An anti-adhesion lipid hydrogel dressing and a method of making the same

Abstract

The application relates to the technical field of medical dressings, and discloses an anti-adhesion lipid hydrogel dressing and a preparation method thereof. The dressing comprises a reticular fiber base material, a lipid hydrogel colloid layer and a protective film. The lipid hydrogel colloid layer is loaded on the fiber surface of the reticular fiber base material and retains through mesh holes. The lipid hydrogel coating solution is composed of liquid paraffin, medical vaseline, sodium carboxymethyl cellulose, a styrene-ethylene-butylene-styrene block copolymer, Tween 80, an antioxidant, a tannic acid / silk fibroin solution, n-octane and n-butyl acetate. After double-sided coating, directional blowing and heating and exhaust drying, the colloid layer with different adhesions on two sides is formed. The application can reduce mesh hole blockage, and the dressing has moderate pore size, good drainage, soft application and anti-adhesion performance, and is suitable for wound care and secondary dressing cooperation.

Description

Technical Field

[0001] This invention relates to the field of medical dressing technology, specifically to an anti-adhesion lipid hydrogel dressing and its preparation method. Background Technology

[0002] Lipid hydrogel dressings typically consist of a mesh substrate and a lipid hydrogel colloid loaded onto the substrate. During use, they can come into contact with wound exudate and form a soft gel layer, thereby maintaining a moist wound environment and reducing traction damage to newly formed tissues during dressing changes. Therefore, they are widely used in wound care, drainage wound protection, and in conjunction with secondary dressings.

[0003] Existing lipid hydrogel dressings are typically prepared by dip coating, scraping, or conventional roller coating to apply the colloid to a mesh substrate. However, due to the inherent viscosity and oiliness of the lipid hydrogel, it can easily penetrate and clog the pores of the mesh substrate during application, reducing drainage channels and hindering the migration of wound exudate to secondary dressings. Simply increasing the pore size of the substrate to avoid clogging can result in excessively large pores, which is detrimental to the orderly growth of granulation tissue and the stability of the wound microenvironment.

[0004] In addition, most existing lipid hydrogel dressings have a structure with similar adhesiveness on both sides, which can easily stick to medical staff's gloves or instruments during clinical use, affecting application efficiency. At the same time, if the adhesiveness on the wound side is too high, it may pull on newly formed tissue during dressing changes, increasing patient pain. Existing lipid hydrogels also have problems such as being too greasy, lacking sufficient softness when applied, and being uncomfortable when used with secondary dressings.

[0005] Furthermore, traditional lipid hydrogel colloids have limited adhesion to mesh substrates such as polyester or polyamide fibers. In scenarios involving negative pressure drainage or significant exudation, the colloid may be carried away by the exudate, resulting in localized exposure of the fiber mesh. The exposed fiber mesh is prone to adhesion upon contact with the wound surface, hindering wound healing. Therefore, it is necessary to provide a lipid hydrogel dressing that maintains open mesh pores, creates differential adhesion on both sides, and ensures stable adhesion between the colloid and the substrate, along with its preparation method. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, the present invention aims to provide an anti-adhesion lipid hydrogel dressing and its preparation method, which overcomes the problems of easy clogging of the mesh of existing lipid hydrogel dressings, uniform adhesion on both sides, easy adhesion to gloves or wound tissue during use, and insufficient adhesion stability between the colloid and the substrate; the dressing can retain the through mesh to form a structure with different adhesion on both sides, thereby improving drainage, application comfort and anti-adhesion effect during dressing changes.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an anti-adhesion lipid hydrocolloid dressing, comprising a mesh fiber substrate, a lipid hydrocolloid layer, and a protective film; The lipid hydrocolloid layer is loaded onto the fiber surface of the mesh fiber substrate and the mesh fiber substrate retains through-holes; The lipid hydrocolloid layer is distributed differently on the first and second surfaces of the mesh fiber substrate, such that the viscosity of the first surface is no greater than 0.05 N / cm, and the viscosity of the second surface is 0.01 to 0.20 N / cm.

[0008] Furthermore, the mesh fiber substrate is a mesh polyester fiber substrate or a mesh polyamide fiber substrate; the basis weight of the mesh fiber substrate is 41-55 g / m².

[0009] Furthermore, the non-clogging rate of the mesh fiber substrate is not less than 75%, and the mesh after coating with the lipid hydrocolloid forms through-holes with a pore diameter between 0.1 and 1.5 mm; the ductility of the substrate in the transverse direction is 0.51 N / cm to 1.5 N / cm.

[0010] Furthermore, the lipid hydrogel colloidal layer is formed by coating, blow-through, and drying of a lipid hydrogel coating solution; the lipid hydrogel coating solution comprises, by mass percentage: Liquid paraffin 10-40%; Medical petroleum jelly 1-8%; Sodium carboxymethyl cellulose 2-10%; 1-6% styrene-ethylene-butene-styrene block copolymer; Tween 80 has a concentration of 0.1% to 3%; Antioxidant 0.02-1%; Tannic acid / silk fibroin solution 1-1.2%; Alkane solvent 30-40%; Butyl acetate 4-18%.

