Polyvinyl alcohol hydrogel sampling swab, preparation method thereof and tear fluid collector

Abstract

The invention provides a polyvinyl alcohol hydrogel sampling swab, a preparation method of the polyvinyl alcohol hydrogel sampling swab and a tear fluid collector, and relates to the technical field of tear fluid sampling swads.The sampling swab is made of hydrogel, and the hydrogel is a copolymer formed by polyvinyl alcohol and polysaccharide. The technical problems that an existing sampling swab easily causes eye discomfort in the sampling process, and meanwhile, the sampling efficiency and the utilization rate of a sampled sample are low, and the detection precision is low are effectively solved, and the purposes that no stimulation is caused to the eyes during sampling, the sample can be completely released into a detection solvent, and the detection accuracy is high are achieved. Therefore, the sample utilization rate is effectively improved, and the detection precision is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of tear fluid sampling swabs, and in particular to a polyvinyl alcohol hydrogel sampling swab and a preparation method thereof, and a tear fluid collector. Background Art

[0002] Tear sampling swabs are usually made of fiber materials, such as polyester and cellulose, which do not produce specific and permanent adsorption with proteins. Their microstructures contain microcapillaries and microchannels, which can quickly absorb liquids and collect the test objects. During the test, the sampling swab is immersed in a buffer solution, and the collected samples are released into the buffer solution for subsequent immunoassays. However, due to the low content of tears, the sample content that can be collected is low. During the transfer of samples to the detection solvent, the structure and properties of the protein may be destroyed, and not all samples adsorbed in the sampling swab can be transferred to the solvent. In this case, after dilution with the buffer solution, the sample concentration is lower, which will reduce the detection sensitivity. In addition, when wiping the mucous membrane of the eye, the fiber swab will cause discomfort due to its rough surface.

[0003] U.S. Patent No. 8,445,293 discloses a tear sample collection device, in which the collection swab material is fiber material, and the tear fluid is collected in the swab by using the capillary effect. Unlike the traditional detection method, it does not need to immerse the collector in a buffer solution to release the sample, but uses the capillary effect to allow the swab to continue to absorb the buffer solution. A collector is connected to the tail end of the swab, and the buffer solution flushes the sample collected in the swab into the collector, thereby improving the sensitivity of the detection without excessively diluting the sample. However, this method still does not solve the problem of discomfort caused by the rough surface of the sampling swab during sampling.

[0004] In summary, the existing technology for collecting tear samples has the problems of low collection efficiency, low utilization rate of the collected protein samples that can be used for detection, and easy to cause eye discomfort.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] One of the purposes of the present invention is to provide a polyvinyl alcohol hydrogel sampling swab, which not only does not irritate the eyes during sampling and does not cause discomfort, but also can completely release the sample into the detection solvent.

[0007] The second object of the present invention is to provide a method for preparing a polyvinyl alcohol hydrogel sampling swab, which has a simple process, high efficiency and high success rate.

[0008] The third object of the present invention is to provide a tear liquid collector, which is beneficial to improving sample utilization and detection accuracy.

[0009] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0010] In a first aspect, a polyvinyl alcohol hydrogel sampling swab is provided, wherein the sampling swab is made of a hydrogel material;

[0011] The hydrogel material is a copolymer formed by polyvinyl alcohol and polysaccharide.

[0012] Furthermore, the molecular weight of the polyvinyl alcohol is between 50,000 and 150,000.

[0013] Furthermore, the alcoholysis rate of the polyvinyl alcohol is between 80% and 99%.

[0014] Further, the polysaccharide includes at least one of dextran and chitosan;

[0015] Preferably, the molecular weight of the polysaccharide is between 40,000 and 500,000.

[0016] Furthermore, the ratio of polyvinyl alcohol to polysaccharide is between 2:1 and 1:2.

[0017] In a second aspect, a method for preparing a polyvinyl alcohol hydrogel sampling swab as described in any one of the above items comprises the following steps:

[0018] Mixing polyvinyl alcohol and polysaccharide in water to obtain a mixed solution;

[0019] The mixed solution is first subjected to freeze-thaw treatment, or a cross-linking agent is added to react, and then freeze-dried to obtain the polyvinyl alcohol hydrogel sampling swab.

