A filter device for virus removal filtration of a protein-containing feed liquid and a method of virus removal filtration of a protein-containing feed liquid

Abstract

The application discloses a filtering device for virus removal filtration of a protein-containing feed liquid and a method for virus removal filtration of a protein-containing feed liquid, and relates to the technical field of biological filtration. The filtering device comprises a filtering unit, a packaging layer, a liquid inlet channel, a filtrate channel and a filtering layer, wherein the filtering layer comprises a virus removal membrane, the LRV of the virus removal membrane for virus impurities is not less than 4, and the protein yield is not less than 98%, the virus removal membrane comprises a pre-filtering layer and a separation layer for intercepting viruses and having a pore size smaller than that of the pre-filtering layer, and at least one pre-filtering layer is arranged on the surface of the side of the virus removal membrane away from the filtrate guide screen. The filtering device has the advantages of simple structure, convenient operation, good virus removal effect of the virus removal membrane on the protein-containing feed liquid, and the like.

Description

Technical Field

[0001] This invention relates to the field of biological filtration technology, and in particular to a filtration device and method for filtering protein-containing liquids to remove viruses. Background Technology

[0002] With societal development, recombinant protein and antibody drugs have become important components of the biopharmaceutical industry due to their widespread application in the treatment of various major diseases. Recombinant protein drugs are products expressed using genetic engineering technology, used to compensate for the deficiency of certain functional proteins in the human body. Antibody drugs, such as monoclonal antibodies, are antibodies secreted by a single B lymphocyte clone. Because B lymphocytes can only produce one specific antibody targeting a single antigenic determinant, they possess highly specific physicochemical properties, singular biological activity, and strong antigen-binding specificity. They have made significant progress in the treatment of tumors and autoimmune diseases. After more than 30 years of development, recombinant protein and antibody drugs now account for more than one-third of the domestic biopharmaceutical market and represent the fastest-growing and most promising development direction in the pharmaceutical field.

[0003] In the production of recombinant protein and antibody drugs, it is necessary to separate and purify the product protein in the drug solution containing recombinant protein or antibody. Separation and purification are the key technologies for the preparation of recombinant protein and antibody drugs. Among them, virus removal filtration is a key step in separation and purification. However, at present, existing technologies usually use box-type filter devices for virus removal filtration, such as patent CN112387119A. However, box-type filters are not only complicated to manufacture, but the filter membrane also needs to be welded to the shell. This process can easily damage the filter membrane, thereby affecting the final filtration effect. Summary of the Invention

[0004] The purpose of this invention is to provide a filtration device and method for filtering protein-containing liquids to remove viruses. The device has a simple structure, is easy to operate, and has a high virus removal rate.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A filtration device for filtering proteins containing filtrate to remove viruses, comprising: A filtration unit includes at least a filtrate guiding screen and a filter layer disposed on the side of the filtrate guiding screen; multiple filtration units are stacked and a liquid inlet channel is formed between the filtration units; An encapsulation layer is used to encapsulate and fix multiple stacked filter units; The inlet channel is used to transport the protein-containing liquid to be filtered to the inlet flow channel; The filtrate channel is connected to the filtrate guide screen and is used to discharge the protein-containing liquid after virus removal. The filter layer includes a virus-removing membrane, wherein the virus-removing membrane has an LRV of not less than 4 for viral impurities and a protein yield of not less than 98%. The virus-removing membrane includes a pre-filtering layer and a separation layer for retaining viruses, wherein the pore size is smaller than that of the pre-filtering layer, and at least one pre-filtering layer is located on the surface of the virus-removing membrane away from the filtrate guide screen.

[0006] The filtration device of this invention has multiple filtration units, an inlet channel, and a filtrate channel. The filtration units are stacked and sealed by an outer encapsulation layer. The inlet channel communicates only with the inlet flow channel formed between the filtration units, and the filtrate channel communicates only with the filtrate guiding screen within the filtration unit. When filtering a protein-containing liquid for virus removal, the protein-containing liquid to be filtered can be transported into the inlet flow channel through the inlet channel. At this time, the protein-containing liquid will fill the inlet channel and, after being filtered for virus removal by the filtration layers, form a permeate that enters the filtrate guiding screen. In the filtration units stacked inside, the filtrate guiding screen has filtration layers on both sides, while in the outermost filtration unit, the filtrate guiding screen can have a filtration layer only facing inward. This arrangement of the filtrate guiding screen can open the flow channels between the liquid outlet surfaces of the filtration layers, preventing them from sticking together and providing good filtration space for the filtration units. Finally, the permeate is discharged through the filtrate channel connected to the filtrate guiding screen to obtain the target virus-free protein-containing liquid.

[0007] Meanwhile, to ensure the filter layer of this invention has a good virus removal effect, the filter layer uses a virus removal membrane with an LRV of not less than 4 for viral impurities and a protein yield of not less than 98%. The resulting virus-free protein-containing liquid has a good virus removal filtration effect. The virus removal membrane includes a pre-filtration layer and a separation layer for virus interception with a smaller pore size than the pre-filtration layer. At least one pre-filtration layer is located on the surface of the virus removal membrane away from the filtrate guide screen. Therefore, during use, the protein-containing liquid to be filtered first passes through the pre-filtration layer. The pre-filtration layer has a larger pore size, which can be used to hold contaminants and mainly intercepts large particulate impurities in the fluid. It also helps to improve the overall filtration speed of the virus removal membrane, resulting in a shorter filtration time and lower time cost for the protein-containing liquid. Subsequently, the protein-containing liquid passes through the separation layer, which has a relatively smaller pore size, which helps to improve the filtration accuracy of the virus removal membrane and ensures that the virus removal membrane has a high virus interception effect. Therefore, at least one pre-filtration layer is located on the side of the virus-removing membrane away from the filtrate guiding screen. This ensures that the inlet aperture of the virus-removing membrane is relatively large, with a large dirt-holding capacity, effectively removing larger particulate impurities beforehand, reducing the likelihood of clogging, and achieving a good filtration effect. Therefore, this invention has a simple structure, is easy to operate, and has a good virus-removing effect on protein-containing solutions.

[0008] Furthermore, Both the liquid inlet channel and the liquid filtrate channel are located in the filtration unit; or At least one of the liquid inlet channel and the liquid filtrate channel is located in the encapsulation layer.

[0009] In this invention, both the inlet channel and the filtrate channel can be located within the filtration unit. In this case, the inlet channel and the filtrate channel penetrate the filtration unit. Since the permeate flows towards the filtrate channel during protein-containing filtrate filtration, the permeate in the filtrate guiding screen far from the filtrate channel needs to flow towards the filtrate guiding screen closer to the filtrate channel first. This results in uneven filtration efficiency of the virus-removing membrane in different areas. However, when both the inlet channel and the filtrate channel are located within the filtration unit, especially when the inlet channel and / or the filtrate channel are located in the middle of the filtration unit, the filtration of the virus-removing membrane becomes more uniform, increasing the service life of the filtration device. Alternatively, at least one of the inlet channel and the filtrate channel can be located in the encapsulation layer. Located in the encapsulation layer, compared to having them both located within the filtration unit, prevents a reduction in the effective usable area of ​​the filtration unit.

[0010] Furthermore, the filtration units are provided with inlet guide screens to support the inlet flow channels.

