KR20080051011A - Micro filtration device for the separation of blood plasma - Google Patents

Abstract

A micro filtration device for separation of blood plasma is provided to separate the blood plasma from the whole blood by itself without the help of external equipment like a syringe pump. A micro filtration device for separation of blood plasma includes a whole blood inlet(120), a blood plasma outlet, a blood plasma storing chamber(150), a paper filter(200) and a micro-structure(190). The blood plasma outlet is used to discharge the blood plasma separated from the flowing whole blood to the outside. The paper filter is formed between the whole blood inlet and the blood plasma storing chamber, and separates the blood plasma from the whole blood. The micro-structure is formed inside the blood storing chamber to move the blood plasma.

Description

Micro filter element for plasma separation {MICRO FILTRATION DEVICE FOR THE SEPARATION OF BLOOD PLASMA}

The present invention relates to a micro filter element, and more particularly, to a micro filter element capable of separating plasma from whole blood by itself using capillary force without external driving.

The present invention is derived from the research conducted as part of the IT new growth engine core technology development project of the Ministry of Information and Communication and the Ministry of Information and Communication Research and Development. [Task Management No .: 2006-S-007-01, Title: Ubiquitous Health Management Module] /system]

In general, whole blood, human blood, is the best indicator for diagnosing health because it collects and contains a lot of information while constantly circulating inside all human tissues.

In particular, a protein chip, which is a kind of biochip, can diagnose specific cancer by quantitatively detecting or concentrating specific proteins dissolved in plasma from whole blood samples. At this time, the whole blood of a person used includes blood cell components such as red blood cells, white blood cells and platelets, and plasma components such as water, proteins, fats, sugars and other mineral ions. Therefore, it is very important to manufacture a biochip that can be detected with high sensitivity by effectively removing blood cells and other unnecessary components in human blood to isolate or concentrate only a specific protein.

Accordingly, various methods have been proposed for separating plasma from whole blood. For example, by placing microstructures smaller than blood cells in the flow path and pumping blood with a syringe pump installed outside, blood cells are filtered by the microstructures so that only plasma is extracted. A low-level diaphragm that prevents the release of plasma components only through the diaphragm by capillary forces; a porous medium or membrane is placed on the side or front of the blood flow to separate blood cells; By using the sedimentation effect of the blood cells caused by the formation of the blood cells and plasma layered method to extract only the plasma, the method of deflecting the flow of blood cells by applying an electrical signal has been proposed.

Hereinafter, looking at the conventional technical field proposed to separate plasma from whole blood.

Korean Patent No. 10-0577367, registered on April 28, 2006, entitled "Powerless Micro Blood Separator", suggests an apparatus for separating plasma by forceless capillary force. It is characterized in that the blood cell is installed by the blood extraction unit so as not to pass through only the plasma passes through the capillary force.

International Publication No. WO 04/027391, published on April 1, 2004 under the name of "blood analyzer and method of separating plasma," is provided with blood collection means, plasma separation means, and analysis means sequentially, An automatic analyzer for separating plasma in a flow path has been proposed, and the size of some flow paths is manipulated so that blood cell components can be stored and plasma components proceed smoothly.

United States Patent No. US 2005/0069459 A1, registered March 31, 2005, entitled “On chip sample preparation for whole blood analysis,” forms a channel on a biochip to separate biological particles and a large and short section at the inlet. We propose a technique and a device for separating by changing the particle transfer force by applying a pressure pulse of. It can be separated without a filter structure in the microchannel.

International Publication No. WO99 / 058172, published May 13, 1999 under the name of "filter device and method for processing blood," is wound in a state in which a blood processing filter layer and a space on a sheet in which blood flows more easily are stacked. It is related with the blood process filter apparatus which exposed the edge part of the sheet-shaped space layer to the outer peripheral surface or outer peripheral surface of a filter material. The laminated structure is spirally wound, and the filter material is characterized by using a nonwoven fabric, a woven fabric, a porous sheet, or the like.

However, in the related art, blood cells are stacked on a microstructure, a diaphragm, a membrane, a porous medium formed to separate plasma from whole blood, and the separation efficiency of plasma is reduced while closing the flow path, or it takes a long time to separate plasma. There is this. In addition, when an external device, such as a syringe pump, is used to move the sample, there is a problem in that it is difficult to separate or concentrate plasma continuously and efficiently due to a complicated driving method.

The present invention has been proposed to solve the above problems, and an object thereof is to provide a micro filter element capable of separating plasma from whole blood by itself without the help of an external device such as a syringe pump.

