Antibacterial blood bag and preparation method thereof

Abstract

The invention discloses an antibacterial blood bag and a preparation method thereof.The antibacterial blood bag comprises a blood bag body, a bionic self-repairing antibacterial surface and an environment adaptability adjusting film, the blood bag body is made of an improved material based on polylactic acid, and quaternary ammonium salt groups of a specific structure and content are introduced through a molecular grafting technology; the invention further discloses a preparation method of the antibacterial blood bag. The preparation method comprises the following steps of S1, material preparation, S2, main body material preparation, S3, bionic surface preparation and S4, adjusting film installation. According to the bionic self-repairing bacteriostatic surface microcapsule innovative design, a unique double-layer microcapsule structure is adopted, when the surface of the blood bag is slightly damaged, the microcapsule can rapidly flow out, the damaged position can be rapidly filled up, the integrity of the surface of the blood bag is recovered, the high-viscosity bacteriostatic repairing liquid packaged on the outer layer can continuously release bacteriostatic components in the follow-up process, and the effect of repairing the surface of the blood bag is achieved. The surface physical damage is repaired, and the antibacterial protection is enhanced.

Description

Technical Field

[0001] The present invention relates to the field of chemical engineering technology, and particularly to an antibacterial blood bag and a preparation method thereof. Background Art

[0002] The antibacterial blood bag is a new type of medical supply to ensure blood safety. It consists of a specially designed blood bag body, a bionic self-healing antibacterial surface, and an environmental adaptability adjustment membrane. During preparation, various materials are strictly screened and processed, and it is made through multiple fine processes. It has excellent antibacterial performance, can adapt to complex environments, has high biological safety, can effectively prevent blood from being contaminated during storage and transportation, and ensure blood transfusion safety.

[0003] In the field of medical blood transfusion, the performance of blood bags is extremely crucial for blood quality and blood transfusion safety. However, traditional blood bags have many deficiencies. In terms of surface protection, their materials are ordinary and lack a self-healing mechanism. During storage and transportation, blood bags are prone to minor damages due to friction and collision, providing channels for bacteria to invade. For example, scratches caused by mutual friction during long-distance transportation seriously threaten blood transfusion safety. In terms of antibacterial methods, they rely on adding antibacterial agents, and it is difficult to accurately control the dosage. Excessive dosage will affect blood components, and long-term use is likely to cause bacteria to develop drug resistance, and it is helpless against bacteria invading from the surface damage. Facing complex environments, traditional blood bags have poor adaptability. Temperature and humidity fluctuations will affect their performance. At high temperatures, the surface of blood bags is more easily damaged, and the bacteria multiply rapidly, while their surface cannot make effective responses. With the progress of medical technology, the requirements for blood bag safety are constantly increasing, and traditional blood bags are difficult to meet clinical needs. Accordingly, this application proposes an antibacterial blood bag and a preparation method thereof. Summary of the Invention

[0004] The purpose of the present invention is to solve the deficiencies existing in the prior art, and to propose an antibacterial blood bag and a preparation method thereof.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions: An antibacterial blood bag and a preparation method thereof, including a blood bag body, a bionic self-healing antibacterial surface, and an environmental adaptability adjustment membrane. The blood bag body uses a modified material based on polylactic acid, and specific structures and contents of quaternary ammonium salt groups are introduced through molecular grafting technology. And 0.5% - 1% of nanocrystalline cellulose whiskers are added to the polylactic acid material; For the bionic self-healing antibacterial surface, its microcapsules adopt a double-layer structure, with a low-viscosity repair liquid encapsulated in the inner layer and a high-viscosity repair liquid encapsulated in the outer layer, and reactive functional groups are introduced on the surface of the microcapsules; For the environmental adaptability adjustment membrane, it adopts a multi-layer composite structure. The middle layer is a temperature and humidity sensitive intelligent material, and the upper and lower layers are polymer materials with protection and strengthening functions, and an antistatic coating is coated on the surface.

[0006] Preferably, the weight-average molecular weight of the polylactic acid raw material of the blood bag body is 179,000 - 181,000, and the molecular weight distribution index is less than 1.28.

[0007] Preferably, the average particle size of the microcapsules on the bionic self-healing antibacterial surface is 7.0 ± 0.1 microns, and the coefficient of variation of the particle size is less than 3%.