[0011] The inlet guide screen supports the gaps between the filtration units, forming an inlet flow channel. This allows for smoother delivery of the protein-containing liquid to the inlet flow channel, resulting in more uniform filtration. However, since the protein-containing liquid filtration in this invention is dead-end filtration, a certain pressure is required to force the liquid to pass through the filter layer. During filtration, the inlet flow channel often experiences high pressure. In this case, because the virus-removing membrane is relatively thin, the adhesion between the membrane's edge and the encapsulation layer is not strong. Under pressure, the protein-containing liquid can easily break through the bond between the membrane and the encapsulation layer, creating gaps. This causes the protein-containing liquid to pass through the gaps between the membrane and the encapsulation layer instead of through the virus-removing membrane, affecting the overall filtration efficiency of the filtration device. This invention incorporates an inlet guide screen, allowing the adhesive in the encapsulation layer to penetrate into the inlet guide screen during the encapsulation process. The encapsulation layer formed by the adhesive in the liquid guide screen can further bond to the surface of the virus-removing membrane, blocking the impact of virus-containing liquid during filtration. Furthermore, the width of the encapsulation layer formed by the adhesive penetrating into the liquid guide screen is adjustable, ensuring a strong bond with the virus-removing membrane. Therefore, the liquid guide screen increases the sealing performance between the encapsulation layer and the virus-removing membrane. Additionally, the surface of the virus-removing membrane away from the filtrate guide screen, i.e., the virus-removing surface bonded and sealed with the encapsulation layer penetrating into the liquid guide screen, is a pre-filtration layer with a larger pore size. This is because the larger pore size facilitates adhesive embedding during bonding, further increasing the bonding and sealing performance between the encapsulation layer penetrating into the liquid guide screen and the virus-removing surface.

[0012] Furthermore, the virus removal membrane separation layer is located on the surface of the virus removal membrane close to the filtrate guiding screen.

[0013] The virus removal membrane separation layer is attached to the side of the filtrate guiding screen. During filtration, the virus-containing liquid first passes through the pre-filtration layer and then flows through the separation layer. Finally, it reaches the filtrate guiding screen without having to pass through the pre-filtration layer again. This simplifies the structure of the virus removal membrane while ensuring good filtration effect.

[0014] Furthermore, the outer side of the pre-filter layer is a first outer surface, the average pore size of the first outer surface is 160-440nm, and the pore area ratio of the first outer surface is 0.5-14%; the outer side of the separation layer is a second outer surface, the average pore size of the second outer surface is 12-40nm, and the pore area ratio of the second outer surface is 2.5-9%.

[0015] In this invention, the average pore sizes of the first and second outer surfaces are different, ensuring both a fast overall flow rate and sufficient contaminant holding capacity, as well as high filtration accuracy. Simultaneously, the average pore size and pore area ratio of the first outer surface have a certain impact on the adhesion strength between the first outer surface of the virus-removing membrane and the encapsulation layer. The average pore size affects the extent to which the adhesive on the encapsulation layer can penetrate into the pre-filtration layer; if the average pore size of the first outer surface is too small, insufficient penetration will result in relatively weak adhesion. Conversely, the pore area ratio of the first outer surface affects the size of the area where the adhesive on the encapsulation layer can penetrate; if the pore area ratio of the first outer surface is too small, the adhesive will also be unable to penetrate effectively, resulting in relatively weak adhesion.

[0016] Furthermore, the average pore size of the virus-removing membrane exhibits a continuous gradient change from the surface region near the filtrate guiding screen to the surface region away from the filtrate guiding screen, with an average pore size change gradient of 2-5.5 μm / 1 μm.

[0017] The average pore size of the virus-removing membrane can vary with thickness in a gradient. The specific value of the average pore size gradient can be obtained by dividing the average pore size of the two surfaces by the thickness, so the unit is μm (representing pore size) / 1μm (representing thickness). In this invention, the pore size gradually decreases from the surface area away from the filtrate guiding screen to the surface area closer to the filtrate guiding screen. The average pore size gradient is 2-5.5μm / 1μm. The gradient value is small, indicating that the membrane pore size of this invention changes with thickness in a small gradient. The membrane pore size will not change too quickly, and there are no excessively large pores (when the pores of the pre-filtration layer are too large, it will lead to low overall mechanical strength of the membrane, making it not pressure-resistant and easily damaged under pressure). In this case, the pre-filtration layer can provide a certain support for the separation layer, and the membrane as a whole has good mechanical strength and pressure resistance, and is not easily damaged under high pressure. It can also ensure the efficient retention of viruses by the virus-removing membrane, which also has a fast flux and a large dirt holding capacity.

[0018] Furthermore, the average pore size of the pre-filter layer is 55-190 nm, and the average pore size of the separation layer is 16-23 nm; the ratio of the average pore size of the pre-filter layer to the average pore size of the separation layer is 4-12.

[0019] If the pore size of the pre-filter layer is too small, the virus removal membrane cannot achieve a good filtration flux; while if the pore size of the separation layer is too large, the separation layer may not be able to play a good retention role. Therefore, the above-mentioned values ​​for the pore size of the pre-filter layer and the separation layer are conducive to ensuring a large flux and high retention efficiency of the virus removal membrane.

[0020] When the ratio of the average pore size of the pre-filtration layer to the average pore size of the separation layer is within a certain range, it not only ensures that the filter membrane has a large flux and a long service life, but also ensures that the filter membrane has a high virus rejection efficiency, meeting the actual needs. However, if the ratio is too large or too small, it can easily lead to insufficient filtration accuracy or too low flux.

[0021] Furthermore, the thickness of the pre-filter layer accounts for 72-89% of the thickness of the virus-removing membrane, and the porosity is 77-90%; the thickness of the separation layer accounts for 11-28% of the thickness of the virus-removing membrane, and the porosity is 62-78%.

[0022] In this invention, the pre-filtration layer of the virus-removing membrane has a relatively high thickness and porosity, ensuring that the membrane as a whole has a high flux and dirt holding capacity, fast filtration speed, and long service life. The separation layer has a relatively low thickness and porosity, which, while further ensuring the membrane's high flux, can effectively retain viruses and ensure filtration efficiency.

[0023] Furthermore, the thickness of the virus-removing membrane is 45-140 μm.

[0024] When the thickness of the virus-removing membrane is too small, its mechanical strength will be low; at the same time, due to the short filtration time, effective filtration cannot be achieved. When the thickness of the membrane is too large, the filtration time will be too long, resulting in excessive time costs. The thickness of the virus-removing membrane within the scope of this invention not only has high mechanical strength, but also enables effective filtration with high filtration efficiency, short filtration time, and low time costs.

[0025] Furthermore, one or more of the following: polyethersulfone virus-removing membrane, regenerated cellulose virus-removing membrane, cellulose acetate virus-removing membrane, or polyvinylidene fluoride virus-removing membrane.

[0026] Furthermore, the filter layer is a multi-layer virus-removing membrane, each of which has an encapsulation hole. The encapsulation hole is at least partially connected to the liquid inlet channel. The multi-layer virus-removing membrane includes at least a first virus-removing membrane with the largest encapsulation hole inner diameter and a second virus-removing membrane with the smallest encapsulation hole inner diameter. The multi-layer virus-removing membranes are stacked to form a radial misalignment region at the encapsulation hole. An annular sealant layer is formed inside the encapsulation hole. This annular sealant layer covers the inner wall of the inlet channel at the filtrate guide screen, the inner wall of the first virus removal membrane encapsulation hole, and the radial misalignment area between adjacent encapsulation holes, so as to form a sealed connection between each virus removal membrane layer and between the filtrate guide screen and the filter layer.

[0027] In this invention, to achieve higher virus removal efficiency, a multi-layer virus removal membrane design can be adopted. When fixing and encapsulating the multi-layer virus removal membrane, especially when the inlet channel is located in the filtration unit, an annular adhesive sealant layer is formed between the multiple virus removal membranes within the encapsulation holes. This annular adhesive sealant layer fills the radially misaligned areas between adjacent virus removal membranes, the inner wall of the inlet channel at the filtrate guide screen, and the inner sidewall of the first virus removal membrane located at the encapsulation hole. Specifically, some adhesive penetrates into the filtrate guide screen, filling the mesh of the filtrate guide screen. The virus removal membranes near the filtrate guide screen are directly bonded to it, while the inner wall of the inlet channel at the filtrate guide screen is covered with an annular adhesive sealant layer. Since the virus removal membranes do not permeate with adhesive, the remaining virus removal membranes are sealed through the encapsulation holes. The adhesive filling the radially misaligned area forms an encapsulation, firmly adhering adjacent virus-removing membranes. Simultaneously, an annular adhesive sealant is also adhered to the inner sidewall of the encapsulation hole of the first virus-removing membrane. This indicates that the sidewall of the first virus-removing membrane, with the largest inner diameter of the encapsulation hole, must be encapsulated with an annular adhesive sealant to adhere multiple virus-removing membranes together through the radially misaligned area adhesion method. Therefore, the annular adhesive sealant creates a stable bond between all virus-removing membranes and the filtrate guide screen, preventing unfiltered virus-containing liquid from passing through the gaps and ensuring good filtration performance of the virus-removing membranes. The sides of the annular adhesive sealant seal the virus-removing membrane, and its upper and lower sides firmly adhere adjacent virus-removing membranes, thereby sealing the encapsulation hole and ensuring that the protein-containing liquid to be filtered enters from the inlet channel during filtration.

