JP7735713B2 - Method for manufacturing hydrophilic glass substrate - Google Patents

Description

This disclosure relates to a method for manufacturing a hydrophilic glass substrate.

A technology has been proposed to coat the surface of a substrate with a special polymer in order to create devices for capturing specific cells in blood and body fluids (blood cells, cancer cells present in blood and body fluids, etc.).

However, it is difficult to create a smooth surface with coating for some special polymers, and the roughness of the surface affects the ability to capture specific cells. Therefore, there is a need for a substrate with a surface with controlled roughness that is excellent for capturing specific cells such as cancer cells (see Patent Document 1, etc.).

Special Publication No. 2005-523981

The present disclosure aims to solve the above-mentioned problems and provide a method for manufacturing a hydrophilic glass substrate on which a hydrophilic polymer layer with controlled surface roughness is formed.

The present disclosure relates to a method for manufacturing a hydrophilic glass substrate, which includes a step of forming a hydrophilic polymer layer on a glass substrate that has been subjected to an alcohol treatment.

The present disclosure provides a method for manufacturing a hydrophilic glass substrate that includes a step of forming a hydrophilic polymer layer on an alcohol-treated glass substrate, making it possible to provide a hydrophilic glass substrate on which a hydrophilic polymer layer having a surface with controlled roughness has been formed. This is expected to improve the ability to capture specific cells, such as cancer cells.

1 is a photograph of a hydrophilic glass substrate prepared in Example 3 and Comparative Example 1. FIG.

The present disclosure relates to a method for manufacturing a hydrophilic glass substrate, which includes the step of forming a hydrophilic polymer layer on a glass substrate that has been subjected to alcohol cleaning. By forming a hydrophilic polymer layer on the surface of a glass substrate that has been previously subjected to alcohol treatment, it is possible to control the unevenness of the substrate surface, and to provide a hydrophilic glass substrate coated with a hydrophilic polymer layer that has low surface roughness and high smoothness.

Tumor cells (e.g., cancer cells) that appear in bodily fluids, such as circulating tumor cells (several to several hundred cells per mL of blood), are very rare. Therefore, capturing as many tumor cells as possible in collected bodily fluids is considered important for testing. The method disclosed herein involves coating the surface of a glass substrate that has been pre-treated with alcohol with a hydrophilic polymer, controlling the surface roughness and forming a hydrophilic polymer layer with low surface roughness and high smoothness. The roughness of the hydrophilic polymer layer affects the capture ability of specific cells, such as cancer cells. Controlling the surface roughness and increasing smoothness is expected to achieve excellent capture performance for specific cells. Therefore, measuring the number of tumor cells captured in the hydrophilic polymer layer formed on the surface of an alcohol-treated glass substrate can determine the number of tumor cells in bodily fluids, which can be used to confirm the effectiveness of cancer treatment. Furthermore, culturing the captured tumor cells and confirming the efficacy of anticancer drugs, etc., using the cultured cells allows for the efficacy of anticancer drugs, etc., to be confirmed outside the body prior to administration, and is also useful for selecting anticancer drugs, etc.

(Method for manufacturing hydrophilic glass substrate)
The method for producing the hydrophilic glass substrate includes a step of forming a hydrophilic polymer layer on a glass substrate that has been subjected to an alcohol treatment (hereinafter also referred to as an "alcohol-treated glass substrate").

The type of glass constituting the glass substrate is not particularly limited, and examples thereof include soda-lime glass, alkali-free glass, borosilicate glass (SiO ₂ -B ₂ O ₃ -ZnO-based glass, SiO ₂ -B ₂ O ₃ -Bi ₂ O ₃ -based glass, etc.), potash glass, crystal glass (glass containing PbO, for example, SiO ₂ -PbO-based glass, SiO ₂ -PbO-B ₂ O _3- based glass, SiO ₂ -B ₂ O ₃ -PbO-based glass, etc.), titanium crystal glass, barium glass, boron glass (B ₂ O _{3 -ZnO} - _PbO - _based glass, _{B 2 O 3} -ZnO-Bi ₂ O ₃ -based glass, B ₂ O ₃ Examples of the glass include soda-zinc glass, soda-barium glass (BaO—SiO _{2-based glass, etc.), strontium glass, alumina silicate glass, soda-zinc glass, and soda-barium glass (BaO—SiO 2} -based glass, etc.). These glasses may be used alone or in combination of two or more.

