Disposable vacuum filtration sterilization device

Abstract

The application discloses a disposable vacuum filtration and sterilization device. The device comprises a filter cup, a connector, a receiving bottle, a suction filter nozzle and a polyether sulfone microporous sterilization filter membrane. The polyether sulfone microporous sterilization filter membrane is placed on a filter membrane placement table. The polyether sulfone microporous sterilization filter membrane is a square corresponding to the size of the filter membrane placement table. The upper surface of the polyether sulfone microporous sterilization filter membrane is a filter layer, and the lower surface is a separation layer. The average pore size of the filter layer is smaller than that of the separation layer. The device structure and the filter membrane of the vacuum filtration and sterilization device are improved. The device has good sterilization effect and high filtration flux.

Description

Technical Field

[0001] This invention belongs to the field of vacuum filtration technology, specifically relating to a disposable vacuum filtration and sterilization device. Background Technology

[0002] In biological research laboratories, many experimental steps involve the handling of biological fluids. These include sterile filtration of culture media, sterile filtration of buffer solutions, protective clarification filtration before ultrafiltration for sample concentration, and sterile filtration of the final sample. Currently, commonly used filtration methods include atmospheric pressure filtration, pressurized filtration, reduced pressure filtration, and centrifugal filtration, with reduced pressure filtration being the most prevalent. Reduced pressure filtration often utilizes vacuum filtration devices. A typical vacuum filtration device consists of a filter cup, a cup lid, a filter membrane, a filtrate receiving bottle, and connecting devices. Its working principle is to use a vacuum pump to provide a pressure difference, forcing the filtrate through the filter membrane, while solid particles, impurities, and bacteria are retained on the membrane, thus achieving separation.

[0003] In biological sterilization filtration experiments, the sterility and sterilization performance of the filtration device are crucial. Existing non-disposable vacuum filtration devices require high-temperature, high-pressure sterilization before use, and the filter membrane must be assembled onto the connecting device before each filtration. During assembly, membrane misalignment or improper connection can easily occur, leading to leakage and failure of sterile filtration. Disposable pre-sterilized vacuum filtration devices equipped with sterile filter membranes avoid these problems, ensuring sterility and sterilization, and making experimental operations simple, quick, and convenient.

[0004] Currently available disposable vacuum filtration devices are diverse, all possessing the advantages of simplicity and speed, leading to their increasingly widespread application. However, existing disposable vacuum filtration devices generally suffer from problems such as small effective filtration area of ​​the filter membrane, low filtration efficiency, and low filtration flux. Furthermore, the insufficient asymmetry of the filter membranes used in existing vacuum filtration devices results in inadequate filtration flux, further impacting the overall filtration capacity of the vacuum filtration system. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a disposable vacuum filtration and sterilization device with good sterilization effect and high filtration throughput.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention discloses a disposable vacuum filtration sterilization device, which includes a filter cup, a connector, a receiving bottle, a suction nozzle, and a polyethersulfone microporous sterilization filter membrane.

[0008] The bottom of the filter cup is recessed downward to form a filter membrane placement platform for placing the filter membrane. The filter membrane placement platform is square, and the edges of the filter membrane placement platform are used to fit the edges of the filter membrane. The middle part of the filter membrane placement platform is further recessed downward to form a filtrate guiding area. The filtrate guiding area has an increasing depth of recess from the edge to the center. The filtrate guiding area is provided with guiding ribs extending from the edge to the center. A filtrate hole is opened in the center of the filtrate guiding area, and the filtrate hole extends downward to form a filtrate outlet pipe.

[0009] The connector includes an upper interface and a lower interface that are interconnected. The upper interface is sleeved and connected to the filtrate outlet pipe, and the lower interface is sleeved and connected to the mouth of the receiving bottle.

[0010] The filter nozzle is used to connect to the air extraction pipeline, and the filter nozzle is connected to the connector.

[0011] The polyethersulfone microporous sterilizing filter membrane is placed on a filter membrane placement platform. The polyethersulfone microporous sterilizing filter membrane is a square corresponding to the size of the filter membrane placement platform. The upper surface of the polyethersulfone microporous sterilizing filter membrane is a filter layer, and the lower surface is a separation layer. The average pore size of the filter layer is smaller than the average pore size of the separation layer.

[0012] As a preferred technical solution, the guide ribs are arranged at long and short intervals within the filtrate guiding zone.

