An antibacterial drainage bag medical film and a preparation process thereof

Abstract

This invention discloses an antibacterial drainage bag medical membrane and its preparation process, belonging to the field of medical device technology. The medical membrane has a multi-layer composite structure, comprising, from the outside to the inside: a breathable and antibacterial outer layer, a structurally reinforcing intermediate layer, and an antibacterial inner layer; the breathable and antibacterial outer layer is a hydrophilically modified polyurethane microporous membrane; the structurally reinforcing intermediate layer is a polypropylene or polyethylene nonwoven fabric; the antibacterial inner layer is a polyvinyl alcohol-chitosan blend membrane loaded with a composite antibacterial agent, which is composed of inorganic and organic antibacterial components; each layer is laminated and fixed by hot melt adhesive bonding or hot pressing. The preparation process includes preparing the breathable and antibacterial outer layer and the antibacterial inner layer separately, and then laminating them with the intermediate layer. This invention solves the problems of retrograde bacterial infection and putrefaction and odor of drainage fluid in existing drainage bags through gradient antibacterial and synergistic functional design of "moisture permeability and antibacterial effect - mechanical reinforcement - contact sterilization," and has the advantages of high-efficiency antibacterial, high breathability and antibacterial effect, and good mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to an antibacterial medical membrane for drainage bags and its preparation process. Background Technology

[0002] Drainage bags are disposable medical devices widely used in clinical medicine for collecting bodily fluids such as urine, exudate, and irrigation fluid, commonly found in urology, general surgery, and orthopedic postoperative drainage. However, drainage bags face two major problems during use: first, the risk of retrograde bacterial infection, as the drainage tube interface and the inside of the bag can easily become a breeding ground for bacteria, leading to urinary tract infections or abdominal infections in patients; second, the problem of foul odor from the putrefaction of drainage fluid, especially when left at room temperature for extended periods, where bacteria decompose urea and protein in urine or exudate, releasing ammonia and thiols, which not only affect the ward environment but also negatively impact patients' psychological well-being and dignity.

[0003] Several solutions have emerged in the prior art to address the aforementioned problems. For example, some patents achieve antibacterial function by coating the inner surface of the drainage bag with a nano-silver or chitosan antibacterial coating; other solutions encapsulate a sterilization liquid reservoir inside the bag, which is punctured during use to release the sterilized liquid and kill bacteria in the drainage fluid; still other technologies impart overall antibacterial properties by adding antibacterial components such as alkyltrimethylammonium methyl sulfate and methylparaben to the plastic body of the drainage bag.

[0004] However, the aforementioned existing technologies still have significant technical shortcomings: First, the cost of nano-silver coatings is high and there are potential controversies regarding biosafety; second, the adhesion between the coating and the plastic substrate is insufficient, and it is easy to fall off and fail during use due to the rinsing effect of the drainage fluid; third, existing antibacterial coatings or additives only focus on antibacterial function, neglecting the key performance requirements of medical membranes for drainage bags—namely, high breathability (to ensure comfort in the skin contact area), high antibacterial properties (to prevent external bacteria from invading), and good mechanical strength; fourth, most solutions use a single antibacterial mechanism, which can easily lead to bacterial resistance with long-term use.

[0005] To address the aforementioned issues, this invention proposes a multi-layer composite structure antibacterial drainage bag medical membrane and its preparation process. Through a rational interlayer functional design and a gradient antibacterial system, it balances long-lasting antibacterial effect, physical and mechanical properties, and biosafety. Summary of the Invention

[0006] Purpose of the invention: The present invention aims to provide a medical membrane for drainage bags that combines high antibacterial efficiency, high air permeability and bacterial barrier properties, good mechanical properties and biosafety, as well as its preparation method, in order to solve the technical problems of existing drainage bags being prone to retrograde bacterial infection and putrefaction and foul odor of drainage fluid.