The thickness of the glass substrate is not particularly limited, but the average thickness is preferably 100 μm or more and 3000 μm or less, and more preferably 100 μm or more and 1000 μm or less. The average thickness is calculated by measuring the thickness at 10 random locations using a micrometer and averaging the measured values.

The alcohol treatment agent used in the alcohol treatment may, for example, be a treatment agent containing various alcohols. Examples of various alcohols include monohydric alcohols and polyhydric alcohols, with monohydric alcohols being preferred. The alcohol may be either an acyclic alcohol (straight-chain or branched alcohol) or a cyclic alcohol, with acyclic alcohols being preferred. The alcohol may be either saturated or unsaturated, with saturated alcohols being preferred. The alcohol may contain an ether bond in the hydrocarbon chain or various substituents other than hydroxyl groups. The alcohol is preferably in a liquid state at room temperature (25°C). One or more types of alcohol may be used in combination.

The number of carbon atoms in the monohydric alcohol is preferably 1 to 8, more preferably 1 to 4, and even more preferably 1 to 2. Specific examples of monohydric alcohols include aliphatic alcohols such as methanol, ethanol, (n-, iso-)propanol, (n-, sec-, tert-)butanol, pentanol, hexanol, heptanol, octanol, nonanol, and decanol. Among these, from the viewpoint of controlling the unevenness of the hydrophilic polymer layer, methanol treatment, ethanol treatment, and propanol treatment using methanol, ethanol, or propanol are preferred.

The number of carbon atoms in the polyhydric alcohol is preferably 2 to 8, and more preferably 2 to 4. Specific examples of polyhydric alcohols include dihydric aliphatic alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, 1,3-propanediol, and dipropylene glycol; trihydric aliphatic alcohols such as glycerin; and the like.

The alcohol treatment may be either a treatment using a treatment agent containing only one or more alcohols, or a treatment using a mixed treatment agent containing one or more alcohols with water and/or an organic solvent other than the alcohols (mixed solvent treatment). The organic solvent other than the alcohol is preferably one that has good compatibility with alcohol, such as the aforementioned organic solvents other than alcohol that have good compatibility. In a mixed treatment agent containing alcohol and water and/or an organic solvent other than the alcohols, the alcohol content may be selected as appropriate, but is preferably 50% by mass or more, and more preferably 80% by mass or more.

The treatment method using the alcohol treatment agent can be any method that allows contact between the alcohol treatment agent and the glass substrate. Examples include immersing the glass substrate in the alcohol treatment agent, applying the alcohol treatment agent to the glass substrate (using a brush, etc.) or spraying it, and injecting the alcohol treatment agent into a container (glass substrate) such as a slide chamber.

From the perspective of controlling the surface irregularities, it is preferable to perform the alcohol treatment two or more times. One alcohol treatment is defined as the period from contacting (treating) the alcohol treatment agent with the glass substrate (while rocking the alcohol treatment agent in approximately horizontal and vertical directions as necessary) to stopping the contact (treatment) between the alcohol treatment agent and the glass substrate. For example, one alcohol treatment consists of injecting the alcohol treatment agent into a container (glass substrate) and leaving it there (contacting), sucking or pushing out the alcohol treatment agent using a discharging device such as a pipette as necessary (by rocking in approximately horizontal and vertical directions), and then discharging the alcohol treatment agent from the container (releasing contact). This series of processes corresponds to one alcohol treatment, and if such a series of processes is performed twice, the number of alcohol treatments is two.

The treatment temperature for the alcohol treatment agent can be set appropriately taking into consideration the treatment efficiency, the unevenness of the hydrophilic polymer layer, etc., and can be, for example, between 5 and 80°C.

The treatment time for the alcohol treatment agent (contact time between the alcohol treatment agent and the glass substrate) can also be selected appropriately from the same perspective, but is preferably 1 minute or more, more preferably 3 minutes or more, and even more preferably 5 minutes or more. There are no particular limitations on the upper limit of the treatment time, but from the perspective of production efficiency, it is preferably 5 hours or less, more preferably 1 hour or less, and even more preferably 30 minutes or less. Note that the treatment time is the treatment time for one alcohol treatment (the time the alcohol treatment agent is in contact with the glass substrate); for example, if alcohol treatment is performed two or more times, it is desirable that the treatment time for each alcohol treatment be within the above range.

