ergothioneine-quercetin mixture, and DPPH + modified ergothioneine powder. Detailed Implementation

[0040] The present application will be further described in detail below with reference to the embodiments and examples. It should be understood that these embodiments and examples are for illustrative purposes only and are not intended to limit the scope of the present application. The purpose of providing these embodiments and examples is to enable a more thorough and comprehensive understanding of the disclosure of the present application. It should also be understood that the present application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various modifications or alterations without departing from the spirit of the present application, and the equivalent forms obtained also fall within the protection scope of the present application. Furthermore, numerous specific details are set forth in the following description to provide a fuller understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0041] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0042] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0043] The terms "and / or," "or / and," and "and / or" as used herein include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes technical solutions connected by "logical AND," and also undoubtedly includes technical solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, a technical solution that is connected by "logical OR"), as well as any and all combinations of A, B, C, and D, that is, combinations of any two or three of A, B, C, and D, and also combinations of all four of A, B, C, and D (that is, a technical solution that is connected by "logical AND").

[0044] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0045] The terms “combinations of,” “any combination of,” and “any combination of” used in this article include all suitable combinations of any two or more of the listed items.

[0046] In this document, the term "suitable" as used in phrases such as "suitable combination," "suitable method," and "any suitable method" refers to the ability to implement the technical solution of this application, solve the technical problem of this application, and achieve the expected technical effect of this application.

[0047] In this application, terms such as "further," "even more," and "particularly" are used for descriptive purposes and to indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0048] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0049] In this application, the technical features described in an open-ended manner include both closed technical solutions composed of the listed features and open technical solutions composed of the listed features.

[0050] In this application, numerical intervals (i.e., numerical ranges) are involved. Unless otherwise specified, the selected numerical distributions within the aforementioned numerical intervals are considered continuous and include the two endpoints (i.e., the minimum and maximum values) of the numerical range, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints. In this document, this is equivalent to directly listing every integer. For example, if t is an integer selected from 1 to 10, it means that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Furthermore, when multiple ranges are provided to describe features or characteristics, these ranges can be merged. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0051] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0052] In this application, % (w / w) and wt% both represent weight percentage, % (v / v) refers to volume percentage, and % (w / v) refers to mass-volume percentage.

[0053] All references to documents mentioned in this application are incorporated herein by reference as if each document were individually incorporated herein by reference. Unless they conflict with the inventive purpose and / or technical solution of this application, all cited documents are incorporated herein by reference in their entirety and for all purposes. When citing documents in this application, the definitions of relevant technical features, terms, nouns, phrases, etc., are also incorporated herein by reference. When citing documents in this application, examples and preferred embodiments of the cited technical features may also be incorporated herein by reference, but only to the extent that they enable the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, this application shall prevail or modifications shall be made adaptably to the description in this application.

[0054] The term "modified chitosan" as used in this application refers to the product obtained by modifying the molecular structure of natural chitosan through chemical modification. Chitosan itself is a natural alkaline polysaccharide obtained from the deacetylation of chitin, possessing good biocompatibility, biodegradability, and hemostatic activity. However, natural chitosan suffers from limited solubility (soluble only in dilute acids), low mechanical strength, and slow degradation rate in vivo.

[0055] In this application, aspartic acid is used to esterify and modify pretreated chitosan. Aspartic acid is an acidic amino acid containing two carboxyl groups. By grafting it onto the sugar chains of chitosan through esterification, hydrophilic carboxyl groups can be introduced, thereby improving the solubility and dispersibility of chitosan in a neutral environment, regulating its degradation rate, and utilizing the unique cell affinity of aspartic acid to promote cell adhesion and proliferation. The "pretreatment" refers to the process of swelling and precipitation to disrupt the original compact crystalline structure of chitosan, allowing its molecular chains to expand and increasing reaction sites, thereby improving the efficiency and uniformity of subsequent esterification reactions.

[0056] The term "modified ergothioneine" as used in this application does not refer to a simple physical mixture, but rather to a three-dimensional network complex formed by the complexation of ergothioneine with quercetin and extracellular matrix (ECM) through a cross-linking agent.

[0057] This application utilizes a cross-linking reaction to load ergothioneine and quercetin onto the macromolecular backbone of an ECM. This "modified" structure, on the one hand, enhances the stability of ergothioneine and quercetin through the encapsulation effect of the ECM, preventing their rapid degradation or loss; on the other hand, it enables the sustained release of the active ingredients, allowing them to exert a synergistic effect of antioxidation, anti-inflammation, and repair promotion during wound healing.

[0058] The term "extracellular matrix (ECM)" as used in this application refers to a complex mixture secreted by cells into the extracellular space, mainly including collagen, elastin, proteoglycans, and glycoproteins. In the embodiments of this application, ECM can be derived from decellularized extracts of animal tissues (such as porcine dermis and small intestinal submucosa), or it can be commercially available ECM powder or a mixture of its main components (such as type I collagen). ECM plays a crucial scaffold role in dressings, inducing cell migration, proliferation, and differentiation, and accelerating tissue regeneration.

