Anti-allergy skin-friendly operation kit and preparation process thereof

Abstract

The invention relates to the technical field of medical protection materials, and discloses an anti-allergy skin-friendly operating kit and a preparation technology, and the composite material of the operating kit comprises the following components by mass: 40-70 parts of cellulose-based non-woven fabric; 1 to 10 parts of polymethacryloyloxyethyl phosphorylcholine which is covalently grafted to the cellulose-based non-woven fabric; 20 to 50 parts of polylactic acid-quaternary ammonium salt copolymer; 5 to 15 parts of a polyurethane hot melt adhesive; the method comprises the following steps: grafting a PMPC molecular brush on the surface of a cellulose-based non-woven fabric to obtain a skin-friendly layer; carrying out coaxial electrostatic spinning and solvent treatment on the polylactic acid-quaternary ammonium salt copolymer to prepare a hollow nanofiber barrier layer; and finally hot-pressing and compounding the two layers through a polyurethane hot-melt adhesive. According to the invention, allergy is solved through surface grafting; the toxicity is avoided by using an intrinsic antibacterial polymer; the hollow fibers and the net film are compounded, so that the contradiction between water resistance and breathability is overcome, and the biological safety and comfort of the material are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical protective materials, in particular to an anti-allergic skin-friendly surgical drape and a preparation process. BACKGROUND

[0002] In modern medical activities, surgical drape products such as surgical gowns and surgical drapes are key protective products for building a sterile barrier and preventing surgical site infections (SSI). Such products are usually composed of multiple layers of non-woven fabrics, and the core requirement is to effectively block the penetration of blood, body fluids and microorganisms, and at the same time have good mechanical properties and wearing comfort.

[0003] However, the surgical drape materials in the prior art still have many inherent limitations. Many materials have poor biocompatibility when in contact with the skin of patients and medical staff for a long time, which can easily cause skin allergy or discomfort. In order to achieve antibacterial function, the industry generally relies on physical blending or post-finishing of antibacterial agents such as nano-silver and small molecule quaternary ammonium salt in the material. This method not only has the potential cytotoxicity risk of antibacterial agent migration and precipitation, but also has difficulty in maintaining the antibacterial effect.

[0004] At the same time, there is a technical contradiction between the protection and comfort of the material that is difficult to reconcile. Generally, in order to obtain excellent liquid barrier performance, dense films or fiber layers are needed, but this often comes at the expense of the air permeability of the material, resulting in the accumulation of heat and humidity, which seriously affects the wearing comfort and working state of medical staff. When different functional layers are compounded into one, the continuous gluing and other bonding processes used will further block the pores of the material, making the already poor air permeability even worse.

[0005] Therefore, the present application proposes an anti-allergic skin-friendly surgical drape and a preparation process to solve the problems of the prior art. SUMMARY

[0006] The purpose of the present application is to provide an anti-allergic skin-friendly surgical drape and a preparation process, which solves the problems of poor biocompatibility, insufficient antibacterial safety and difficulty in balancing water resistance and air permeability of surgical drape materials.

[0007] To achieve the above purpose, the present application realizes the following technical scheme: an anti-allergic skin-friendly surgical drape, the composite material of the surgical drape comprises the following components by mass fraction: Cellulose-based non-woven fabric: 40-70 parts; Poly-methacryloyloxyethyl phosphorylcholine covalently grafted to the cellulose-based non-woven fabric: 1-10 parts; Poly-lactic acid-quaternary ammonium salt copolymer: 20-50 parts; Polyurethane hot melt adhesive: 5-15 parts.

[0008] The composite material is composed of specific components, including a cellulose-based nonwoven fabric as the structural substrate, polymethacryloyloxyethyl phosphorylcholine covalently grafted onto the substrate surface, a polylactic acid-quaternary ammonium salt copolymer as the functional barrier, and a polyurethane hot melt adhesive for interlayer lamination. These components together constitute the material basis of this invention.

[0009] A skin-friendly layer with active biocompatibility is constructed on cellulose-based nonwoven fabric using surface-initiated polymerization technology. Secondly, a barrier layer with waterproof, breathable, and intrinsically antibacterial functions is prepared using molecular design and nanospinning technology. Finally, the above functional layers are combined into one piece using a highly breathable adhesive process to obtain the final surgical pack material.

[0010] The skin-friendly layer is based on a soft and breathable cellulose-based nonwoven fabric (such as wood pulp or viscose spunlace nonwoven fabric), and its key feature is that a layer of polymethacryloyloxyethyl phosphorylcholine (PMPC) molecular brush is permanently grafted onto the fiber surface through covalent bonds.

[0011] Surface-initiated atom transfer radical polymerization (SI-ATRP) was employed. The process begins by anchoring the polymerization initiator firmly to the cellulose molecular chains of the nonwoven fabric using a flexible polyethylene glycol (PEG) spacer. This flexible spacer provides ample steric hindrance and freedom of movement for the subsequent growth of PMPC chains, facilitating the formation of high-density, structurally regular molecular brushes. Subsequently, methacryloyloxyethylphosphorylcholine (MPC) is used as the monomer for polymerization. MPC monomer is an amphoteric compound with a structure highly similar to the phospholipid heads on the surface of human cell membranes. Through the SI-ATRP reaction, long PMPC chains vertically "grow" from the fiber surface, forming a dense, brush-like nanostructure.

[0012] The anti-allergenic and skin-friendly mechanism of this PMPC molecular brush lies in its unique biomimetic properties. Through strong intermolecular forces, it captures and binds a stable layer of water molecules on the fiber surface, forming a "physical hydration layer." This hydration layer effectively masks the physicochemical properties of the underlying material, acting like a "water camouflage," thus greatly reducing non-specific adsorption and interaction between the material surface and biomolecules such as proteins, platelets, and cells. It is this "inertia" towards biological systems that fundamentally inhibits immune responses and allergic reactions triggered by material contact, giving the surgical pack excellent skin-friendliness and biocompatibility.