[0028] Furthermore, the second virus-removing membrane is located on the side of the filter layer away from the filtrate guiding screen; or, the second virus-removing membrane is located on the side of the filter layer closer to the filtrate guiding screen.

[0029] The second virus-removing membrane with the largest inner diameter of the encapsulation hole is located on the outside, allowing the adhesive to flow from the larger inner diameter encapsulation hole to the relatively smaller inner diameter encapsulation hole. This simplifies the fabrication of the annular seal and makes the adhesive structure more stable. The second virus-removing membrane with the largest inner diameter of the encapsulation hole is located on the inside, preventing the second virus-removing membrane with the smallest inner diameter from being located on the inside. This would prevent the adhesive layer on the inner wall of the encapsulation hole from being scraped off during the adhesive scraping process, which would prevent the annular seal from achieving a good seal. At the same time, it also allows the adhesive to flow down the steps to achieve a better seal.

[0030] Furthermore, the inner diameter of the encapsulation hole varies in a stepped manner, gradually decreasing from the side closest to the filtrate guiding screen outwards, or gradually increasing from the side closest to the filtrate guiding screen outwards.

[0031] The structure design ensures that the annular sealant covers all radially misaligned areas, resulting in stronger adhesion between all virus-removing membranes in the filter layer. Because the inner diameter of the encapsulation holes varies in a stepped manner, all adjacent virus-removing membranes have annular sealants not only on their sidewalls but also on the steps of the radially misaligned areas, leading to more stable adhesion between the membranes. Due to the stable adhesion in both directions, protein-containing liquids are less likely to break through the annular sealant and permeate into the encapsulation holes, ensuring that the permeate is discharged from the filtrate channel connected to the filtrate guide screen.

[0032] Furthermore, the filtration unit also includes an isolation layer disposed between the filtration layer and the filtrate guiding screen.

[0033] During the filtration process, under high pressure from the liquid to be filtered, the filtrate guide screen can easily become embedded in the filter layer, damaging the membrane pores and reducing the virus removal rate. This also affects the overall lifespan of the virus removal filtration device. This invention addresses this by incorporating an isolation layer between the filter layer and the filtrate guide screen. This isolation layer separates the filter layer from the filtrate guide screen, preventing the screen from embedding in the filter layer and damaging its membrane pores, thus providing excellent protection for the filter layer. During filtration, the isolation layer can be attached to both the filter layer and the filtrate guide screen on either side, or there can be gaps between the isolation layer and the filter layer, and also between the isolation layer and the filtrate guide screen. The isolation layer not only provides isolation but also guides the flow, creating a two-layer drainage space with the filtrate guide screen. This reduces back pressure, increases filtration flux, and makes filtration smoother and more efficient.

[0034] Furthermore, the surface roughness of the isolation layer on the side close to the filter layer is 2-25μm, and the softness is 100-250mN.

[0035] Excessive surface roughness on the side of the isolation layer closest to the filter layer can create multiple protrusions. Under pressure during filtration, these protrusions can become embedded in the pores of the virus-removing membrane, damaging its pore structure. Alternatively, the filter layer may become embedded between adjacent protrusions, reducing filtration efficiency. The selected surface roughness value ensures the smoothness of the isolation layer surface while minimizing its impact on the filter layer. Simultaneously, the flexibility of the isolation layer also affects the filter layer. Insufficient flexibility can lead to hard protrusions damaging the filter layer, while excessive flexibility can cause deformation, resulting in wrinkles between the filter and isolation layers, thus affecting filtration efficiency.

[0036] Furthermore, the thickness of the isolation layer is h1, and the thickness of the filtrate guiding screen is h2, with h1:h2 being 1:1-5.

[0037] The greater the thickness of the isolation layer, the larger the drainage space and the higher the contribution to the filtration flux. However, if the thickness is too large, it will easily lead to an increase in the thickness of the filtration device. If the thickness is too small, it will not be able to play a good isolation role and will easily deform, causing the filter guide screen to embed into the virus removal membrane. The above thickness ratio can ensure filtration efficiency while avoiding an excessively large overall thickness of the filtration device.

[0038] Furthermore, the thickness of the isolation layer is 80-150 μm, and the air permeability is 60-160 cc / cm. 2 / sec; the thickness of the filtrate guiding screen is 400-650μm, and the porosity is 25-35%.

[0039] Within the aforementioned value range, the thickness of the isolation layer provides effective isolation, preventing the virus-removing membrane from embedding and allowing for more drainage space, thus increasing the filtration flux. Excessive air permeability results in too many pores, potentially causing embedding of the filtrate guiding screen; conversely, insufficient air permeability reduces the filtration flux. Furthermore, within the specified air permeability range, the adhesive can penetrate well during the encapsulation of the virus-removing filter, facilitating the sealing process. Simultaneously, the thickness and porosity settings of the filtrate guiding screen ensure that the filtration flux of the virus-removing filter remains within a suitable range, while maintaining good filtration efficiency.

[0040] Furthermore, the fiber diameter of the insulating layer is 10-25 μm, and the basis weight is 15-40 g / m². 2 .

[0041] By employing a combination of coarser diameter and lower fiber density, the air permeability of the isolation layer is achieved, thereby ensuring the filtration flux of the virus removal filter and facilitating the bonding and encapsulation of the virus removal filter. Compared to a solution using a finer diameter but higher fiber density, the isolation layer of this invention has better support performance and a smaller specific surface area. This not only reduces the non-specific adsorption of proteins by the isolation layer but also reduces the probability of protein inactivation due to repeated collisions between proteins and the fibers of the isolation layer. Furthermore, during the flow of the permeate, fewer eddies are formed within the isolation layer, reducing the shear force on the proteins and resulting in higher protein yield and effective protein rate.

[0042] Furthermore, the isolation layer is one or more of nonwoven fabric, woven fabric, or porous membrane.

[0043] Furthermore, the isolation layer has an inlet port that is at least partially directly opposite and connected to the liquid inlet channel, and the isolation layer is bonded to the filter layer and the filtrate guide screen through an adhesive layer on the isolation layer.

[0044] Furthermore, the adhesive layer permeates within the isolation layer and surrounds the liquid inlet of the isolation layer, and the adhesive layer covers the inner wall of the liquid inlet of the isolation layer to prevent the formation of a through liquid flow channel between the liquid inlet of the isolation layer and the isolation layer, allowing liquid to enter from the inner wall of the liquid inlet of the isolation layer.

[0045] The adhesive layer of this invention can penetrate into the isolation layer, thereby achieving the purpose of bonding with the filter layer and the filtrate guiding screen. Furthermore, in order to prevent liquid from entering from the inner wall of the liquid inlet of the isolation layer, the adhesive layer of this invention surrounds the liquid inlet of the isolation layer and covers the inner wall of the liquid inlet of the isolation layer, thereby preventing the formation of a through liquid flow channel between the liquid inlet of the isolation layer and the isolation layer, thus blocking the liquid from entering from the liquid inlet of the isolation layer.

[0046] Furthermore, a stepped misalignment area is formed between the liquid inlet of the isolation layer and the inner wall of the liquid inlet channel of the filter layer.