[0059] To address the problem of existing hemostatic materials swelling upon contact with water, this application provides a dressing composition, an absorbable hemostatic dressing, and a method for preparing the same.

[0060] The first aspect of this application provides a dressing composition comprising: modified chitosan and modified ergothioneine;

[0061] The modified chitosan is the reaction product of chitosan and aspartic acid under the action of an esterification agent;

[0062] The modified ergothionein is a reaction product of ergothionein and quercetin under the action of a crosslinking agent;

[0063] The modified chitosan is prepared from the following components by weight: 0.8-1.2 parts chitosan, 0.5-2 parts aspartic acid, and 0.2-0.5 parts esterification reagent.

[0064] This application provides a dressing composition that combines modified chitosan with modified ergothioneine to form a dressing composition with non-swelling properties upon contact with water. The chitosan in this application is esterified to introduce hydrophilic carboxyl groups, improving its solubility. In a body fluid environment, the dressing prepared from this composition maintains a stable shape and volume, without causing mechanical pressure on surrounding tissues. This effectively avoids various complications caused by material expansion, thereby improving the safety and success rate of surgery and effectively avoiding the risk of traditional hemostatic materials swelling and compressing nerve tissue upon contact with water. Simultaneously, aspartic acid itself has cell proliferation-promoting activity, further enhancing the biocompatibility and healing-promoting effect of the dressing.

[0065] In some embodiments, the raw materials for preparing the modified chitosan include the following components in parts by weight: 0.8-1.2 parts chitosan, 0.5-2 parts aspartic acid, and 0.2-0.5 parts esterification reagent;

[0066] Specifically, the chitosan content can be selected from any value among 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, and 1.2 parts; the aspartic acid content can be selected from any value among 0.5 parts, 0.8 parts, 1.0 parts, 1.2 parts, 1.5 parts, and 2 parts.

[0067] In some embodiments, the mass ratio of the modified chitosan to the modified ergothioneine is (0.8-1.2):(3-5.5). For example, the mass ratio of the modified chitosan to the modified ergothioneine is (0.8, 0.9, 1.0, 1.1, 1.2):(3, 3.5, 4, 4.5, 5, 5.5).

[0068] In some embodiments, the raw materials for preparing the modified chitosan also include DMSO;

[0069] In some embodiments, the number of DMSO parts is 5 to 8;

[0070] In some embodiments, the raw materials for preparing the modified chitosan include the following components in parts by weight: 0.8-1.2 parts chitosan, 0.5-2 parts aspartic acid, 5-8 parts DMSO, and 0.2-0.5 parts esterification reagent;

[0071] Specifically, the chitosan content can be selected from any value among 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, and 1.2 parts; the aspartic acid content can be selected from any value among 0.5 parts, 0.8 parts, 1.0 parts, 1.2 parts, 1.5 parts, and 2 parts.

[0072] The content of DMSO can be selected from any value of 5 parts, 6 parts, 7 parts, or 8 parts; the content of esterification reagent can be selected from any value of 0.2 parts, 0.3 parts, 0.4 parts, or 0.5 parts.

[0073] In some embodiments, the esterification agent includes concentrated sulfuric acid. Concentrated sulfuric acid, as an esterification catalyst, can effectively catalyze the esterification reaction between the carboxyl groups of aspartic acid and the hydroxyl groups of chitosan.

[0074] The raw materials for preparing the modified ergothioneine include ergothioneine, quercetin, extracellular matrix, and cross-linking agent.

[0075] In some embodiments, the raw materials for preparing the modified ergothioneine include the following components in parts by weight: 0.8-1.2 parts ergothioneine, 0.3-0.6 parts quercetin, 6-10 parts extracellular matrix, 0.2-0.5 parts crosslinking agent, and 46-50 parts anhydrous ethanol.

[0076] Specifically, the ergothionein content can be selected from any value among 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, and 1.2 parts.

[0077] The quercetin content can be selected from any value among 0.3 parts, 0.4 parts, 0.5 parts, and 0.6 parts.

[0078] The content of extracellular matrix can be selected from any value among 6, 7, 8, 9, and 10 parts.

[0079] The content of the crosslinking agent can be selected from any value among 0.2 parts, 0.3 parts, 0.4 parts, and 0.5 parts; the content of anhydrous ethanol can be selected from any value among 46 parts, 47 parts, 48 ​​parts, 49 parts, and 50 parts.

[0080] This application modifies chitosan by esterification, introducing hydrophilic carboxyl groups to improve its solubility. Simultaneously, aspartic acid itself promotes cell proliferation and wound healing, further enhancing the dressing's bioactivity. DMSO, as a reaction solvent, dissolves aspartic acid and promotes the esterification reaction. The esterified chitosan of this application effectively overcomes the defect of swelling upon contact with water. In a body fluid environment, the dressing prepared from this composition maintains a stable shape and volume, without mechanically compressing surrounding tissues. This effectively avoids various complications caused by material expansion, thereby improving surgical safety and success rates, and effectively avoiding the risk of traditional hemostatic materials swelling upon contact with water and compressing nerve tissue.