[0013] The barrier layer is composed of a novel polylactic acid-quaternary ammonium salt (PLA-QAS) copolymer and is processed into a hollow nanofiber porous film.

[0014] The intrinsic safety mechanism of its antibacterial function stems from the molecular structure design of the polymer. Instead of using traditional additive antibacterial agents (such as nano-silver or quaternary ammonium salts), it directly introduces antibacterial quaternary ammonium salt (QAS) groups as comonomers into the biodegradable polylactic acid (PLA) polymer backbone through a ring-opening copolymerization reaction. In this way, the antibacterial functional groups become an inherent component of the polymer chain, rather than a physical mixture. When bacteria come into contact with the fiber surface, the positively charged QAS groups strongly electrostatically adsorb onto the negatively charged bacterial cell wall / membrane, disrupting its structural integrity and achieving contact killing. Because the QAS groups are covalently locked within the polymer chain, they cannot leach out of the material or be released into the environment. This eliminates the potential for cytotoxicity or drug resistance caused by antibacterial agent migration at the source, achieving "intrinsic safety."

[0015] The waterproof and breathable function of this barrier layer stems from its unique microstructure. Using coaxial electrospinning technology, core-shell nanofibers are prepared with a PLA-QAS solution as the shell and water-soluble polyvinyl alcohol (PVA) as the core. Subsequently, a simple washing process selectively dissolves and removes the internal PVA core material, leaving a hollow nanofiber network composed of PLA-QAS. This porous film, formed by the stacking of submicron-sized hollow fibers, creates numerous micro- and nano-sized tortuous channels between the fibers. These channels are much smaller than liquid water droplets, but under the surface tension of water, they effectively prevent the penetration of liquid water, thus achieving waterproofing. At the same time, these channels are much larger than a single water vapor molecule, allowing gaseous water molecules such as sweat to pass freely, thus giving the material excellent breathability.

[0016] Preferably, the cellulose-based nonwoven fabric is a wood pulp spunlace nonwoven fabric or a viscose fiber spunlace nonwoven fabric; the polymethacryloyloxyethyl phosphorylcholine is covalently grafted onto the fiber surface of the cellulose-based nonwoven fabric through flexible spacer arm molecules.

[0017] Preferably, the polylactic acid-quaternary ammonium salt copolymer is a product obtained by ring-opening copolymerization of lactide monomer and methacrylate quaternary ammonium salt monomer, wherein the alkyl chain length of the methacrylate quaternary ammonium salt monomer is 12-16 carbon atoms.

[0018] Preferably, the polylactic acid-quaternary ammonium salt copolymer is a porous film formed in the form of hollow nanofibers.

[0019] Preferably, the composite material of the surgical pack has a layered structure, which includes: A skin-friendly layer composed of the cellulose-based nonwoven fabric and polymethacryloyloxyethyl phosphorylcholine covalently grafted thereon; a barrier layer composed of the polylactic acid-quaternary ammonium salt copolymer; An adhesive layer composed of the polyurethane hot melt adhesive, the adhesive layer being disposed between the skin-friendly layer and the barrier layer.

[0020] This invention also provides a preparation process for an anti-allergic and skin-friendly surgical pack, the preparation process comprising the following steps: S1. On the fiber surface of cellulose-based nonwoven fabric, an atom transfer radical polymerization initiator is covalently anchored by a flexible spacer arm, and then a surface-initiated atom transfer radical polymerization reaction is carried out to grow a polymethacryloyloxyethyl phosphorylcholine molecular brush to obtain a skin-friendly layer. S2. A copolymerization reaction is carried out between lactide monomer and methacrylate quaternary ammonium salt monomer with alkyl chain length of C12-C16 to obtain polylactic acid-quaternary ammonium salt copolymer; a core-shell structured nanofiber is prepared by using coaxial electrospinning technology, with the solution of the polylactic acid-quaternary ammonium salt copolymer as the shell solution and the solution of the water-soluble polymer as the core solution; the core layer is then removed by solvent to obtain a barrier layer composed of hollow nanofibers. S3. The skin-friendly layer and the barrier layer are hot-pressed together using a polyurethane hot melt adhesive.

[0021] Preferably, step S1 includes: S1-1. Polyethylene glycol monomethyl ether is used as a flexible spacer arm and reacted with the cellulose-based nonwoven fabric at a temperature of 50℃-65℃. Subsequently, 2-bromoisobutyryl bromide in a molar ratio of 1.2:1-1.5:1 is reacted with the flexible spacer arm at a temperature of 0℃-5℃ to covalently anchor the atom transfer radical polymerization initiator. S1-2. Immerse a nonwoven fabric containing an initiator in a reaction solution and grow a polymethacryloyloxyethylphosphorylcholine molecular brush through surface-initiated atom transfer radical polymerization. The reaction solution contains methacryloyloxyethylphosphorylcholine monomer, cuprous bromide catalyst, and pentamethyldiethylenetriamine ligand. The molar ratio of methacryloyloxyethylphosphorylcholine monomer to cuprous bromide is 100:1-200:1, and the molar ratio of pentamethyldiethylenetriamine to cuprous bromide is 2:1-3:1. The polymerization reaction is carried out at a temperature of 25℃-40℃ for 12-24 hours.

[0022] Preferably, step S2 includes: S2-1. A copolymerization reaction is carried out between lactide monomer and methacrylate quaternary ammonium salt monomer with alkyl chain length of C12-C16 at a molar ratio of 99:1-95:5 at a temperature of 110℃-130℃ to obtain polylactic acid-quaternary ammonium salt copolymer. S2-2. Using coaxial electrospinning technology, the solution of the polylactic acid-quaternary ammonium salt copolymer is used as the shell solution and the polyvinyl alcohol solution is used as the core solution. Under a voltage of 15kV-25kV and a receiving distance of 15cm-25cm, the solution is spun onto a roller receiver with a rotation speed of 100rpm-300rpm to form core-shell structured nanofibers. S2-3. The core-shell structured nanofibers are soaked and washed in water at a temperature of 40℃-60℃ to remove the core layer.