In addition, another object of the present invention is to provide a micro filter device which can prevent the plasma separation efficiency from being reduced due to the closing of the flow path by blood cells.

It is another object of the present invention to provide a micro filter element capable of shortening the time taken to separate plasma.

It is also another object to provide a micro filter element capable of detecting, separating or concentrating a particular biomaterial from separated plasma.

In addition, another object of the present invention is to provide a micro filter device that can be manufactured at a low price to be used as a disposable biochip.

Micro-filter element for separating the plasma from the whole blood of the present invention according to an aspect for achieving the above object is a whole blood inlet for introducing whole blood; A plasma outlet through which plasma separated from the introduced whole blood is released to the outside; A plasma storage chamber connected to the whole blood inlet and the plasma discharge port and configured to store the separated plasma; The plasma is formed between the whole blood inlet and the plasma storage chamber, the paper filter for separating the plasma from the introduced whole blood, and the plasma to move the whole blood flowing in the direction of the plasma discharge by the capillary force generated by itself without external driving. It comprises a microstructure formed in the storage chamber. The apparatus may further include a plasma pumping port for providing air pressure for releasing plasma stored in the plasma storage chamber to the outside and a channel connecting the plasma pumping port and the plasma storage chamber.

Here, the plasma inlet, the plasma discharge port and the plasma pumping port may be formed in the upper substrate, the plasma storage chamber, the microstructure and the channel may be formed in the lower substrate, between the upper substrate and the lower substrate The paper filter can be formed in the. At this time, the air gap of the paper filter may be smaller than 1um.

The upper substrate and the lower substrate may be formed of any one selected from the group consisting of plastic, silicon, rubber, and glass, polydimethyl siloxane (PDMS), polymethyl methacrylate (polymethylmethacrylate, PMMA) , Polycarbonate (PC), cycloolefin copolymer (CCO), polyamide (PA), polyethylene (PE), polypropylene (PP), polyphenylene ether , PPE), polystyrene (PS), polyoxymethylene (POM), polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE), polyvinyl chloride (polyvinylchloride, PVC ), Polyvinylidene fluoride (PVDF), polybutylene terephthalate (PBT), fluorinated ethylene propylene (fl uorinated ethylenepropylene (FEP) and perfluoroalkoxyalkane (PFA).

The microstructure and the plasma storage chamber preferably have a hydrophilic surface, and may be formed to have a hydrophilic surface by using an O ₂ plasma treatment or a surfactant.

The plasma storage chamber may be formed to increase the width in the direction of the plasma discharge port to increase the capillary force, the microstructure is selected from the group consisting of cylinders, cubes, cubes and polyhedra having a size in the range of 1um ~ 500um It may be formed of any one or a combination thereof.

In addition, it may further comprise a complementary capture probe ligand (ligand) formed on the surface of the microstructure in order to detect, isolate or concentrate a specific biomaterial.

In addition, the plasma storage chamber and the microstructure are hot embossing, injection molding, NC (numeric control) machining, laser ablation, electrical discharge, casting, light shaping It may be formed using any one method selected from the group consisting of Stereolithography, Rapid Prototyping and photolithography.

The upper substrate, the lower substrate and the paper filter may be formed using any one method selected from the group consisting of hot bonding, epoxy bonding, chemical bonding, ultrasonic bonding and plasma bonding.

The present invention can improve the plasma separation efficiency by using a paper filter with a larger number of structures per unit area than the microstructure for plasma separation, thereby having the effect of separating plasma from whole blood in a short time. In addition, by separating the plasma from the whole blood in a short time, there is an effect that can be prevented from reducing the plasma separation efficiency due to the blockage of the blood flow path.

The present invention can simplify the driving method as compared to the micro filter element that separates the plasma through the external drive by moving the plasma by the capillary force generated by itself without the external drive inside the micro filter element, through which the continuous and efficient It is effective to separate the plasma.

In addition, the micro-filter element of the present invention has an effect of detecting, separating or concentrating a desired specific biomaterial from the separated plasma by forming a microstructure to which the complementary capture probe ligand is attached.

In addition, by manufacturing the micro-filter element of the present invention made of a low-cost plastic, there is an effect that can be applied to a disposable biochip for detecting a specific disease using blood.

Hereinafter, the most preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the technical idea of the present invention.

1 is a perspective view of the plasma separation micro-filter element according to an embodiment of the present invention separated, Figure 2 is a plasma separation micro-filter element according to an embodiment of the present invention shown in Figure XX` It is a cross-sectional view shown.