[0081] In some embodiments, the crosslinking agent includes genipin. Genipin is a natural crosslinking agent with good biocompatibility, capable of effectively crosslinking proteins and peptides. In this application, it is used to crosslink ergothioneine, quercetin, and the extracellular matrix to form a stable complex structure.

[0082] Anhydrous ethanol, used as the reaction solvent, effectively dissolves ergothioneine and quercetin, promoting their uniform mixing and cross-linking reaction with the extracellular matrix. The proportions of each raw material were optimized to ensure the full progress of the composite reaction and the stability of the final product.

[0083] Another aspect of this application provides an absorbable hemostatic dressing, prepared by dissolving the dressing composition in a solvent.

[0084] In some embodiments, the solvent includes a sodium citrate solution;

[0085] In some embodiments, the concentration of the sodium citrate solution is 28 w / v%-32 w / v%. For example, the concentration of the sodium citrate solution is 28 w / v%, 29 w / v%, 30 w / v%, 31 w / v%, or 32 w / v%, or any value in between.

[0086] In some embodiments, the mass-to-volume ratio of the modified chitosan to the sodium citrate solution is 1:(5-10); for example, the mass-to-volume ratio of the modified chitosan to the sodium citrate solution is 1:5, 1:6, 1:7, 1:8, 1:9, or 1:10, and any value in between.

[0087] In some embodiments, the mass-to-volume ratio of the modified ergothioneine to the sodium citrate solution is (3-5):(5-10). For example, the mass-to-volume ratio of the modified ergothioneine to the sodium citrate solution is (3, 4, 5):(5, 6, 7, 8, 9, 10).

[0088] Another aspect of this application provides a method for preparing the absorbable hemostatic dressing, which involves mixing the modified chitosan, modified ergothioneine, and solvent to prepare the absorbable hemostatic dressing.

[0089] In some embodiments, this includes preparing modified ergothioneine and modified chitosan, respectively; and

[0090] The modified chitosan, the modified ergothioneine, and the solvent are mixed evenly to prepare the absorbable hemostatic dressing.

[0091] In some embodiments, the method for preparing modified ergothioneine includes:

[0092] Ergothioneine, quercetin, and anhydrous ethanol were mixed and dissolved, and then an extracellular matrix and a cross-linking agent were added to carry out a composite reaction. After the reaction, the mixture was freeze-dried and ground to prepare modified ergothioneine powder.

[0093] In some embodiments, the temperature of the composite reaction is 36℃-38℃ and the time is 12h-48h; the temperature of the composite reaction is close to the human body temperature, which is beneficial to maintaining the stability of bioactive substances; the esterification reaction temperature is moderate, which can ensure the reaction rate and avoid the occurrence of side reactions; the pretreatment conditions are mild and can effectively improve the physicochemical properties of chitosan.

[0094] For example, the temperature of the complex reaction is 36℃, 37℃, or 38℃, or any value in between; the time is 12h, 16h, 20h, 24h, 28h, 32h, 36h, 40h, 44h, or 48h, or any value in between.

[0095] In some embodiments, the method for preparing modified chitosan includes:

[0096] Chitosan is pretreated by mixing the pretreated chitosan, DMSO containing dissolved aspartic acid, and an esterification reagent, followed by an esterification reaction; and

[0097] After esterification, post-processing is performed to prepare modified chitosan.

[0098] In some embodiments, the pretreatment of chitosan includes: adding chitosan to an acetic acid solution and stirring to swell; dropping the swollen mixture into a sodium hydroxide solution to precipitate; filtering, washing and drying.

[0099] Through pretreatment, chitosan powder swells fully in acetic acid solution, and the molecular chains unfold. It is then redeposited in sodium hydroxide solution. This process can remove impurities from chitosan, improve its crystal structure, and enhance the efficiency and uniformity of subsequent esterification reactions, thereby obtaining modified chitosan products with better performance.

[0100] In some embodiments, the concentration of the acetic acid solution is 1.5 w / v%-2.5 w / v; the concentration of the sodium hydroxide solution is 0.2 mol / L-0.3 mol / L.

[0101] For example, the concentration of acetic acid solution can be 1.5 w / v%, 1.6 w / v%, 1.7 w / v%, 1.8 w / v%, 1.9 w / v%, 2.0 w / v%, 2.1 w / v%, 2.2 w / v%, 2.3 w / v%, 2.4 w / v%, or 2.5 w / v%, or any value in between.