[0008] Preferably, the average particle size of the microcapsules on the bionic self-healing antibacterial surface is 7.0 ± 0.1 microns, and the coefficient of variation of the particle size is less than 3%.

[0009] The preparation method of the antibacterial blood bag described above includes the following steps: S1. Material preparation: Perform vacuum drying treatment on the polylactic acid raw material, and detect the moisture content and volatile organic compound content; perform purity detection and structural analysis on the quaternary ammonium salt grafting reagent; screen microcapsules and polymer composites; evaluate the intelligent regulating membrane material; detect the performance of auxiliary materials; S2. Preparation of the main material: Put the treated polylactic acid raw material and quaternary ammonium salt grafting reagent into a reaction kettle for reaction, and extrude and form through an extruder with nine-zone temperature gradient control; S3. Preparation of the bionic surface: Perform surface activation treatment on the microcapsules, and coat and cure the polymer composite containing the activated microcapsules on the outer layer of the blood bag body; S4. Installation of the regulating membrane: Coat an adhesive on the outer layer of the blood bag body, install the intelligent regulating membrane and press and fit it thermally, and perform cooling treatment.

[0010] Preferably, the polylactic acid raw material is dried for 15 hours under the vacuum degree of -0.15 MPa and the temperature condition of 72 °C, and the moisture content is reduced to less than 0.006%.

[0011] Preferably, during the coating process of the bionic self-healing antibacterial surface, the spraying voltage is set at 55 kV, the distance between the spray gun and the blood bag body is kept at 20.3 - 20.5 cm, for a 500 ml blood bag, the spraying time is controlled within 7.4 - 7.6 minutes, and the coating thickness error is controlled within ±0.0015 mm.

[0012] Preferably, when installing the regulating membrane, the thermal pressing temperature is set at 129 - 131 °C, the pressure is 0.29 - 0.31 MPa, and the time is 1.54 - 1.56 minutes.

[0013] The present invention has the following beneficial effects: 1. Through precise molecular grafting technology: On the polylactic acid material of the blood bag body, specific quaternary ammonium salt groups with a precise structure and content are accurately introduced. This innovation endows the blood bag body with a powerful antibacterial ability. The quaternary ammonium salt groups can effectively damage the cell membrane structure of bacteria, hinder the metabolism and reproduction of bacteria, providing a first stable and long-lasting antibacterial defense line for the blood, greatly reducing the possibility of bacteria growing in the blood bag, and effectively ensuring the safety of blood storage.

[0014] 2. By means of the innovative design of microcapsules with bionic self-healing antibacterial surfaces: A unique double-layer microcapsule structure is adopted. The inner layer encapsulates a low-viscosity repair liquid, which can quickly flow out when the blood bag surface suffers minor damage, rapidly fill the damaged area, and restore the integrity of the blood bag surface. The high-viscosity antibacterial repair liquid encapsulated in the outer layer can continuously release antibacterial components subsequently, not only repairing the surface physical damage but also strengthening the antibacterial protection. This design not only improves the anti-damage ability of the blood bag surface but also can continuously inhibit bacteria during the service life of the blood bag, extending the safe storage time of the blood.

[0015] 3. Through the innovative design of the environmental adaptability adjustment membrane: It can automatically and continuously adjust its own pore size according to the changes in the external environmental temperature from 3°C to 68°C and humidity in the range of 8% - 100%. When in a high-temperature and high-humidity environment, the pore size becomes smaller, reducing the entry of water vapor and external pollutants; when in a low-temperature and dry environment, the pore size is appropriately adjusted to ensure the stability of the internal environment. The upper and lower layers of polymer materials enhance the mechanical properties of the adjustment membrane itself, making it more resistant to friction, puncture and other external forces, improving stability, extending the service life. At the same time, the antistatic coating on the surface effectively reduces the adsorption of dust particles and bacteria, further protecting the internal environment of the blood bag.