[0013] As a preferred technical solution, the filtrate guiding zone is further provided with reinforcing support ribs that span the filtrate guiding zone.

[0014] As a preferred technical solution, the polyethersulfone microporous antibacterial filter membrane is prepared by the following method:

[0015] (1) Dissolve polyethersulfone in a solvent and add a pore-forming agent, mix well to obtain a casting solution;

[0016] (2) The casting solution obtained in step (1) is scraped to form a liquid film;

[0017] (3) The upper surface of the liquid film obtained in step (2) is swept with cold air at 2-10℃, and the lower surface is heated with a graphene heating module at 30-60℃.

[0018] (4) The liquid membrane treated in step (3) is passed through a steam box with a humidity of 40-80% to obtain a nascent membrane;

[0019] (5) The nascent membrane obtained in step (4) is solidified into a membrane by water bath, and then washed and dried to obtain a polyethersulfone microporous antibacterial filter membrane.

[0020] As a preferred technical solution, the solvent is one or more of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylformamide, and dimethyl sulfoxide; the porogen is one or two of polyethylene glycol and polyvinylpyrrolidone.

[0021] As a preferred technical solution, the casting solution comprises, by weight, 10-30 parts polyethersulfone, 30-60 parts pore-forming agent, and 10-60 parts solvent.

[0022] The beneficial effects of this invention are as follows:

[0023] This invention improves both the device structure and the filter membrane of the vacuum filtration sterilization device:

[0024] In terms of device structure, the present invention sets the filter membrane placement platform at the bottom of the filter cup to be square. With the filter cup diameter unchanged, the effective filtration area of ​​the filter membrane can be increased by more than 20%. At the same time, the middle part of the filter membrane placement platform is further recessed to form a filtrate guiding area. The filtrate guiding area is provided with guiding ribs, which can further improve filtration efficiency and increase filtration throughput.

[0025] Regarding the filter membrane, this invention employs a unique hot-cold interaction system to prepare an asymmetric polyethersulfone microporous sterilization filter membrane. During the membrane preparation process, the lower surface of the membrane is heated using a graphene heating module (temperature controlled at 30-60℃) to reduce the phase separation rate; the upper surface of the membrane is purged with cold air (2-10℃) to accelerate the surface phase separation rate. This results in a filter membrane with high porosity, high hydrophilicity, and high asymmetry. A filter layer with smaller pore size is formed on the upper surface of the membrane, while a separation layer with larger pore size is formed on the lower surface. Filter membranes with this structure have good sterilization effect and high filtration flux. Attached Figure Description

[0026] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration:

[0027] Figure 1 This is a schematic diagram of the structure of the disposable vacuum filtration sterilization device of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of the disposable vacuum filtration sterilization device of the present invention (with the cup lid and filter membrane removed);

[0029] Figure 3 for Figure 2 A longitudinal sectional view;

[0030] Figure 4 This is a cross-sectional SEM image of the polyethersulfone microporous antibacterial filter membrane prepared in Example 1;

[0031] Figure 5This is a SEM image of the lower surface of the polyethersulfone microporous antibacterial filter membrane prepared in Example 1;

[0032] Figure 6 SEM image of the upper surface of the polyethersulfone microporous antibacterial filter membrane prepared in Example 1;

[0033] Figure 7 This is a cross-sectional SEM image of the polyethersulfone microporous antibacterial filter membrane prepared in Example 2;

[0034] Figure 8 This is a SEM image of the lower surface of the polyethersulfone microporous antibacterial filter membrane prepared in Example 2;

[0035] Figure 9 This is a SEM image of the upper surface of the polyethersulfone microporous antibacterial filter membrane prepared in Example 2. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0037] like Figures 1 to 3 The disposable vacuum filtration sterilization device shown includes a filter cup 1, a connector 2, a receiving bottle 3, a suction nozzle 4, and a polyethersulfone microporous sterilization filter membrane.