[0007] Technical solution: The present invention provides an antibacterial drainage bag medical film, wherein the medical film has a multi-layer composite structure, comprising, from the outside to the inside: a breathable and antibacterial outer layer, a structurally reinforcing middle layer, and an antibacterial inner layer; The breathable and antibacterial outer layer is a polyurethane microporous membrane that has been modified with hydrophilicity, with a pore size controlled at 0.1-0.5 μm, a porosity of 60%-85%, and a thickness of 20-50 μm. The structurally reinforcing intermediate layer is made of polypropylene or polyethylene nonwoven fabric with a basis weight of 15-40 g / m² and a thickness of 50-150 μm. The antibacterial inner layer is a polyvinyl alcohol-chitosan blend film loaded with a composite antibacterial agent, with a thickness of 10-30 μm, wherein the composite antibacterial agent is composed of inorganic antibacterial components and organic antibacterial components. The breathable and antibacterial outer layer, the structurally reinforced middle layer, and the antibacterial inner layer are laminated and fixed by hot melt adhesive bonding or hot pressing composite method.

[0008] As a preferred embodiment, in the composite antibacterial agent, the inorganic antibacterial component is silver-loaded zeolite or nano zinc oxide, and the organic antibacterial component is polyhexamethylene biguanide or ε-polylysine, with the mass ratio of the inorganic antibacterial component to the organic antibacterial component being 1:1 to 1:4.

[0009] As a preferred embodiment, in the antibacterial inner layer, the mass ratio of polyvinyl alcohol to chitosan is 4:1-9:1, and the amount of composite antibacterial agent added is 0.5%-5% of the total mass of polyvinyl alcohol and chitosan.

[0010] As a preferred embodiment, the polyurethane microporous membrane of the breathable and antibacterial outer layer is prepared by a non-solvent phase separation method or an electrospinning method, and its water vapor transmission rate is 500-2000 g / (m²·24h), and its bubble point is 0.05-0.20 MPa.

[0011] As a preferred embodiment, the hot melt adhesive is one of ethylene-vinyl acetate copolymer, polyurethane hot melt adhesive, or polyolefin hot melt adhesive, and the coating amount is 3-10 g / m².

[0012] This invention further provides a process for preparing the above-mentioned antibacterial drainage bag medical film, comprising the following steps: Step 1: Preparation of the breathable and antibacterial outer layer: Thermoplastic polyurethane is dissolved in an organic solvent to prepare a casting solution with a mass fraction of 8%-20%. The film is formed by non-solvent phase separation method, and the coagulation bath temperature is controlled at 20-40℃. After washing with water and drying, a polyurethane microporous membrane is obtained. Then, the membrane surface is subjected to plasma treatment or hydrophilic agent coating treatment. Step 2: Preparation of the antibacterial inner layer: Dissolve polyvinyl alcohol in deionized water to prepare a 3%-10% polyvinyl alcohol aqueous solution, and dissolve chitosan in a 1%-3% acetic acid aqueous solution to prepare a 1%-5% chitosan solution. Mix the two in proportion, add the composite antibacterial agent and stir evenly. After degassing, form a film using solution casting or blade coating. The drying temperature is 40-80℃ and the drying time is 2-8 hours to obtain the antibacterial inner layer film. Step 3, interlayer lamination: Using hot melt adhesive spraying or hot pressing lamination process, the breathable and antibacterial outer layer, the structurally reinforced middle layer and the antibacterial inner layer are sequentially laminated. The lamination temperature is 80-150℃ and the lamination pressure is 0.2-1.0MPa, thus obtaining the antibacterial drainage bag medical film.

[0013] As a preferred embodiment, in step one, the organic solvent is one or a mixture of dimethylformamide, dimethylacetamide, or tetrahydrofuran.

[0014] As a preferred embodiment, in step one, the plasma treatment process parameters are: the atmosphere is air or oxygen, the treatment power is 50-300W, and the treatment time is 30-180 seconds.