[0016] 4. Achieving multiple benefits through the innovative application of polylactic acid raw materials: Polylactic acid raw materials play a core role in the preparation of antibacterial blood bags, bringing significant benefits in many aspects. When the blood bag is discarded after use, polylactic acid can be gradually decomposed in the natural environment, greatly reducing the environmental pollution caused by the accumulation of a large number of discarded blood bags, reducing the subsequent environmental governance cost, and contributing to sustainable development. From the perspective of cost-benefit, the source of polylactic acid raw materials is relatively wide, and the price is more advantageous compared with some high-performance and difficult-to-degrade materials, which reduces the raw material procurement cost to a certain extent. Moreover, its good processing performance combined with the optimized production process further improves the production efficiency and reduces the comprehensive production cost. Brief Description of the Drawings

[0017] Figure 1 It is a schematic diagram of the preparation method steps of an antibacterial blood bag and its preparation method proposed by the present invention. Detailed Embodiments

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0019] Example 1: Preparation of standard-capacity blood bags Blood bag structure: To prepare a 500 ml standard-capacity blood bag, the main body of the blood bag is made of a modified material based on polylactic acid, and specific quaternary ammonium salt groups are introduced through molecular grafting technology. The microcapsules with a biomimetic self-healing antibacterial surface adopt a double-layer structure, with a low-viscosity repair liquid in the inner layer and a high-viscosity antibacterial repair liquid in the outer layer. The environmental adaptability adjustment membrane adopts a multi-layer composite structure, with a temperature- and humidity-sensitive intelligent material in the middle layer and polymer materials in the upper and lower layers.

[0020] Preparation method: Material preparation: Select polylactic acid raw materials with a weight-average molecular weight of 179,000 - 181,000 and a molecular weight distribution index of less than 1.28. After vacuum drying treatment as required, they are ready together with quaternary ammonium salt grafting reagents with a purity of over 99.99%. Microcapsules with an average particle size of 7.0 ± 0.1 microns and a structural integrity rate of over 99.98% and the adapted polymer composite materials are screened out. The intelligent adjustment membrane materials are tested in an environmental simulation test chamber, and all performance indicators meet the standards. Auxiliary materials such as organosilicon-modified acrylate adhesives and silane coupling agents have completed performance tests as specified.

[0021] Preparation of the main material: Put the treated polylactic acid raw materials and quaternary ammonium salt grafting reagents into the reaction kettle in precise proportions. At the initial stage of the reaction, the temperature is quickly raised to 190 °C, the pressure is stabilized at 0.62 MPa, and the stirring speed is 550 revolutions per minute. The reaction continues for 42 minutes. When the reaction reaches 63%, gradually lower the temperature to 170 °C, adjust the pressure to 0.38 MPa, and lower the stirring speed to 250 revolutions per minute. The reaction continues for 85 minutes to make the grafting rate stable at 33.5%. After the reaction is completed, extrusion molding is carried out through an extruder with nine-zone temperature gradient control, and the temperatures of each zone and other extrusion parameters are strictly controlled.

[0022] Preparation of the biomimetic surface: Activate and strengthen the surface of the microcapsules, stir in a 34 °C constant-temperature water bath for 6 hours to graft active groups. The polymer composite material containing the activated microcapsules is evenly coated on the outer layer of the blood bag main body through an improved high-voltage electrostatic spraying device. The spraying voltage is 55 kV, the distance is 20.4 cm, and the spraying time is 7.5 minutes. First, microwave curing is carried out, and then secondary hot air curing is carried out. The performance of the coating is detected according to the standards.

[0023] Adjustable membrane installation: Uniformly apply silicone-modified acrylate adhesive on the outer layer of the blood bag body, with a thickness of 0.0255 mm. After pre-drying, accurately place the intelligent adjustable membrane, and the hot-pressing and laminating temperature is 130 °C, the pressure is 0.3 MPa, and the time is 1.55 minutes. After the hot-pressing and laminating is completed, perform forced air cooling. The wind speed of the cooling fan is 6.4 m / s, the cooling temperature is 23.5 °C, and the cooling time is 13.8 minutes. Finally, conduct a comprehensive quality inspection.

[0024] Example 2: Customized large-capacity blood bag Blood bag structure: For the demand of 1000 ml large-capacity blood bags, 0.8% nanocellulose whiskers are added to the main material of the blood bag body, and the physical properties are enhanced to adapt to the storage pressure of large-capacity blood. The bionic self-healing antibacterial surface and the structure of the environmental adaptability adjustment membrane are the same as those of the standard-capacity blood bag, but the size is adjusted according to the size of the blood bag.

[0025] Preparation method: Material preparation: The selection and treatment of polylactic acid raw materials and other materials are the same as in Example 1. However, considering that the large-capacity blood bag has higher requirements for material properties, more strict tests are conducted on the thermal stability and chemical corrosion resistance of microcapsules and polymer composites.

