A water-absorbing-antibacterial carboxymethyl cellulose fiber fabric medical dressing and a preparation method thereof

Abstract

This invention discloses a water-absorbing and antibacterial carboxymethyl cellulose fiber fabric-based medical dressing, comprising carboxymethyl modified lyocell fiber fabric and an antibacterial component loaded therein. The carboxymethyl modified lyocell fiber fabric is obtained by sequentially subjecting the lyocell fiber fabric to etherification-deep eutectic solvent pretreatment, followed by alkalization treatment. The antibacterial component is loaded into the carboxymethyl modified lyocell fiber fabric matrix by loading an antibacterial liquid and then performing ionic crosslinking to achieve loading within the carboxymethyl modified lyocell fiber matrix. This invention effectively avoids problems such as pore blockage that can easily occur with antibacterial agent loading, while imparting high moisture absorption, moisturizing and antibacterial properties to the material, effectively maintaining the original fiber morphology and network structure. It combines strong water absorption, high antibacterial properties, and good mechanical properties, making it widely applicable.

Description

Technical Field

[0001] This invention belongs to the field of medical materials technology, specifically relating to a water-absorbing and antibacterial carboxymethyl cellulose fiber fabric-based medical dressing and its preparation method. Background Technology

[0002] Carboxymethyl cellulose (CMC) is a common water-soluble cellulose ether, widely used in medical dressings due to its excellent water solubility, thickening properties, film-forming ability, and biocompatibility. While these dressings offer good moisture retention, they also suffer from several drawbacks: poor mechanical properties, insufficient softness and elasticity, and poor conformability to the body's contours; poor breathability, leading to wound dampness and hindering healing; and the inability to form a porous fiber structure to promote exudate absorption and cell growth, while only providing a moisture barrier. Currently, common cellulose carboxymethylation reactions are mostly carried out in pulp or powder form, resulting in vigorous reactions that completely destroy the fiber morphology of the raw material. Achieving carboxymethylation of the fiber surface with minimal damage to the fiber morphology is a key technical challenge in preparing CMC dressings that retain the fiber morphology and maintain its inherent excellent mechanical properties. Lyocell fiber, an environmentally friendly regenerated cellulose fiber, possesses advantages such as softness, high strength, moisture absorption, and breathability, making its physical form an ideal dressing substrate. If lyocell fiber can be used as a backbone and carboxymethyl groups can be introduced into its molecular chain to give it the moisturizing and gelling properties of CMC, while retaining its inherent fiber morphology and mechanical strength, it is expected that high-performance medical dressings can be prepared.

[0003] Furthermore, wound infection is a major obstacle to the healing process, making the development of dressings with both high antibacterial efficacy and excellent moist healing capabilities crucial. However, existing technologies often face a trade-off when imparting antibacterial properties to materials: 1) The earliest chemical grafting method (-OH, -COOH, etc.), while providing strong bonds, has a complex synthesis process, often requiring toxic coupling agents or harsh reaction conditions, which can easily damage the biocompatibility and fiber morphology of CMC itself, and the grafting rate is difficult to control, resulting in high costs; 2) Traditional physical adsorption methods also have significant drawbacks: firstly, the binding force is weak, with the antibacterial agent merely floating on the surface, easily releasing and being lost upon contact with exudate, leading to poor long-term antibacterial properties; secondly, pore blockage is prone to occur, resulting in limited swelling of the dried dressing upon rehydration, significantly reducing the dressing's absorption rate and volume.