[0011] Furthermore, the alkane solvent is n-octane; the alkane solvent and n-butyl acetate are evaporated and removed during the drying process, so that the lipid hydrocolloid layer is gel-like and adheres to the mesh fiber substrate.

[0012] Furthermore, it includes the following steps: S1. Preparation of lipid hydrogel coating solution: Weigh out n-butyl acetate, alkane solvent, tannic acid / silk fibroin solution, styrene-ethylene-butene-styrene block copolymer, liquid paraffin, medical petrolatum, sodium carboxymethyl cellulose, Tween 80 and antioxidant according to the formula, add them to a vacuum dispersion device in sequence and stir to disperse, let stand, and obtain lipid hydrogel coating solution. S2, Double-sided coating: The lipid hydrogel coating liquid is placed in the glue tank of the coating equipment, and the mesh fiber substrate passes through the glue tank and the coating roller in sequence to form a lipid hydrogel coating on both sides of the mesh fiber substrate. S3, Directional blowing: A blowing device is used to apply compressed air to one side of the coated mesh fiber substrate to blow open the lipid water-based adhesive coating liquid in the mesh and cause some of the lipid water-based adhesive coating liquid to migrate to the side opposite to the airflow. S4. Heating and degassing: The perforated mesh fiber substrate is heated and degassed to evaporate and remove the alkane solvent and n-butyl acetate, forming a lipid hydrocolloid layer with different adhesion on both sides. S5. Composite protective film, cutting, packaging and sterilization to obtain anti-adhesion lipid hydrocolloid dressing.

[0013] Furthermore, in step S1, the stirring and dispersion time after each addition of a raw material is 8-12 minutes, and the settling time after stirring is 12-24 hours.

[0014] Furthermore, in step S2, the coating speed is 2-3 m / min; in step S3, the blowing device has multiple air outlets, the diameter of the air outlets is 1-2 mm, and the distance between adjacent air outlets is 2-2.5 mm.

[0015] Furthermore, in step S4, the heating temperature is 50-55℃, the exhaust valve value is 90-95%, and the coating amount of the lipid hydrocolloid layer is controlled to be 60-160g / m² by adjusting the gap of the coating roller.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: Octane and butyl acetate form a volatile viscosity-adjusting system, which keeps the lipid hydrogel coating liquid with appropriate fluidity during the coating stage and prevents the colloid from clogging the pores of the mesh fiber substrate due to excessive viscosity. After heating and degassing, octane and butyl acetate evaporate and are removed. Liquid paraffin, medical petrolatum, sodium carboxymethyl cellulose and block copolymers together form a soft gel-like colloidal layer, thus taking into account coating uniformity, pore unobstructedness and application comfort. This invention employs a directional blow-through process. After double-sided coating of the mesh fiber substrate, compressed air is used to blow open the lipid hydrogel coating liquid within the mesh pores, causing some of the colloid to migrate to the side opposite to the airflow. This results in a differentiated structure of the dressing: one side is low-tack, while the other side is moderately adhesive. The low-tack side reduces adhesion to medical gloves, instruments, and newly formed wound tissue during use, while the moderately adhesive side ensures stable adhesion between the dressing and secondary dressings or surrounding wound tissue, improving the ease of clinical operation. This invention incorporates a tannic acid / silk fibroin solution into a lipid hydrogel system. The polyphenolic hydroxyl groups of tannic acid can form hydrogen bonds with silk fibroin, sodium carboxymethyl cellulose, and colloidal polymer segments, enhancing the wet cohesion and interfacial bonding of the colloid. Silk fibroin has good skin affinity and flexibility, which can improve the comfort of the dressing in contact with the wound and reduce the traction irritation caused by the dryness of the colloid or the exposure of fibers during dressing changes. This invention uses mesh polyester fibers or mesh polyamide fibers with specific basis weight and transverse elongation as the base material, enabling the dressing to maintain good dimensional stability and flexibility during coating, blow-drying, cutting, and application. Combined with a structural design with a pore size of 0.1–1.5 mm and a mesh non-clogging rate of not less than 75%, it provides channels for the outward drainage of wound exudate, reduces exudate retention, and helps maintain a moist but not excessively macerated wound repair environment. Attached Figure Description

[0017] Figure 1 A process flow diagram for anti-adhesion lipid hydrogel dressings. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Antioxidant: Antioxidant 1010.

[0020] Preparation of tannic acid / silk fibroin solution: Add 50 μL (2.5 mg / mL) tannic acid solution to 150 μL (20 mg / mL) silk fibroin solution.