The alcohol-treated glass substrate can be produced by contacting the alcohol treatment agent with the glass substrate using various methods and then drying (natural drying, etc.) as necessary.

At least a part (part or all) of the surface of the alcohol-treated glass substrate (on which a hydrophilic polymer layer is not formed) preferably has a water contact angle of 65° or less, more preferably 62° or less. The lower limit is not particularly limited, and the smaller the limit, the better.
In this specification, the contact angle of water can be measured by the method described in the examples below.

After preparing an alcohol-treated glass substrate using the method described above, a hydrophilic polymer layer is formed on the surface of the alcohol-treated glass substrate. This results in a hydrophilic glass substrate with a hydrophilic polymer layer formed on the surface of the alcohol-treated glass substrate.

The hydrophilic polymer constituting the hydrophilic polymer layer can be appropriately selected from those having hydrophilic properties. Examples include homopolymers and copolymers of one or more hydrophilic monomers, and copolymers of one or more hydrophilic monomers with other monomers. The hydrophilic polymers may be used alone or in combination of two or more.

Examples of homopolymers and copolymers of the hydrophilic monomers include polyacrylic acid, polyacrylic acid esters, polymethacrylic acid, polymethacrylic acid esters, polyacryloylmorpholine, polymethacryloylmorpholine, polyacrylamide, polymethacrylamide, polyalkoxyalkyl acrylates, and polyalkoxyalkyl methacrylates.

As the hydrophilic monomer in the copolymer of the hydrophilic monomer and another monomer, various monomers having a hydrophilic group can be used. Examples of the hydrophilic group include known hydrophilic groups such as an amide group, a sulfate group, a sulfonic acid group, a carboxylic acid group, a hydroxyl group, an amino group, an amide group, and an oxyethylene group.

Specific examples of hydrophilic monomers include (meth)acrylic acid, (meth)acrylic acid esters, (alkoxyalkyl (meth)acrylates such as methoxyethyl (meth)acrylate, and hydroxyalkyl (meth)acrylates such as hydroxyethyl (meth)acrylate), (meth)acrylamide, and (meth)acrylamide derivatives having a cyclic group (such as (meth)acryloylmorpholine). Of these, (meth)acrylic acid, (meth)acrylic acid esters, alkoxyalkyl (meth)acrylates, and (meth)acryloylmorpholine are preferred, with alkoxyalkyl (meth)acrylates being more preferred, and 2-methoxyethyl acrylate being particularly preferred.

The other monomer in the copolymer of the hydrophilic monomer and another monomer may be selected appropriately as long as it does not interfere with the effects of the hydrophilic polymer. Examples include aromatic monomers such as styrene, vinyl acetate, and N-isopropylacrylamide, which can impart temperature responsiveness.

Among these, the hydrophilic polymer is preferably at least one selected from the group consisting of a polymer represented by the following formula (I) and poly(meth)acryloylmorpholine.
(In the formula, ^R1 represents a hydrogen atom or a methyl group, ^R2 represents an alkyl group, m represents 1 to 5, and n represents the number of repetitions.)

The number of carbon atoms in the alkyl group of ^R2 is preferably 1 to 10, and more preferably 1 to 5. Of these, ^R2 is particularly preferably a methyl group or an ethyl group. m is preferably 1 to 3. n (the number of repeating units) is preferably 70 to 2500, and more preferably 90 to 1500.

Furthermore, as the hydrophilic polymer, a copolymer of at least one hydrophilic monomer selected from the group consisting of a compound represented by the following formula (I-1) and (meth)acryloylmorpholine and the other monomers described above can also be suitably used.
(wherein R ¹ , R ² and m are the same as above.)

Among the hydrophilic polymers mentioned above, the hydrophilic polymer represented by formula (I) is particularly suitable from the viewpoint of the roughness of the hydrophilic polymer layer, etc.

The thickness (film thickness) of the hydrophilic polymer layer (layer formed from a hydrophilic polymer) is preferably 10 to 1,000 nm, more preferably 30 to 700 nm, and even more preferably 50 to 350 nm. By adjusting the thickness within this range, good low adsorption to proteins and cells and selective capture of cancer cells can be expected.