[0038] The top opening of the filter cup 1 is covered with a cup lid 5. The bottom of the filter cup 1 is recessed downward to form a filter membrane placement platform 6 for placing the filter membrane. The filter membrane placement platform 6 is square. The edges of the filter membrane placement platform 6 are used to fit the edges of the filter membrane. The middle of the filter membrane placement platform 6 is further recessed downward to form a filtrate guiding area 7. The filtrate guiding area 7 is recessed deeper from the edge to the center. The filtrate guiding area 7 is provided with guide ribs 8 extending from the edge to the center. The guide ribs 8 are arranged at intervals of different lengths in the filtrate guiding area 7. The filtrate guiding area 7 is also provided with reinforcing support ribs 9 that span the filtrate guiding area 7. The filtrate guiding area 7 has a filtrate hole 10 in the center. The filtrate hole 10 extends downward to form a filtrate outlet pipe 11. The filtrate outlet pipe 11 has a guide rod 12 in the center.

[0039] The connector 2 includes an upper interface 13 and a lower interface 14 that are interconnected. The upper interface 13 is fitted and snapped into the filtrate outlet pipe 11, and the lower interface 14 is fitted and threaded into the mouth of the receiving bottle 3.

[0040] The filter nozzle 4 is used to connect to the air extraction pipeline, and the filter nozzle 4 is connected to the connector 2.

[0041] The filter cup 1 and the receiving bottle 3 are respectively provided with volume scales for easy observation during the filtration process; the receiving bottle 3 is provided with a recessed part 15 for easy gripping and handling.

[0042] The polyethersulfone microporous sterilizing filter membrane is placed on the filter membrane placement platform 6. The polyethersulfone microporous sterilizing filter membrane is a square corresponding to the size of the filter membrane placement platform. The upper surface of the polyethersulfone microporous sterilizing filter membrane is a filter layer, and the lower surface is a separation layer. The average pore size of the filter layer is smaller than the average pore size of the separation layer.

[0043] In this invention, the polyethersulfone microporous antibacterial filter membrane is prepared by the following method:

[0044] Example 1

[0045] (1) Mix 15g polyethersulfone, 8g polyvinylpyrrolidone, 37g polyethylene glycol and 40g N-methylpyrrolidone, heat and stir at 60°C for 8 hours until uniform and clear, forming a liquid film, seal and store for 24 hours.

[0046] (2) The obtained homogeneous casting solution is applied to the release film using a 300μm doctor blade to form a liquid film;

[0047] (3) The upper surface of the liquid film is swept with 2℃ cold air and the lower surface is heated with a 60℃ graphene heating module;

[0048] (4) Pass the liquid membrane after cold and heat treatment through a steam box with a humidity of 70% to obtain a nascent membrane;

[0049] (5) The nascent membrane was cured in a pure water bath at 30°C, then washed and dried to obtain a polyethersulfone microporous antibacterial filter membrane.

[0050] Flow rate and bubble point tests: The bubble point pressure (test liquid was deionized water) and flux (test liquid was deionized water) of the filter membrane prepared in Example 1 were tested according to GB / T32361-2015 "Test Method for Pore Size of Separation Membranes - Bubble Point and Average Flow Rate Method". The test results showed that the pure water flux was 25 ml / min / cm. 2 -10 psi, bubble point is 0.39~0.40 MPa.

[0051] Figure 4 This is a cross-sectional SEM image of the polyethersulfone microporous antibacterial filter membrane prepared in Example 1. Figure 5 This is a SEM image of the lower surface of the polyethersulfone microporous antibacterial filter membrane prepared in Example 1. Figure 6 The image shows a SEM image of the upper surface of the polyethersulfone microporous antibacterial filter membrane prepared in Example 1. As can be seen from the image, a filter layer with smaller pore size is formed on the upper surface of the filter membrane, and a separation layer with larger pore size is formed on the lower surface.

[0052] Example 2

[0053] (1) Mix 12g polyethersulfone, 10g polyvinylpyrrolidone, 43g polyethylene glycol and 35g N-methylpyrrolidone, heat and stir at 60°C for 8 hours until uniform and clear, forming a liquid film, seal and store for 24 hours.

[0054] (2) The obtained homogeneous casting solution is applied to the release film using a 300μm doctor blade to form a liquid film;

[0055] (3) The upper surface of the liquid film is swept with 10°C cold air and the lower surface is heated with a 30°C graphene heating module;

[0056] (4) Pass the liquid membrane after cold and heat treatment through a steam box with a humidity of 70% to obtain a nascent membrane;

[0057] (5) The nascent membrane was cured in a pure water bath at 30°C, then washed and dried to obtain a polyethersulfone microporous antibacterial filter membrane.