As shown in Figure 1 and 2, the micro-filter element for plasma separation of the present invention is the whole blood inlet 120, the whole blood is introduced, the plasma discharge port 130 is released from the plasma separated from the introduced whole blood, Whole blood inlet 120 and the plasma discharge port 130 is connected, and formed between the plasma storage chamber 150, the whole blood inlet 120 and the plasma storage chamber 150 for storing the separated plasma, introduced whole blood Paper structure 200 for separating plasma from the microstructure formed in the plasma storage chamber 150 to move the whole blood flowing in the direction of the plasma discharge port 130 by the capillary force generated by itself without external drive ( 190).

In addition, the plasma pumping port 160 for providing the air pressure for releasing the plasma stored in the plasma storage chamber 150 and the channel 180 for connecting the plasma pumping port 160 and the plasma storage chamber 150 further It may include.

In addition, it may further include a complementary capture probe ligand (ligand) formed on the surface of the microstructure 190 in order to detect, separate or concentrate the specific biomaterial. In addition, an analytical device for detecting a biochemical reaction and a specific biomaterial may be additionally formed from the plasma stored in the plasma storage chamber 150. In particular, the protein detection biosensor for detecting protein components in blood and the micro filter element of the present invention are preferably combined.

At this time, the plasma inlet 120, the plasma discharge port 130 and the plasma pumping port 160 is formed on the upper substrate 110, the plasma storage chamber 150, the microstructure 190 and the channel 180 is lower The paper filter 200 is formed on the substrate 100 and is formed between the upper substrate 110 and the lower substrate 100. In addition, the plasma pumping hole corresponding part 170 corresponding to the plasma pumping hole 160 formed on the upper substrate 100 may be formed on the lower substrate 100.

The paper filter 200 may be formed at the bottom of the whole blood inlet 120, and may be fixed to the micro filter element by the combination of the upper substrate 110 and the lower substrate 100. In this case, in order to minimize the loss of the sample generated as the whole blood is absorbed by the paper filter 200, the paper filter 200 is preferably formed of a thin material, the air gap (gap) to properly filter blood cells It is good that it is several micrometers or less, Preferably it is smaller than 1 micrometer. In addition, in order to reduce clogging by blood cells, it is preferable that the porosity is large and formed so as to have a sufficient surface area for the blood volume. In this case, a large porosity means a large surface area per unit volume.

In addition, since the paper filter 200 is fixed through the combination of the upper substrate 110 and the lower substrate 100, the stack combination of the upper substrate 110, the lower substrate 100 and the paper filter 200 is introduced whole blood The upper substrate 110 and the lower substrate 100 should be in close contact with each other so as not to leak. To this end, the upper substrate 110, the lower substrate 100, and the paper filter 200 may be formed by using any one method selected from the group consisting of hot bonding, epoxy bonding, chemical bonding, ultrasonic bonding, and plasma bonding. Can be combined.

The plasma storage chamber 150 and the microstructure 190 may be formed of a hydrophilic material to generate strong capillary pressure and flow, or may be treated with oxygen plasma treatment on the surfaces of the microstructure 190 and the plasma storage chamber 150. It is preferable to form a hydrophilic surface using ₂ plasma treatment) or a surfactant.

Here, the microstructure 190 may generate a strong capillary pressure as the size is smaller, but adjusts the size of the microstructure 190 in consideration of process limitations, an increase in the volume and flow resistance of the plasma storage chamber 150. There is a need, and it is preferable to form to have a size in the range of 1um to 500um.

The plasma storage chamber 150 may be formed to increase in width in the direction of plasma discharge port 130, that is, in the advancing direction of plasma, in order to further increase capillary force by the microstructure 190.

The whole blood inlet 120, the plasma discharge port 130, the plasma pumping port 160, the plasma storage chamber 150, the microstructure 190 and the channel 180 are the upper substrate 110 and the lower substrate 100. ), And can be formed by, for example, hot embossing, injection molding, numerical control machining, laser ablation, electrical discharge, casting, optical molding It can be formed using any one method selected from the group consisting of Stereolithography, Rapid Prototyping and photolithography.

Here, when the upper substrate 110 and the lower substrate 100 is formed of plastic in order to apply to a low-cost disposable biochip, it is suitable to form using hot embossing or injection molding method.