[0047] The staggered design allows the adhesive to fill the staggered areas, achieving encapsulation of the isolation and filter layers without the adhesive penetrating into the isolation layer. This prevents the liquid from flowing out from the gaps between the isolation and filter layers, ensuring good filtration performance of the virus removal membrane.

[0048] A method for removing viruses from protein-containing liquid using a filtration device includes the following steps: S1: Buffer replacement: Buffer is continuously supplied from the inlet channel into the inlet flow channel until it flows out from the filtrate channel of the filter device to form a permeation buffer, thereby filling the filter device with buffer. S2: Liquid Inlet: The protein-containing liquid is continuously conveyed from the liquid inlet channel into the liquid inlet flow channel; S3: Filtration: Protein-containing liquid permeates tangentially through the inlet guide screen and passes through the filter layer in the filtration unit to form a virus-removing permeate; S4: Drainage: The virus-free permeate flows along the filtrate guide screen and is discharged from the filtrate channel to obtain the virus-free protein-containing liquid.

[0049] In this invention, when using a filtration device to remove viruses from protein-containing liquids, the original protective solution or air in the filtration device is first replaced with a buffer solution. This buffer solution is continuously supplied from the inlet channel into the inlet flow channel until it flows out from the filtrate channel of the filtration device, ensuring the buffer solution fills the filtration device. Then, the liquid inlet operation is performed. Before liquid inlet, if the filtration device has multiple inlet channels, these channels can be filled simultaneously. Preferably, when multiple inlet channels are present, the protein-containing liquid is supplied to one inlet channel while the others are blocked. This is because simultaneous liquid inlet from multiple channels makes it difficult to adjust the overall throughput of the filtration device, requiring adjustment of the inlet pressure of each channel. Furthermore, there is a possibility that the protein-containing liquid may backflow due to insufficient inlet pressure in one channel. Subsequently, after the protein-containing liquid passes through the filter layer in the filtration unit, a virus-removing permeate is formed. This permeate flows along the filtrate guide screen and is discharged from the filtrate channel, resulting in the virus-removed protein-containing liquid. The virus removal filtration device of this invention is simple to operate and has high efficiency.

[0050] Furthermore, the inlet pressure in step S2 is 20-40 psi.

[0051] Furthermore, the filtration flux is greater than 180 L / (m²). 2 *h).

[0052] The filtration device of this invention has a simple structure and is easy to operate. It has a good virus removal effect on protein-containing liquids. The virus removal membrane includes a pre-filtration layer and a separation layer with a smaller pore size than the pre-filtration layer for virus interception. At least one pre-filtration layer is located on the surface of the virus removal membrane away from the filtrate guide screen. This not only ensures the efficient interception of viruses by the filtration device, but also has a large throughput and dirt holding capacity. Attached Figure Description

[0053] The present invention will be further described below with reference to the accompanying drawings: Figure 1 This is an exploded structural diagram of the filtration device of the present invention.

[0054] Figure 2 This is a cross-sectional view of the filtering device of the present invention.

[0055] Figure 3 This is a partial cross-sectional view of the filter unit of the present invention (excluding the annular sealant layer), where the isolation layer is a non-woven fabric.

[0056] Figure 4 This is a partial cross-sectional view of the filter unit of the present invention, in which the isolation layer is a non-woven fabric.

[0057] Figure 5This is a partial cross-sectional view of the filter unit of the present invention (excluding the annular sealant layer), where the isolation layer is a porous membrane.

[0058] Figure 6 This is a partial cross-sectional view of the filter unit of the present invention, where the isolation layer is a porous membrane.

[0059] Figure 7 This is an electron microscope image of the nonwoven fabric as the isolation layer of the present invention.

[0060] Figure 8 This is a partial cross-sectional view of the filter unit of the present invention (excluding the annular sealant layer), in which the number of virus-removing membranes is three layers.

[0061] Figure 9 This is a partial cross-sectional view of the filter unit of the present invention, in which the number of virus-removing membranes is three layers.

[0062] Figure 10 This is a cross-sectional view of the virus removal filtration device of the present invention, in which the virus removal membrane includes a pre-filtration layer and a separation layer.

[0063] Figure 11 The image shows an electron microscope image of the virus-removing membrane of the present invention, which includes a pre-filtering layer and a separation layer.

[0064] Figure 12 This is a cross-sectional view of the virus removal filtration device of the present invention. At this time, the virus removal membrane includes two pre-filtration layers and one separation layer.

[0065] Figure 13 This is a schematic diagram of the filtration device in Embodiment 2 of the present invention.

[0066] Figure 14 This is a cross-sectional view of the liquid inlet channel of the filtration device in Embodiment 2 of the present invention.

[0067] Figure 15 This is a cross-sectional view of the filtrate channel of the filtration device in Embodiment 2 of the present invention.

[0068] Figure 16 This is a schematic diagram of the filtration device in Embodiment 3 of the present invention.

[0069] Figure 17 This is an exploded structural diagram of the filtration device in Embodiment 5 of the present invention.

[0070] Among them, 101-liquid inlet channel, 102-filtrate channel, 103-encapsulation layer, 1-liquid inlet guide screen, 11-first liquid inlet, 12-first filtrate inlet, 2-filtration unit, 21-isolation layer, 211-isolation layer liquid inlet, 212-isolation layer filtrate inlet, 22-second liquid inlet, 23-second filtrate inlet, 3-filtrate guide screen, 4-filtration layer, 41-virus removal membrane, 411-encapsulation hole, 412-conducting port, 413-first virus removal membrane, 414-second virus removal membrane, 415-third virus removal membrane, 416-pre-filtration layer, 417-separation layer, 5-radial misalignment area, 51-step misalignment area, 6-annular adhesive sealing layer, 61-adhesive layer. Detailed Implementation

[0071] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0072] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below. Example 1:

[0073] like Figure 1 As shown, a filtration device for filtering proteins containing filtrate to remove viruses includes: The liquid inlet guide screen 1 has a first liquid inlet 11 and a first filter outlet 12, which is used to guide the fluid to be filtered to permeate along the tangential direction; In this embodiment, the liquid inlet guide screen 1 is provided with a first liquid inlet 11 and a first liquid filter 12 at both ends, and the inner wall of the first liquid filter 12 is sealed by an adhesive that permeates into the liquid inlet guide screen 1. The filter unit 2 is located downstream of the liquid inlet guide screen 1, and has a second liquid inlet 22 and a second liquid outlet 23 that are at least partially directly connected to the first liquid inlet 11 and the first liquid outlet 12, and are respectively opened at both ends; the filter unit 2 includes at least a liquid guide screen 3 and a filter layer 4 disposed on both sides of the liquid guide screen 3, and the filter layer 4 is disposed on the inner side of the outermost filter unit 2; In this embodiment, both the liquid inlet channel 101 and the filtrate channel 102 are located in the filtration unit. The first liquid inlet 11 and the second liquid inlet 22 together form the liquid inlet channel 101, and the first filtrate port 12 and the second filtrate port 23 form the filtrate channel 102. The diameters of the first liquid inlet and the second liquid inlet are 11 mm, and the diameters of the first filtrate port and the second filtrate port are 6 mm. Multiple filtration units and liquid inlet guiding screens 1 are stacked and fixed by encapsulation layer 103. The encapsulation layer 103 penetrates into the liquid inlet guiding screen 1 and is bonded and fixed to the first outer surface of the virus removal membrane 41.

[0074] Of course, in other embodiments, the inlet guide screen 1 may not be provided. During filtration, the virus-containing liquid can be opened by pressure after being transported into the inlet channel, thereby completing the filtration.

[0075] In this embodiment, the filter layer 4 includes a virus removal membrane 41, which has an LRV of not less than 4 for viral impurities and a protein yield of not less than 98%. The virus removal membrane 41 further includes a pre-filter layer 416 and a separation layer 417. The pore size of the separation layer 417 is smaller than that of the pre-filter layer 416, and it is used for interception. At least one pre-filter layer 416 is located on the side of the virus removal membrane 41 away from the filtrate guiding screen.