[0026] Main body material preparation: The reaction parameters in the reaction kettle are basically the same as in Example 1. However, due to the increase in material usage, the stirring speed and reaction time in the reaction kettle are slightly adjusted. The initial stirring speed is 560 revolutions per minute, and the reaction time is 43 minutes. The subsequent stirring speed is 260 revolutions per minute, and the reaction time is 88 minutes to ensure uniform and sufficient reaction. During extrusion molding, the extrusion pressure and material flow rate are optimized to ensure that the thickness of the main body material of the blood bag is uniform and meets the strength requirements of the large-capacity blood bag.

[0027] Bionic surface preparation: The process parameters of microcapsule surface activation and coating are similar to those in Example 1. However, due to the increase in the surface area of the blood bag, the spraying time is appropriately extended to 9 minutes to ensure uniform coating coverage. In the curing process, according to the increase in coating thickness, the microwave curing and hot air secondary curing times are slightly adjusted to ensure the curing effect of the coating.

[0028] Adjustable membrane installation: Parameters such as the adhesive coating thickness, hot-pressing and laminating temperature, pressure, and time are adjusted accordingly according to the blood bag size and material usage to ensure that the intelligent adjustable membrane is tightly bonded to the blood bag body. During the cooling process, the cooling wind speed is appropriately increased to 6.5 m / s to ensure rapid and sufficient curing of the adhesive and enhance the bonding strength between the membrane and the blood bag body.

[0029] Example 3: Blood bag applicable to special environments Blood bag structure: To adapt to the special environment of high temperature and high humidity, a model with a faster response speed and a wider adjustment range is selected for the temperature and humidity sensitive intelligent material in the middle layer of the environmental adaptability adjustment membrane. The main body of the blood bag and the bionic self-repairing antibacterial surface structure remain unchanged, but more attention is paid to corrosion resistance in material selection.

[0030] Preparation method: Material preparation: Conduct more rigorous environmental simulation tests on the intelligent adjustment membrane material to ensure that under high temperature (68°C) and high humidity (100%) conditions, the water vapor transmission rate is reduced to less than 15% of the initial value, and the air permeability is reduced to less than 25% of the initial value. The screening and treatment of other materials are the same as in Example 1, but additional corrosion resistance tests are conducted on the polylactic acid raw material and the quaternary ammonium salt grafting reagent.

[0031] Preparation of the main body material: During the reaction process, appropriately increase the reaction temperature and pressure. The initial reaction temperature is 192°C and the pressure is 0.65 MPa to promote better reaction of the raw materials and improve the corrosion resistance of the main body material of the blood bag. When extrusion molding, adjust the temperature gradient to make the crystal structure of the main body material of the blood bag more compact, enhancing its physical properties and corrosion resistance.

[0032] Preparation of the bionic surface: Optimize the surface activation process of the microcapsules, increase the concentration of the silane coupling agent to 5%, and extend the stirring time to 7 hours to enhance the binding force between the microcapsules and the polymer composite material and improve the stability of the coating in a special environment. During the coating and curing process, strictly control the environmental temperature and humidity to avoid affecting the coating quality due to environmental factors.

[0033] Installation of the adjustment membrane: Select a more moisture and heat resistant type of adhesive, adjust the coating thickness to 0.0258 mm, and improve the bonding effect of the adhesive. Increase the hot pressing and laminating temperature to 132°C and the pressure to 0.32 MPa to ensure that the intelligent adjustment membrane and the main body of the blood bag can be closely bonded in a special environment. During the cooling process, closely monitor the temperature and stress changes on the surface of the blood bag to prevent deformation of the blood bag or detachment of the membrane due to temperature and humidity changes.

[0034] Example 4: Material substitution optimized blood bag Blood bag structure: A new type of polylactic acid copolymer is tried to replace the traditional polylactic acid material for the main body of the blood bag. This copolymer has better flexibility and processing performance. A new preparation process is used for the microcapsules on the bionic self-repairing antibacterial surface to make the particle size distribution of the microcapsules more uniform, and the average particle size is adjusted to 6.8 ± 0.1 microns. The structure of the environmental adaptability adjustment membrane remains unchanged, but the formula of the intelligent material in the middle layer is slightly adjusted to improve the sensitivity to temperature and humidity changes.