[0004] Therefore, further exploring a mild and simple process to construct a special microstructure that allows the antibacterial agent to form a stable interaction with the fiber matrix (not a simple physical accumulation) without sacrificing or even synergistically improving the material's moisture absorption and swelling properties is a key technical challenge that urgently needs to be solved in the development of high-performance cellulose-based antibacterial dressings. Summary of the Invention

[0005] The main objective of this invention is to provide a carboxymethyl cellulose medical dressing that integrates both high absorbency and antibacterial properties. By utilizing the effective ionic interaction between the negatively charged carboxymethylated fiber skeleton and the cationic antibacterial agent to promote the formation of an ionic cross-linking network, problems such as pore blockage can be effectively avoided. While giving the material high moisture absorption, moisturizing and antibacterial properties, it perfectly retains its original fiber morphology and network structure, and has strong water absorption, high antibacterial properties and good mechanical properties.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A water-absorbing and antibacterial carboxymethyl cellulose fiber fabric-based medical dressing comprises a carboxymethyl modified lyocell fiber fabric matrix and an antibacterial component loaded therein. The carboxymethyl modified lyocell fiber fabric is obtained by sequentially subjecting the lyocell fiber fabric to etherification-deep eutectic solvent pretreatment, followed by alkalization treatment. The antibacterial component is effectively loaded into the carboxymethyl modified lyocell fiber fabric matrix by loading an antibacterial liquid into the matrix, undergoing ionic cross-linking and promoting network reconstruction (new ionic networks are embedded in the cellulose network structure).

[0007] According to the above scheme, the conditions for ionic crosslinking and network reconstruction include: a constant temperature reaction of 35-65℃ for 0.5-5h.

[0008] In the above scheme, the Lyocell fiber fabric can specifically be Lyocell fiber gauze, Lyocell fiber spunlace nonwoven fabric, or Lyocell fiber needle-punched nonwoven fabric.

[0009] Furthermore, in the lyocell fiber fabric, the single-layer thickness is 0.3-0.6 mm and the pore size is 0.5-0.8 mm.

[0010] According to the above scheme, the etherification-deep eutectic solvent pretreatment adopts a mixed solution system of deep eutectic solvent and etherifying agent.

[0011] According to the above scheme, the deep eutectic solvent is composed of hydrogen bond acceptors and hydrogen bond donors, and the molar ratio of hydrogen bond acceptors to hydrogen bond donors is 0.1-1.5:1.

[0012] Preferably, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 0.5-1:1.

[0013] According to the above scheme, the hydrogen bond acceptor is one or more of choline chloride, betaine, proline, citric acid, etc.; the hydrogen bond donor is one or more of glycerol, lactic acid, chloroacetic acid, citric acid, urea, etc.

[0014] According to the above scheme, the etherifying agent used in the etherification step can be one or more of chloroacetic acid, sodium chloroacetate, 2-chloropropionic acid, 3-chloropropionic acid, etc.

[0015] According to the above scheme, the mass ratio of the lyocell fiber fabric to the deep eutectic solvent is 1:4-6.

[0016] According to the above scheme, the mass ratio of the etherifying agent to the Lyocell fiber fabric is 1-2:1.

[0017] According to the above scheme, the etherification-deep eutectic solvent pretreatment time is 0.5-1h, and the temperature is 40-60℃.

[0018] According to the above scheme, the alkalizing agent used in the alkalization step can be one or more of the following: sodium hydroxide, sodium oxide, sodium bicarbonate, potassium hydroxide, lithium hydroxide, tetrabutylammonium hydroxide, urea, etc.

[0019] According to the above scheme, in step (3), the alkalization treatment time is 0.5-5h, preferably 1-2h; the temperature is 50-80℃.

[0020] According to the above scheme, the antibacterial component may be selected from one or more of polyhexamethylene biguanide hydrochloride, chlorhexidine gluconate, hexadecyltrimethylammonium bromide, chlorhexidine acetate, and polyhexamethylene monoguanide hydrochloride; preferably polyhexamethylene biguanide hydrochloride.

[0021] According to the above scheme, the solvent used for the antibacterial solution is an aqueous ethanol solution.

[0022] Preferably, the volume ratio of the solvent ethanol to water is 2-8:1, and more preferably 4:1.