[0076] Specifically, such as Figure 10 As shown, the virus-free membrane 41 includes a pre-filtration layer 416 and a separation layer 417. The separation layer 417 is located on the side close to the filtrate guiding screen 3. The outer side of the pre-filtration layer is a first outer surface with an average pore size of 160-440 nm and a pore area ratio of 0.5-14%. The outer side of the separation layer is a second outer surface with an average pore size of 12-40 nm and a pore area ratio of 2.5-9%. The average pore size of the pre-filtration layer is 55-190 nm. The thickness of the pre-filtration layer accounts for 72-89% of the thickness of the virus-removing membrane, and the porosity is 77-90%. The average pore size of the separation layer is 16-23 nm, the thickness of the separation layer accounts for 11-28% of the thickness of the virus-removing membrane, and the porosity is 62-78%. The ratio of the average pore size of the pre-filtration layer to the average pore size of the separation layer is 4-12. The average pore size of the virus-removing membrane changes continuously in a gradient from the surface area near the filtrate guiding screen to the surface area away from the filtrate guiding screen, with an average pore size change gradient of 2-5.5 μm / 1 μm. The overall thickness of the virus-removing membrane is 45-140 μm.

[0077] Combined Figure 11As shown, in this embodiment, the upper side is a pre-filter layer and the lower side is a separation layer. The overall thickness of the virus membrane is 60 μm. The average pore size of the first outer surface is 230 nm, and the pore area ratio is 10.6%. The average pore size of the second outer surface is 20.6 nm, and the pore area ratio is 8.4%. The average pore size gradient is 3.49 μm / 1 μm. The average pore size of the pre-filter layer is 80 nm, the thickness is 52 μm, and the porosity is 81.1%. The average pore size of the separation layer is 19 nm, the thickness is 8 μm, and the porosity is 74%.

[0078] In other embodiments, such as Figure 12 As shown, at this time, the virus-free membrane 41 includes two pre-filtering layers 416 and a separation layer 417, with the separation layer 417 located between the two pre-filtering layers 416; at this time, one of the pre-filtering layers 416 is located on the side away from the isolation layer 21, and the other pre-filtering layer 416 is located on the side close to the isolation layer 21.

[0079] In the filtration unit of this embodiment, the porosity of the filtrate guiding screen 3 is 25-35%, and its thickness is 400-650μm.

[0080] The filter layer 4 is a single-layer virus removal membrane 41 or a multi-layer virus removal membrane 41. The two ends of the virus removal membrane 41 are respectively provided with a sealing hole 411 and a through port 412. The sealing hole 411 is at least partially directly opposite and connected to the second liquid inlet 22.

[0081] In this embodiment, as Figure 1-4 As shown, the virus-removing membrane 41 is a PES virus-removing membrane, and the filtration unit 2 includes an isolation layer 21 disposed between the filter layer 4 and the filtrate guiding screen 3. The thickness of this isolation layer 21 is defined as h1, and the thickness of the filtrate guiding screen 3 is defined as h2, then h1:h2 is 1:1-5. More specifically, in this embodiment, the thickness of the isolation layer 21 is 80-150 μm, and the air permeability is 60-160 cc / cm². 2 / sec.

[0082] The pore size of the surface of the isolation layer 21 closest to the filter layer 4 is defined as d1, and the average pore size of the side of the filter layer 4 closest to the isolation layer 21 (excluding the second outer surface of the virus membrane in this embodiment) is defined as d2. Therefore, the ratio of d1 to d2 is 1000-5000. More specifically, in this embodiment, the pore size of the surface of the isolation layer 21 closer to the filter layer 4 is 20-120 μm.

[0083] The softness of the isolation layer 21 is 100-250 mN; the surface roughness of the side of the isolation layer 21 close to the filter layer 4 is 2-25 μm; the isolation layer 21 can be a non-woven fabric with a fiber diameter of 10-25 μm and a basis weight of 15-40 g / m². 2The isolation layer 21 can also be a woven fabric or a porous membrane, and the material can be a polymer material, such as PP, PE, PES, etc.

[0084] The isolation layer 21 has an isolation layer inlet 211 and an isolation layer filter outlet 212, which are at least partially directly connected to the second liquid inlet 22 and the second filtrate outlet 23, respectively. The isolation layer is bonded to the filter layer and the filtrate guiding screen by an adhesive layer 61 on the isolation layer. The adhesive layer 61 permeates within the isolation layer and surrounds the isolation layer inlet, covering the inner wall of the inlet to prevent the formation of a through-flow channel for liquid entering from the inner wall of the inlet. The width of the adhesive layer is l, and the diameter of the isolation layer inlet is d, the same as the diameter of the first liquid inlet. The ratio l:d is 1-10:10. Alternatively, a stepped misalignment area can be formed between the isolation layer inlet and the second liquid inlet of the filter layer, allowing the adhesive to fill the stepped misalignment area to form the adhesive layer 61. In this embodiment, when the isolation layer 21 is made of non-woven fabric, such as... Figure 7 As shown, the adhesive can penetrate into the nonwoven fabric at this time, and a stable bond can be achieved by using an adhesive layer that penetrates into the isolation layer or by setting a stepped misalignment region 51. In other embodiments, when the isolation layer 21 is a porous membrane, since the adhesive cannot penetrate, the aforementioned stepped misalignment region 51 must be provided, such as... Figure 5 , Figure 6 As shown.

[0085] In other embodiments, the virus-removing membrane 41 can be one or more of the following: a regenerated cellulose virus-removing membrane, a cellulose acetate virus-removing membrane, or a polyvinylidene fluoride virus-removing membrane.

[0086] In this embodiment, the filter layer 4 is a multi-layer virus removal membrane 41. Each virus removal membrane 41 has an encapsulation hole 411 and a through port 412. The encapsulation hole 411 is at least partially directly connected to the second liquid inlet 22. The multi-layer virus removal membrane 41 includes at least a first virus removal membrane 413 with the largest inner diameter of the encapsulation hole and a second virus removal membrane 414 with the smallest inner diameter of the encapsulation hole. The multi-layer virus removal membranes 41 are stacked to form a radial misalignment region 5 at the encapsulation hole.

[0087] An annular sealant layer 6 is formed inside the encapsulation hole. The annular sealant layer 6 covers the inner wall of the second liquid inlet 22, the inner wall of the isolation layer liquid inlet 211, the inner wall of the first virus removal membrane 413, and the radial misalignment area 5 between adjacent encapsulation holes, so that a sealed connection is formed between each virus removal membrane 41 and between the filtrate guide screen 3 and the filter layer 4.

[0088] Specifically, such as Figure 3 , Figure 4As shown, in this embodiment, the filter layer 4 includes two virus-removing membranes 41, specifically a first virus-removing membrane 413 with a larger inner diameter of the encapsulation hole and a second virus-removing membrane 414 with a smaller inner diameter of the encapsulation hole. The first virus-removing membrane 413 is located on the inner side close to the filtrate guiding screen 3, and the second virus-removing membrane 414 is located on the outer side away from the filtrate guiding screen 3.

[0089] like Figure 4 As shown, an annular sealant layer 6 is formed inside the encapsulation hole. This annular sealant layer 6 covers the inner wall of the second liquid inlet 22, the inner wall of the isolation layer liquid inlet 211, the inner wall of the first virus removal membrane 413, and the radially misaligned region 5 of the first virus removal membrane 413 and the second virus removal membrane 414, so that a sealed connection is formed between the first virus removal membrane 413 and the second virus removal membrane 414, as well as between the filtrate guide screen 3 and the first virus removal membrane 413.

[0090] During encapsulation, the through port 412 and the second filtrate port 23 are at least partially connected to each other. A vacuum is drawn between the second filtrate port 23 and the through port 412. The adhesive injected into the second liquid inlet port 22 and the encapsulation hole 411 flows circumferentially under the action of negative pressure to form an annular sealant layer 6.