[0015] As a preferred option, in step three, the hot melt adhesive is applied using slit spraying or dot spraying, with a coating amount of 3-10 g / m².

[0016] Beneficial effects: Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention adopts a three-layer composite structure design, with each layer having a clear function and synergistic effect: the outer layer achieves "moisture permeability and antibacterial barrier", the inner layer achieves "contact sterilization", and the middle layer provides mechanical support, which solves the technical problems of easy peeling of antibacterial coating and difficulty in achieving both air permeability and antibacterial barrier in the prior art.

[0017] (2) The present invention adopts an inorganic / organic composite antibacterial system, which achieves a broad-spectrum, efficient and long-lasting antibacterial effect through the synergistic effect of multiple antibacterial mechanisms, and effectively reduces the risk of bacterial resistance.

[0018] (3) The preparation process of the present invention is mature and controllable. Each layer of material can be obtained by conventional film forming process. The interlayer composite adopts hot melt adhesive bonding technology, which is suitable for industrial continuous production and the cost is controllable.

[0019] (4) According to the test, the antibacterial drainage bag medical film prepared by the present invention has an antibacterial rate of ≥99.9% against common pathogens such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, a water vapor transmission rate of ≥800g / (m²·24h), a tensile strength of ≥15MPa, and an elongation at break of ≥150%, which has good comprehensive performance. Detailed Implementation

[0020] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention. Example

[0021] This embodiment provides an antibacterial drainage bag medical film and its preparation process.

[0022] (1) Preparation of an air-permeable and antibacterial outer layer Thermoplastic polyurethane (TPU, BASF, Germany, grade 1185A) was dissolved in dimethylformamide to prepare a 12% (w / w) casting solution. The solution was stirred and dissolved in a 60°C water bath for 4 hours until completely transparent. After the casting solution was allowed to stand to remove bubbles, it was coated onto a glass plate using a doctor blade with a gap of 150 μm. The plate was immediately immersed in a 25°C deionized water coagulation bath, and the solvent and non-solvent were exchanged for 10 minutes to form a film. The membrane was removed and rinsed in deionized water for 24 hours to remove residual solvent, then allowed to air dry at room temperature. The dried polyurethane microporous membrane was then placed in an air plasma treatment instrument and treated at 150W for 90 seconds to obtain a hydrophilic polyurethane microporous membrane. Testing showed that the membrane had an average pore size of 0.3 μm, a porosity of 72%, and a thickness of 35 μm.

[0023] (2) Preparation of antibacterial inner layer Weigh 8g of polyvinyl alcohol (PVA, degree of hydrolysis 98%, molecular weight approximately 80,000), add it to 92g of deionized water, and stir to dissolve in a 90℃ water bath for 2 hours to obtain an 8% PVA solution. Weigh 2g of chitosan (CS, degree of deacetylation ≥90%, molecular weight approximately 100,000), add it to 98g of a 2% (v / v) acetic acid aqueous solution, and stir to dissolve overnight at room temperature to obtain a 2% CS solution. Mix the PVA solution and the CS solution at a mass ratio of 8:2 (equivalent to a PVA to CS mass ratio of 6.4:1.6 = 4:1), and stir until homogeneous.

[0024] Weigh 0.05 g of silver-loaded zeolite (silver content approximately 2.5%, average particle size ≤ 1 μm) and 0.15 g of polyhexamethylene biguanide hydrochloride (PHMB), and add them to the above mixed polymer solution (total polymer solid content 8 g, composite antibacterial agent added at 2.5% of total polymer content). Disperse evenly by high-speed stirring and degas under vacuum. Apply the casting solution to the release film using a doctor blade coating method with a doctor blade gap of 200 μm. Dry in a 60℃ oven for 4 hours to obtain an antibacterial inner layer film with a thickness of approximately 22 μm.