[0023] According to the above scheme, a large number of non-film-forming particulate precipitates (antibacterial components) were observed on the fiber surface and deep in the folds of the water-absorbing and antibacterial carboxymethyl cellulose fiber fabric-based medical dressing; the water absorption rate was 2950-4660% (preferably 4400-4660%); and the volume expansion rate was 2900-4650% (preferably 4000-4650%, more preferably 4620-4650%).

[0024] The present invention also provides a method for preparing the above-mentioned absorbent-antibacterial carboxymethyl cellulose fiber fabric-based medical dressing, comprising the following steps: (1) The hydrogen bond acceptor and hydrogen bond donor are stirred and heated at 40-60℃ to form a uniform transparent liquid to obtain a functionalized deep eutectic solvent. An etherifying agent is added and the lyocell fiber fabric matrix is ​​soaked in it for 0.5-1h to form a mixed system of deep eutectic solvent with etherification activity and fiber composite. (2) Add an alkalizing agent (alkali solution) to the obtained mixture and react at 50-80℃ for 0.5-5h to obtain carboxymethyl modified Lyocell fiber fabric; (3) After washing and drying, the obtained carboxymethyl modified lyocell fiber fabric is immersed in the prepared antibacterial functional solution and heated to react, and then crosslinked and reconstructed to obtain the water-absorbing and antibacterial carboxymethyl cellulose fiber fabric-based medical dressing.

[0025] According to the above scheme, in step (2), an aqueous ethanol solution is also introduced as a solvent, and the mass-volume ratio of Lyocell fiber fabric to aqueous ethanol solution is 1g:50-200ml, preferably 1g:80-150ml.

[0026] According to the above scheme, in step (2), the mass ratio of alkalizing agent to Lyocell fiber fabric is 5-20:1.

[0027] According to the above scheme, in step (3), washing is performed using an ethanol-water solution, wherein the volume concentration of ethanol is 80-100%; preferably 80%. According to the above scheme, in step (3), the solvent used in the impregnation solution (antibacterial functional solution) is ethanol, with a volume fraction of 75-100%, preferably 100%.

[0028] According to the above scheme, in step (3), the concentration range of the antibacterial component in the impregnation solution is 0.02-5 g / ml, preferably 0.05-0.1 g / ml, and more preferably 0.06-0.08 g / ml.

[0029] According to the above scheme, in step (3), the temperature of the heating reaction is 35-65℃.

[0030] According to the above scheme, in step (3), the heating reaction time is 0.5-2.5h.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Breakthrough synergistic mechanism of moisture absorption and antibacterial action: This invention effectively overcomes the technical challenge of traditional antibacterial modification leading to material pore blockage or the occupation of hydrophilic groups, thus reducing moisture absorption performance. It utilizes long-chain cationic antibacterial agents (such as polyhexamethylene biguanide) to act as molecular scaffolds within the cellulose network of carboxymethylated lyocell fiber fabric. Combined with the heating reaction conditions of this invention, the introduced antibacterial component's molecular chains effectively inhibit excessive hydrogen bonding between carboxymethyl cellulose molecular chains through electrostatic repulsion and steric hindrance, preserving more free volume and amorphous regions. This synergistic effect allows the dressing to swell more rapidly upon contact with wound exudate, forming a highly water-retaining gel network and providing an extremely superior moist healing environment for the wound.

[0032] 2. Stable structures and in-situ crosslinking based on ion coordination assembly: Unlike traditional physical surface adsorption mechanisms with poor binding, this invention utilizes a precise combination of etherification-deep eutectic solvent pretreatment and carboxymethylation. This simplifies the process, enhances reactivity, and exposes specific active sites on the fiber backbone, facilitating the induction of cationic antibacterial agents and anionic carboxyl groups (-COO). - In-situ ionic crosslinking occurs; this strong electrostatic interaction and hydrogen bond network not only endow the material with excellent antibacterial properties, but also enhance the gel strength in the wet state as a physical crosslinking point, which can effectively solve the problems of easy disintegration and poor strength of traditional CMC gel when exposed to water; the formed ionic network structure enables the antibacterial agent to be stably anchored on the fiber surface to achieve contact sterilization, while also taking into account good water absorption and swelling properties.