[0091] Of course, in other embodiments, such as Figure 8 , Figure 9 As shown, the number of virus-removing membranes 41 can be three layers. The first virus-removing membrane 413, which has the largest inner diameter of the encapsulation hole, is located on the outermost side away from the filtrate guiding screen 3. The second virus-removing membrane 414, which has the smallest inner diameter of the encapsulation hole, is located close to the filtrate guiding screen 3. The third virus-removing membrane 415 is located between the first virus-removing membrane 413 and the second virus-removing membrane 414. Its inner diameter of the encapsulation hole is smaller than that of the first virus-removing membrane 413 and larger than that of the second virus-removing membrane 414.

[0092] In other words, the inner diameter of the encapsulation hole changes in a stepped manner, gradually increasing in size from the side closest to the filtrate guide screen 3 outwards. This structural design results in stronger adhesion between all the virus-removing membranes 41 in the filter layer 4.

[0093] like Figure 9 As shown, an annular sealant layer 6 is formed inside the encapsulation hole. This annular sealant layer 6 covers the inner wall of the third virus-removing membrane 415, the inner wall of the first virus-removing membrane 413, the inner wall of the liquid inlet 211 of the isolation layer, and the radially misaligned areas of the third virus-removing membrane 415 and the first virus-removing membrane 413, as well as the radially misaligned areas of the third virus-removing membrane 415 and the second virus-removing membrane 414. This ensures a sealed connection between the second virus-removing membrane 414 and the third virus-removing membrane 415, between the third virus-removing membrane 415 and the first virus-removing membrane 413, between the isolation layer 21 and the first virus-removing membrane 413, and between the filtrate guide screen 3 and the isolation layer 21.

[0094] The average pore size of the membrane surface can be measured by characterizing the membrane structure using a scanning electron microscope (SEM), followed by measurement using computer software (such as Matlab, NIS-Elements, etc.) or manually, and then performing corresponding calculations. During membrane fabrication, in the direction perpendicular to the membrane thickness (if the membrane is a flat sheet, this direction is planar; if the membrane is a hollow fiber membrane, this direction is perpendicular to the radius), its characteristics, such as pore size distribution, are generally uniform and consistent. Therefore, the average pore size of a portion of the corresponding plane can reflect the overall average pore size of that plane. In actual measurement, the membrane surface can be characterized using an electron microscope to obtain the corresponding SEM image. Since the pores on the membrane surface are generally uniform, a certain area, such as 1 μm, can be selected. 2 (1μm x 1μm) or 25μm 2 (5μm x 5μm), the specific area size depends on the actual situation. Then, the pore diameter of all holes in this area is measured using appropriate computer software or manually, and then calculated to obtain the average pore diameter of the surface. Of course, those skilled in the art can also obtain the above parameters through other measurement methods, and the above measurement methods are for reference only. The average pore diameter, porosity, thickness and other parameters of the pre-filter layer and separation layer can be obtained by first tearing the virus removal membrane into a separation layer and a pre-filter layer, and then testing the corresponding parameters of the pre-filter layer, where the average pore diameter is tested using a PMI pore size analyzer; or by using a scanning electron microscope to characterize the morphology of the membrane cross-section structure, and then using computer software (such as Matlab, NIS-Elements, etc.) or manually to measure and calculate the parameters. Of course, those skilled in the art can also obtain the above parameters through other measurement methods, and the above measurement methods are for reference only.

[0095] Roughness testing: The ContourGT-X 3D optical profilometer (Bruker, Geman) was used to scan three surface regions of approximately 0.65 × 0.45 mm in size within a 6 × 6 mm surface area (the region size was defined by a constant 5x magnification and the use of an autofocusing scanning microscope). n = 6 linear orbits (each 200 μm) were taken. The profilometer filter had a cutoff wavelength of λs = 0.8 μm and λc = 0.08 mm. The roughness was measured and the average value was calculated.

[0096] Softness test: according to standard ASTM D6828-2002(2011), test speed: 1.2mm / s.

[0097] A method for filtering protein-containing liquid for virus removal using the above-mentioned filtration device includes the following steps: S1: Buffer replacement: Buffer solution is continuously supplied from the inlet channel 101 on one side of the filter device, i.e., the first inlet 11, into the inlet flow channel until it flows out from the filtrate channel of the filter device, i.e., the second filtrate outlet 23, to form a permeation buffer solution, thereby filling the filter device with buffer solution. S2: Liquid Inlet: Block the liquid inlet channel on one side and continuously transport the protein-containing liquid from the liquid inlet channel on the other side into the liquid inlet flow channel, wherein the liquid inlet pressure is 20-40psi; S3: Filtration: Protein-containing liquid permeates tangentially through the inlet guide screen and passes through the filter layer in the filtration unit to form a virus-removing permeate; S4: Drainage: The virus-free permeate flows along the filtrate guide screen and is discharged from the filtrate channel to obtain the virus-free protein-containing liquid.

[0098] In the specific application of the filtration device with the structure of this embodiment for virus removal filtration, 7 samples were taken, namely: Sample 1, with an isolation layer 21. The isolation layer 21 is made of non-woven fabric, with a surface roughness of 3μm and a softness of 100mN on the side close to the filter layer 4. The ratio of d1:d2 is 1000; l:d is 3:10. The thickness of the isolation layer 21, h1:h2, is 1:5, where h1 is 85μm. The thickness h2 of the inlet and filtrate guiding screens is 425μm. The porosity of the filtrate guiding screen is 25%. The air permeability of the isolation layer 21 is 60cc / cm. 2 / sec; the fiber diameter of the isolation layer 21 is 12μm, and the basis weight is 16g / m². 2 .

[0099] Sample 2 was fitted with an isolation layer 21 made of non-woven fabric. The surface roughness of the side closest to the filter layer 4 was 18 μm, the softness was 118 mN, the d1:d2 ratio was 1300, and the l:d ratio was 1:2. The thickness h1:h2 of the isolation layer 21 was 1:4, where h1 was 140 μm. The thickness h2 of the inlet and filtrate guiding screens was 560 μm, the porosity of the filtrate guiding screen was 28%, and the air permeability of the isolation layer 21 was 115 cc / cm³. 2 / sec; the fiber diameter of the isolation layer 21 is 10μm, and the basis weight is 15g / m². 2 .

[0100] Sample 3 was fitted with an isolation layer 21. The isolation layer 21 was made of non-woven fabric, with a surface roughness of 19 μm and a softness of 165 mN on the side closest to the filter layer 4. The ratio of d1:d2 was 2100; l:d was 2:5. The thickness of the isolation layer 21, h1:h2, was 1:4.5, where h1 was 142 μm. The thickness h2 of the inlet and filtrate guiding screens was 639 μm. The porosity of the filtrate guiding screen was 30%, and the air permeability of the isolation layer 21 was 92 cc / cm³.2 / sec; the fiber diameter of the isolation layer 21 is 14μm, and the basis weight is 40g / m². 2 .

[0101] Sample 4 is equipped with an isolation layer 21 made of non-woven fabric. The surface roughness of the side closest to the filter layer 4 is 12 μm, the softness is 195 mN, the d1:d2 ratio is 2200, and the l:d ratio is 3:5. The thickness h1:h2 of the isolation layer 21 is 1:3.5, where h1 is 121 μm. The thickness h2 of the inlet and filtrate guiding screens is 423.5 μm, the porosity of the filtrate guiding screen is 32%, and the air permeability of the isolation layer 21 is 124 cc / cm³. 2 / sec; the fiber diameter of the isolation layer 21 is 17μm, and the basis weight is 18g / m². 2 .

[0102] Sample 5 was fitted with an isolation layer 21 made of non-woven fabric. The surface roughness of the side closest to the filter layer 4 was 20 μm, the softness was 220 mN, the d1:d2 ratio was 3200, and the l:d ratio was 3:10. The thickness h1:h2 of the isolation layer 21 was 1:3.8, where h1 was 150 μm. The thickness h2 of the inlet and filtrate guiding screens was 426 μm, the porosity of the filtrate guiding screen was 35%, and the air permeability of the isolation layer 21 was 152 cc / cm³. 2 / sec; the fiber diameter of the isolation layer 21 is 18μm, and the basis weight is 36g / m². 2 .