[0020] Furthermore, the freeze-thaw treatment includes first treating at -18°C to -25°C for 30min to 6h, and then treating at room temperature for 30min to 6h;

[0021] Preferably, the freeze-thaw treatment is performed 2 to 10 times.

[0022] Furthermore, the amount of the cross-linking agent added is between 1% and 5%, and the reaction time is between 12h and 24h.

[0023] Furthermore, the freeze-drying step further includes precooling the obtained product;

[0024] Preferably, the precooling temperature is -75°C to -85°C.

[0025] In a third aspect, a tear collector comprises the polyvinyl alcohol hydrogel sampling swab described in any one of the above items.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects:

[0027] The polyvinyl alcohol hydrogel sampling swab provided by the present invention, on the one hand, has a soft surface of the hydrogel material and a jelly-like property after contacting water, so it does not irritate the eyes during sampling and does not cause discomfort; on the other hand, the material can be dissolved after contacting sufficient water, so the sample attached to the surface can be completely released into the detection solvent, thereby effectively improving the sample utilization rate and significantly improving the detection accuracy.

[0028] The preparation method of the polyvinyl alcohol hydrogel sampling swab provided by the invention has simple process, high efficiency and high success rate.

[0029] The tear liquid collector provided by the present invention is beneficial to improving sample utilization and detection accuracy. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The existing tear collector for in vitro testing has a rough surface of the sampling swab, which can irritate the eye mucosa, causing foreign matter and discomfort in the eyes during use. It also has the disadvantages of low collection efficiency and low utilization rate of sampled samples, resulting in low detection accuracy. In order to solve the above problems, the technical solution of the present invention is proposed.

[0032] According to a first aspect of the present invention, a polyvinyl alcohol hydrogel sampling swab is provided, wherein the sampling swab is made of a hydrogel material;

[0033] Polyvinyl alcohol (PVA) hydrogel is similar to jelly in properties, with a soft surface and stickiness. Therefore, when wiping the intraocular mucosa, it does not produce a rough pulling feeling, and the collected sample can also adhere to the surface of the swab.

[0034] The hydrogel material is a copolymer formed by polyvinyl alcohol and polysaccharides. Since polysaccharides have good water solubility, the dry hydrogel material formed by it can form a gel when encountering a small amount of water, and can dissolve when encountering a large amount of water. Therefore, the sample collected on the surface can be completely dissolved in the solvent with basically no loss of sample, which is beneficial to improve the detection accuracy.

[0035] In a preferred embodiment, the molecular weight of polyvinyl alcohol (PVA) can be between 50,000 and 150,000, and its typical but non-limiting molecular weight is, for example, 50,000, 70,000, 90,000, 110,000, 130,000, and 150,000. The appropriate molecular weight of polyvinyl alcohol is more conducive to crystallization and gel formation under simple freeze-thaw conditions, and the mechanical properties of the prepared hydrogel will not be too strong or too weak to affect subsequent use; if the molecular weight of polyvinyl alcohol is too low, it will require a longer freezing time and more freeze-thaw times to form gel, and the gelation process is cumbersome; if the molecular weight of polyvinyl alcohol is too high, the mechanical properties of the formed hydrogel will be too strong, it will not be easily soluble in water, and the release rate of the protein in subsequent use will be reduced.

[0036] In a preferred embodiment, the alcoholysis rate of polyvinyl alcohol can be between 80% and 99%, and its typical but non-limiting alcoholysis rates are, for example, 80%, 82%, 84%, 86%, 88%, 90%, 95%, and 99%. An appropriate alcoholysis rate of polyvinyl alcohol is more conducive to improving the degree of crosslinking of gelation and enhancing the mechanical properties. If the alcoholysis rate of polyvinyl alcohol is too low, it will lead to difficulty in gelation, and the resulting hydrogel will have a low degree of crosslinking and too low mechanical strength.

[0037] In the present invention, the polysaccharide includes but is not limited to at least one of dextran and chitosan.