The upper substrate 110 and the lower substrate 100 may be any one selected from the group consisting of plastic, silicon, rubber, and glass. Preferably, the upper substrate 110 and the lower substrate 100 may be formed of a plastic having low cost so as to be utilized in a disposable biochip. Examples of plastics include cycloolefin copolymers (COC), polydimethyl siloxane (PDMS), polymethylmethacrylate (PMMA), polycarbonate (PC) and polyamide. (polyamide, PA), polyethylene, PE, polypropylene, PP, polyphenylene ether (PPE), polystyrene (PS), polyoxymethylene (POM), polyether Polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE), polyvinylchloride (PVC), polyvinylidene fluoride (PVDF), polybutylene terephthalate (PBT) , Selected from the group consisting of fluorinated ethylenepropylene (FEP) and perfluoroalkoxyalkane (PFA) You can use one.

As such, the present invention can improve plasma separation efficiency by separating the plasma using the paper filter 200 having a larger number of structures per unit area than the micro filter device using the microstructure to separate plasma from whole blood. This can shorten the time required to separate plasma from whole blood.

In addition, by separating the plasma from the whole blood in a short time, it is possible to prevent the plasma separation efficiency from being reduced by the blockage of the blood cells.

In addition, the present invention can simplify the driving method as compared to the micro filter element that separates the plasma through the external drive by moving the plasma by the capillary force generated by itself without external drive, through which the plasma can be continuously and efficiently Can be separated.

In addition, the present invention by forming a microstructure 190 is attached to the complementary capture probe ligand, it is possible to detect, separate or concentrate the desired specific biomaterial from the separated plasma, additional reaction and detection unit in the micro filter element Easy to integrate

In addition, by manufacturing the micro-filter element of the present invention made of a low-cost plastic, it can be applied to disposable biochips that detect specific diseases using blood.

1 and 2, the operation principle of the micro filter element according to the embodiment of the present invention will be described.

First, when whole blood is injected into the micro filter element through the whole blood inlet 120, the paper filter 200 is first wetted by whole blood, and then the microstructures formed in the plasma storage chamber 150 under the paper filter 200 ( 190) and whole blood come into contact. Then, a strong capillary flow occurs in the direction of the plasma discharge port 130 due to the microstructure 190 formed in the plasma storage chamber 150. In this process, among the components constituting whole blood, blood cells are filtered by the paper filter 200 and only the plasma components are stored in the plasma storage chamber 150.

When the plasma stored in the plasma storage chamber 150 is to be discharged to the outside, the air flows into the plasma pumping port 160 connected to the plasma storage chamber 150 through the channel 180 to store the plasma storage chamber with air pressure ( The plasma stored in the 150 may be released to the outside through the plasma discharge port 130.

Here, the surface of the microstructure 190 is preferably hydrophilic so as to generate a strong capillary pressure, and the size of the microstructure 190 is very small. This will be described with reference to FIG. 3.

3 is a conceptual diagram illustrating capillary force in a microchannel.

Referring to FIG. 3A, the pressure in the capillary flow of the contact angle θ and the surface tension σ in the microchannel 300 composed of the two-dimensional slits having the height H is as follows.

Referring to FIG. 3B, the pressure in the capillary flow of the contact angle θ and the surface tension σ in the cuboidal microchannel 300 having a height H and a width W is as follows.

As in Equation 1 and Equation 2, the capillary pressure is inversely proportional to the size of the microchannel 300, and the smaller the contact angle, the greater the hydrophilicity. Therefore, in order to generate a strong capillary pressure, the surface of the channel becomes hydrophilic, and it is preferable to form a small channel, that is, a small microstructure, and a small gap between adjacent microstructures to induce strong capillary force.

In addition, it will be described with reference to FIGS. 4 and 5 where a difference in capillary force may occur depending on the shape and arrangement of the microstructure.

FIG. 4 is an exemplary diagram for describing capillary forces according to the arrangement of the microstructures formed in the plasma storage chamber shown in FIG. 1, and FIG. 5 illustrates the diversity of the microstructure shapes formed in the plasma storage chamber shown in FIG. 1. It is an illustrative diagram for explanation.

Referring to FIG. 4, the capillary pressure may be adjusted by adjusting a distance d1 (width direction) and d2 (length direction length) between the microstructures 190 as shown in Equation 1. That is, the size of the capillary force can be adjusted according to the arrangement of the microstructure 190, and preferably, it should be formed to have a size and arrangement capable of minimizing the induction resistance while maximizing the capillary force.