[0103] Sample 6 was fitted with an isolation layer 21, which was made of non-woven fabric. The surface roughness of the side closest to the filter layer 4 was 25 μm, the softness was 248 mN, the d1:d2 ratio was 4300, and the l:d ratio was 2:5. The thickness h1:h2 of the isolation layer 21 was 1:3.5, where h1 was 138 μm. The thickness h2 of the inlet and filtrate guiding screens was 570 μm, the porosity of the filtrate guiding screen was 27%, and the air permeability of the isolation layer 21 was 148 cc / cm³. 2 / sec; the fiber diameter of the isolation layer 21 is 20μm, and the basis weight is 32g / m². 2 . Example 2:

[0104] The difference from Example 1 is as follows: like Figure 13-15As shown: The liquid inlet channel 101 of the present invention is disposed on the encapsulation layer 103, and the filtrate channel 102 is disposed at the center of the stacked structure of the filter unit 2 and the liquid inlet guide screen. The liquid inlet channel 101 and the liquid inlet guide screen 1 are connected, and the filter unit 2 on the inner wall of the liquid inlet channel 101 is sealed by the annular adhesive layer 6. The liquid inlet guide screen 1 on the inner wall of the filtrate channel 102 is sealed by the adhesive that permeates therein.

[0105] The method for filtering protein-containing liquid for virus removal using the above-mentioned filtration device includes the following steps: S1: Buffer replacement: Buffer solution is continuously supplied from the inlet channel 10 on one side of the filter device into the inlet flow channel until it flows out from the filtrate channel of the filter device to form a permeation buffer solution, thereby filling the filter device with buffer solution. S2: Liquid Inlet: The protein-containing liquid is continuously conveyed from the liquid inlet channel into the liquid inlet flow channel, where the liquid inlet pressure is 20-40psi; S3: Filtration: Protein-containing liquid permeates tangentially through the inlet guide screen and passes through the filter layer in the filtration unit to form a virus-removing permeate; S4: Drainage: The virus-free permeate flows along the filtrate guide screen and is discharged from the filtrate channel to obtain the virus-free protein-containing liquid.

[0106] In this embodiment, the virus-removing membrane is a PES virus-removing membrane with an overall thickness of 50 μm. The average pore size of the first outer surface is 200 nm, with a pore area ratio of 8.7%. The average pore size of the second outer surface is 18.2 nm, with a pore area ratio of 6.9%. The average pore size gradient is 3.64 μm / 1 μm. The average pore size of the pre-filter layer is 70 nm, the thickness is 44 μm, and the porosity is 78.2%. The average pore size of the separation layer is 17 nm, the thickness is 6 μm, and the porosity is 72.1%.

[0107] In this embodiment, an isolation layer 21 is provided. The isolation layer 21 is made of non-woven fabric, and its surface roughness on the side close to the filter layer 4 is 8μm, its softness is 135mN, d1:d2 is 3800; l:d is 3:10, the thickness h1:h2 of the isolation layer 21 is 1:4.8, where h1 is 98μm, the thickness h2 of the filtrate guiding screen is 470.4μm, the porosity of the filtrate guiding screen is 26%, and the air permeability of the isolation layer 21 is 155cc / cm. 2 / sec; the fiber diameter of the isolation layer 21 is 22μm, and the basis weight is 21g / m². 2 . Example 3:

[0108] The difference from Example 2 is as follows: like Figure 16As shown: The liquid inlet channel 101 and the filtrate channel 102 of the present invention are both provided on the encapsulation layer 103. The liquid inlet channel 101 is connected to the liquid inlet guide screen 1, and the filter unit 2 on the inner wall of the liquid inlet channel 101 is sealed by the annular adhesive layer 6. The liquid inlet guide screen 1 on the inner wall of the filtrate channel 102 is also sealed by the adhesive that permeates therein.

[0109] In this embodiment, the virus-removing membrane is a PES virus-removing membrane with an overall thickness of 70 μm. The average pore size of the first outer surface is 260 nm, and the pore area ratio is 12.4%. The average pore size of the second outer surface is 22.1 nm, and the pore area ratio is 8.9%. The average pore size gradient is 3.4 μm / 1 μm. The average pore size of the pre-filter layer is 90 nm, the thickness is 60 μm, and the porosity is 83.4%. The average pore size of the separation layer is 20 nm, the thickness is 10 μm, and the porosity is 75.7%.

[0110] In this embodiment, an isolation layer 21 is provided. The isolation layer 21 is made of non-woven fabric, and its surface roughness on the side close to the filter layer 4 is 10 μm, its softness is 210 mN, d1:d2 is 5000, and l:d is 3:10. The thickness h1:h2 of the isolation layer 21 is 1:2.8, where h1 is 150 μm. The thickness h2 of the filtrate guiding screen is 420 μm, the porosity of the filtrate guiding screen is 33%, and the air permeability of the isolation layer 21 is 160 cc / cm. 2 / sec; the fiber diameter of the isolation layer 21 is 24μm, and the basis weight is 25g / m². 2 . Example 4:

[0111] The difference from Example 1 is as follows: The isolation layer 21 does not have an isolation layer inlet 211 or an isolation layer filter outlet 212, such as Figure 17 As shown, at this time, the area around the isolation layer can be bonded to the filtrate guide screen and the filter layer using adhesive.

[0112] In this embodiment, the isolation layer 21 is made of non-woven fabric, with a surface roughness of 15μm and a softness of 145mN on the side close to the filter layer 4. The ratio of d1:d2 is 1800; l:d is 7:10. The thickness of the isolation layer 21, h1:h2, is 1:3, where h1 is 148μm. The thickness of the filtrate guiding screen, h2, is 444μm, and the porosity of the filtrate guiding screen is 29%. The air permeability of the isolation layer 21 is 85cc / cm³. 2 / sec; the fiber diameter of the isolation layer 21 is 25μm, and the basis weight is 30g / m². 2 . Example 5:

[0113] The difference from sample 6 is that this embodiment uses a double-layer CA virus removal membrane, with an average pore size of 95 nm for the pre-filtration layer and an average pore size of 20 nm for the separation layer. Example 6:

[0114] The difference between this sample and sample 6 is that the thickness h1:h2 ratio is 1:6, where h1 is 70 μm. Example 7:

[0115] The difference between this sample and sample 6 is that the air permeability of the isolation layer is 40 cc / cm. 2 / sec. Example 8:

[0116] The difference between this sample and sample 6 is that the fiber diameter of the insulating layer 21 is 7 μm and the basis weight is 32 g / m². 2 .

[0117] Comparative Example 1:

[0118] The difference from sample 6 is that no isolation layer is provided.

[0119] Comparative Example 2:

[0120] The difference from sample 6 is that the roughness is 35 μm.

[0121] Comparative Example 3:

[0122] The difference from sample 6 is that the softness is 350mN.

[0123] The filtration devices described in the above embodiments and comparative examples were subjected to virus removal filtration tests. The test conditions were as follows: filtration of a 10 g / L monoclonal antibody protein solution containing 7.5 logpfu / ml MVM virus (particle size 20 nm) at a pressure of 30 psi. The virus removal filtration device employed 8 filtration units 2, which is equivalent to 16 filtration layers 4 and 32 virus removal membranes 41, resulting in a filtration area of ​​0.08 m². 2 The results are shown in the table below.

[0124]

[0125] As shown in the table above, the embodiments of the present invention have a good virus removal and filtration effect on protein-containing liquids.

[0126] As can be seen from Example 6, when the thickness of the isolation layer 21 and the value of h1:h2 are too small, the filtration flux of the filter device is relatively small.

[0127] As can be seen from Example 7, when the air permeability of the isolation layer is too small, the filtration flux of the filter device is relatively small.