[0038] In a preferred embodiment, the molecular weight of the polysaccharide may be between 40,000 and 500,000, and typical but non-limiting molecular weights include 40,000, 60,000, 80,000, 100,000, 150,000, 200,000, 250,000, 300,000, 350,000, 400,000, 450,000, and 500,000. If the molecular weight of the polysaccharide is too low, the sugar molecules will not be easily entangled in the PVA crystals, and the resulting hydrogel will have a low sugar content and will not be easily soluble in water during use, resulting in a low protein release rate. If the molecular weight of the polysaccharide is too high, the hydrogel will not be easily soluble in water, affecting subsequent use.

[0039] In a preferred embodiment, the mass ratio of polyvinyl alcohol (PVA) to polysaccharide can be between 2:1 and 1:2, for example, 2:1, 1.5:1, 1:1, 1:1.5, 1:2, but not limited to this; if the PVA ratio is too high, the resulting hydrogel will be too strong and insoluble in water, thereby reducing the protein release rate; if the polysaccharide ratio is too high, it will be difficult to prepare the hydrogel, resulting in the resulting hydrogel being too low in strength, being extremely soluble in water, and being unable to be used for sampling.

[0040] According to a second aspect of the present invention, there is provided a method for preparing the polyvinyl alcohol hydrogel sampling swab described in any one of the above items, comprising the following steps:

[0041] Mixing polyvinyl alcohol and polysaccharide in water to obtain a mixed solution;

[0042] The mixed solution is first freeze-thawed, or a cross-linking agent is added to react, and then freeze-dried to obtain a polyvinyl alcohol hydrogel sampling swab.

[0043] The preparation method of the polyvinyl alcohol hydrogel sampling swab provided by the invention has simple process, high efficiency and high success rate.

[0044] In a preferred embodiment, the freeze-thaw treatment includes first treating at -18°C to -25°C for 30 min to 6 h, and then treating at room temperature for 30 min to 6 h; wherein the number of freeze-thaw treatments may be between 2 and 10 times, and typical but non-limiting numbers are, for example, 2, 3, 4, 5, 6, 7, 8, 9, and 10 times, which are more conducive to improving the formation effect of the hydrogel.

[0045] In a preferred embodiment, the amount of cross-linking agent added can be between 1% and 5%, and its typical but non-limiting amount is, for example, 1%, 2%, 3%, 4%, and 5%, which is more conducive to improving the cross-linking effect of the hydrogel. The reaction time can be between 12h and 24h, and its typical but non-limiting time is, for example, 12h, 14h, 16h, 18h, 20h, 22h, and 24h, which is more conducive to ensuring that the hydrogel is fully cross-linked; wherein, the cross-linking agent can be glutaraldehyde, but is not limited thereto.

[0046] In a preferred embodiment, the process further includes precooling the obtained product before freeze-drying; wherein the precooling temperature may be -75°C to -85°C, which can rapidly condense water molecules in the hydrogel network, thereby forming pores after freeze-drying.

[0047] A typical preparation method of a polyvinyl alcohol hydrogel sampling swab comprises the following steps:

[0048] (1) dissolving polyvinyl alcohol (PVA) and polysaccharide in water to obtain a polyvinyl alcohol solution and a polysaccharide solution, respectively;

[0049] Wherein, the concentration of polyvinyl alcohol solution is 3% to 10%, and the concentration of polysaccharide solution is 5% to 20%;

[0050] The polyvinyl alcohol solution and the polysaccharide solution are mixed at room temperature, and bubbles are removed by ultrasound to obtain a mixed solution;

[0051] (2) subjecting the mixed solution obtained in step (1) to a freeze-thaw cycle to form a gel; or by adding a chemical crosslinking agent and stirring the reaction at room temperature to form a gel;

[0052] The freeze-thaw process includes first treating the sample at -18°C to -25°C for 30 minutes to 6 hours, and then treating the sample at room temperature for 30 minutes to 6 hours, which is considered as one cycle. The number of freeze-thaw cycles is between 2 and 10.

[0053] The amount of the chemical cross-linking agent is 1% to 5%, and the stirring reaction time at room temperature is 12h to 24h.