Referring to Figure 5, the shape of the microstructure may be formed of any one selected from the group consisting of a cylinder, a cube, a cube and a polyhedron or a combination thereof. In this case, the cross-sectional shape of the microstructure may be any one selected from the group consisting of a circle, a triangle, a square, a rhombus, an ellipse, and a polyhedron or a combination thereof.

As such, the present invention can control the size of the capillary force by adjusting the size, shape and arrangement of the microstructure, the strong capillary force induced by controlling the size, shape and arrangement of the microstructure frame in the plasma storage chamber Increases the plasma's rate of movement, which means that plasma separation can proceed rapidly.

Although the technical spirit of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will appreciate that various embodiments within the scope of the technical idea of the present invention are possible.

1 is a perspective view showing the separation of the micro-filter element for plasma separation according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the microfilter device for plasma separation according to the embodiment of the present invention taken along the line X-X ′ of FIG. 1;

3 is a conceptual diagram illustrating capillary force in a microchannel.

4 is an exemplary view for explaining the capillary force according to the arrangement of the microstructure shown in FIG.

5 is an exemplary view for explaining the variety of microstructure shapes shown in FIG.

    *** Explanation of symbols on the main parts of the drawing ***

100: lower substrate 110: upper substrate

120: whole blood inlet 130: plasma outlet

140: plasma outlet counter 150: plasma storage chamber

160: plasma pumping port 170: plasma pumping port counterpart

180: channel 190: microstructure

200: paper filter 300: microchannel

Claims (14)

In a micro filter element for separating plasma from whole blood, Whole blood inlet for whole blood flow; A plasma outlet through which plasma separated from the introduced whole blood is released to the outside; A plasma storage chamber connected to the whole blood inlet and the plasma outlet, for storing the separated plasma; A paper filter formed between the whole blood inlet and the plasma storage chamber to separate plasma from the whole blood; And Microstructure formed in the plasma storage chamber to move the whole blood flowing in the direction of the plasma discharge port by the capillary force generated by itself without external drive Micro filter element comprising a. The method of claim 1, A plasma pumping port providing air pressure for releasing plasma stored in the plasma storage chamber to the outside; And A channel connecting the plasma pumping port and the plasma storage chamber Mite filter element further comprising. The method of claim 2, The plasma inlet, the plasma discharge port and the plasma pumping port are formed on an upper substrate, the plasma storage chamber, the microstructure and the channel are formed on a lower substrate, and the paper filter is formed between the upper substrate and the lower substrate. Micro filter element. The method of claim 3, And the upper substrate and the lower substrate are formed of any one selected from the group consisting of plastic, silicon, rubber, and glass. The method of claim 3, The upper substrate and the lower substrate are polydimethyl siloxane (PDMS), polymethyl methacrylate (PMMA), polycarbonate (PC), cycloolefin copolymer (cycloolefin copolymer, COC) , Polyamide (PA), polyethylene (PE), polypropylene (PP), polyphenylene ether (PPE), polystyrene (PS), polyoxymethylene (POM) , Polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE), polyvinylchloride (PVC), polyvinylidene fluoride (PVDF), polybutylene terephthalate ( polybutyleneterephthalate (PBT), fluorinated ethylenepropylene (FEP) and perfluoroalkoxyalkane (PFA) Micro filter element formed of any one selected. The method of claim 1, The air filter of the paper filter is less than 1um micro filter element. The method of claim 1, The microstructure and the plasma storage chamber have a hydrophilic surface. The method of claim 1, Micro-filter element formed of the fine structure and the plasma containing chamber by using the plasma treatment (O ₂ plasma treatment) or a surface active agent so as to have a hydrophilic surface. The method of claim 1, And the plasma storage chamber is formed to increase in width in the direction of plasma discharge to increase capillary force. The method of claim 1, The microstructure is a micro filter element having a size in the range of 1um ~ 500um. The method of claim 1, The microstructure is a micro filter element formed of any one or a combination thereof selected from the group consisting of a cylinder, a cube, a cube and a polyhedron. The method of claim 1, The plasma storage chamber and the microstructure are formed by hot embossing, injection molding, normal control machining, laser ablation, electrical discharge, casting, steoliolithography, and the like. ), A micro filter element formed using any one method selected from the group consisting of rapid prototyping and photolithography. The method of claim 3, And the upper substrate, the lower substrate, and the paper filter are formed using any one method selected from the group consisting of hot bonding, epoxy bonding, chemical bonding, ultrasonic bonding, and plasma bonding. The method of claim 1, And a complementary capture probe ligand formed on the surface of the microstructure to detect, isolate or concentrate a particular biomaterial.

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