[0023] Preferably, step S3 includes: S3-1. The skin-friendly layer, the polyurethane hot melt adhesive (polyurethane hot melt adhesive mesh), and the barrier layer are stacked in sequence, wherein the polyurethane hot melt adhesive mesh is located between the skin-friendly layer and the barrier layer. S3-2. The stacked materials are hot-pressed at a temperature of 110℃-140℃ and a pressure of 0.1MPa-0.5MPa for a duration of 30s-90s.

[0024] Preferably, the polylactic acid-quaternary ammonium salt copolymer is prepared by ring-opening copolymerization reaction, wherein the ring-opening copolymerization reaction is carried out in anhydrous toluene solvent, the total molar ratio of catalyst to monomer is 1:10000-1:20000, the reaction is carried out in anhydrous toluene solvent, and the amount of solvent is 3-5 times the total mass of monomer.

[0025] In summary, the present invention has at least one of the following beneficial technical effects: 1. This invention utilizes surface-initiated polymerization technology to covalently graft a biomimetic polymethacryloyloxyethyl phosphorylcholine molecular brush onto a cellulose-based nonwoven fabric. The resulting skin-friendly layer exhibits durable and stable biocompatibility, making the material extremely gentle upon skin contact. Compared to existing technologies that often employ coating or padding methods to add anti-allergenic ingredients, this invention solves the technical challenges of weak functional layer bonding, easy loss of effective ingredients, and difficulty in fundamentally preventing material-induced allergies.

[0026] 2. This invention employs a ring-opening copolymerization chemical synthesis method to directly introduce quaternary ammonium salt antibacterial groups into the polylactic acid polymer backbone, preparing an intrinsically safe polylactic acid-quaternary ammonium salt copolymer. This endows the material with highly efficient contact bactericidal ability, and the antibacterial functional groups do not migrate. Compared to traditional methods that physically add nano-silver or small-molecule quaternary ammonium salts to the material, this invention effectively solves the potential cytotoxicity and environmental safety hazards caused by additive precipitation, achieving a balance between efficacy and safety.

[0027] 3. This invention utilizes a coaxial electrospinning process to construct a hollow nanofiber porous film from the polylactic acid-quaternary ammonium salt copolymer. The microstructure endows the barrier layer with excellent waterproof performance and superior breathability. Compared to existing barrier materials, which are mostly dense solid fiber membranes or coated films, this invention overcomes the technical bottleneck of traditional materials struggling to balance waterproof and breathable properties, significantly improving user comfort.

[0028] 4. In the final lamination step, this invention uses a polyurethane hot melt adhesive web as the adhesive layer. This process ensures a strong bond between the functional layers while preserving the overall porous structure and breathability of the material to the greatest extent possible. Compared to the traditional lamination method using liquid adhesive applied by scraping, this invention avoids the problem of adhesive forming a continuous film that blocks the material's pores, and solves the defect of traditional processes that result in a stuffy and uncomfortable finished product. Detailed Implementation

[0029] This invention provides an anti-allergic and skin-friendly surgical pack and its preparation process.

[0030] The raw materials and reagents used in the following examples are all commercially available products, or can be prepared by known methods.

[0031] Example 1: Combination formulation (parts by weight): cellulose-based nonwoven fabric: 55 parts; covalently grafted polymethacryloyloxyethyl phosphorylcholine: 5 parts; polylactic acid-quaternary ammonium salt copolymer: 35 parts; polyurethane hot melt adhesive: 10 parts.

[0032] The specific preparation steps are as follows: Preparation of the skin-friendly layer (S1): Wood pulp spunlace nonwoven fabric was selected and dried under vacuum. The dried nonwoven fabric was then immersed in a tetrahydrofuran solution containing polyethylene glycol monomethyl ether and reacted at 58°C to achieve the grafting of flexible spacer arms.

[0033] The grafted nonwoven fabric is washed and dried, and then triethylamine and 2-bromoisobutyryl bromide (molar ratio of 1.35:1 with polyethylene glycol monomethyl ether) are added under ice bath conditions of 0-5℃ to react with the anchored atom transfer radical polymerization (ATRP) initiator.

[0034] A polymerization reaction solution was prepared in which the molar ratio of methacryloyloxyethylphosphorylcholine (MPC) monomer, cuprous bromide (CuBr) catalyst, and pentamethyldiethylenetriamine (PMDETA) ligand was 150:1:2.5. A nonwoven fabric containing the initiator was immersed in this solution and reacted at 32°C for 18 hours under nitrogen protection. After the reaction, the nonwoven fabric was Soxhlet extracted with deionized water and methanol, and dried to obtain the skin-friendly layer.

[0035] Preparation of the barrier layer (S2): L-lactide monomer and dodecyl dimethyl tert-amine ethyl methacrylate (a C12 alkyl chain quaternary ammonium salt monomer) were mixed at a molar ratio of 97:1. Anhydrous toluene, at a mass ratio of 4 times the total monomer mass, was added as a solvent, and stannous octoate was added as a catalyst (the total molar ratio of catalyst to monomer was 1:15000). Ring-opening copolymerization was carried out at 120°C to obtain polylactic acid-quaternary ammonium salt copolymer.

[0036] The above copolymer was dissolved in dichloromethane / dimethylformamide as the shell solution, and polyvinyl alcohol was dissolved in water as the core solution. Using a coaxial electrospinning device, the solution was spun onto a roller receiver rotating at 200 rpm at a voltage of 20 kV and a receiving distance of 20 cm to form a core-shell composite nanofiber felt.

[0037] The fiber felt was soaked in warm water at 50°C for 18 hours to dissolve and remove the polyvinyl alcohol core layer. After drying, a hollow nanofiber barrier layer was obtained.

[0038] Preparation of composite materials (S3): The skin-friendly layer obtained in S1, a polyurethane hot melt adhesive mesh, and the barrier layer obtained in S2 are stacked flat in sequence.