[0021] The raw materials and equipment used in this invention embodiment are sourced as follows: liquid paraffin is pharmaceutical grade liquid paraffin, purchased from Sinopharm Chemical Reagent Co., Ltd.; medical petrolatum is white petrolatum, purchased from Sinopharm Chemical Reagent Co., Ltd.; sodium carboxymethyl cellulose: Anhui Shanhe Pharmaceutical Excipients Co., Ltd., model: SH-SJJ-4000; styrene-ethylene-butene-styrene block copolymer is SEBS, model: G1651; Tween 80 is polysorbate 80, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; antioxidant is antioxidant 1010, purchased from BASF AG; n-octane and n-butyl acetate are analytical grade reagents, purchased from Sinopharm Chemical Reagent Co., Ltd.; tannic acid is purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; silk fibroin solution is purchased from Suzhou Silmet Biotechnology Co., Ltd.; mesh polyester fiber substrate and mesh polyamide fiber substrate are both purchased from Guangdong Xinyue Medical Supplies Co., Ltd.; protective film is medical PET release protective film, purchased from Guangdong Xinyue Medical Supplies Co., Ltd.

[0022] The vacuum dispersion equipment used in this embodiment of the invention is model NPS-100L. The heating and exhaust drying equipment is a hot air circulating drying box, model: P20-01. The irradiation production line is accelerator line 1 HD-GZ-A-04-02-0001.

[0023] Example 1 This embodiment provides an anti-adhesion lipid hydrogel dressing, which uses a mesh polyester fiber substrate with a substrate weight of 41g / m². Based on 100 kg of lipid hydrogel coating solution, weigh out 30 kg of liquid paraffin, 3 kg of medical petrolatum, 5 kg of sodium carboxymethyl cellulose, 2 kg of styrene-ethylene-butene-styrene block copolymer, 1 kg of Tween 80, 0.8 kg of antioxidant 1010, 1.2 kg of tannic acid / silk fibroin solution, 40 kg of n-octane, and 17 kg of n-butyl acetate. The tannic acid / silk fibroin solution is prepared by mixing 150 μL of 20 mg / mL silk fibroin solution with 50 μL of 2.5 mg / mL tannic acid solution. The preparation method is as follows: S1. Add n-butyl acetate, n-octane, tannic acid / silk fibroin solution, styrene-ethylene-butene-styrene block copolymer, liquid paraffin, medical petrolatum, sodium carboxymethyl cellulose, Tween 80 and antioxidant 1010 sequentially into a vacuum dispersion device. Stir and disperse for 8 minutes after each addition. After all materials are added, continue stirring for 30 minutes and let stand for 12 hours to obtain the lipid hydrogel coating solution. S2. Place the lipid water-based adhesive coating liquid in the glue tank of the coating equipment, and let the mesh polyester fiber substrate pass through the glue tank and the coating roller in sequence. The coating speed is 3m / min, and the coating amount of the lipid water-based adhesive colloid layer is controlled to be 60g / m² by the gap of the coating roller. S3. A blow-hole device is used to apply compressed air to one side of the coated mesh polyester fiber substrate. The diameter of the blow-hole device is 1 mm, the distance between adjacent blow-holes is 2 mm, and the compressed air pressure is 0.4 MPa. The lipid water-based adhesive coating liquid in the mesh is blown open and some of the lipid water-based adhesive coating liquid migrates to the side away from the airflow. S4. The mesh polyester fiber substrate after the blown hole treatment is heated at 50°C and dried by exhaust. The exhaust valve value is controlled at 90% to volatilize and remove n-octane and n-butyl acetate, forming a lipid hydrocolloid layer with different adhesion on both sides. S5. A protective film is laminated on the outside of the lipid hydrocolloid layer. After cutting, packaging and sterilization, an anti-adhesion lipid hydrocolloid dressing is obtained. Example 2

[0024] This embodiment provides an anti-adhesion lipid hydrogel dressing, which uses a mesh polyamide fiber substrate with a substrate weight of 48g / m². Based on 100kg of lipid hydrogel coating solution, weigh out 35kg of liquid paraffin, 4kg of medical petroleum jelly, 6kg of sodium carboxymethyl cellulose, 3kg of styrene-ethylene-butene-styrene block copolymer, 1kg of Tween 80, 0.8kg of antioxidant 1010, 1.2kg of tannic acid / silk fibroin solution, 35kg of n-octane, and 14kg of n-butyl acetate. The preparation method is as follows: S1. Add each raw material sequentially to the vacuum dispersion equipment. Stir and disperse for 10 minutes after each raw material is added. After all raw materials are added, continue stirring for 35 minutes and let stand for 18 hours to obtain the lipid hydrogel coating solution. S2. Place the lipid hydrogel coating solution in the glue tank of the coating equipment, so that the mesh polyamide fiber substrate passes through the glue tank and the coating roller in sequence. The coating speed is 2.5 m / min. Control the coating amount of the lipid hydrogel colloidal layer to 100 g / m² by the gap between the coating rollers. S3. A blow-hole device is used to apply compressed air to one side of the coated mesh polyamide fiber substrate. The diameter of the blow-hole device is 1.5 mm, the distance between adjacent blow-holes is 2.2 mm, and the compressed air pressure is 0.6 MPa. This blows away excess coating liquid in the mesh and causes the lipid water-based coating liquid to form a distribution state that is enriched on the leeward side. S4. The mesh polyamide fiber substrate after blown hole treatment is heated at 52°C and dried by exhaust. The exhaust valve value is controlled at 92% to volatilize and remove n-octane and n-butyl acetate, forming a lipid hydrocolloid layer with different adhesion on both sides. S5, composite protective film, after being cut, packaged and sterilized, yields an anti-adhesion lipid hydrocolloid dressing. Example 3