[0102] For example, the concentration of sodium hydroxide solution can be 0.2 mol / L, 0.21 mol / L, 0.22 mol / L, 0.23 mol / L, 0.24 mol / L, 0.25 mol / L, 0.26 mol / L, 0.27 mol / L, 0.28 mol / L, 0.29 mol / L, or 0.30 mol / L, or any value in between.

[0103] In some embodiments, the post-processing includes one or more of the following: neutralization, filtration, drying, and grinding.

[0104] In some of these embodiments, the esterification reaction is carried out at a temperature of 30°C-40°C for 24-48 hours.

[0105] For example, the temperature for esterification reactions can be 30℃, 31℃, 32℃, 33℃, 34℃, 35℃, 36℃, 37℃, 38℃, 39℃, or 40℃, or any value in between. The time can be 24 h, 28 h, 32 h, 36 h, 40 h, 44 h, or 48 h, or any value in between.

[0106] The embodiments of this application will be described in detail below with reference to examples. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. For experimental methods in the following embodiments where specific conditions are not specified, please refer to the guidelines given in this application, or follow experimental manuals or conventional conditions in the art, or follow the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0107] In the specific embodiments described below, the measurement parameters involving raw material components may have slight deviations within the weighing accuracy range unless otherwise specified. Temperature and time parameters are subject to acceptable deviations due to instrument testing accuracy or operational precision.

[0108] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0109] The raw material information is shown in Table 1 below:

[0110] Table 1

[0111]

[0112] Example 1

[0113] This embodiment provides an absorbable hemostatic dressing and its preparation method.

[0114] 1. Preparation of modified ergothioneine

[0115] (1) Weigh 1 part of ergothioneine powder and 0.3 parts of quercetin, add 4 parts of anhydrous ethanol, and stir magnetically for 0.5 h to fully dissolve them into a homogeneous solution.

[0116] (2) Add 6 parts of ECM and 0.2 parts of genipin to the ergothioneine-quercetin mixed solution, and shake in a constant temperature shaker at 37℃ for 12 hours to react;

[0117] (3) The compounded mixture is freeze-dried, cut into pieces and ground into powder to obtain modified ergothioneine powder.

[0118] 2. Preparation of modified chitosan

[0119] (1) Weigh 0.5 parts of aspartic acid, dissolve it in 5 parts of DMSO, and heat it to 40°C; pretreat chitosan: add chitosan to acetic acid solution and stir to swell, then drop the swollen mixture into sodium hydroxide solution to precipitate, filter, wash and dry.

[0120] (2) Add 1 part of pretreated chitosan to the system, slowly add 0.2 parts of concentrated sulfuric acid, and react at 30°C for 24 hours;

[0121] (3) After the esterification reaction is completed, neutralize with sodium hydroxide solution to neutral, filter, dry the filter cake and grind it into powder.

[0122] 3. Preparation of absorbable hemostatic dressings

[0123] Add 1 part modified chitosan, 3 parts modified ergothioneine, and 5 parts 30w / v% sodium citrate solution, mix well, and you will get an absorbable hemostatic dressing.

[0124] Example 2

[0125] This embodiment provides an absorbable hemostatic dressing composition and its preparation method.

[0126] 1. Preparation of modified ergothioneine

[0127] (1) Weigh 1 part of ergothioneine powder and 0.4 parts of quercetin, add 5 parts of anhydrous ethanol, and stir magnetically for 1 hour to fully dissolve them into a homogeneous mixed solution.

[0128] (2) Add 7 parts of ECM and 0.3 parts of genipin to the ergothioneine-quercetin mixed solution, and shake in a constant temperature shaker at 37℃ for 20 hours for compound reaction;

[0129] (3) The compounded mixture is freeze-dried, cut into pieces and ground into powder to obtain modified ergothioneine powder.

[0130] 2. Preparation of modified chitosan

[0131] (1) Weigh 0.8 parts of aspartic acid, dissolve it in 6 parts of DMSO, and heat it to 45°C; pretreat chitosan: add chitosan to acetic acid solution and stir to swell, then drop the swollen mixture into sodium hydroxide solution to precipitate, filter, wash and dry.

[0132] (2) Add 1 part of pretreated chitosan to the system, slowly add 0.3 parts of concentrated sulfuric acid, and react at 35°C for 30 h;

[0133] (3) After the esterification reaction is completed, neutralize with sodium hydroxide solution to neutral, filter, dry the filter cake and grind it into powder.

[0134] 3. Preparation of absorbable hemostatic dressings

[0135] Add 1 part modified chitosan, 3.5 parts modified ergothioneine, and 6 parts 30w / v% sodium citrate solution, mix well, and you will get an absorbable hemostatic dressing.

[0136] Example 3

[0137] This embodiment provides an absorbable hemostatic dressing composition and its preparation method.

[0138] 1. Preparation of modified ergothioneine

[0139] (1) Weigh 1 part of ergothioneine powder and 0.45 parts of quercetin, add 6 parts of anhydrous ethanol, and stir magnetically for 1 hour to fully dissolve them into a homogeneous mixed solution.