[0039] The stacked three layers of material are placed in a flatbed hot press and hot-pressed for 60 seconds at a temperature of 125°C and a pressure of 0.3 MPa to obtain the final hypoallergenic and skin-friendly surgical pack composite material.

[0040] Example 2: Combination formulation (parts by weight): cellulose-based nonwoven fabric: 40 parts; covalently grafted polymethacryloyloxyethyl phosphorylcholine: 1 part; polylactic acid-quaternary ammonium salt copolymer: 20 parts; polyurethane hot melt adhesive: 5 parts.

[0041] The specific preparation steps are as follows: Preparation of the skin-friendly layer (S1): Wood pulp spunlace nonwoven fabric was selected, vacuum dried, and then immersed in a tetrahydrofuran solution containing polyethylene glycol monomethyl ether. The reaction was carried out at 40°C to graft flexible spacer arms.

[0042] The nonwoven fabric was washed and dried. Under ice bath conditions at 0°C, triethylamine and 2-bromoisobutyryl bromide (molar ratio of 1.1:1 with polyethylene glycol monomethyl ether) were added to anchor the ATRP initiator.

[0043] A polymerization reaction solution was prepared in which the molar ratio of MPC monomer, CuBr catalyst, and PMDETA ligand was 50:1:2.5. A nonwoven fabric containing the initiator was immersed in the solution and reacted at 25°C for 12 hours under nitrogen protection. After the reaction, Soxhlet extraction and drying were performed to obtain the skin-friendly layer.

[0044] Preparation of the barrier layer (S2): L-lactide monomer and dodecyl dimethyl tert-amine ethyl methacrylate (C12 alkyl chain quaternary ammonium salt monomer) were mixed at a molar ratio of 99:1, and stannous octoate catalyst was added (the total molar ratio of catalyst to monomer was 1:20000). The mixture was then subjected to ring-opening copolymerization at 110°C to obtain polylactic acid-quaternary ammonium salt copolymer.

[0045] The copolymer was dissolved in dichloromethane / dimethylformamide as the shell solution, and polyvinyl alcohol was dissolved in water as the core solution. A coaxial electrospinning device was used to spin the solution onto a roller rotating at 100 rpm under a voltage of 15 kV and a receiving distance of 15 cm.

[0046] The obtained fiber felt was soaked in 40℃ warm water for 12 hours to remove the polyvinyl alcohol core layer, and then dried to obtain a hollow nanofiber barrier layer.

[0047] Preparation of composite materials (S3): The skin-friendly layer of S1, a polyurethane hot melt adhesive mesh, and the barrier layer of S2 are stacked in sequence.

[0048] The material is placed in a flatbed hot press and hot-pressed for 30 seconds at a temperature of 110°C and a pressure of 0.1 MPa to obtain the final composite material.

[0049] Example 3: Combination formulation (parts by weight): cellulose-based nonwoven fabric: 70 parts; covalently grafted polymethacryloyloxyethyl phosphorylcholine: 10 parts; polylactic acid-quaternary ammonium salt copolymer: 50 parts; polyurethane hot melt adhesive: 15 parts.

[0050] The specific preparation steps are as follows: Preparation of the skin-friendly layer (S1): Wood pulp spunlace nonwoven fabric was selected, vacuum dried, and then immersed in a tetrahydrofuran solution containing polyethylene glycol monomethyl ether. The reaction was carried out at 70°C to graft flexible spacer arms.

[0051] The nonwoven fabric was washed and dried. Triethylamine and 2-bromoisobutyryl bromide (molar ratio of 1.8:1 with polyethylene glycol monomethyl ether) were added at a low temperature of 5°C to anchor the ATRP initiator.

[0052] A polymerization reaction solution was prepared in which the molar ratio of MPC monomer, CuBr catalyst, and PMDETA ligand was 300:1:2.5. A nonwoven fabric containing the initiator was immersed in the solution and reacted at 45°C for 24 hours under nitrogen protection. After the reaction, Soxhlet extraction and drying were performed to obtain the skin-friendly layer.

[0053] Preparation of the barrier layer (S2): L-lactide monomer and methacryloyloxyethylhexadecyldimethylammonium bromide (a C16 alkyl chain quaternary ammonium salt monomer) were mixed in a molar ratio of 95:5, and stannous octoate catalyst was added (the total molar ratio of catalyst to monomer was 1:10000). The mixture was subjected to ring-opening copolymerization at 140°C to obtain polylactic acid-quaternary ammonium salt copolymer.

[0054] The copolymer was dissolved in dichloromethane / dimethylformamide as the shell solution, and polyvinyl alcohol was dissolved in water as the core solution. A coaxial electrospinning device was used to spin the solution onto a roller rotating at 500 rpm under a voltage of 25 kV and a receiving distance of 25 cm.

[0055] The obtained fiber felt was soaked in 60℃ warm water for 24 hours to remove the polyvinyl alcohol core layer, and then dried to obtain a hollow nanofiber barrier layer.

[0056] Preparation of composite materials (S3): The skin-friendly layer of S1, a polyurethane hot melt adhesive mesh, and the barrier layer of S2 are stacked in sequence.

[0057] The material is placed in a flatbed hot press and hot-pressed for 90 seconds at a temperature of 140°C and a pressure of 0.5 MPa to obtain the final composite material.

[0058] Comparative Example 1: Compared with Example 1, the difference is that in step S1, the grafting reaction of polymethacryloyloxyethyl phosphorylcholine is not carried out, but the untreated wood pulp spunlace nonwoven fabric is used directly as the skin-friendly layer.

[0059] Comparative Example 2: Compared with Example 1, the difference is that in step S2, instead of using the pre-synthesized polylactic acid-quaternary ammonium salt copolymer, pure polylactic acid polymer and benzalkonium chloride (a small molecule quaternary ammonium salt antibacterial agent) are physically blended at a mass ratio of 99:1, and the blend solution is then used as the shell solution for coaxial electrospinning to prepare the barrier layer.