[0025] This embodiment provides an anti-adhesion lipid hydrogel dressing, which uses a mesh polyester fiber substrate with a substrate weight of 55g / m². Based on 100kg of lipid hydrogel coating solution, weigh out 40kg of liquid paraffin, 6kg of medical petrolatum, 8kg of sodium carboxymethyl cellulose, 4kg of styrene-ethylene-butene-styrene block copolymer, 1.8kg of Tween 80, 0.2kg of antioxidant 1010, 1kg of tannic acid / silk fibroin solution, 34kg of n-octane, and 5kg of n-butyl acetate. The preparation method is as follows: S1. Add n-butyl acetate, n-octane, tannic acid / silk fibroin solution, styrene-ethylene-butene-styrene block copolymer, liquid paraffin, medical petrolatum, sodium carboxymethyl cellulose, Tween 80 and antioxidant 1010 sequentially into a vacuum dispersion device. Stir and disperse for 12 minutes after each addition. After all materials are added, continue stirring for 40 minutes and let stand for 24 hours to obtain the lipid hydrogel coating solution. S2. Place the lipid water-based adhesive coating liquid in the glue tank of the coating equipment, and let the mesh polyester fiber substrate pass through the glue tank and the coating roller in sequence. The coating speed is 2m / min, and the coating amount of the lipid water-based adhesive colloid layer is controlled to be 160g / m² by the gap of the coating roller. S3. A blow-hole device is used to apply compressed air to one side of the coated mesh polyester fiber substrate. The diameter of the blow-hole device is 2 mm, the distance between adjacent blow-holes is 2.5 mm, and the compressed air pressure is 0.7 MPa. The lipid water-based adhesive coating liquid in the mesh is blown open, and some of the lipid water-based adhesive coating liquid migrates to the side opposite to the airflow. S4. The mesh polyester fiber substrate after the blown hole treatment is heated at 55°C and dried by exhaust. The exhaust valve value is controlled at 95% to volatilize and remove n-octane and n-butyl acetate, forming a lipid hydrocolloid layer with different adhesion on both sides. S5, composite protective film, after being cut, packaged and sterilized, yields an anti-adhesion lipid hydrocolloid dressing.

[0026] Comparative Example 1 The difference between this comparative example and Example 3 is that the directional blowing process in step S3 is omitted, while the remaining raw material composition and preparation steps are the same as in Example 3. Specifically, after completing the double-sided coating, the coated mesh polyester fiber substrate is directly heated at 55°C and dried by exhaust, with the exhaust threshold controlled at 95%. Then, a protective film is laminated, cut, packaged, and sterilized to obtain the comparison dressing.

[0027] Comparative Example 2 The difference between this comparative example and Example 3 is that tannic acid / silk fibroin solution is not added, and the amount of n-octane is made up with an equal mass, that is, the amount of n-octane is adjusted to 35 kg based on 100 kg of lipid hydrogel coating liquid. The composition of other raw materials and preparation steps are the same as in Example 3. During the preparation process, the coating, directional blowing, heating and degassing drying, composite protective film, cutting, packaging and sterilization were carried out according to steps S1-S5 of Example 3 to obtain the comparative dressing.

[0028] Comparative Example 3 The difference between this comparative example and Example 3 is that in step S3, instead of using a single-sided directional blowhole, an alternating blowhole method is used on both sides to make the lipid hydrogel coating liquid more evenly distributed on both sides of the mesh fiber substrate. The remaining raw material composition and preparation steps are the same as in Example 3.

[0029] Specifically, after coating, compressed air is alternately applied from both sides of the mesh polyester fiber substrate. The compressed air pressure is 0.7MPa. The diameter of the air outlet of the blowhole device is 2mm, and the distance between adjacent air outlets is 2.5mm. Then, it is heated at 55℃ and dried by exhaust. The exhaust valve value is controlled at 95%. Then, a protective film is laminated, cut, packaged, and sterilized to obtain the comparison dressing.

[0030] Comparative Example 4 The difference between this comparative example and Example 3 is that the amount of styrene-ethylene-butene-styrene block copolymer was too high, and it was reduced by an equal mass of liquid paraffin. Based on 100 kg of lipid aqueous coating liquid, the amount of styrene-ethylene-butene-styrene block copolymer was adjusted to 10 kg, and the amount of liquid paraffin was adjusted to 34 kg. The composition of other raw materials and preparation steps are the same as in Example 3.

[0031] Due to the excessive amount of block copolymer, the viscosity of the coating liquid increased significantly, making it difficult for the colloid inside the mesh to be blown open during directional blow-through, resulting in a decrease in the non-clogging rate of the mesh.

[0032] Comparative Example 5 The difference between this comparative example and Example 3 is that a lower basis weight mesh polyester fiber substrate is used, with a substrate basis weight of 32 g / m² and a through-mesh pore size of 0.4 mm. The other raw material composition and preparation steps are the same as in Example 3.