At least a portion (part or all) of the surface of the hydrophilic polymer layer (the surface of the hydrophilic polymer layer in the hydrophilic glass substrate) preferably has a water contact angle of 60 degrees or less, and more preferably 50 degrees or less. There is no particular lower limit, and the smaller the limit, the better.

The surface of the hydrophilic polymer layer (the surface of the hydrophilic polymer layer in the hydrophilic glass substrate) preferably has a surface roughness Ra of 0.30 μm or less, more preferably 0.20 μm or less, even more preferably 0.10 μm or less, and particularly preferably 0.06 μm or less. There is no particular lower limit, and the smaller the limit, the better.
In this specification, the surface roughness Ra is the centerline surface roughness Ra defined in JIS B0601-2001.

Hydrophilic polymer layers can be produced by coating all or part of the surface of an alcohol-treated glass substrate with a hydrophilic polymer solution or dispersion, prepared by dissolving or dispersing a hydrophilic polymer in various solvents, onto the surface (concave portions of the substrate), holding the substrate for a predetermined period of time, and drying. (2) Coating (spraying) the hydrophilic polymer solution or dispersion onto the surface of the alcohol-treated glass substrate. This allows for the production of hydrophilic glass substrates with a polymer layer formed from a hydrophilic polymer (hydrophilic glass substrates with a hydrophilic polymer layer formed on their surface). Furthermore, by adding other components as needed to the hydrophilic glass substrate with a hydrophilic polymer layer formed on the surface of the alcohol-treated glass substrate, devices capable of capturing, culturing, testing, etc., specific cells can be produced.

As the solvent, injection method, coating (spraying) method, and the like, conventionally known materials and methods can be applied.
The holding and drying times of (1) and (2) may be set appropriately depending on the size of the substrate, the type of liquid introduced, etc. The holding time is preferably 10 seconds to 10 hours, more preferably 1 minute to 5 hours, and even more preferably 5 minutes to 2 hours. Drying is preferably carried out at room temperature (about 23°C) to 80°C, and more preferably room temperature to 40°C. Drying may also be carried out under reduced pressure. Furthermore, after a certain period of holding, excess hydrophilic polymer solution/dispersion may be appropriately discharged and dried.

The solvent is not particularly limited as long as it can dissolve the hydrophilic polymer, and can be selected appropriately depending on the hydrophilic polymer being used. Examples include water, organic solvents, and mixed solvents of these. Examples of organic solvents include alcohols such as methanol, ethanol, n-propanol, i-propanol, and methoxypropanol; ketones such as acetone and methyl ethyl ketone; tetrahydrofuran, acetonitrile, ethyl acetate, and toluene.

The method for manufacturing the hydrophilic glass substrate involves first treating the surface of the glass substrate with alcohol, and then forming a hydrophilic polymer layer on the surface of the alcohol-treated glass substrate. This controls the surface irregularities, allowing for the formation of a hydrophilic polymer layer with low surface roughness and high smoothness.

For example, by bringing a sample (blood or body fluid) into contact with a hydrophilic glass substrate in which a hydrophilic polymer layer has been formed on the surface of an alcohol-treated glass substrate, it is possible to capture specific cells. Then, by measuring the number of captured specific cells, it is possible to determine the number of specific cells in the collected blood or body fluid, which is expected to enable confirmation of the effectiveness of cancer treatment, etc.

The present disclosure will be explained in detail below based on examples, but the present disclosure is not limited to these examples.

(Preparation of Hydrophilic Polymer)
2-Methoxyethyl acrylate (25 wt % toluene) was thermally polymerized at 60° C. for 7 hours using a 12.5 mg/ml toluene solution of AIBN (azobisisobutyronitrile) to prepare poly(2-methoxyethyl acrylate) (PMEA).

Example 1
Methanol was added to slide chamber A (non-coated slide, manufactured by Matsunami Glass Industry Co., Ltd.; bottom surface: soda-lime glass; water contact angle: 69.7°) and left for 5 minutes. The bottom surface was then treated by sucking up and pushing out methanol twice with a pipette. The methanol was then sucked out and the slide was allowed to air dry (alcohol treatment: 1 time).
The resulting alcohol-treated slide chamber was filled with the prepared 0.16% methanol solution of PMEA, and then immediately dried in a vacuum oven at 40°C for 5 minutes to prepare a hydrophilic glass substrate.