[0140] (2) Add 8 parts of ECM and 0.35 parts of genipin to the ergothioneine-quercetin mixed solution, and shake in a constant temperature shaker at 37℃ for 28 hours for compound reaction;

[0141] (3) The compounded mixture is freeze-dried, cut into pieces and ground into powder to obtain modified ergothioneine powder.

[0142] 2. Preparation of modified chitosan

[0143] (1) Weigh 1 part of aspartic acid, dissolve it in 6.5 parts of DMSO, and heat it to 50°C; pretreat chitosan: add chitosan to acetic acid solution and stir to swell, then drop the swollen mixture into sodium hydroxide solution to precipitate, filter, wash and dry.

[0144] (2) Add 1 part of pretreated chitosan to the system, slowly add 0.35 parts of concentrated sulfuric acid, and react at 35°C for 36 h;

[0145] (3) After the esterification reaction is completed, neutralize with sodium hydroxide solution to neutral, filter, dry the filter cake and grind it into powder.

[0146] 3. Preparation of absorbable hemostatic dressings

[0147] Add 1 part modified chitosan, 4 parts modified ergothioneine, and 7 parts 30w / v% sodium citrate solution, mix well, and you will get an absorbable hemostatic dressing.

[0148] Example 4

[0149] This embodiment provides an absorbable hemostatic dressing composition and its preparation method.

[0150] 1. Preparation of modified ergothioneine

[0151] (1) Weigh 1 part of ergothioneine powder and 0.5 parts of quercetin, add 7 parts of anhydrous ethanol, and stir magnetically for 1.5 hours to fully dissolve them into a homogeneous solution.

[0152] (2) Add 9 parts of ECM and 0.4 parts of genipin to the ergothioneine-quercetin mixed solution, and shake in a constant temperature shaker at 37℃ for 40h for compound reaction;

[0153] (3) The compounded mixture is freeze-dried, cut into pieces and ground into powder to obtain modified ergothioneine powder.

[0154] 2. Preparation of modified chitosan

[0155] (1) Weigh 1.5 parts of aspartic acid and dissolve it in 7 parts of DMSO. Heat to 55°C. Pre-treat chitosan: Add chitosan to acetic acid solution and stir to swell. Add the swollen mixture to sodium hydroxide solution to precipitate. Filter, wash and dry.

[0156] (2) Add 1 part of pretreated chitosan to the system, slowly add 0.4 parts of concentrated sulfuric acid, and react at 40°C for 42 h;

[0157] (3) After the esterification reaction is completed, neutralize with sodium hydroxide solution to neutral, filter, dry the filter cake and grind it into powder.

[0158] 3. Preparation of absorbable hemostatic dressings

[0159] Add 1 part modified chitosan, 4.5 parts modified ergothioneine, and 8 parts 30w / v% sodium citrate solution, mix well, and you will get an absorbable hemostatic dressing.

[0160] Example 5

[0161] This embodiment provides an absorbable hemostatic dressing composition and its preparation method.

[0162] 1. Preparation of modified ergothioneine

[0163] (1) Weigh 1 part of ergothioneine powder and 0.6 parts of quercetin, add 8 parts of anhydrous ethanol, and stir magnetically for 2 hours to fully dissolve them into a homogeneous solution.

[0164] (2) Add 10 parts of ECM and 0.5 parts of genipin to the ergothioneine-quercetin mixed solution, and shake in a constant temperature shaker at 37℃ for 48 hours for compound reaction;

[0165] (3) The compounded mixture is freeze-dried, cut into pieces and ground into powder to obtain modified ergothioneine powder.

[0166] 2. Preparation of modified chitosan

[0167] (1) Weigh 2 parts of aspartic acid and dissolve it in 8 parts of DMSO. Heat to 60°C. Pre-treat chitosan: Add chitosan to acetic acid solution and stir to swell. Add the swollen mixture to sodium hydroxide solution to precipitate. Filter, wash and dry.

[0168] (2) Add 1 part of pretreated chitosan to the system, slowly add 0.5 parts of concentrated sulfuric acid, and react at 40°C for 48 h;

[0169] (3) After the esterification reaction is completed, neutralize with sodium hydroxide solution to neutral, filter, dry the filter cake and grind it into powder.

[0170] 3. Preparation of absorbable hemostatic dressings

[0171] Add 1 part modified chitosan, 5 parts modified ergothioneine, and 10 parts 30w / v% sodium citrate solution, mix well, and you will get an absorbable hemostatic dressing.

[0172] Example 6

[0173] This embodiment provides an absorbable hemostatic dressing composition and its preparation method.

[0174] 1. Preparation of modified ergothioneine

[0175] (1) Weigh 1 part of ergothioneine powder and 0.25 parts of quercetin, add 3 parts of anhydrous ethanol, and stir magnetically for 20 minutes to fully dissolve them into a homogeneous solution.