[0128] As can be seen from Example 8, under the same basis weight, the smaller the fiber diameter, the more eddies are formed in the isolation layer, and the higher the specific surface area, the greater the probability of protein collision, and the relatively lower the effective protein yield and final protein yield.

[0129] As shown in Comparative Example 1, the LRV was relatively low when using the PES virus removal membrane without an isolation layer, indicating that the isolation layer can provide good protection for the pores of the virus removal membrane separation layer.

[0130] As can be seen from Comparative Example 2, the virus removal rate (LRV) of the protein-containing drug solution after filtration is relatively low, indicating that when the surface roughness of the isolation layer 21 is too large, the pores of the separation layer membrane 41 of the virus removal membrane are easily damaged during the experiment.

[0131] As can be seen from Comparative Example 3, the virus removal rate (LRV) of the protein-containing drug solution after filtration is relatively low, indicating that when the softness of the isolation layer 21 is too small, the pores of the separation layer membrane 41 of the virus removal membrane are easily damaged during the test.

[0132] The preferred embodiments of the present invention have been described in detail above. However, it should be understood that after reading the above teachings, those skilled in the art can make various alterations or modifications to the present invention. These equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A filtration device for filtering protein-containing liquids to remove viruses, characterized in that: include: A filtration unit, which includes at least a filtrate guiding screen and a filter layer disposed on the side of the filtrate guiding screen; Multiple filter units are stacked together, and liquid inlet channels are formed between the filter units; An encapsulation layer is used to encapsulate and fix multiple stacked filter units; The inlet channel is used to transport the protein-containing liquid to be filtered to the inlet flow channel; The filtrate channel is connected to the filtrate guide screen and is used to discharge the protein-containing liquid after virus removal. The filter layer is a multi-layer virus-removing membrane. Each layer of the virus-removing membrane has a sealing hole. The sealing hole is at least partially connected to the liquid inlet channel. The multi-layer virus-removing membrane includes at least a first virus-removing membrane with the largest inner diameter of the sealing hole and a second virus-removing membrane with the smallest inner diameter of the sealing hole. The multi-layer virus-removing membranes are stacked to form a radial misalignment region at the sealing hole. An annular sealant layer is formed inside the encapsulation hole. This annular sealant layer covers the inner wall of the liquid inlet channel at the filtrate guide screen, the inner wall of the first virus removal membrane encapsulation hole, and the radial misalignment area between adjacent encapsulation holes, so as to form a sealed connection between each virus removal membrane layer and between the filtrate guide screen and the filter layer. The virus removal membrane has an LRV of not less than 4 for viral impurities and a protein yield of not less than 98%. The virus removal membrane includes a pre-filtration layer and a separation layer for retaining viruses with a pore size smaller than the pre-filtration layer. At least one pre-filtration layer is located on the surface of the virus removal membrane away from the filtrate guide screen.

2. The filtration device according to claim 1, characterized in that, Both the liquid inlet channel and the liquid filtrate channel are located in the filtration unit; or At least one of the liquid inlet channel and the liquid filtrate channel is located in the encapsulation layer.

3. The filtration device according to claim 1, characterized in that, The filtration units are provided with inlet guide screens to support the inlet flow channels.

4. The filtration device according to claim 1, characterized in that, The virus removal membrane separation layer is located on the surface of the virus removal membrane close to the filtrate guide screen.

5. The filtration device according to any one of claims 1-4, characterized in that, The outer side of the pre-filter layer is a first outer surface, with an average pore size of 160-440 nm and a pore area ratio of 0.5-14%; the outer side of the separation layer is a second outer surface, with an average pore size of 12-40 nm and a pore area ratio of 2.5-9%.

6. The filtration device according to any one of claims 1-4, characterized in that, The average pore size of the virus-removing membrane changes continuously in a gradient from the surface region near the filtrate guiding screen to the surface region away from the filtrate guiding screen, with an average pore size change gradient of 2-5.5 μm / 1 μm.

7. The filtration device according to claim 1, characterized in that, The average pore size of the pre-filter layer is 55-190 nm, and the average pore size of the separation layer is 16-23 nm; the ratio of the average pore size of the pre-filter layer to the average pore size of the separation layer is 4-12.

8. The filtration device according to claim 1, characterized in that, The pre-filtration layer has a thickness of 72-89% of the virus removal membrane thickness and a porosity of 77-90%; the separation layer has a thickness of 11-28% of the virus removal membrane thickness and a porosity of 62-78%.

9. The filtration device according to claim 1, characterized in that, The thickness of the virus-removing membrane is 45-140 μm.

10. The filtration device according to claim 1, characterized in that, The virus-removing membrane includes one or more of polyethersulfone virus-removing membranes, regenerated cellulose virus-removing membranes, or cellulose acetate virus-removing membranes.

11. The filtration device according to claim 1, characterized in that, The second virus-removing membrane is located on the side of the filter layer away from the filtrate guiding screen; or, the second virus-removing membrane is located on the side of the filter layer closer to the filtrate guiding screen.

12. The filtration device according to claim 11, characterized in that, The inner diameter of the encapsulation hole varies in a stepped manner, gradually decreasing from the side closest to the filtrate guiding screen outwards, or gradually increasing from the side closest to the filtrate guiding screen outwards.

13. The filtration device according to claim 1 or 2, characterized in that, The filtration unit also includes an isolation layer disposed between the filtration layer and the filtrate guiding screen.

14. The filtration device according to claim 13, characterized in that, The surface roughness of the isolation layer on the side close to the filter layer is 2-25μm, and the softness is 100-250mN.

15. The filtration device according to claim 13, characterized in that, The thickness of the isolation layer is h1, and the thickness of the filtrate guiding screen is h2, with h1:h2 being 1:1-5.

16. The filtration device according to claim 13, characterized in that, The thickness of the isolation layer is 80-150 μm, and the air permeability is 60-160 cc / cm. 2 / sec; the thickness of the filtrate guiding screen is 400-650μm, and the porosity is 25-35%.

17. The filtration device according to claim 13, characterized in that, The isolation layer is one or more of non-woven fabric or PES film.

18. The filtration device according to claim 13, characterized in that, The isolation layer has an inlet port that is at least partially directly opposite and connected to the liquid inlet channel. The isolation layer is bonded to the filter layer and the filtrate guide screen by an adhesive layer on the isolation layer.

19. The filtration device according to claim 18, characterized in that, The adhesive layer permeates within the isolation layer and surrounds the liquid inlet of the isolation layer. The adhesive layer also covers the inner wall of the liquid inlet of the isolation layer to prevent the formation of a through-flow channel for liquid entering from the inner wall of the liquid inlet of the isolation layer between the liquid inlet of the isolation layer and the isolation layer.

20. The filtration device according to claim 18, characterized in that, The liquid inlet of the isolation layer and the inner wall of the liquid inlet channel of the filter layer form a stepped misalignment area.

21. A method for filtering protein-containing liquid for virus removal using the filtration device according to any one of claims 1-20, characterized in that, Includes the following steps: S1: Buffer replacement: Buffer is continuously supplied from the inlet channel into the inlet flow channel until it flows out from the filtrate channel of the filter device to form a permeation buffer, thereby filling the filter device with buffer. S2: Liquid Inlet: The protein-containing liquid is continuously conveyed from the liquid inlet channel into the liquid inlet flow channel; S3: Filtration: Protein-containing liquid permeates tangentially through the inlet guide screen and passes through the filter layer in the filtration unit to form a virus-removing permeate; S4: Drainage: The virus-free permeate flows along the filtrate guide screen and is discharged from the filtrate channel to obtain the virus-free protein-containing liquid.

22. The method for virus removal filtration of protein-containing liquid according to claim 21, characterized in that, In step S2, the inlet pressure is 20-40 psi.

23. The method for virus removal filtration of protein-containing liquid according to claim 21, characterized in that, Filtration flux greater than 180 L / (m 2 *h).

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