Example 2
Methanol was added to slide chamber A (bottom: soda-lime glass, water contact angle: 69.7°) and left for 5 minutes. After that, the bottom was treated by sucking up and pushing out the methanol twice with a pipette. Then, the methanol was sucked out.
Methanol was added again and the mixture was left to stand for 5 minutes. After that, the bottom surface was treated by sucking up and pushing out the methanol twice with a pipette. Then, the methanol was sucked out and the mixture was allowed to dry naturally (alcohol treatment: 2 times).
The resulting alcohol-treated slide chamber was filled with the prepared 0.16% methanol solution of PMEA, and then immediately dried in a vacuum oven at 40°C for 5 minutes to prepare a hydrophilic glass substrate.

Example 3
Methanol was added to slide chamber A (bottom: soda-lime glass, water contact angle: 69.7°) and left for 5 minutes. After that, the bottom was treated by sucking up and pushing out the methanol twice with a pipette. Then, the methanol was sucked out.
Methanol was added again and the mixture was left to stand for 5 minutes. After that, the bottom of the mixture was treated by sucking up and pushing out the methanol twice with a pipette. Then, the methanol was sucked out.
Methanol was added once more and the mixture was left to stand for 5 minutes. After that, the mixture was washed twice by sucking up and pushing out the methanol with a pipette. Then, the mixture was sucked up and air-dried (alcohol treatment: 3 times).
The prepared 0.16% methanol solution of PMEA was poured into the obtained alcohol-treated slide chamber (alcohol-treated glass substrate), and then immediately vacuum-dried in an oven at 40°C for 5 minutes to prepare a hydrophilic glass substrate.

Example 4
A hydrophilic glass substrate was prepared in the same manner as in Example 3, except that the time for adding methanol and leaving it to stand was changed to 1 minute.

Example 5
A hydrophilic glass substrate was prepared in the same manner as in Example 3, except that the time for adding methanol and leaving it to stand was changed to 3 minutes.

Example 6
A hydrophilic glass substrate was prepared in the same manner as in Example 1, except that slide chamber A was changed to slide chamber B (manufactured by AGC Technoglass Co., Ltd., bottom surface made of soda-lime glass, water contact angle: 60.4 degrees).

Example 7
A hydrophilic glass substrate was prepared in the same manner as in Example 3, except that methanol was replaced with ethanol.

(Example 8)
A hydrophilic glass substrate was prepared in the same manner as in Example 3, except that propanol was used instead of methanol.

(Comparative Example 1)
A hydrophilic glass substrate was prepared in the same manner as in Example 1, except that the slide chamber A was not subjected to the methanol treatment.

(Comparative Example 2)
A hydrophilic glass substrate was prepared in the same manner as in Example 6, except that the slide chamber B was not subjected to the methanol treatment.

(Comparative Example 3)
The prepared 0.25% methanol solution of PMEA was poured into the untreated slide chamber B. Then, it was immediately vacuum dried in an oven at 40°C for 5 minutes.
Thereafter, methanol was poured into the glass (treatment temperature: room temperature) and the glass was naturally dried to prepare a hydrophilic glass substrate.

[Water contact angle (alcohol-treated glass substrate and untreated glass substrate)]
2 μl of distilled water was dropped onto the surface of the alcohol-treated or untreated glass substrate, and the contact angle after 30 seconds was measured by the θ/2 method (room temperature).

[Water contact angle (hydrophilic glass substrate)]
2 μl of distilled water was dropped onto the surface of the prepared hydrophilic glass substrate (surface of the hydrophilic polymer layer), and the contact angle after 30 seconds was measured by the θ/2 method (room temperature).

[Thickness of hydrophilic polymer layer (coating layer)]
The thickness (film thickness) of the hydrophilic polymer layer on the hydrophilic glass substrate was measured (photographed) by using a TEM to measure (photograph) a cross section of the hydrophilic polymer layer at an acceleration voltage of 15 kV and 1000 times magnification.

[Surface roughness Ra]
Using a laser microscope, the surface roughness was measured in a non-contact manner at four points (first peak) on one hydrophilic glass substrate (hydrophilic polymer layer), and the average of the Ra values at the four points was taken as the surface roughness Ra (μm) (average of the center line surface roughness Ra specified in JIS B 0601-2001).

[Surface condition]
The condition of the surface of the prepared hydrophilic glass substrate (surface of the hydrophilic polymer layer) was visually observed.