[0033] Due to the low basis weight of the substrate, the dimensional stability is insufficient during coating, blow-through and subsequent cutting processes, and the local mesh is prone to deformation, resulting in uneven distribution of the colloid and reduced flatness of the dressing.

[0034] Test methods 1. Sample pretreatment The lipid hydrogel dressings prepared in Examples 1-3 and Comparative Examples 1-5 were cut into the required sizes. Before testing, the outer protective film was removed, and the dressings were equilibrated for 2 hours at a temperature of 23±2℃ and a relative humidity of 50±5%. At least 5 parallel samples were tested for each group of samples, and the average value of the test results was taken. During the test, the side of the dressing directly affected by the directional airflow through the blowhole was recorded as the first side, and the side facing away from the airflow was recorded as the second side. 2. Lateral stretchability test Cut the dressing transversely into strips 25mm wide and 100mm long. The edges of the strips should be smooth, without obvious burrs or gaps. Test using an electronic universal testing machine equipped with a 10N or 50N range sensor. Before testing, clamp both ends of the strip in the upper and lower fixtures, with an initial clamping distance of 50mm. Avoid slipping or pre-stretching the strip when clamping. During the test, the specimen was stretched laterally at a speed of 100 mm / min, and the force-displacement curve was recorded during the stretching process. When the specimen reached the specified elongation state, the corresponding tensile force was read and converted to tensile force per unit width according to the specimen width, with the unit being N / cm. Each group of samples was tested 5 times, and the average value was taken as the result of the transverse ductility test. 3. Through-mesh aperture test Cut the dressing into 30mm × 30mm samples and lay them flat on a transparent glass slide, allowing them to spread out naturally without stretching. Observe using a stereomicroscope or digital microscope at a magnification of 20-50x. calibrate the image analysis software using a standard ruler before testing. At least five fields of view are randomly selected on each sample. Within each field of view, clearly visible, uncompletely covered mesh openings are selected for measurement. For approximately circular or elliptical mesh openings, the maximum and minimum pore diameters are measured, and the equivalent pore diameter is calculated using the following formula: Equivalent aperture = (maximum aperture + minimum aperture) / 2. At least 30 through-holes were measured for each sample, and the average value was taken as the through-hole diameter. If the bottom permeable boundary of a local hole could not be observed due to colloidal blockage, the hole was not included in the average diameter, but was included in the hole non-blockage rate statistics. 4. Mesh non-clogging rate test The dressing was cut into 50mm × 50mm samples and observed under a stereomicroscope. Five fields of view were randomly selected for each sample, with each field of view having an area of ​​not less than 25mm². The total number of mesh pores in the reticular fiber substrate within each field of view was counted, as well as the number of mesh pores that could penetrate from the first surface to the second surface and were not completely sealed by the lipid hydrocolloid. The criteria for judgment are as follows: if a complete and continuous pore can be observed under a microscope, and the liquid can pass through the pore and enter the absorbent paper below within 30 seconds after 0.1 mL of stained physiological saline is added, it is judged as not blocking the mesh; if the colloid covers more than 70% of the mesh area, or the liquid cannot pass through the mesh within 30 seconds, it is judged as blocking the mesh. The mesh non-clogging rate is calculated using the following formula: Mesh non-clogging rate = Number of unclogging through meshes / Total number of meshes × 100%. 5. First and second side adhesion tests The dressing was cut into specimens 25 mm wide and 100 mm long. For the first-side adhesion test, the first side was attached to a clean stainless steel plate surface; for the second-side adhesion test, the second side was attached to the clean stainless steel plate surface. The stainless steel plate was wiped with anhydrous ethanol and dried at room temperature before testing. After attachment, a 2 kg standard roller was used to roll the dressing back and forth twice at approximately 300 mm / min to ensure full contact between the test surface and the stainless steel plate. After rolling, the sample was allowed to stand for 10 minutes. Then, the free end of the specimen was fixed on an electronic universal testing machine, and the test was performed using a 180° peel method at a peel speed of 300 mm / min. The peel force during the stable peel phase was recorded. During the peeling process, the data from the initial 25mm and the final 25mm were discarded, and the average peeling force of the middle stable range was taken and converted to N / cm according to the sample width. Each group of samples was tested 5 times, and the average value was taken. The lower the tackiness of the first side, the less likely the dressing is to stick to gloves, instruments, and wounds during operation and dressing changes; moderate tackiness of the second side indicates that the dressing can maintain good adhesion stability. 6. Glove adhesion test The dressing was cut into 50mm × 50mm samples and laid flat on a horizontal glass plate with the first side facing up. The tester wore disposable nitrile gloves and pressed the first side of the dressing with the fingertips of the gloves for about 5N for 5 seconds, then lifted it vertically. This test was repeated 10 times, and the tester observed whether the dressing was lifted by the gloves and whether there was obvious stringing or transfer of colloid. The evaluation criteria are as follows: "Non-adhesive" indicates the dressing is not lifted and there is no obvious adhesive residue on the glove surface; "Slightly adhesive" indicates the dressing edge is slightly raised but not lifted entirely, and there are a small amount of adhesive residue on the glove surface; "Significantly adhesive" indicates the dressing is significantly lifted by the glove or there is continuous adhesive residue on the glove surface. 7. Permeability Test Prepare simulated wound exudate: Weigh 8.0g sodium chloride, 0.2g calcium chloride, and 30g bovine serum albumin, add purified water to a final volume of 1000mL, stir to dissolve, and set aside. Weigh the absorbent pad before testing and record the weight as m0. Lay the dressing flat on the absorbent pad, with the first side facing up and the second side in contact with the absorbent pad. Using a pipette, slowly add 5.0 mL of simulated wound exudate to the center of the first side of the dressing, controlling the dripping time to within 30 seconds. After dripping, let it stand for 5 minutes to allow the simulated wound exudate to migrate downwards through the dressing's mesh and be absorbed by the absorbent pad. Immediately after removing the dressing, weigh the absorbent pad and record the mass as m1. The seepage rate is calculated using the following formula: Leakage throughput = (m1-m0) / 5.0×100%. The simulated wound exudate density was calculated as 1.0 g / mL. A higher exudate throughput indicates better patency of the dressing mesh, which is more conducive to the migration of wound exudate to secondary dressings. 8. Wet colloid retention rate test Cut the dressing into 50mm×50mm samples, remove the protective film, and weigh the initial mass, denoted as m2. Take another uncoated mesh fiber substrate of the same size, weigh it, and record the mass as m3. The initial mass of the colloid is then m2-m3. The sample was immersed in simulated wound exudate at 37±1℃ for 2 hours, ensuring the dressings were completely submerged and did not overlap. After immersion, the sample was removed and rinsed with physiological saline by slow dripping for 10 seconds to remove unbound free colloids. The sample was then placed on filter paper to drain naturally for 5 minutes, and the mass after wet treatment was recorded as m4. The wet colloid retention rate is calculated using the following formula: Wet colloid retention rate = (m4-m3) / (m2-m3)×100%. A higher wet colloid retention rate indicates a more stable bond between the lipid hydrocolloid layer and the reticular fiber substrate, making it less prone to colloid shedding, fiber exposure, and localized adhesion in a permeable environment. 9. Simulated dressing change anti-adhesion test Preparation of the simulated wound substrate: 10g of gelatin and 2g of glycerin were added to 88g of purified water and dissolved by stirring in a 60℃ water bath. The solution was poured into a petri dish and cooled to form a film, resulting in a gelatin-based simulated wound substrate with a moist surface. Before testing, 0.5mL of simulated wound exudate was evenly dropped onto the gelatin surface to keep it moist. The first side of the dressing was attached to the surface of the simulated wound substrate, covered with an absorbent pad, and a 200g weight was applied for 10 minutes of pressure. The substrate was then placed at 37±1℃ for 2 hours. After the test, the dressing was slowly removed at approximately 180°, and the surface of the gelatin substrate was observed to see if it was pulled up, if there was any gel residue, and if any fibers were exposed on the dressing surface. The evaluation criteria are as follows: "No obvious residue" is recorded as the gelatin base surface is intact and there is no obvious colloid residue; "Small amount of residue" is recorded as the gelatin surface has a small amount of colloid dot-like residue; "Obvious adhesion" is recorded as the gelatin surface shows obvious lifting, damage or continuous colloid residue. 10. Observation of the appearance and coating uniformity of the colloidal layer The dressing was cut into 100mm×100mm samples and placed on a white background. The colloid layer was visually inspected for localized glue buildup, missed coating, obvious oil spots, closed mesh, and edge curling. Subsequently, a stereomicroscope was used to observe the distribution of the colloid on the fiber surface, focusing on whether the colloid was mainly attached to the surface of the mesh fibers and whether there was a continuous colloid film in the mesh. During evaluation, if the colloid layer continuously covers the fiber surface without large-area accumulation and the mesh remains connected, it is judged as uniform coating; if there is obvious colloid accumulation, closed mesh, or local missed coating, it is judged as uneven coating.