[0033] 3. Green, simultaneous process for fiber morphology preservation and functionalization: This invention eliminates the toxic cross-linking agents and complex purification steps required by traditional chemical grafting, and also differs from the generally poor performance of simple physical impregnation. Employing a swelling-in-situ assembly strategy, it simultaneously achieves hydrophilic modification of the fiber matrix and deep assembly of the antibacterial agent while fully preserving the fiber's three-dimensional morphology. This process avoids damage to fiber strength caused by violent reactions, ensuring excellent mechanical processing properties of the dressing (cuttable and fillable); it also greatly simplifies the production process by utilizing self-assembly chemistry principles, reducing energy consumption and costs, demonstrating extremely high clinical translational potential and industrial value. Attached Figure Description

[0034] Figure 1 These are morphological images of the dressing products obtained in Example 3 and Comparative Example 1.

[0035] Figure 2 The image shows a scanning electron microscope (SEM) image of the dressing products described in Example 6 and Comparative Examples 1-2.

[0036] Figure 3 Infrared spectra of the dressings described in Examples 1, 6, and Comparative Examples 1-2, as well as the pure antibacterial agent.

[0037] Figure 4 The images show the comparison of inhibition zones of the dressings described in Example 6 and Comparative Examples 3-4 against Staphylococcus aureus and Escherichia coli.

[0038] Figure 5 Examples 1-5 and Comparative Example 1 show plate micrographs of the dressings used against Staphylococcus aureus and Escherichia coli.

[0039] Figure 6Examples 1-5 and Comparative Example 1 show a comparison of the antibacterial rates of the dressings against Staphylococcus aureus and Escherichia coli.

[0040] Figure 7 This is a comparison chart of water absorption rate and volume expansion rate for Examples 1-5 and Comparative Example 1. Detailed Implementation

[0041] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. The following embodiments are only illustrative and explanatory of the present invention, but should not be construed as limiting the scope of protection of the present invention.

[0042] In the following examples, the lyocell fiber cloth used was provided by Dangyang Hongyang New Material Technology Co., Ltd., with a single layer thickness of 0.3-0.6 mm and a pore size of 0.5-0.8 mm.

[0043] Example 1 A water-absorbing and antibacterial carboxymethyl cellulose fiber fabric-based medical dressing, the preparation method of which includes the following steps: (1) Choline chloride and chloroacetic acid were stirred and heated at 60°C in a molar ratio of 2:3 to form a uniform transparent liquid to obtain a functionalized deep eutectic solvent (6g in total). A 20cm×20cm Lyocell fiber cloth (about 1g) was soaked in the deep eutectic solvent for 3-5 minutes to make the fiber surface partially swell. An etherifying agent (chloroacetic acid, 1g) was added, and the Lyocell fiber matrix was soaked in it at a constant temperature of 60°C for 2 hours to form a fiber composite with simultaneous etherification-deep eutectic solvent pretreatment. (2) Prepare an aqueous solution of NaOH / NaHCO3 (containing 3g NaOH and 3g NaHCO3) and mix it with ethanol at a volume ratio of 1:4 to prepare an alkalization treatment solution; completely immerse the fiber composite pretreated in step (1) in the alkalization solution (the mass-volume ratio of Lyocell fiber fabric to alkalization solution is 1g:100ml) and react at 65℃ for 2 hours; after the reaction is completed, take out the fabric sample, wash the fabric sample thoroughly with anhydrous ethanol until the washing solution is neutral, and then dry it to constant weight to obtain carboxymethyl modified Lyocell fiber matrix; (3) The carboxymethylated fiber cloth is immersed in 50 ml of a prepared 0.02 g / ml polyhexamethylene biguanide hydrochloride ethanol solution (solvent is ethanol), and is kept at 35 °C for 1 hour to carry out ionic crosslinking and network reconstruction. After drying and sealing, the absorbent-antibacterial carboxymethyl cellulose fiber fabric-based medical dressing is obtained.