[0035] Preparation method: Material preparation: Conduct comprehensive performance tests on the new polylactic acid copolymer, including molecular weight, glass transition temperature, crystallinity and other indicators. Screen out microcapsules with more uniform particle size distribution, and test their structural integrity and surface properties. After the intelligent adjustment membrane material is adjusted according to the formula, re-test the environmental simulation to ensure that all performance requirements meet.

[0036] Preparation of main material: Since the reactivity of the new polylactic acid copolymer is different from that of traditional polylactic acid, the reaction temperature, pressure and stirring speed are re-optimized. The initial reaction temperature is 188°C, the pressure is 0.6MPa, and the stirring speed is 540 rpm. After 40 minutes of reaction, the temperature is adjusted to 168°C, the pressure is 0.36MPa, and the stirring speed is 240 rpm. The reaction lasts for 82 minutes. During extrusion molding, the temperature gradient and screw parameters are adjusted according to the rheological properties of the material to ensure the quality of the main material of the blood bag.

[0037] Bionic surface preparation: The microcapsule surface activation process is adjusted according to its new characteristics, and the time and frequency of the ultrasonic disperser are optimized to improve the reaction effect between the microcapsules and the silane coupling agent. In the coating process, the spraying voltage and the distance between the spray gun and the blood bag body are adjusted to ensure the uniformity of the coating. The curing process adjusts the microwave power and curing time according to the changes in microcapsule particle size and material properties, as well as the temperature and time of hot air secondary curing.

[0038] Adjustment film installation: The choice of adhesive is adjusted according to the characteristics of the new blood bag main body material and the intelligent adjustment film material to ensure good bonding effect. Parameters such as coating thickness, hot pressing lamination temperature, pressure and time are optimized accordingly according to material changes to ensure that the intelligent adjustment film fits tightly with the blood bag main body. During the cooling process, pay close attention to the changes in the physical properties of the blood bag to ensure the stable quality of the blood bag.

[0039] Example 5: Preparation of cost-controlled blood bags Blood bag structure: Under the premise of ensuring the performance of the blood bag body, the proportion of nanocellulose whiskers added is appropriately reduced to 0.6% to reduce material costs. The bionic self-repairing antibacterial surface and environmental adaptability regulating membrane structure remain unchanged, but in terms of material selection, products with higher cost performance are preferred.

[0040] Preparation method: Material preparation: The selection and processing of materials such as polylactic acid raw materials and quaternary ammonium salt grafting agents are the same as those in Example 1. However, when selecting microcapsules, polymer composite materials, and intelligent regulating membrane materials, on the basis of meeting performance requirements, multiple suppliers are compared to select products with more reasonable prices. Cost-benefit analysis is performed on auxiliary materials to ensure that costs are reduced without affecting quality.

[0041] Preparation of the main body material: The reaction process and the extrusion molding process parameters are basically the same as those in Example 1. However, on the premise of ensuring product quality, the reaction time is appropriately shortened and the energy consumption is reduced. For example, the initial reaction time is shortened to 40 minutes, and the subsequent reaction time is shortened to 80 minutes. During extrusion molding, the temperature control is optimized to reduce energy waste.

[0042] Preparation of the bionic surface: On the basis of ensuring quality, the process parameters of surface activation, coating, and curing of the microcapsules are optimized to reduce raw material and energy consumption. For example, during the surface activation process of the microcapsules, the concentration of the silane coupling agent is reduced to 4.2%, but the activation effect is ensured by extending the stirring time to 6.5 hours. During the coating process, the spray gun parameters are optimized to reduce material waste. In the curing process, the microwave power and hot air temperature are reasonably adjusted to shorten the curing time and improve production efficiency.

[0043] Adjustable membrane installation: On the premise of ensuring the bonding quality, the process parameters of adhesive coating and hot press bonding are optimized to reduce costs. For example, the thickness of the adhesive coating is appropriately reduced to 0.0253 mm, the hot press bonding temperature is adjusted to 128 °C, the pressure is 0.28 MPa, and the time is 1.53 minutes. During the cooling process, the cooling equipment and process are reasonably selected to reduce energy consumption. In the quality inspection link, the inspection process is optimized to reduce unnecessary inspection items, improve inspection efficiency, and reduce inspection costs.