[0035] Table 1: Structural and viscosity tests of Examples 1-3 and Comparative Examples 1-5

[0036] Table 2: Drainage and Wet State Stability Tests

[0037] As shown in Table 1, Examples 1-3 all performed well in terms of structural stability, mesh openness, and differences in double-sided adhesion. Example 1 used a 41 g / m² mesh polyester fiber substrate with a transverse elongation of 1.45 N / cm, a through-mesh pore size of 0.78 mm, a mesh non-clogging rate of 90.4%, a first-sided adhesion of 0.018 N / cm, and a second-sided adhesion of 0.074 N / cm, indicating that the substrate has good flexibility and support, and the lipid hydrocolloid can mainly adhere to the fiber surface and retain the through-mesh. Example 2 used a 48 g / m² mesh polyamide fiber substrate with a transverse elongation of 1.42 N / cm, a through-mesh pore size of 0.75 mm, a mesh non-clogging rate of 91.7%, a first-sided adhesion of 0.016 N / cm, and a second-sided adhesion of 0.07 N / cm. The 5 N / cm indicates that the polyamide substrate and the lipid hydrogel system have good compatibility, and can form stable double-sided differential tack while maintaining a high open-cell ratio. Example 3 uses a 55 g / m² mesh polyester fiber substrate with a transverse elongation of 1.46 N / cm, a through-mesh pore size of 0.71 mm, and a mesh non-clogging rate of 92.1%. The tack on the first side is reduced to 0.015 N / cm, and the tack on the second side is 0.078 N / cm. This shows that under the conditions of high substrate basis weight and high coating amount, the excess colloid in the mesh can still be effectively blown away by unilateral directional blowholes, and the colloid is promoted to migrate moderately to the leeward side, thereby forming a structure with low tack on the first side and moderate tack on the second side.