[0044] Example 2 A water-absorbing and antibacterial carboxymethyl cellulose fiber fabric-based medical dressing is prepared in a manner similar to that of Example 1, except that the concentration of the polyhexamethylene biguanide hydrochloride solution in step (3) is 0.04 g / ml.

[0045] Example 3 A water-absorbing and antibacterial carboxymethyl cellulose fiber fabric-based medical dressing is prepared in a manner similar to that of Example 1, except that the concentration of the polyhexamethylene biguanide hydrochloride solution in step (3) is 0.06 g / ml.

[0046] Example 4 A water-absorbing and antibacterial carboxymethyl cellulose fiber fabric-based medical dressing is prepared in a manner similar to that of Example 1, except that the concentration of the polyhexamethylene biguanide hydrochloride solution in step (3) is 0.08 g / ml.

[0047] Example 5 This embodiment provides a method for preparing an antibacterial carboxymethyl cellulose fabric-based medical moisturizing dressing. The difference between Example 4 and Example 1 is that the concentration of polyhexamethylene biguanide hydrochloride solution in step (3) is 0.10 g / ml, and the other steps are the same as in Example 1.

[0048] Example 6 A water-absorbing and antibacterial carboxymethyl cellulose fiber fabric-based medical dressing is prepared in a manner similar to that of Example 1, except that the concentration of the polyhexamethylene biguanide hydrochloride solution in step (3) is 2.00 g / ml.

[0049] Comparative Example 1 A carboxymethyl cellulose fabric-based medical moisturizing dressing is prepared in a manner similar to that of Example 1, except that in step (3), the dressing is impregnated with an aqueous ethanol solution which does not contain an antibacterial agent. The remaining steps are the same as those in Example 1.

[0050] Comparative Example 2 Blank Lyocell fiber finished fabric that has not been treated with functionalized deep eutectic solvent.

[0051] Comparative Example 3 A water-absorbing and antibacterial carboxymethyl cellulose fiber fabric-based medical dressing is prepared in a manner similar to that of Example 1, except that the concentration of the polyhexamethylene biguanide hydrochloride solution in step (3) is 4.00 g / ml.

[0052] Comparative Example 4 A water-absorbing and antibacterial carboxymethyl cellulose fiber fabric-based medical dressing is prepared in a manner similar to that of Example 1, except that the concentration of the polyhexamethylene biguanide hydrochloride solution in step (3) is 6.00 g / ml.

[0053] The dressings obtained in the above embodiments and comparative examples were subjected to performance tests, and the specific steps and results are as follows: (1) Scanning electron microscopy test Figure 2 The images show the morphology of the dressing products obtained in Example 3 and Comparative Example 1. Compared to the smooth, dense, and fine surface (average diameter of approximately 9.56 μm) of the original Lyocell fibers (Comparative Example 2), the fibers pretreated with DES and carboxymethylated (Comparative Example 1) exhibit a significant swelling state, with etched wrinkles on the surface, and the average diameter significantly increased to 11.61 μm (an increase of approximately 21%). This microscale "expansion" is attributed to the selective erosion of the amorphous regions of cellulose by the carboxymethylation process, and the introduction of high-density carboxylate groups (-COO). - The electrostatic repulsion generated by the cellulose molecules forces the spacing between the molecular chains to increase, thus providing ample free volume for subsequent functionalization.