[0058] Flow rate and bubble point tests: The bubble point pressure (test liquid was deionized water) and flux (test liquid was deionized water) of the filter membrane prepared in Example 2 were tested according to GB / T32361-2015 "Test Method for Pore Size of Separation Membranes - Bubble Point and Average Flow Rate Method". The test results showed that the pure water flux was 20 ml / min / cm. 2 -10 psi, bubble point is 0.37~0.38 MPa.

[0059] Figure 7 This is a cross-sectional SEM image of the polyethersulfone microporous antibacterial filter membrane prepared in Example 2. Figure 8 This is a SEM image of the lower surface of the polyethersulfone microporous antibacterial filter membrane prepared in Example 2. Figure 9 The image shows an SEM image of the upper surface of the polyethersulfone microporous antibacterial filter membrane prepared in Example 2. As can be seen from the image, a filter layer with smaller pore size is formed on the upper surface of the filter membrane, and a separation layer with larger pore size is formed on the lower surface.

[0060] Example 3

[0061] (1) Mix 12g polyethersulfone, 10g polyvinylpyrrolidone, 40g polyethylene glycol and 38g N-methylpyrrolidone, heat and stir at 60°C for 8 hours until uniform and clear, forming a liquid film, seal and store for 24 hours.

[0062] (2) The obtained homogeneous casting solution is applied to the release film using a 300μm doctor blade to form a liquid film;

[0063] (3) The upper surface of the liquid film is swept with 8°C cold air and the lower surface is heated with a 30°C graphene heating module;

[0064] (4) Pass the liquid membrane after cold and heat treatment through a steam box with a humidity of 70% to obtain a nascent membrane;

[0065] (5) The nascent membrane was cured in a pure water bath at 30°C, then washed and dried to obtain a polyethersulfone microporous antibacterial filter membrane.

[0066] Flow rate and bubble point tests: The bubble point pressure (test liquid was deionized water) and flux (test liquid was deionized water) of the filter membrane prepared in Example 3 were tested according to GB / T32361-2015 "Test Method for Pore Size of Separation Membranes - Bubble Point and Average Flow Rate Method". The test results showed that the pure water flux was 22 ml / min / cm. 2 -10 psi, bubble point is 0.34~0.36 MPa.

[0067] Example 4

[0068] The disposable vacuum filtration sterilization device was subjected to a bacterial challenge test by our CINAS-accredited laboratory (filter membrane samples 1-3 used in the bacterial challenge test were polyethersulfone microporous sterilization filter membranes prepared in Examples 1-3, respectively):

[0069] Bacterial strain: The strain used for the 0.22μm challenge was Pseudomonas quinquefolius (ATCC19146).

[0070] Bacterial colony counting: Take eight 10mL sterile centrifuge tubes, add 4.5mL of sterile physiological saline to each tube, thoroughly mix the bacterial solution in the reagent bottle, and aseptically pipette 0.5mL into the first 10mL centrifuge tube. Mix thoroughly, and then perform serial dilutions 10-fold. After each dilution, mix thoroughly using a vortex mixer before proceeding to the next serial dilution. Take three dilutions (e.g., 10⁴, 10⁵, 10⁶), and plate 100μL of each dilution onto two plates. Incubate at 30°C for 48 hours, then count the colonies. Plates with more than 300 colonies or fewer than 10 colonies are invalid. Calculate the bacterial concentration.

[0071] For detailed instructions on colony counting, please refer to GB 4789.2-2016. After incubation, the bacterial culture can be stored in a refrigerator at 4 degrees Celsius. If the culture exceeds one week, the colony count needs to be repeated.

[0072] Bacterial Challenge: Filter 1000mL per filter cup, challenge bacterial count must be at least 10. 7 CFU / cm 2 Calculate the required bacterial culture volume, which is 495 μL. Transfer the diluted bacterial culture into a filter cup. Use an MCE045 small filter cup to detect bacterial retention in the filtrate. After vacuum filtration, remove the membrane with tweezers and place it on a TSA culture dish. Incubate at 30°C. Observe the plates on the third and seventh days to observe the bacterial growth on each filter membrane.

[0073] The initial bacterial concentration was 1.3*10. 9 CFU / mL, effective membrane area of ​​filter is 64 cm² 2 Each filter cup should be challenged with at least 64*10 bacteria. 7 CFU. For each filter cup that filters 1000 mL of bacterial suspension, 495 μL of bacterial suspension is taken from the initial bacterial suspension and added to 1000 mL of sterile physiological saline.