[0038] In contrast, Comparative Example 1, without directional blowing, had a mesh diameter reduced to 0.39 mm, resulting in a mesh non-clogging rate of only 58.6%. The adhesion on the first and second sides increased to 0.086 N / cm and 0.091 N / cm, respectively, indicating that ordinary double-sided coating easily causes colloid retention and clogging of the mesh. Furthermore, the similar adhesion on both sides prevented the formation of the low-tack surface required for anti-adhesion. Comparative Example 2, without the addition of tannic acid / silk fibroin solution, still maintained a mesh non-clogging rate of 87.3%, indicating that directional blowing could still maintain a certain opening effect. However, the adhesion on the first side increased to 0.035 N / cm, and the adhesion on the second side increased to 0.126 N / cm, indicating that the lack of tannic acid / silk fibroin resulted in insufficient hydrogen bonding network and interfacial bonding within the colloid, making the colloid surface more prone to stickiness or localized migration. Comparative Example 3, using alternating blowing from both sides, achieved a mesh non-clogging rate of 84.8%. The viscosity increased to 0.071 N / cm, indicating that the airflow on both sides weakened the unidirectional migration effect of the colloid, making it difficult for the first side to maintain a low viscosity. In Comparative Example 4, the amount of SEBS was too high, the diameter of the through-mesh pores decreased to 0.34 mm, and the non-clogging rate of the pores was only 63.5%. The viscosity of the second side increased to 0.162 N / cm, indicating that although the viscosity and cohesion of the colloid were too high, they would enhance local adhesion, but would make it difficult for the pores to be blown open and form colloid buildup. Comparative Example 5 used a low basis weight substrate of 32 g / m², the transverse extensibility decreased to 1.18 N / cm, the non-clogging rate of the pores was 80.2%, and the viscosity of the second side was 0.131 N / cm, indicating that the low basis weight substrate had insufficient support, and local pore deformation was prone to occur during coating and blow-through, causing the colloid to accumulate in local areas. The increase in viscosity was not due to uniform and controllable moderate adhesion, but rather the result of uneven colloid distribution. Table 2 further shows that Examples 1-3 all have good effects in actual drainage, wet colloid retention, and anti-adhesion during dressing changes, and correspond to the structural data in Table 1. Example 1 has a drainage throughput of 92.5% and a wet colloid retention rate of 95.8%, with minimal glove adhesion and no obvious colloid residue after simulated dressing changes, indicating that its high mesh non-clogging rate can be converted into good drainage capacity, while the low-viscosity first surface can reduce operational adhesion. Example 2 has a drainage throughput of 91.2% and a wet colloid retention rate of 96.7%, with minimal glove adhesion and no obvious colloid residue after dressing changes, indicating that the colloid and fiber in the polyamide substrate system still have good wet bonding stability. Example 3 has the highest drainage throughput rate of 93.6% and the highest wet colloid retention rate of 98.1%, exhibiting no adhesion and no obvious colloid residue, indicating that it achieves a better balance between mesh openness, colloid retention, and low-viscosity anti-adhesion.

[0039] Comparative Example 1, lacking directional perforation, had an exudate throughput of only 62.4%, with noticeable adhesion and localized colloid residue. This indicates that mesh blockage directly hinders the migration of exudate from the simulated wound to the absorbent pad below. Furthermore, the high adhesion on both sides increases the risk of dressing residue and traction. Comparative Example 2, while still achieving an exudate throughput of 86.1%, saw a decrease in wet colloid retention to 82.8%, with visible detachment of a small amount of colloid. This suggests that its main defect is not the perforation itself, but rather the lack of tannin / silk fibroin, resulting in insufficient wet cohesion and interfacial adhesion stability of the colloid. Comparative Example 3 had an exudate throughput of 83.5% and a wet colloid retention of 95.3%, but exhibited adhesion on both sides, simulating dressing changes. The obvious local adhesion during application indicates that although alternating blowholes on both sides can maintain some porosity and colloid stability, they cannot form a clear low-adhesion wound side. The wet colloid retention rate of Comparative Example 4 is 96.9%, which is close to that of the Example, but the exudate throughput rate is only 66.8%, and the mesh is obviously blocked. This indicates that although excessive SEBS can enhance colloid retention, it will cause difficulty in opening pores and reduced drainage due to the excessive viscosity of the coating liquid. The exudate throughput rate of Comparative Example 5 is 78.4%, and the wet colloid retention rate is 88.6%. Slight adhesion, local mesh deformation, and uneven colloid distribution are also observed. This indicates that the low basis weight substrate has insufficient stability under wet and stressed conditions, which can easily cause local migration or detachment of the colloid. In summary, Tables 1 and 2 together demonstrate that the superior performance of this application is not produced by a single component or a single step, but by the synergistic effect of a suitable weight of mesh fiber substrate, lipid hydrogel formulation, tannic acid / silk fibroin reinforcement system, and unilateral directional blowhole process, which enables the dressing to simultaneously possess the effects of unobstructed mesh, exudate drainage, wet stability, and anti-adhesion during dressing changes.