[0054] After loading PHMB (specifically, in Example 6), Figure 2 In Example 6, numerous non-film-forming particulate precipitates were observed on the fiber surface and deep within the folds. This confirms that the cationic antibacterial agent is not simply physically attached, but rather undergoes in-situ ionic assembly with the active sites on the fiber surface through electrostatic interactions. These firmly anchored particles act as a molecular scaffold at the microscopic level, effectively inhibiting excessive hydrogen bonding between carboxymethyl cellulose segments during the heating reaction (drying process), maintaining the open three-dimensional network structure of the fiber. This, to some extent, explains the synergistic mechanism by which the dressing of this invention exhibits strong antibacterial properties while its liquid absorption and swelling performance increases (within a certain range).

[0055] (2) Infrared spectroscopy determination Figure 3 For comparative examples 1-2, Example 1, and Example 6, the infrared spectra of the pure antibacterial agent show that, compared with pure lyocell fiber (blue curve) and CMC (green curve), CMC has a lower concentration at 1590 cm⁻¹. -1 A significant broad and strong absorption peak appeared nearby, corresponding to the carboxylate anion (-COO). - The asymmetric stretching vibration of ) . The appearance of this characteristic peak conclusively proves that a high density of active anion sites was successfully introduced into the cellulose matrix after DES pretreatment and etherification process.

[0056] Secondly, the modified fiber profile of Example 6 with 2% PHMB loading. Figure 3 As can be seen from the orange curve, not only are the CMC skeletal features preserved, but also at 2180 cm... -1 Characteristic absorption peaks consistent with pure PHMB (red curve) appeared at positions such as (-C=N- stretching vibration), confirming the effective loading of the antibacterial agent.

[0057] Finally, and most importantly, comparing the spectra of pure CMC (Comparative Example 1, green) and CMC-PHMB (Example 6, orange) revealed that at 1600 cm⁻¹... -1 The nearby carboxyl absorption bands showed significant peak broadening and shift. This spectroscopic change is not a simple physical superposition, but rather strong chemical evidence indicating a strong electrostatic interaction and ionic coordination between the positively charged PHMB guanidine groups and the carboxyl anions on the fiber surface. This in-situ formed ionic bonding network not only endows the antibacterial agent with excellent resistance to runoff, but also microscopically supports the ion-crosslinked cellulose network. This verifies that the dressing of this invention provides a solid chemical structural basis for achieving synergistic enhancement of high antibacterial activity and high moisture absorption and swelling, while also exhibiting superior mechanical properties.

[0058] (3) Antibacterial performance test The antibacterial effects of each example and comparative example against Staphylococcus aureus and Escherichia coli were evaluated using the plate dilution spread method. The prepared solid culture media, liquid culture media, and samples were sterilized. The lyophilized bacteria were activated in liquid culture media and shaken at 37°C and 130 rpm for 18 h. The bacterial suspension was diluted and added dropwise to 70 mL of PBS buffer containing the sample, and shaken at 24°C and 150 rpm for 18 h. The bacterial suspension in the sample vial was diluted and evenly spread onto the solid culture medium. After further dilution, it was incubated together with the solid culture medium at 37°C for 24 h, and the colony count in each culture medium was recorded. The inhibition rate (Y) was calculated using the following formula: K=Z×R Y=(K0-K t ) / K0 In the formula, K is the viable bacterial concentration in the sample vial (CFU / mL); Z is the colony count in the petri dish; R is the dilution factor; Y represents the sample inhibition rate (%); K0 is the viable bacterial concentration in the control group (CFU / mL); K t This represents the concentration of viable bacteria in the sample.

[0059] The results of the antibacterial zone test showed that, Figure 4All samples in the examples formed clear and regular transparent inhibition zones in culture dishes against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli), confirming that the material has significant broad-spectrum antibacterial ability. As the PHMB concentration in the impregnation solution increased from 2% (Example 6) to 6% (Comparative Example 4), the diameter of the inhibition zone showed a clear concentration-dependent increasing trend (from 7.1 mm to 7.78 mm, and finally reached 8.22 mm).