[0074] Positive and Negative Challenges: A negative control test was conducted before the filter bacterial challenge. 500 mL of sterile saline was pumped through a sterile filter using a peristaltic pump, and the filtrate was collected. The filtrate was then tested for bacterial retention using an MCE045 small filter cup. After vacuum filtration, the membrane was removed with forceps and placed on a TSA culture dish for incubation at 30°C. The plates were observed on days three and seven. A positive control test was conducted after the filter bacterial challenge. The filter was replaced with a 0.45 mm pore size filter, and the test was performed according to the bacterial challenge procedure and conditions. The plates were observed on the second day.

[0075] Acceptable criteria for bacterial challenges:

[0076] The final bacterial challenge level is no less than 1×10⁻⁶. 7 cfu / cm 2 EFA.

[0077] The negative control showed no bacterial growth, while the positive control showed bacterial growth (referring to defective shortwave monoclonal bacteria).

[0078] No bacteria grew in the filtrate.

[0079] Experimental results and conclusions:

[0080]

[0081] Experimental conclusion: The amount of bacteria used in the bacterial challenge is sufficient to ensure that the EFA of the filter cup is ≥10. 7 cfu / cm 2 The standard is that the filtrate shows no bacterial growth, the negative control shows no bacterial growth, and the positive control shows bacterial growth (referring to the defective pseudomonad ATCC19146).

[0082] Based on the above experimental results, it can be concluded that the disposable vacuum filtration sterilization device in this bacterial challenge test can achieve the sterilization level.

[0083] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A disposable vacuum filter sterilization device, characterized by: The disposable vacuum filtration sterilization device comprises a filter cup, a connector, a receiving bottle, a suction filter nozzle and a polyether sulfone microporous sterilization filter membrane; The inner bottom of the filter cup is concave downward to form a filter membrane placement platform for placing the filter membrane, the filter membrane placement platform is square, the edge of the filter membrane placement platform is used for fitting the edge of the filter membrane, the middle part of the filter membrane placement platform is further concave downward to form a filtrate flow guide area, the depth of the concave part increases from the edge to the center of the filtrate flow guide area, the filtrate flow guide area is provided with a flow guide rib extending from the edge to the center, and a filtrate hole is formed in the center of the filtrate flow guide area, and the filtrate hole extends downward to form a filtrate outlet pipe; The connector comprises an upper interface and a lower interface which are in communication with each other, the upper interface is sleeved with the filtrate outlet pipe, and the lower interface is sleeved with the bottle mouth of the receiving bottle; The suction filter nozzle is used for connecting the air suction pipeline, and the suction filter nozzle is in communication with the connector; The polyether sulfone microporous sterilization filter membrane is placed on the filter membrane placement platform, the polyether sulfone microporous sterilization filter membrane is square corresponding to the size of the filter membrane placement platform, the upper surface of the polyether sulfone microporous sterilization filter membrane is a filter layer, and the lower surface is a separation layer, the average pore size of the filter layer is smaller than that of the separation layer; The polyether sulfone microporous sterilization filter membrane is prepared by the following method: (1) polyether sulfone is dissolved in a solvent, a pore former is added, and the mixture is uniformly mixed to obtain a casting solution; the solvent is one or more of N-methyl pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylformamide and dimethyl sulfoxide; the pore former is one or both of polyethylene glycol and polyvinyl pyrrolidone; the components of the casting solution are as follows in parts by weight: polyether sulfone 10-30 parts, pore former 30-60 parts, and solvent 10-60 parts; (2) the casting solution obtained in step (1) is scraped to form a liquid membrane; (3) the upper surface of the liquid membrane obtained in step (2) is blown with cold air at 2-10 DEG C, and the lower surface is heated by a graphene heating module at 30-60 DEG C; (4) the liquid membrane treated in step (3) is passed through a steam box with a humidity of 40-80% to obtain a nascent membrane; (5) the nascent membrane obtained in step (4) is solidified into a membrane by water bath, and then washed, dried to obtain a polyether sulfone microporous sterilization filter membrane.

2. The disposable vacuum filter-sterilizer device according to claim 1, characterized in that: The flow guide ribs are arranged at intervals in length in the filtrate flow guide area.

3. The disposable vacuum filter-sterilizer device according to claim 1, characterized in that: The filtrate flow guide area is further provided with a reinforcing support rib which spans the filtrate flow guide area.

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