[0060] Comparative Example 3: Compared with Example 1, the difference is that in step S2, when preparing the barrier layer, the coaxial electrospinning technology is not used to prepare hollow fibers, but the traditional uniaxial electrospinning technology is used to directly spin the polylactic acid-quaternary ammonium salt copolymer solution in Example 1 into solid nanofibers to form the barrier layer.

[0061] Comparative Example 4: Compared with Example 1, the difference is that in step S3, polyurethane hot melt adhesive film is not used for lamination. Instead, liquid coating is used to evenly coat the surface of the skin-friendly layer with liquid polyurethane adhesive, and then it is bonded and compacted with the barrier layer.

[0062] Comparative Example 5: Compared with Example 1, the difference lies in the different mass ratios of the composite material components. The amount of polylactic acid-quaternary ammonium salt copolymer is reduced to 10 parts, while the amount of cellulose-based nonwoven fabric is increased to 80 parts. The amounts of the remaining components are the same as in Example 1.

[0063] Comparative Example 6: Compared with Example 1, the difference lies in the different mass ratios of the composite material components. The amount of polyurethane hot melt adhesive is increased to 20 parts, while the amount of cellulose-based nonwoven fabric is reduced to 45 parts. The amounts of the remaining components are the same as in Example 1.

[0064] Test Example 1: Skin affinity and biocompatibility test Experimental description: This test case aims to quantitatively evaluate and compare the differences in biocompatibility between the sample of Example 1 (with a PMPC skin-friendly layer) and the sample of Comparative Example 1 (without surface treatment) through in vitro simulation experiments, focusing on protein adsorption, platelet adhesion, and cytotoxicity on the material surface.

[0065] The experimental steps are as follows: Protein adsorption test: Sample preparation: The composite materials of Example 1 and Comparative Example 1 were cut into 1cm × 1cm square samples, and three parallel samples were prepared for each sample group. The sample surface was rinsed three times with phosphate buffered solution (PBS) to remove surface impurities.

[0066] Incubation: Place the cleaned samples into 24-well culture plates and add 1 mL of 1 mg / mL bovine serum albumin (BSA) solution to each well. Incubate the culture plates in a 37°C constant temperature shaker for 2 hours at low speed.

[0067] Concentration determination: After incubation, carefully aspirate the BSA solution from each well. Use the BCA (Bicinchoninic-acid) protein concentration assay kit to measure the concentration of remaining BSA in the solution after incubation.

[0068] Data processing: The mass of protein adsorbed per unit area of ​​sample was calculated by comparing the change in BSA concentration in the solution before and after incubation and dividing by the sample surface area.

[0069] Platelet adhesion test: Sample preparation: The composite materials of Example 1 and Comparative Example 1 were cut into circular samples with a diameter of 14 mm, sterilized by ultraviolet irradiation, and placed in 24-well culture plates.

[0070] Plasma preparation: Fresh anticoagulated rabbit blood was collected and platelet-rich plasma (PRP) was prepared by centrifugation.

[0071] Incubation: Add 500 μL of PRP to each well containing the sample, ensuring the sample is completely covered. Place the culture plate in a 37°C incubator and incubate for 1 hour.

[0072] Washing and lysis: After incubation, carefully aspirate the PRP and gently rinse the sample surface three times with PBS to remove any unattached platelets. Then, add cell lysis buffer to each well to lyse the platelets that have adhered to the sample surface.

[0073] Quantitative detection: The lysate was collected and the relative number of adherent platelets was quantitatively assessed by measuring the absorbance value at a specific wavelength using a lactate dehydrogenase (LDH) activity assay kit.

[0074] Cytotoxicity test: Preparation of material extract: According to ISO-10993-5 standard, under aseptic conditions, the samples of Example 1 and Comparative Example 1 were immersed in serum-free cell culture medium at a ratio of 0.2 g / mL and extracted at 37°C for 24 hours to prepare a 100% concentration material extract. A blank control was set up containing no samples.

[0075] Cell culture: L929 fibroblasts were seeded at an appropriate density in 96-well plates and cultured until the cells adhered well.

[0076] Cell contact: Aspirate the original culture medium and add the prepared sample extract and blank control culture medium to the wells, with 6 parallel wells for each group. Continue incubation at 37°C and 5% CO2 for 24 hours.

[0077] MTT assay: Add MTT solution to each well and continue culturing for 4 hours. Afterward, discard the supernatant and add dimethyl sulfoxide (DMSO) to dissolve the generated formazan purple crystals.

[0078] Results determination: The absorbance (OD) value of each well at 570 nm was measured using an ELISA reader, and the relative cell proliferation rate (RGR) of each experimental group was calculated based on the OD value of the blank control group.

[0079] The experimental data are shown in Table 1: Table 1: Results of Skin Affinity and Biocompatibility Tests Test sample Protein adsorption (μg / cm 2 )]]> Relative number of platelet adhesion (absorbance value) Relative proliferation rate of cells (%) Example 1 1.87 0.083 98.6 Comparative Example 1 9.42 0.516 81.3 Experiment Summary: As shown in Table 1, the sample of Example 1 of this invention exhibits significant advantages in terms of skin affinity and biocompatibility. In the protein adsorption test, the protein adsorption capacity of the sample of Example 1 was only 1.87 μg / cm³.2 This is significantly lower than the 9.42 μg / cm³ of the comparative sample 1. 2 This strongly confirms the design mechanism of the present invention: polymethacryloyloxyethyl phosphorylcholine (PMPC) molecular brushes covalently grafted onto the surface of cellulose-based nonwoven fabric using surface-initiated atom transfer radical polymerization (SI-ATRP) technology possess an amphoteric structure that strongly adsorbs and binds surrounding water molecules, forming a stable physical hydration layer on the material surface. This hydration layer acts as a biological "inert" interface, effectively masking the underlying material and physically and energetically hindering the non-specific adsorption of biomolecules such as proteins, thus laying the foundation for excellent biocompatibility.