[0054] (3) freeze-drying the material obtained in step (2) to obtain a polyvinyl alcohol hydrogel sampling swab;

[0055] Before freeze-drying, the obtained hydrogel is placed in a refrigerator at -75°C to -85°C for pre-cooling, which can make the water molecules in the hydrogel network condense quickly, thereby forming pores after freeze-drying.

[0056] According to a third aspect of the present invention, a tear collector is provided, comprising the polyvinyl alcohol hydrogel sampling swab described in any one of the above items.

[0057] The tear liquid collector provided by the present invention is beneficial to improving sample utilization and detection accuracy.

[0058] The present invention is further described below by way of examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or directly purchased from the market.

[0059] Example 1

[0060] A method for preparing a polyvinyl alcohol hydrogel sampling swab comprises the following steps:

[0061] S1: Dissolve 1g of polyvinyl alcohol (PVA, 28-99 type, molecular weight 125000) in 20ml of 90℃ deionized water, and dissolve 1g of dextran (molecular weight 500000) in 10ml of deionized water. Dissolve the two fully and then mix them. Stir at room temperature. Remove bubbles by ultrasound during stirring to obtain a mixed solution.

[0062] S2: placing the mixed solution obtained in step S1 in a culture dish and placing it in a -20°C environment overnight; taking it out, placing it at room temperature for 1 hour, and then placing it in -20°C for 1 hour, which is a freeze-thaw cycle, and repeating the freeze-thaw cycle 3 times until the material in the culture dish has no fluidity at room temperature;

[0063] S3: The product obtained in step S2 is placed in a -80°C refrigerator for precooling, and then freeze-dried to obtain a polyvinyl alcohol hydrogel sampling swab.

[0064] Example 2

[0065] The difference between this embodiment and embodiment 1 is that, in step S1, the amount of dextran is 2 g, which is dissolved in 20 ml of deionized water;

[0066] The remaining steps are the same as those in Example 1 to obtain a polyvinyl alcohol hydrogel sampling swab.

[0067] Example 3

[0068] The difference between this embodiment and embodiment 1 is that, in step S1, 1 g of polyvinyl alcohol (type 28-99) is dissolved in 10 ml of 90° C. deionized water;

[0069] The remaining steps are the same as those in Example 1 to obtain a polyvinyl alcohol hydrogel sampling swab.

[0070] Example 4

[0071] The difference between this embodiment and embodiment 1 is that in step S2, the freeze-thaw cycle is repeated 5 times;

[0072] The remaining steps are the same as those in Example 1 to obtain a polyvinyl alcohol hydrogel sampling swab.

[0073] Example 5

[0074] A method for preparing a polyvinyl alcohol hydrogel sampling swab comprises the following steps:

[0075] S1: Dissolve 1g of polyvinyl alcohol (PVA, 17-88 type) in 20ml of 90°C deionized water, and dissolve 1g of dextran in 10ml of deionized water. Dissolve the two separately and mix them. Add 4ml of 50% glutaraldehyde solution at the same time, stir at room temperature, remove bubbles by ultrasound during stirring, and obtain a mixed solution.

[0076] S2: stirring the mixed solution obtained in step S1 at room temperature for 18 hours until the solution coagulates;

[0077] S3: The product obtained in step S2 is placed in a -80°C refrigerator for precooling, and then freeze-dried to obtain a polyvinyl alcohol hydrogel sampling swab.

[0078] Example 6

[0079] The difference between this embodiment and embodiment 1 is that in step S1, the amount of polyvinyl alcohol used is 2 g;

[0080] The remaining steps are the same as those in Example 1 to obtain a polyvinyl alcohol hydrogel sampling swab.

[0081] Example 7

[0082] The difference between this embodiment and embodiment 1 is that in step S1, the amount of polyvinyl alcohol used is 1.5 g;

[0083] The remaining steps are the same as those in Example 1 to obtain a polyvinyl alcohol hydrogel sampling swab.

[0084] Example 8

[0085] The difference between this embodiment and embodiment 1 is that, in step S1, the molecular weight of polyvinyl alcohol is between 89000 and 98000, and the alcoholysis rate is 99%;

[0086] The remaining steps are the same as those in Example 1 to obtain a polyvinyl alcohol hydrogel sampling swab.