[0176] (2) Add 5 parts of ECM and 0.15 parts of genipin to the ergothioneine-quercetin mixed solution, and shake in a constant temperature shaker at 37℃ for 10 hours to react;

[0177] (3) The compounded mixture is freeze-dried, cut into pieces and ground into powder to obtain modified ergothioneine powder.

[0178] 2. Preparation of modified chitosan

[0179] (1) Weigh 0.45 parts of aspartic acid, dissolve it in 4.5 parts of DMSO, and heat it to 35°C; pretreat chitosan: add chitosan to acetic acid solution and stir to swell, then drop the swollen mixture into sodium hydroxide solution to precipitate, filter, wash and dry.

[0180] (2) Add 1 part of pretreated chitosan to the system, slowly add 0.15 parts of concentrated sulfuric acid, and react at 25°C for 22 hours; c. After the esterification reaction is completed, neutralize with sodium hydroxide solution to neutral, filter, dry the filter cake, and grind it into powder.

[0181] (3) Preparation of absorbable hemostatic dressings

[0182] Add 1 part modified chitosan, 2.5 parts modified ergothioneine, and 4 parts 30w / v% sodium citrate solution, mix well, and you will get an absorbable hemostatic dressing.

[0183] Example 7

[0184] This embodiment provides an absorbable hemostatic dressing composition and its preparation method.

[0185] 1. Preparation of modified ergothioneine

[0186] (1) Weigh 1 part of ergothioneine powder and 0.65 parts of quercetin, add 9 parts of anhydrous ethanol, and stir magnetically for 2.5 hours to fully dissolve them into a homogeneous solution.

[0187] (2) Add 11 parts of ECM and 0.55 parts of genipin to the ergothioneine-quercetin mixed solution, and shake in a constant temperature shaker at 37°C for 50 hours to react;

[0188] (3) The compounded mixture is freeze-dried, cut into pieces and ground into powder to obtain modified ergothioneine powder.

[0189] 2. Preparation of modified chitosan

[0190] (1) Weigh 2.2 parts of aspartic acid, dissolve it in 8.5 parts of DMSO, and heat it to 65°C; pretreat chitosan: add chitosan to acetic acid solution and stir to swell, then drop the swollen mixture into sodium hydroxide solution to precipitate, filter, wash and dry.

[0191] (2) Add 1 part of pretreated chitosan to the system, slowly add 0.55 parts of concentrated sulfuric acid, and react at 45°C for 50 h;

[0192] (3) After the esterification reaction is completed, neutralize with sodium hydroxide solution to neutral, filter, dry the filter cake and grind it into powder.

[0193] 3. Preparation of absorbable hemostatic dressings

[0194] Add 1 part modified chitosan, 5.5 parts modified ergothioneine, and 11 parts 30w / v% sodium citrate solution, mix well, and you will get an absorbable hemostatic dressing.

[0195] Example 8

[0196] This embodiment is basically the same as Embodiment 1, except that the mass ratio of modified chitosan to modified ergothionein is 2:5.

[0197] Example 9

[0198] This embodiment is basically the same as Embodiment 1, except that the mass ratio of modified chitosan to modified ergothionein is 1:6.

[0199] Example 10

[0200] This embodiment is basically the same as Embodiment 1, except that the solvent used in the preparation of the absorbable hemostatic dressing is Ringer's solution.

[0201] Comparative Example 1

[0202] This comparative example provides a hemostatic dressing, which differs from Example 1 in that it uses chloroacetic acid carboxymethylated modified chitosan.

[0203] Raw materials for preparation: 1 part pretreated chitosan powder, 3 parts modified ergothioneine powder, and 5 parts sodium citrate solution.

[0204] Preparation method: The pretreated chitosan powder, modified ergothioneine powder and sodium citrate solution are mixed evenly.

[0205] Comparative Example 2

[0206] This comparative example provides a hemostatic dressing that differs from Example 1 in that it uses ordinary chitosan (untreated and unmodified).

[0207] Raw materials for preparation: 1 part of ordinary chitosan powder (95% degree of deacetylation, untreated), 3 parts of modified ergothioneine powder, and 5 parts of sodium citrate solution.

[0208] Preparation method: Mix ordinary chitosan powder, modified ergothioneine powder and sodium citrate solution evenly.

[0209] Comparative Example 3 provides a hemostatic dressing that differs from Example 1 in that it uses collagen.

[0210] I. The absorbable hemostatic dressings prepared in Examples 1-7 were tested respectively, and the following indicators were tested:

[0211] The expansion rate was measured using an expansion rate measuring instrument. No specific testing standard for the expansion rate of hemostatic materials could be found; most of them were calculated based on the volume expansion rate.

[0212] T-peel tensile strength is tested according to YY / T 0729.2-2009 (N / cm);

[0213] Hemostasis time was measured according to the YY / T 1477.5-2020 (s) standard;

[0214] Cytotoxicity was determined according to GB / T 16886.5-2017 (%).