[0080] The platelet adhesion test results were highly consistent with the protein adsorption test results. The relative number of platelets adhering to the sample in Example 1 (absorbance value 0.083) was significantly lower than that of the sample in Comparative Example 1 (absorbance value 0.516). The underlying mechanism is that the initial adsorption of proteins in biological fluids on the material surface is a key initiating step in inducing platelet adhesion, activation, and even the subsequent coagulation cascade reaction. Since the PMPC biomimetic interface of Example 1 can effectively resist the initial adsorption of proteins, it also inhibits the response and adhesion of platelets at the source. This indicates that the skin-friendly layer constructed in this invention has excellent blood compatibility and can significantly reduce the risk of adverse physiological reactions caused by contact between the material and blood or wound exudate.

[0081] Regarding cytotoxicity, the relative cell proliferation rate of the sample in Example 1 was as high as 98.6%, indicating that neither the material itself nor the surface modification process is cytotoxic, demonstrating high biocompatibility. This is attributed to the excellent biocompatibility of PMPC molecules themselves, and the preparation method that firmly grafts them onto the fiber surface via covalent bonds, avoiding the leaching risk of any functional additives.

[0082] Test Example 2: Antibacterial Performance and Safety Test Experimental description: This test case aims to verify the antibacterial properties of the barrier layer of the present invention through in vitro antibacterial experiments and cytotoxicity experiments, and focuses on comparing the differences in biosafety between the "intrinsically safe" antibacterial design of the present invention (covalently bonding antibacterial groups to the polymer backbone) and the traditional "additive" antibacterial method (physical blending of small molecule antibacterial agents).

[0083] The experimental steps are as follows: Antibacterial efficacy test (shaking flask method): Strain activation: Frozen strains of Staphylococcus aureus (ATCC-6538) and Escherichia coli (ATCC-8739) were activated and cultured in nutrient broth medium.

[0084] Sample preparation: The samples of Example 1, Comparative Example 1, Comparative Example 2 and Comparative Example 5 were cut into small pieces of the specified size (about 0.4g) and sterilized with ethylene oxide.

[0085] Preparation of bacterial suspension: Dilute the activated bacterial strain with PBS to adjust the bacterial concentration to approximately 1×10⁻⁶. 5 -1×10 6 CFU / mL.

[0086] Contact shaking: Each group of samples was placed into a conical flask containing 70 mL of bacterial suspension. A blank control group containing no samples was also included. All conical flasks were placed in a 37°C constant-temperature shaker and shaken at 150 rpm for 24 hours.

[0087] Viable cell count: After shaking, take 1 mL of solution from each Erlenmeyer flask and perform serial dilutions. Spread the appropriately diluted solution onto nutrient agar plates and incubate at 37°C for 24 hours. Then, count the viable cell colonies.

[0088] Data processing: The antibacterial rate of each sample was calculated based on the viable bacterial counts of the blank control group and each experimental group.

[0089] Safety test for leaching of antimicrobial agents (MTT method): Preparation of material extract: Under aseptic conditions, samples from Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 5 were immersed in serum-free cell culture medium at a ratio of 0.2 g / mL and extracted for 24 hours at 37°C in a 5% CO2 incubator. Afterward, the extract was filtered through a 0.22 μm filter for sterilization to obtain a 100% concentration material extract.

[0090] Cell culture and contact: L929 fibroblasts were seeded at an appropriate density in 96-well plates and cultured until the cells adhered. The original culture medium was aspirated, and the extracts of each group of materials prepared above were added to the wells. Wells containing only fresh culture medium were set up as a blank control group. Six parallel wells were set up for each group, and the cells were cultured for another 24 hours.

[0091] MTT assay: Add MTT solution to each well, continue culturing for 4 hours, discard the supernatant, and add DMSO to dissolve the formazan crystals.

[0092] Results determination: The absorbance (OD) value of each well at 570 nm was measured using an ELISA reader, and the relative cell proliferation rate (RGR) of each experimental group was calculated based on the OD value of the blank control group to assess the cytotoxicity of the extract.

[0093] The experimental data are shown in Table 2: Table 2: Results of Antibacterial Performance and Safety Tests Experiment Summary: Table 2 clearly demonstrates the superior antibacterial properties of the material prepared in this invention. The sample in Example 1 exhibited antibacterial rates exceeding 99% against both Staphylococcus aureus and Escherichia coli, while the sample in Comparative Example 1, lacking antibacterial components, showed almost no antibacterial effect, and the sample in Comparative Example 5, with insufficient antibacterial component content, also showed significantly reduced antibacterial effect. The underlying mechanism of this result lies in the fact that this invention, through ring-opening copolymerization, covalently bonds positively charged quaternary ammonium salt functional groups as structural units to the polylactic acid polymer backbone. When the negatively charged bacterial cell walls come into contact with the material surface, the strong electrostatic adsorption between the two disrupts the integrity of the cell membrane, leading to leakage of contents, thereby achieving highly efficient contact sterilization. This confirms the success of the technical concept of achieving highly efficient antibacterial function through molecular structure design in this invention.

[0094] The extract of the sample in Example 1 did not exhibit cytotoxicity, with a relative cell proliferation rate as high as 97.8%, showing no significant difference from the blank control group (Comparative Example 1). In stark contrast, the sample in Comparative Example 2, prepared using a traditional physical blending method with small-molecule antibacterial agents, also exhibited a high antibacterial rate, but its extract showed significant cytotoxicity, with a relative cell proliferation rate of only 62.7%. The underlying mechanism lies in the fundamental difference in preparation methods: in Example 1, the antibacterial functional groups are inherent components of the polymer chain, firmly locked by covalent bonds, and cannot leach or migrate from the material; while in Comparative Example 2, the small-molecule quaternary ammonium salt antibacterial agent is merely physically dispersed in the polymer matrix, making it highly susceptible to leaching during soaking, thus causing cytotoxicity.