[0044] Table 1: Matrix of material properties and bionic functions (unit: % / μm / MPa, ±SD is the standard deviation, and the coefficient of variation CV% is in ()) Table 1: Material properties and bionic functions

[0045] 1. Grafting rate: In Examples 1 to 5, antibacterial properties are achieved through quaternary ammonium salt grafting. 33% ± 1% is the stable industrial value (there is no grafting in the comparative example). In Example 3, due to the high-temperature reaction (192 °C), the grafting rate is the highest (34.0%), but the fluctuation needs to be controlled within ±1.0% (±1.5% in actual factories). 2. Microcapsule particle size: 7.0 μm is the optimal particle size for bionic repair (Biomaterials 2024, 45: 123). In Example 4, the particle size is reduced to 6.8 μm through a new process (CV% = 1.5%, excellent in the industry <2%). In the comparative example, there are no microcapsules, and the self-healing rate is 0% (clinically, it is scrapped when punctured).

[0046] 3. Bacteriostatic rate (log reduction): 3 log = 99.9% (the passing line of ISO 22196), and all of Examples 1 - 5 meet the standard. Example 3 is against Pseudomonas aeruginosa (a high - humidity pathogenic bacterium), and its bacteriostatic rate is 3.5 log (exceeding the national standard by 0.5 log). In Comparative Example 2, due to its rough surface (without coating), the bacterial survival rate is even higher than that of traditional PVC (0.5 log vs 0.3 log). 4. Self - repair rate: A 0.2 - mm needle puncture is used to simulate clinical misoperation, and the repair is carried out at 37°C to simulate the human body temperature. In Example 3, due to the high - temperature acceleration of the release of the repair liquid (68°C pretreatment process), the repair rate is the highest (95.8%), and the ±2.5% fluctuation comes from the uneven distribution of microcapsules.

[0047] It should be noted that in terms of material properties and bionic functions, the examples show incomparable advantages. In terms of the grafting rate, the examples are in the range of 32.7% - 34.0% (±1.0%), and this ratio enables the material to have antibacterial ability. Taking Example 3 as an example, through specific process conditions, a grafting rate of 34.0% is achieved, which can effectively inhibit the growth of bacteria. While the grafting rate of the comparative example is 0%, and it completely lacks the basis for this active antibacterial ability.

[0048] Furthermore, in terms of the bacteriostatic rate, the examples can reach 3.0 - 3.5 log, which means that 99.9% or more of the bacteria can be killed. For example, in Example 2, with the optimized grafting process and material formula, the bacteriostatic rate reaches 3.3 log, which can effectively inhibit the growth of common bacteria. In contrast, the bacteriostatic rate of the comparative example is only 0.3 - 0.5 log, and the bacterial survival rate is as high as over 70%. The bacteriostatic rate of Comparative Example 1 is 0.3 log, and a large number of bacteria survive and reproduce on its surface, greatly increasing the risk of blood contamination.

[0049] Furthermore, the self - repair rate is another prominent advantage of the examples, and its range is 90.2% - 95.8%. This means that when the blood bag is punctured by a 0.2 - mm needle, in an environment of 37°C, most blood bags can achieve self - repair. For example, in Example 3, due to the use of special microcapsule materials and distribution processes, the self - repair rate can reach 95.8%, greatly reducing the risk of blood leakage caused by accidental puncture of the blood bag. While the self - repair rate of the comparative example is 0%, and once punctured, the blood will surely leak, which is a very serious problem in clinical applications.

[0050] Furthermore, the particle size of the microcapsules plays a crucial role in bionic repair. The particle size of the examples is 6.8 - 7.1 μm (CV ≤ 1.6%), and this precisely controlled particle size distribution provides stable and effective structural support for bionic repair. Taking Example 4 as an example, by improving the microcapsule preparation process, a particle size of 6.8 μm (CV = 1.5%) was achieved, enabling the repair material to function more uniformly and efficiently when the blood bag is damaged. The comparative example does not have this key structure, so the self-repair function of the blood bag cannot be achieved.

[0051] Table 2: Physical Property and Cost Data Matrix (unit: MPa / ml / yuan, ±SD is production fluctuation, and the values in () are design values) Table 2: Physical Properties and Costs

[0052] 1. Tensile strength: Example 2 (57.6 MPa) is enhanced by 0.8% nanocrystalline cellulose whiskers, exceeding the industry standard (≥30 MPa), and meeting the 1000 ml large-capacity drop test (no rupture at 1.2 m). Comparative Example 1 (24.5 MPa) only reaches the lower limit of the national standard and is prone to rupture during clinical filling (burst volume - 4%).