In Comparative Examples 1 and 2, the entire surface was slightly cloudy. This cloudiness is thought to be due to the surface irregularities that were created due to the surface roughness of the polymer layer, which caused light to be diffusely reflected by these irregularities. In Comparative Example 3, which was treated with methanol after the polymer layer was formed, the surface was highly rough and slightly cloudy.

In contrast, Examples 1 to 8, which used alcohol-treated glass substrates, were transparent with no visible cloudiness. Furthermore, the surface roughness was also reduced. It is easy to imagine that a surface with cloudiness and high surface roughness will exhibit different capture performance for specific cells than a transparent substrate with low surface roughness, which will cause variation in capture performance. For this reason, it was expected that a surface with controlled roughness and no cloudiness (small Ra) would exhibit capture performance with less variation.

The present disclosure (1) relates to a method for manufacturing a hydrophilic glass substrate, which includes a step of forming a hydrophilic polymer layer on a glass substrate that has been subjected to an alcohol treatment.

The present disclosure (2) is a method for producing a hydrophilic glass substrate according to the present disclosure (1), in which the alcohol used in the alcohol treatment is at least one selected from the group consisting of methanol, ethanol, and propanol.

The present disclosure (3) is a method for producing a hydrophilic glass substrate according to the present disclosure (1) or (2), in which the alcohol treatment is carried out two or more times.

The present disclosure (4) is a method for producing a hydrophilic glass substrate according to any one of the present disclosures (1) to (3), in which the alcohol treatment is carried out for 1 minute or more.

The present disclosure (5) is a method for producing a hydrophilic glass substrate according to any one of the present disclosures (1) to (3), in which the alcohol treatment is carried out for 3 minutes or more.

The present disclosure (6) is a method for producing a hydrophilic glass substrate according to any one of the present disclosures (1) to (3), in which the alcohol treatment is carried out for 5 minutes or more.

The present disclosure (7) is a method for producing a hydrophilic glass substrate according to any one of the present disclosures (1) to (6), in which the hydrophilic polymer layer is formed using a hydrophilic polymer solution.

The present disclosure (8) is a method for producing a hydrophilic glass substrate according to any one of the present disclosures (1) to (7), wherein the hydrophilic polymer layer is formed from a hydrophilic polymer represented by the following formula (I):
(In the formula, ^R1 represents a hydrogen atom or a methyl group, ^R2 represents an alkyl group, m is 1 to 5, and n represents the number of repetitions.)

The present disclosure (9) is a method for producing a hydrophilic glass substrate according to any one of the present disclosures (1) to (8), wherein the thickness of the hydrophilic polymer layer is 10 to 1,000 nm.

Claims (8)

The method includes forming a hydrophilic polymer layer on an alcohol-treated glass substrate,
The hydrophilic polymer layer is formed from a hydrophilic polymer represented by the following formula (I):
the thickness of the hydrophilic polymer layer is 10 to 1000 nm;
The method for producing a hydrophilic glass substrate , wherein the hydrophilic polymer layer has a surface roughness Ra of 0.10 μm or less .
(In the formula, R1 ^represents a hydrogen atom or a methyl group, R2 ^represents an alkyl group, m represents 1 to 5, and n represents the number of repetitions.) The method for manufacturing a hydrophilic glass substrate according to claim 1, wherein the alcohol used in the alcohol treatment is at least one selected from the group consisting of methanol, ethanol, and propanol. The method for manufacturing a hydrophilic glass substrate according to claim 1 or 2, wherein the alcohol treatment is carried out two or more times. The method for manufacturing a hydrophilic glass substrate according to any one of claims 1 to 3, wherein the alcohol treatment is carried out for 1 minute or more. The method for manufacturing a hydrophilic glass substrate according to any one of claims 1 to 3, wherein the alcohol treatment lasts for 3 minutes or more. The method for manufacturing a hydrophilic glass substrate according to any one of claims 1 to 3, wherein the alcohol treatment is carried out for 5 minutes or more. The method for manufacturing a hydrophilic glass substrate according to any one of claims 1 to 6, wherein the hydrophilic polymer layer is formed using a hydrophilic polymer solution. 8. The method for producing a hydrophilic glass substrate according to claim 1 , wherein the thickness of the hydrophilic polymer layer is 30 to 700 nm.