[0215] Antibacterial rate according to WS / T 650-2019 (%);

[0216] The DPPH free radical scavenging rate was tested according to GB / T 39100-2020 (%). The performance test results are shown in Table 2.

[0217] Table 2

[0218]

[0219] Based on a comparison of the performance data of Examples 1-10 and Comparative Examples 1-3, the absorbable hemostatic dressing of this application exhibits excellent comprehensive performance within the optimal formulation range. All indicators of Examples 1-5 are significantly better than those of Examples 6-10 and the comparative examples, with Example 4 showing the most outstanding comprehensive performance: hemostasis time of only 15 seconds, T-peel tensile strength as high as 758 N / cm, cell viability of 102%, antibacterial rate of 97.8%, DPPH free radical scavenging rate of 93.2%, and swelling rate controlled at a low level of 0.6%. This indicates that when the mass ratio of modified chitosan to modified ergothioneine is controlled between 1:3 and 1:4.5, and the modification reaction conditions are suitable, the dressing achieves a high balance between hemostatic efficiency, mechanical strength, biocompatibility, antibacterial properties, and antioxidant properties.

[0220] Comparative analysis shows that deviations from the optimal formulation range lead to a significant decrease in performance. In Examples 6-10, when the proportion of modified ergothioneine was too low (2.5 parts) or too high (5.5 parts), or the reaction time was insufficient or too long, the hemostasis time was prolonged to 52-80 seconds, the T-peel tensile strength decreased to 500-567 N / cm, and the cell viability and antibacterial rate were also significantly reduced. Crucially, although Comparative Examples 1-2 used modified ergothioneine, the chitosan was not modified, resulting in an abnormally high swelling rate of 8.6%-10.5%, which may cause pressure damage to the wound. In Comparative Example 3, collagen was used instead of modified chitosan, and all performance indicators decreased significantly, especially the antibacterial rate of only 66.2% and the DPPH clearance rate of only 58.2%, demonstrating the irreplaceable nature of the synergistic system of modified chitosan and modified ergothioneine in this application.

[0221] In summary, this application successfully constructed a multifunctional hemostatic dressing with rapid hemostasis, good mechanical properties, high biocompatibility, strong antibacterial activity, and excellent antioxidant function through the composite modification of ergothioneine with quercetin and ECM, and the aspartic acid esterification modification of chitosan. The optimal formulation is the parameter range represented by Example 4. This system effectively solves the problems of high expansion rate, slow hemostasis speed, and limited functionality of traditional hemostatic materials, and has clear clinical application value in the field of trauma hemostasis.

[0222] II. Types of Skin Irritation Reactions in Experimental Rabbits

[0223] 1. Experimental steps:

[0224] 1.1 Animal preparation: 12 hours before the experiment, the fur on both sides of the spine on the back of the experimental rabbits was removed (approximately 10cm × 15cm in size) to serve as the experimental and observation sites.

[0225] 1.2. Apply the sample to the skin at the specified location according to GB / T 16886.10-2017, and then fix the patch with a closed bandage for 4 hours. Apply a negative control to the skin at the specified location using the same method. For the positive control group, use a positive control solution instead of the sample and perform the same procedure. After 4 hours, remove the patch, mark the contact area with a marker, wash the test area with warm water, and observe the test results.

[0226] 1.3. Score the skin reaction according to the scoring criteria in Table 3:

[0227] Table 3

[0228]

[0229] 1.4. Evaluate the experiment according to the rabbit stimulus response type criteria in Table 4:

[0230] Table 4

[0231]

[0232] 2. The experimental results are shown in Table 5:

[0233] Table 5

[0234]

[0235] III. Guinea Pig Allergic Skin Reactions

[0236] 1. Experimental steps:

[0237] 1.1 Experimental Preparation

[0238] One day before the experiment, the guinea pigs were marked and weighed. The fur on the test area was completely trimmed with an electric razor, and the animals' general condition was observed daily.

[0239] 1.2 Main Experiment

[0240] Induction: Sample patches and control patches prepared according to the three sample and control samples were applied topically to the upper back of each animal in the experimental and control groups, respectively. After 6 hours, the occlusive bandages and patches were removed. This step was repeated for 3 consecutive days in 1 week, and the same procedure was performed for 3 weeks.

[0241] Triggering: One day prior to triggering, the hair on one side of the animal's abdomen was removed. Fourteen days after the final local induction phase, the prepared sample patch was applied to the hairless area of ​​the abdomen of each animal (the area not tested during the induction phase). It was secured with a closed bandage and removed after 6 hours ± 0.5 hours.

[0242] Observation: Skin reactions at the stimulation sites were observed in the experimental and control groups 24 and 48 hours after patch removal. Erythema and edema reactions at each stimulation site and at each observation time were described and graded according to the Magnusson and Kligman grading system.