[0053] 2. High-temperature hemolysis rate: The national standard is ≤0.8%. Example 1 (0.78%) is just qualified, and Example 5 (0.91%#) requires additional clinical verification (hospitals accept ≤1.0%). The test conditions for Example 3 are 68°C / 7 days (exceeding the normal 40°C), and the hemolysis rate is 0.48% to verify the stability in extreme environments.

[0054] 3. Burst volume: The designed burst volume of Example 2 is 1000 ml, and the actual measurement is 1060 ml (+6% safety redundancy), meeting the AABB requirement of "nominal volume + 5 - 10%". Comparative Example 2 (950 ml) has a - 5% deviation, and the clinical rejection rate is 12% (referring to the 2023 notice of the National Medical Products Administration). 4. Cost coefficient: Based on Comparative Example 1 (12 yuan), Example 5 (15.8 yuan) reduces costs by 15%, and the yield is 98.5% (the industry average is 96%), achieving a balance between cost and quality.

[0055] Comparative Example 2 (7.8 yuan) omits the core process, and the yield is only 85.7%. The hidden rework cost exceeds 30% of the selling price.

[0056] It should be noted that in terms of physical properties and cost, the embodiments also perform excellently. In terms of tensile strength, the range of the embodiments is 40.2 - 57.6 MPa (≥40 MPa). In Embodiment 2, by adding reinforcing materials such as nanocrystalline cellulose whiskers in a specific proportion, the tensile strength reaches 57.6 MPa, which can withstand greater external forces and ensure the integrity of the blood bag during storage and transportation. In contrast, the tensile strength of the comparative examples is only 24.5 - 27.8 MPa (<30 MPa), and the tensile strength of Comparative Example 1 is 24.5 MPa, far lower than that of the embodiments, and problems such as rupture are more likely to occur in actual use.

[0057] Furthermore, the high-temperature hemolysis rate is an important indicator to measure the safety of the blood bag. The embodiments are in the range of 0.48% - 0.91% (≤0.8% is qualified). Embodiment 3 optimized the materials for high-temperature and high-humidity environments. In a high-humidity environment at 68°C, the hemolysis rate is only 0.48%, effectively ensuring the quality of blood in special environments. The high-temperature hemolysis rate of the comparative examples is as high as 4.3% - 5.2%, exceeding the standard by 5 - 6 times. The hemolysis rate of Comparative Example 1 is 5.2%, which will cause a large number of red blood cells to rupture, seriously affecting the blood quality and unable to meet the clinical use requirements.

[0058] Furthermore, in terms of burst volume, the embodiments are in the range of 510 - 1060 ml (with a 2% - 6% redundancy). Embodiment 2 is designed as a 1000-ml blood bag, and the actual burst volume reaches 1060 ml, with a 6% safety redundancy, which can cope with possible pressure changes and other situations. The comparative examples are in the range of 480 - 950 ml (with a 4% - 5% shortage). Comparative Example 2 is designed as a 1000-ml blood bag, but the actual burst volume is only 950 ml, with a 5% shortage. This may cause the blood bag to rupture due to insufficient pressure bearing during clinical use, resulting in blood leakage.

[0059] Furthermore, in terms of the cost coefficient, the embodiments are in the range of 15.8 - 25.1 yuan (32% - 109% higher than the benchmark). Embodiment 5 optimized the material formula and production process, with a cost of 15.8 yuan, only 32% higher than the cost of 12 yuan of traditional Comparative Example 1, but it can achieve all core functions, including antibacterial, self-repair, good physical properties, etc. The comparative examples are in the range of 7.8 - 12 yuan. Although the cost of Comparative Example 2 is as low as 7.8 yuan, saving 35% of the cost, almost all functions are lost, and it cannot meet the clinical requirements for the safety and functionality of the blood bag.

[0060] Furthermore, in terms of production yield, the examples are in the range of 95.8% - 98.5% (ranking in the top 3% of the industry). Through refined production management and quality control, the production yield of Example 5 reaches 98.5%, greatly reducing the defective rate, improving production efficiency and economic benefits. In contrast, the comparative examples are in the range of 85.7% - 92.3%, and the production yield of Comparative Example 2 is only 85.7%, with a relatively high unqualified rate, which not only increases production costs but also may bring serious medical risks due to unqualified products flowing into the market.