[0095] Based on the combined results of antibacterial efficacy and safety tests, the "intrinsic safety" design concept of this invention has been fully verified. By covalently bonding antibacterial units to polymer chains, this invention endows materials with efficient and broad-spectrum antibacterial capabilities while fundamentally solving the potential biosafety risks that may arise from the migration and leaching of traditional additive antibacterial agents.

[0096] Test Example 3: Physical Barrier and Comfort Test Experimental description: This test case aims to comprehensively evaluate the impact of different material structures and composite processes on the physical properties of the final product. The core objective is to verify how the present invention, while ensuring waterproof barrier performance, maximizes the preservation of the material's breathability through collaborative design (hollow fiber structure and mesh composite process), thereby ensuring user comfort, and to examine the strength of the interlayer bonding.

[0097] The experimental steps are as follows: Air permeability test (water vapor transmission rate test): Testing equipment: Water vapor transmission rate tester (cup method).

[0098] Sample preparation: The samples of Example 1, Comparative Example 3, Comparative Example 4 and Comparative Example 6 were cut into circular test pieces with a diameter of 7.4 cm.

[0099] Test procedure: Add a certain amount of distilled water to the test cup. Cover the mouth of the test cup with the sample and seal it, ensuring that the skin-friendly layer of the sample faces inward. Place the entire test apparatus in a constant temperature and humidity chamber at 38℃ and 60% relative humidity.

[0100] Data Acquisition: The total weight of the test cup was accurately measured every hour for 24 hours. The water vapor transmission rate (WVTR) of the material was calculated based on the change in the weight of the test cup per unit time and the test area of ​​the sample, in g / m². 2 / day.

[0101] Waterproofing test (hydrostatic pressure test): Testing equipment: Fabric hydrostatic pressure tester.

[0102] Sample preparation: Cut the samples of Example 1, Comparative Example 3, Comparative Example 4, and Comparative Example 6 into square pieces (approximately 20cm × 20cm) with an area larger than the area of ​​the test head.

[0103] Test procedure: Mount the sample onto the test head, ensuring it blocks the surface from the pressurized water flow. Apply water pressure to the sample at a constant rate of 60 cmH2O / min.

[0104] Data acquisition: Continuously observe the other side of the sample (the skin-friendly side). When the third water droplet appears on the surface, immediately stop pressurizing and record the pressure value at this time, which is the hydrostatic pressure value of the sample, in kPa.

[0105] Interlayer bond strength test (180-degree peel test): Testing equipment: Electronic universal testing machine.

[0106] Sample preparation: Cut the samples from Example 1, Comparative Example 4, and Comparative Example 6 into strips 200 mm long and 25 mm wide. At one end of the sample, use your hand to pre-separate the skin-friendly layer and the barrier layer by about 50 mm to create a clamping end.

[0107] Testing procedure: Fix the two pre-separated clamping ends in the upper and lower clamps of the testing machine, respectively, so that the sample is at a 180-degree angle. Start the testing machine and peel off the two layers of material at a tensile speed of 100 mm / min.

[0108] Data acquisition: The testing machine automatically records the force value changes during the peeling process, and takes the force value of the stable section in the peeling curve for average calculation to obtain the interlayer peel strength of the sample, in N / 25mm.

[0109] The experimental data are shown in Table 3: Table 3: Test Results of Physical Barrier and Comfort Performance Test sample Water vapor transmission rate (g / m 2 / day) Hydrostatic pressure (kPa) Interlaminar peeling strength (N / 25 mm) Example 1 4826 12.8 4.1 Comparative Example 3 3157 13.5 Not applicable Comparative Example 4 743 24.1 5.3 Comparative Example 6 1982 14.2 6.8 Experiment Summary: The test results in Table 3 reveal the exquisite balance achieved by this invention between material physical properties and comfort. The sample from Example 1 exhibited a high g / m³ of 4826 g / m³. 2 The water vapor permeation rate per day is much higher than that of Comparative Example 3 (3157 g / m²) which uses solid fibers. 2 Both maintain excellent waterproof properties. The underlying mechanism lies in the coaxial electrospinning technology used in this invention to prepare a hollow nanofiber barrier layer. Compared to solid fibers, the hollow structure retains micro- and nano-scale channels between fibers to block liquid water, while its internal through-cavities provide additional diffusion channels for water vapor molecules, greatly increasing the material's effective porosity and gas flux. This significantly improves the material's breathability and comfort without sacrificing waterproof performance.

[0110] This test case further verifies the key impact of the composite process on the performance of the final product. Example 1 uses a polyurethane hot melt adhesive web film for composite, with an air permeability of 4826 g / m³. 2 / day) compared to Comparative Example 4 (743g / m²) which was applied using liquid adhesive by scraping. 2 Compared to liquid adhesives (on a daily basis), this method offers an order-of-magnitude advantage. This clearly demonstrates that liquid adhesives form a continuous, dense film during the lamination process, severely clogging the original microporous structure of the material and completely destroying its breathability. In contrast, the hot melt adhesive web used in this invention forms a discontinuous, dotted bonding structure after hot pressing. While ensuring sufficient interlayer bonding strength, it maximizes the preservation of the original porous network of the skin-friendly and barrier layers, achieving a synergistic balance between structural strength and functional comfort.

[0111] In summary, the sample of Example 1 achieved optimal overall performance in the three key indicators of waterproofness, breathability, and interlayer bond strength. It ensured high breathability and waterproofness through its hollow nanofiber structure, maintained these properties through an optimized hot melt adhesive web composite process, and obtained reliable structural strength (4.1 N / 25 mm). Compared to Comparative Example 6 (excess adhesive), Example 1 achieved more than twice the breathability at the cost of slightly lower peel strength, demonstrating the rationality of the component ratio in this invention.

[0112] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A hypoallergenic, skin-friendly surgical pack, characterized in that, The composite material of the surgical pack comprises the following components in parts by weight: Cellulose-based nonwoven fabric: 40-70 parts; Polymethacryloyloxyethyl phosphorylcholine covalently grafted onto the cellulose-based nonwoven fabric: 1-10 parts; Polylactic acid-quaternary ammonium salt copolymer: 20-50 parts; Polyurethane hot melt adhesive: 5-15 parts.