[0025] (3) Interlayer composite Polyolefin hot melt adhesive (3M, brand name 3798LM) was used to uniformly spray onto both sides of polypropylene nonwoven fabric (25 g / m²) using a slit nozzle, with a coating amount of approximately 5 g / m² on each side. Then, the breathable and antibacterial outer layer, the adhesive-coated nonwoven fabric, and the antibacterial inner layer were sequentially stacked and hot-pressed together at 100°C and 0.5 MPa for 30 seconds. After cooling, a three-layer composite antibacterial drainage bag medical film was obtained.

[0026] The aforementioned medical membrane was cut into appropriate shapes and assembled with other components of the drainage bag (drainage tube, bag body, drainage port, etc.) using a high-frequency heat sealing process to form an antibacterial drainage bag. Testing showed that the drainage bag exhibited an inhibition rate of ≥99.9% against both Escherichia coli and Staphylococcus aureus under simulated usage conditions (37℃, 24 hours). Example

[0027] This embodiment is basically the same as Embodiment 1, except that the composition and dosage of the composite antibacterial agent in the antibacterial inner layer are different.

[0028] Step (2) Preparation of the antibacterial inner layer: The mass ratio of PVA to CS is adjusted to 7:3 (i.e., 7g PVA, 3g CS). The composite antibacterial agent uses nano zinc oxide (average particle size ≤50nm) and ε-polylysine (ε-PL, molecular weight about 4000), with a mass ratio of 1:2. The amount of composite antibacterial agent added is 3.0% of the total polymer mass (i.e., 10g of PVA+CS, 0.1g of nano zinc oxide and 0.2g of ε-PL).

[0029] The remaining steps are the same as in Example 1. The thickness of the antibacterial inner layer of the resulting antibacterial drainage bag medical membrane is approximately 25 μm. Testing showed that this antibacterial drainage bag exhibits better inhibitory effects against Pseudomonas aeruginosa than in Example 1.

[0030] Comparative Example 1 To illustrate the advantages of the multilayer composite structure of the present invention, Comparative Example 1 was set up: only the antibacterial inner layer formula in Example 1 was used as a single-layer membrane directly as a medical membrane for drainage bags (thickness of about 80 μm, similar to the total thickness of the composite membrane), without composite air-permeable and antibacterial outer layer and intermediate reinforcing layer.

[0031] Referring to the national standard GB / T 1040.3-2006 for testing the tensile strength of the film, the composite film of this invention has a tensile strength of approximately 18 MPa, while the single-layer film of Comparative Example 1 has a tensile strength of only 6.2 MPa and is prone to breakage during use. Furthermore, in the antibacterial test (referring to YY / T 0471.2-2004), the single-layer film of Comparative Example 1 cannot effectively block the penetration of external bacteria.

[0032] Comparative Example 2 To illustrate the synergistic advantages of the composite antibacterial agent, a comparative example 2 was set up: only 2.5% silver-loaded zeolite was added as a single antibacterial component in the antibacterial inner layer, without any organic antibacterial components, and the rest was the same as in Example 1.

[0033] Continuous antibacterial testing (immersing the membrane sample in saline containing bacteria and taking it out every 8 hours to detect the number of viable bacteria) showed that the composite membrane of Example 1 still maintained an antibacterial rate of ≥99.9% after 72 hours; while the membrane of Comparative Example 2 showed an antibacterial rate of about 92% after 24 hours and about 78% after 48 hours, indicating that the antibacterial effect of the single inorganic antibacterial agent was reduced due to the decrease in the slow release rate of silver ions.

[0034] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A medical membrane for an antibacterial drainage bag, characterized in that, The medical membrane has a multi-layer composite structure, which includes, from the outside to the inside: a breathable and antibacterial outer layer, a structurally reinforced middle layer, and an antibacterial inner layer; The breathable and antibacterial outer layer is a polyurethane microporous membrane that has been modified with hydrophilicity, with a pore size controlled at 0.1-0.5 μm, a porosity of 60%-85%, and a thickness of 20-50 μm. The structurally reinforcing intermediate layer is made of polypropylene or polyethylene nonwoven fabric with a basis weight of 15g / m²-40g / m² and a thickness of 50μm-150μm; The antibacterial inner layer is a polyvinyl alcohol-chitosan blend film loaded with a composite antibacterial agent, with a thickness of 10-30 μm, wherein the composite antibacterial agent is composed of inorganic antibacterial components and organic antibacterial components. The breathable and antibacterial outer layer, the structurally reinforced middle layer, and the antibacterial inner layer are laminated and fixed by hot melt adhesive bonding or hot pressing composite method.