[0061] Furthermore, generally speaking, the examples comprehensively outperform the comparative examples in terms of material properties, bionic functions, physical properties, and cost control. Relying on unique grafting techniques, precisely controlled microcapsule structures, reasonable material formulations, and process optimization, the examples achieve powerful antibacterial and self-healing functions, and at the same time perform excellently in physical property indicators such as strength, hemolysis control, and bursting volume. In terms of cost, although it is relatively higher than that of the comparative examples, it is within an acceptable range, and a high production yield is maintained. On the contrary, the comparative examples lack functions seriously and do not meet the physical property standards. Despite the low cost, due to huge hidden losses, such as production waste caused by a high unqualified rate, medical risks brought by blood pollution and leakage, etc., their comprehensive performance lags far behind that of the examples.

[0062] As described above, only the preferred specific embodiments of the present invention are provided, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes should be covered by the protection scope of the present invention.

Claims

1. An antibacterial blood bag, comprising a blood bag body, a bionic self-repairing antibacterial surface, and an environmental adaptability regulating membrane, characterized in that: The blood bag body adopts a modified material based on polylactic acid, and a quaternary ammonium salt group with a specific structure and content is introduced through molecular grafting technology, and 0.5%-1% nanocellulose whiskers are added to the polylactic acid material; The bionic self-repairing antibacterial surface has a double-layer structure in which the microcapsules are encapsulated with a low-viscosity repair liquid in the inner layer and a high-viscosity repair liquid in the outer layer, and reactive functional groups are introduced into the surface of the microcapsules; The environmental adaptability regulating film adopts a multi-layer composite structure, the middle layer is a temperature and humidity sensitive intelligent material, the upper and lower layers are polymer materials with protective and reinforcing effects, and the surface is coated with an antistatic coating.

2. The antibacterial blood bag according to claim 1, characterized in that: The weight average molecular weight of the polylactic acid raw material of the blood bag body is between 179,000 and 181,000, and the molecular weight distribution index is less than 1.

28.

3. The antibacterial blood bag according to claim 1, characterized in that: The average particle size of the microcapsules on the bionic self-repairing antibacterial surface is 7.0±0.1 microns, and the coefficient of variation of the particle size is less than 3%.

4. The antibacterial blood bag according to claim 1, characterized in that: The average particle size of the microcapsules on the bionic self-repairing antibacterial surface is 7.0±0.1 microns, and the coefficient of variation of the particle size is less than 3%.

5. A method for preparing an antibacterial blood bag according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Material preparation: vacuum drying of polylactic acid raw materials, testing of moisture content and volatile organic compound content; purity testing and structural analysis of quaternary ammonium salt grafting reagents; screening of microcapsules and polymer composite materials; evaluation of intelligent regulating membrane materials; testing of auxiliary material performance; S2, preparation of main material: putting the treated polylactic acid raw material and quaternary ammonium salt grafting reagent into a reactor for reaction, and extruding and molding through an extruder with nine-zone temperature gradient control; S3, bionic surface preparation: performing surface activation treatment on the microcapsules, coating the polymer composite material containing the activated microcapsules on the outer layer of the blood bag body and curing; S4. Adjustment film installation: Apply adhesive to the outer layer of the blood bag body, install the intelligent adjustment film, hot press and fit, and cool it.

6. The method for preparing an antibacterial blood bag according to claim 5, characterized in that: The polylactic acid raw material was dried for 15 hours at a vacuum degree of -0.15 MPa and a temperature of 72° C., and the moisture content was reduced to below 0.006%.

7. The method for preparing an antibacterial blood bag according to claim 5, characterized in that: During the coating process of the bionic self-repairing antibacterial surface, the spraying voltage was set to 55 kV, the distance between the spray gun and the blood bag body was maintained at 20.3-20.5 cm, for a 500 ml blood bag, the spraying time was controlled at 7.4-7.6 minutes, and the coating thickness error was controlled within ±0.0015 mm.

8. The method for preparing an antibacterial blood bag according to claim 5, characterized in that: When the adjustment film is installed, the hot pressing temperature is set to 129 - 131°C, the pressure is set to 0.29 - 0.31MPa, and the time is set to 1.54 - 1.56 minutes.

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