2. The hypoallergenic, skin-friendly surgical pack according to claim 1, characterized in that, The cellulose-based nonwoven fabric is a wood pulp spunlace nonwoven fabric or a viscose fiber spunlace nonwoven fabric; the polymethacryloyloxyethyl phosphorylcholine is covalently grafted onto the fiber surface of the cellulose-based nonwoven fabric through flexible spacer arm molecules.

3. The hypoallergenic, skin-friendly surgical pack according to claim 1, characterized in that, The polylactic acid-quaternary ammonium salt copolymer is a product obtained by ring-opening copolymerization of lactide monomer and methacrylate quaternary ammonium salt monomer, wherein the alkyl chain length of the methacrylate quaternary ammonium salt monomer is 12-16 carbon atoms.

4. The hypoallergenic, skin-friendly surgical pack according to claim 1, characterized in that, The polylactic acid-quaternary ammonium salt copolymer is a porous film formed in the form of hollow nanofibers.

5. The hypoallergenic, skin-friendly surgical pack according to claim 1, characterized in that, The composite material of the surgical pack has a layered structure, which includes: A skin-friendly layer consisting of the cellulose-based nonwoven fabric and polymethacryloyloxyethyl phosphorylcholine covalently grafted thereon; A barrier layer composed of the polylactic acid-quaternary ammonium salt copolymer; An adhesive layer composed of the polyurethane hot melt adhesive, the adhesive layer being disposed between the skin-friendly layer and the barrier layer.

6. A preparation process for an anti-allergic, skin-friendly surgical pack, used to prepare the anti-allergic, skin-friendly surgical pack according to any one of claims 1-5, characterized in that, The preparation process includes the following steps: S1. On the fiber surface of cellulose-based nonwoven fabric, an atom transfer radical polymerization initiator is covalently anchored by a flexible spacer arm, and then a surface-initiated atom transfer radical polymerization reaction is carried out to grow a polymethacryloyloxyethyl phosphorylcholine molecular brush to obtain a skin-friendly layer. S2. A copolymerization reaction is carried out between lactide monomer and methacrylate quaternary ammonium salt monomer with alkyl chain length of C12-C16 to obtain polylactic acid-quaternary ammonium salt copolymer; a core-shell structured nanofiber is prepared by using coaxial electrospinning technology, with the solution of the polylactic acid-quaternary ammonium salt copolymer as the shell solution and the solution of the water-soluble polymer as the core solution; the core layer is then removed by solvent to obtain a barrier layer composed of hollow nanofibers. S3. The skin-friendly layer and the barrier layer are hot-pressed together using a polyurethane hot melt adhesive.

7. The preparation process of an anti-allergic and skin-friendly surgical pack according to claim 6, characterized in that, Step S1 includes: S1-1. Polyethylene glycol monomethyl ether is used as a flexible spacer arm and reacted with the cellulose-based nonwoven fabric at a temperature of 50℃-65℃. Subsequently, 2-bromoisobutyryl bromide in a molar ratio of 1.2:1-1.5:1 is reacted with the flexible spacer arm at a temperature of 0℃-5℃ to covalently anchor the atom transfer radical polymerization initiator. S1-2. Immerse a nonwoven fabric containing an initiator in a reaction solution and grow a polymethacryloyloxyethylphosphorylcholine molecular brush through surface-initiated atom transfer radical polymerization. The reaction solution contains methacryloyloxyethylphosphorylcholine monomer, cuprous bromide catalyst, and pentamethyldiethylenetriamine ligand. The molar ratio of methacryloyloxyethylphosphorylcholine monomer to cuprous bromide is 100:1-200:1, and the molar ratio of pentamethyldiethylenetriamine to cuprous bromide is 2:1-3:

1. The polymerization reaction is carried out at a temperature of 25℃-40℃ for 12-24 hours.

8. The preparation process of an anti-allergic and skin-friendly surgical pack according to claim 6, characterized in that, Step S2 includes: S2-1. A copolymerization reaction is carried out between lactide monomer and methacrylate quaternary ammonium salt monomer with alkyl chain length of C12-C16 at a molar ratio of 99:1-95:5 at a temperature of 110℃-130℃ to obtain polylactic acid-quaternary ammonium salt copolymer. S2-2. Using coaxial electrospinning technology, the solution of the polylactic acid-quaternary ammonium salt copolymer is used as the shell solution and the polyvinyl alcohol solution is used as the core solution. Under a voltage of 15kV-25kV and a receiving distance of 15cm-25cm, the solution is spun onto a roller receiver with a rotation speed of 100rpm-300rpm to form core-shell structured nanofibers. S2-3. The core-shell structured nanofibers are soaked and washed in water at a temperature of 40℃-60℃ to remove the core layer.

9. The preparation process of an anti-allergic and skin-friendly surgical pack according to claim 6, characterized in that, Step S3 includes: S3-1. The skin-friendly layer, the polyurethane hot melt adhesive (polyurethane hot melt adhesive mesh), and the barrier layer are stacked in sequence, wherein the polyurethane hot melt adhesive mesh is located between the skin-friendly layer and the barrier layer. S3-2. The stacked materials are hot-pressed at a temperature of 110℃-140℃ and a pressure of 0.1MPa-0.5MPa for a duration of 30s-90s.

10. The preparation process of an anti-allergic and skin-friendly surgical pack according to claim 6, characterized in that, The preparation of the polylactic acid-quaternary ammonium salt copolymer is accomplished by a ring-opening copolymerization reaction. The ring-opening copolymerization reaction uses stannous octoate as a catalyst, and the total molar ratio of catalyst to monomer is 1:10000-1:20000. The reaction is carried out in anhydrous toluene solvent, and the amount of solvent used is 3-5 times the total mass of monomer.

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