[0060] From the plate bacteria Figure 5 It can be visually observed that the culture dish of Comparative Example 1, without antimicrobial loading, was filled with dense bacterial colonies, indicating that the pure CMC matrix itself has no antibacterial ability. In stark contrast, the number of colonies in the culture dishes of the samples treated by the process of this invention showed a significant decreasing trend with the increase of antimicrobial loading. In particular, when the loading concentration reached 0.1% (Example 5), there was almost no colony growth on the surface of the culture dish, demonstrating extremely strong contact bactericidal ability. Even at a low loading concentration (0.02%, Example 1), the material achieved antibacterial rates of 61.70% and 60.54% against Staphylococcus aureus and Escherichia coli, respectively, proving that the PHMB molecular chains anchored by ionic bonds maintained good activity. As the loading concentration increased to 0.1% (Example 5), the antibacterial rates of the material against the above two bacteria soared to 98.94% and 98.64%, respectively. This result shows that although the ionic cross-linking network constructed by this invention limits the loss of antimicrobial agents, it does not shield its active groups.

[0061] Table 1. Comparison of antibacterial rates against Staphylococcus aureus and Escherichia coli in Examples 1-5 and Comparative Example 1.

[0062] (4) Water absorption test: Water absorption rate test method: Take an appropriate amount of fiber and record the fiber mass as m0. Use a fine iron sieve as the supporting container, with the sieve mass as m. 漏笼 Deionized water is slowly added dropwise into the sifter at a constant rate until the fiber is saturated. The titration is then stopped immediately, and any remaining water droplets on the outer wall of the sifter are quickly blotted dry with filter paper. The total mass of the saturated water-absorbing gel-like fiber and the sifter is recorded as m1. The water absorption rate W (Water Absorption) can then be expressed as:

[0063] Swelling Ratio Test Method: Performed simultaneously with the water absorption rate test, the saturated absorbent fiber (in a gel state) after the water absorption rate test is used as the test sample. It is placed into a graduated cylinder containing a certain volume of anhydrous ethanol V0, ensuring the fiber is completely submerged and evenly dispersed. The volume at this point is recorded as V1. The swelling ratio SR can then be expressed as:

[0064] exist Figure 7 The test data in Table 2 reveals the most significant technical breakthrough of this invention: through ion coordination assembly, a synergistic enhancement of antibacterial agent loading and hygroscopic swelling performance is achieved. Data shows that compared to Comparative Example 1 (pure CMC, water absorption rate 2978.95%, swelling rate 3131.18%), the modified dressing exhibits a significant upward trend in water absorption rate and volume swelling rate as the PHMB concentration increases (from 0.02% to 0.08%). Peak performance: When the loading concentration is 0.08% (Example 4), the water absorption rate reaches a peak of 4653.20%, and the volume swelling rate reaches 4645.26%. Compared to pure CMC without antibacterial agent loading, its liquid absorption capacity is improved by approximately 56%. Further increasing the loading concentration of the antibacterial component leads to the near-inactivation of the ionic network formed by the cationic antibacterial agent and the carboxymethyl cellulose backbone. This results in a sharp drop in water absorption rate due to the antibacterial agent clogging the fiber pores, further demonstrating the successful construction and significant improvement effect of the cross-linked network of this invention.

[0065] Table 2. Comparison of water absorption rate and volume expansion rate for Examples 1-4 and Comparative Examples 1, 3, and 4.

[0066] The above embodiments are merely illustrative and do not constitute a limitation on the scope of protection of this invention. Guided by the technical concept of this invention, those skilled in the art can make reasonable adjustments and improvements to the process parameters, reagent types, or operating procedures without departing from the spirit and scope defined by the claims. Such modifications all fall within the protection scope of this invention.