[0243] 1.3 Evaluation Criteria

[0244] According to the Magnusson and Kligman grading criteria in Table 6, sensitization is generally indicated when the control group animals have a grade less than 1, while the experimental group animals have a grade greater than or equal to 1. If the control group animals have a grade greater than or equal to 1, sensitization is considered to have occurred when the experimental group animals' reactions exceed the most severe reaction in the control group. If a reaction is suspected, rechallenge should be performed to confirm the initial challenge result. The experimental results are represented by the incidence of positive challenge results in both the experimental and control animals.

[0245] Table 6

[0246]

[0247] 2. The experimental results are shown in Table 7 (the data represent the skin reaction scores during the stimulation phase):

[0248] Table 7

[0249]

[0250] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Furthermore, it should be understood that after reading the above teachings of this application, those skilled in the art can make various alterations or modifications to this application, and the equivalent forms obtained also fall within the scope of protection of this application. It should also be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A dressing composition, characterized in that, include: Modified chitosan and modified ergothioneine; The modified chitosan is the reaction product of chitosan and aspartic acid under the action of an esterification agent; The modified ergothionein is a reaction product of ergothionein and quercetin under the action of a crosslinking agent; The raw materials for preparing the modified chitosan include the following components in parts by weight: 0.8-1.2 parts chitosan, 0.5-2 parts aspartic acid, and 0.2-0.5 parts esterification reagent.

2. The dressing composition according to claim 1, characterized in that, The raw materials for preparing the modified chitosan also include DMSO; Optionally, the number of parts of DMSO is 5 to 8; Optionally, the esterification reagent includes concentrated sulfuric acid.

3. The dressing composition according to claim 1, characterized in that, The mass ratio of the modified chitosan to the modified ergothioneine is (0.8-1.2):(3-5.5).

4. The dressing composition according to claim 1, characterized in that, The raw materials for preparing the modified ergothioneine include ergothioneine, quercetin, extracellular matrix, and cross-linking agent; Optionally, the raw materials for preparing the modified ergothioneine include the following components in parts by weight: 0.8-1.2 parts ergothioneine, 0.3-0.6 parts quercetin, 6-10 parts extracellular matrix, 0.2-0.5 parts crosslinking agent, and 46-50 parts anhydrous ethanol. Optionally, the crosslinking agent includes genipin.

5. An absorbable hemostatic dressing, characterized in that, The absorbable hemostatic dressing comprises the dressing composition according to any one of claims 1 to 4; Optionally, the absorbable hemostatic dressing comprises: 0.8-1.2 parts of modified chitosan and 3-5.5 parts of modified ergothioneine; And, solvent.

6. The absorbable hemostatic dressing according to claim 5, characterized in that, The solvent includes one or more of sodium citrate solution, physiological saline, and Ringer's solution; Optionally, the concentration of the sodium citrate solution is 28 w / v%-32 w / v.

7. The absorbable hemostatic dressing according to claim 6, characterized in that, The mass-to-volume ratio of the modified chitosan to the sodium citrate solution is 1:(5-10); and / or The mass-to-volume ratio of the modified ergothioneine to the sodium citrate solution is (3-5):(5-10).

8. The method for preparing the absorbable hemostatic dressing according to any one of claims 5 to 7, characterized in that, include: An absorbable hemostatic dressing was prepared by mixing the modified chitosan, modified ergothioneine, and solvent. Optionally, the preparation method includes: The modified ergothioneine and the modified chitosan were prepared separately. as well as The modified chitosan, the modified ergothioneine, and the solvent are mixed evenly to prepare the absorbable hemostatic dressing.

9. The method for preparing the absorbable hemostatic dressing according to claim 8, characterized in that, The method for preparing the modified ergothioneine includes: The ergothioneine, quercetin, and alcohol solvent are mixed and dissolved, and the extracellular matrix and crosslinking agent are added to carry out a composite reaction. After the reaction, the mixture is freeze-dried and ground to prepare modified ergothioneine powder. Optionally, the temperature of the composite reaction is 36℃-38℃, and the time is 12h-48h; Optionally, the alcohol solvent includes ethanol; And / or, methods for preparing modified chitosan include: Chitosan is pretreated by mixing the pretreated chitosan, DMSO containing dissolved aspartic acid, and an esterification reagent, followed by an esterification reaction; and After esterification, post-processing is performed to prepare modified chitosan.

10. The method for preparing the absorbable hemostatic dressing according to claim 9, characterized in that, The method satisfies one or more of the following conditions: (1) Pretreatment of chitosan includes: adding chitosan to acetic acid solution and stirring to swell, dropping the swollen mixture into sodium hydroxide solution to precipitate, filtering, washing and drying; Optionally, the concentration of the acetic acid solution is 1.5 w / v%-2.5 w / v; and the concentration of the sodium hydroxide solution is 0.2 mol / L-0.3 mol / L. (2) Post-processing includes one or more of the following: neutralization, filtration, drying, and grinding; and (3) The temperature of the esterification reaction is 30℃-40℃ and the time is 24h-48h.

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