2. The antibacterial drainage bag medical film according to claim 1, characterized in that, In the composite antibacterial agent, the inorganic antibacterial component is silver-loaded zeolite or nano zinc oxide, and the organic antibacterial component is polyhexamethylene biguanide or ε-polylysine. The mass ratio of the inorganic antibacterial component to the organic antibacterial component is 1:1 to 1:

4.

3. The antibacterial drainage bag medical film according to claim 1, characterized in that, In the antibacterial inner layer, the mass ratio of polyvinyl alcohol to chitosan is 4:1-9:1, and the amount of composite antibacterial agent added is 0.5%-5% of the total mass of polyvinyl alcohol and chitosan.

4. The antibacterial drainage bag medical film according to claim 1, characterized in that, The water vapor permeability of the polyurethane microporous membrane in the breathable and antibacterial outer layer is 500-2000 g / (m²·24h), and the bubble point is 0.05-0.20 MPa.

5. The antibacterial drainage bag medical film according to claim 1, characterized in that, The hot melt adhesive is one of ethylene-vinyl acetate copolymer, polyurethane hot melt adhesive or polyolefin hot melt adhesive, and the coating amount is 3-10 g / m².

6. A preparation process for an antibacterial drainage bag medical film according to any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1: Preparation of the breathable and antibacterial outer layer: Thermoplastic polyurethane is dissolved in an organic solvent to prepare a casting solution with a mass fraction of 8%-20%. The film is formed by non-solvent phase separation method, and the coagulation bath temperature is controlled at 20-40℃. After washing with water and drying, a polyurethane microporous membrane is obtained. Then, the membrane surface is subjected to plasma treatment or hydrophilic agent coating treatment. Step 2: Preparation of the antibacterial inner layer: Dissolve polyvinyl alcohol in deionized water to prepare a 3%-10% polyvinyl alcohol aqueous solution, and dissolve chitosan in a 1%-3% acetic acid aqueous solution to prepare a 1%-5% chitosan solution. Mix the two in proportion, add the composite antibacterial agent and stir evenly. After degassing, form a film using solution casting or blade coating. The drying temperature is 40-80℃ and the drying time is 2-8 hours to obtain the antibacterial inner layer film. Step 3, interlayer lamination: Using hot melt adhesive spraying or hot pressing lamination process, the breathable and antibacterial outer layer, the structurally reinforced middle layer and the antibacterial inner layer are sequentially laminated. The lamination temperature is 80-150℃ and the lamination pressure is 0.2-1.0MPa, thus obtaining the antibacterial drainage bag medical film.

7. The preparation process of the antibacterial drainage bag medical film according to claim 6, characterized in that, In step one, the organic solvent is one or more of dimethylformamide, dimethylacetamide, or tetrahydrofuran.

8. The preparation process of the antibacterial drainage bag medical film according to claim 6, characterized in that, In step one, the plasma treatment process parameters are: atmosphere is air or oxygen, treatment power is 50-300W, and treatment time is 30-180 seconds.

9. The preparation process of the antibacterial drainage bag medical film according to claim 6, characterized in that, In step three, the hot melt adhesive is applied using slit spraying or dot spraying, with a coating amount of 3-10 g / m².

10. An antibacterial drainage bag, characterized in that, The medical membrane for antibacterial drainage bags as described in any one of claims 1-5 or the medical membrane for antibacterial drainage bags prepared by the preparation process described in any one of claims 6-9.