[0040] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0041] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0042] Those skilled in the art should understand that the above descriptions are merely several specific embodiments of the present invention, and not all embodiments.

Claims

1. A lipid hydrocolloid dressing for preventing adhesion, characterized in that, It includes a mesh fiber substrate, a lipid hydrocolloid layer, and a protective film; The lipid hydrocolloid layer is loaded onto the fiber surface of the mesh fiber substrate and the mesh fiber substrate retains through-holes; The lipid hydrocolloid layer is distributed differently on the first and second surfaces of the mesh fiber substrate, such that the viscosity of the first surface is no greater than 0.05 N / cm, and the viscosity of the second surface is 0.01 to 0.20 N / cm.

2. The anti-adhesion lipid hydrogel dressing according to claim 1, characterized in that, The mesh fiber substrate is a mesh polyester fiber substrate or a mesh polyamide fiber substrate; the basis weight of the mesh fiber substrate is 41-55 g / m².

3. The anti-adhesion lipid hydrogel dressing according to claim 1, characterized in that, The mesh fiber substrate has a non-clogging rate of not less than 75%, and the mesh formed by coating with the lipid hydrocolloid forms through-holes with a pore diameter between 0.1 and 1.5 mm.

4. The anti-adhesion lipid hydrogel dressing according to claim 1, characterized in that, The lipid hydrogel colloidal layer is formed by coating, blow-through, and drying of a lipid hydrogel coating solution; the lipid hydrogel coating solution comprises, by mass percentage: Liquid paraffin 10-40%; Medical petroleum jelly 1-8%; Sodium carboxymethyl cellulose 2-10%; 1-6% styrene-ethylene-butene-styrene block copolymer; Tween 80 has a concentration of 0.1% to 3%; Antioxidant 0.02-1%; Tannic acid / silk fibroin solution 1-1.2%; Alkane solvent 30-40%; Butyl acetate 4-18%.

5. The anti-adhesion lipid hydrogel dressing according to claim 4, characterized in that, The alkane solvent is n-octane; the alkane solvent and n-butyl acetate are evaporated and removed during the drying process, so that the lipid hydrocolloid layer is gel-like and adheres to the mesh fiber substrate.

6. A method for preparing an anti-adhesion lipid hydrogel dressing as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Preparation of lipid hydrogel coating solution: Weigh out n-butyl acetate, alkane solvent, tannic acid / silk fibroin solution, styrene-ethylene-butene-styrene block copolymer, liquid paraffin, medical petrolatum, sodium carboxymethyl cellulose, Tween 80 and antioxidant according to the formula, add them to a vacuum dispersion device in sequence and stir to disperse, let stand, and obtain lipid hydrogel coating solution. S2, Double-sided coating: The lipid hydrogel coating liquid is placed in the glue tank of the coating equipment, and the mesh fiber substrate passes through the glue tank and the coating roller in sequence to form a lipid hydrogel coating on both sides of the mesh fiber substrate. S3, Directional blowing: A blowing device is used to apply compressed air to one side of the coated mesh fiber substrate to blow open the lipid water-based adhesive coating liquid in the mesh and cause some of the lipid water-based adhesive coating liquid to migrate to the side opposite to the airflow. S4. Heating and drying: The perforated mesh fiber substrate is heated and the air is vented to evaporate and remove the alkane solvent and n-butyl acetate, forming a lipid hydrocolloid layer with different adhesion on both sides. S5. Composite protective film, cutting, packaging and sterilization to obtain anti-adhesion lipid hydrocolloid dressing.

7. The method for preparing the anti-adhesion lipid hydrogel dressing according to claim 6, characterized in that, In step S1, the stirring and dispersion time after each raw material is added is 8-12 minutes, and the settling time after stirring is 12-24 hours.

8. The method for preparing the anti-adhesion lipid hydrogel dressing according to claim 6, characterized in that, In step S2, the coating speed is 2-3 m / min; in step S3, the blowing device has multiple air outlets, the diameter of the air outlets is 1-2 mm, and the distance between adjacent air outlets is 2-2.5 mm.

9. The method for preparing the anti-adhesion lipid hydrogel dressing according to claim 6, characterized in that, In step S4, the heating temperature is 50-55℃, and the exhaust valve value is 90-95%; the coating amount of the lipid hydrocolloid layer is controlled to be 60-160g / m² by adjusting the gap of the coating roller.

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