Claims

1. A water-absorbing and antibacterial carboxymethyl cellulose fiber fabric-based medical dressing, characterized in that, It includes a carboxymethyl modified lyocell fiber fabric and an antibacterial component loaded therein. The carboxymethyl modified lyocell fiber fabric is obtained by sequentially subjecting the lyocell fiber fabric to etherification-deep eutectic solvent pretreatment and then alkalization treatment. The antibacterial component is loaded by loading an antibacterial liquid into the carboxymethyl modified lyocell fiber fabric and then performing ionic crosslinking.

2. The absorbent-antibacterial carboxymethyl cellulose fiber fabric-based medical dressing according to claim 1, characterized in that, The ionic crosslinking conditions include: a constant temperature reaction at 35-65℃ for 0.5-5 hours.

3. The absorbent-antibacterial carboxymethyl cellulose fiber fabric-based medical dressing according to claim 1, characterized in that, The lyocell fiber fabric has a single-layer thickness of 0.3-0.6 mm and a pore size of 0.5-0.8 mm.

4. The absorbent-antibacterial carboxymethyl cellulose fiber fabric-based medical dressing according to claim 1, characterized in that, The etherification-deep eutectic solvent pretreatment uses a mixed solution system of deep eutectic solvent and etherifying agent.

5. The absorbent-antibacterial carboxymethyl cellulose fiber fabric-based medical dressing according to claim 4, characterized in that, The mass ratio of the lyocell fiber fabric to the deep eutectic solvent is 1:4-6; the mass ratio of the etherifying agent to the lyocell fiber fabric is 1-2:

1.

6. The absorbent-antibacterial carboxymethyl cellulose fiber fabric-based medical dressing according to claim 1, characterized in that, The deep eutectic solvent is composed of hydrogen bond acceptors and hydrogen bond donors, wherein the molar ratio of hydrogen bond acceptors to hydrogen bond donors is 0.1-1.5:1; the hydrogen bond acceptor is one or more of choline chloride, betaine, proline, and citric acid; and the hydrogen bond donor is one or more of glycerol, lactic acid, chloroacetic acid, citric acid, and urea.

7. The absorbent-antibacterial carboxymethyl cellulose fiber fabric-based medical dressing according to claim 4, characterized in that, The etherifying agent is one or more of chloroacetic acid, sodium chloroacetate, 2-chloropropionic acid, and 3-chloropropionic acid.

8. The absorbent-antibacterial carboxymethyl cellulose fiber fabric-based medical dressing according to claim 1, characterized in that, The etherification-deep eutectic solvent pretreatment time is 0.5-1h, and the temperature is 40-60℃; the alkalization treatment time is 0.5-5h, and the temperature is 50-80℃.

9. The absorbent-antibacterial carboxymethyl cellulose fiber fabric-based medical dressing according to claim 1, characterized in that, The antibacterial component is one or more of the following: polyhexamethylene biguanide hydrochloride, chlorhexidine gluconate, hexadecyltrimethylammonium bromide, chlorhexidine acetate, and polyhexamethylene monoguanide hydrochloride. The concentration of the antibacterial solution is 0.02-5 g / ml.

10. A method for preparing the absorbent-antibacterial carboxymethyl cellulose fiber fabric-based medical dressing according to any one of claims 1 to 9, characterized in that, Includes the following steps: (1) The hydrogen bond acceptor and hydrogen bond donor are stirred and heated at 40-60℃ to form a uniform transparent liquid to obtain a functionalized deep eutectic solvent. An etherifying agent is added and used to soak the Lyocell fiber fabric for 0.5-1h to form a mixed system of deep eutectic solvent with etherification activity and fiber composite. (2) Add an alkalizing agent to the obtained mixture and react at 50-80℃ for 0.5-5h to obtain carboxymethyl modified Lyocell fiber matrix; (3) After washing and drying, the obtained carboxymethyl modified lyocell fiber matrix is ​​immersed in the prepared antibacterial functional solution and heated to react, thus obtaining the water-absorbing and antibacterial carboxymethyl cellulose fiber fabric-based medical dressing.

Images