[0087] Example 9

[0088] The difference between this embodiment and embodiment 1 is that, in step S1, an equal amount of dextran is replaced by chitosan (molecular weight of 500,000);

[0089] The remaining steps are the same as those in Example 1 to obtain a polyvinyl alcohol hydrogel sampling swab.

[0090] Comparative Example 1

[0091] This comparative example provides a sampling swab, which is an existing flocking swab (PVA flocking swab).

[0092] Comparative Example 2

[0093] The difference between this comparative example and Example 1 is that in step S1, an equal amount of polyvinyl alcohol is replaced by polyethylene glycol (PEG);

[0094] The remaining steps are the same as those in Example 1 to obtain a sampling swab.

[0095] Compared with Example 1, the defect of this comparative example is that the hydrogel formation effect is poor.

[0096] Comparative Example 3

[0097] The difference between this comparative example and Example 1 is that in step S1, an equal amount of glucan is replaced by fructose;

[0098] The remaining steps are the same as those in Example 1 to obtain a sampling swab.

[0099] Compared with Example 1, the defect of this comparative example is that the utilization rate of fructose in the gelation process is low, resulting in that most of the obtained hydrogel components are PVA, which has too strong mechanical properties and does not absorb water after freeze-drying, greatly affecting the performance of the sampling swab.

[0100] Test example

[0101] The sampling swabs obtained in Examples 1-9 and Comparative Example 1 were tested for BSA protein adsorption and release rate. The results are shown in Table 1.

[0102] The test method is to soak the freeze-dried swab with 100ul of normal saline, dip it in 20ul of 10mg / ml BSA protein solution, place the swab in 400ul of normal saline, elute the BSA protein on the swab surface; use the BCA method to measure the BSA protein content in the eluate.

[0103] Table 1 Adsorption and release rate of BSA protein by sampling swab

[0104]

[0105] It can be seen from Table 1 that the protein release rate of the sampling swab of the present invention is high, which is significantly better than the flocking swab of Comparative Example 1, which is beneficial to improving sample utilization and detection accuracy.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A polyvinyl alcohol hydrogel sampling swab, characterized in that: The sampling swab is made of hydrogel material; The hydrogel material is a copolymer formed by polyvinyl alcohol and polysaccharide.

2. The polyvinyl alcohol hydrogel sampling swab according to claim 1, characterized in that: The molecular weight of the polyvinyl alcohol is between 50,000 and 150,000.

3. The polyvinyl alcohol hydrogel sampling swab according to claim 2, characterized in that: The alcoholysis rate of the polyvinyl alcohol is between 80% and 99%.

4. The polyvinyl alcohol hydrogel sampling swab according to any one of claims 1 to 3, characterized in that: The polysaccharide comprises at least one of dextran and chitosan; Preferably, the molecular weight of the polysaccharide is between 40,000 and 500,000.

5. The polyvinyl alcohol hydrogel sampling swab according to claim 4, characterized in that: The mass ratio of the polyvinyl alcohol to the polysaccharide is between 2:1 and 1:

2.

6. A method for preparing the polyvinyl alcohol hydrogel sampling swab according to any one of claims 1 to 5, characterized in that: The following steps are involved: Mixing polyvinyl alcohol and polysaccharide in water to obtain a mixed solution; The mixed solution is first subjected to freeze-thaw treatment, or a cross-linking agent is added to react, and then freeze-dried to obtain the polyvinyl alcohol hydrogel sampling swab.

7. The preparation method according to claim 6, characterized in that: The freeze-thaw treatment includes first treating at -18°C to -25°C for 30min to 6h, and then treating at room temperature for 30min to 6h; Preferably, the freeze-thaw treatment is performed 2 to 10 times.

8. The preparation method according to claim 6, characterized in that: The added amount of the cross-linking agent is between 1% and 5%, and the reaction time is between 12h and 24h.

9. The preparation method according to any one of claims 6 to 8, characterized in that: The freeze-drying step also includes precooling the obtained product; Preferably, the precooling temperature is -75°C to -85°C.

10. A tear liquid collector, characterized in that: The invention comprises the polyvinyl alcohol hydrogel sampling swab described in any one of claims 1 to 5.

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