JP6255808B2 - Liquid container - Google Patents

Description

  The present invention relates to a liquid container that contains a liquid containing a biopolymer.

  In general, a liquid containing a biopolymer such as a protein is used as a medium for cell culture, and such a liquid is accommodated in a container made of plastic or the like. However, the amount of protein contained in such a liquid may be reduced by adsorbing to the plastic constituting the container. In addition, there is a possibility that the function is lost due to the protein being decomposed by the ultraviolet rays transmitted through the container. For this reason, there exists a problem that the period which can store such a liquid in a container is short.

  On the other hand, as a method for suppressing the adsorption of protein to plastic, a method of applying a material having a protein adsorption inhibiting action on the surface of the plastic is known (for example, see Patent Document 1). Specifically, a technique is known in which a material having an adsorption inhibiting action, for example, a hydrophilic polymer such as 2-methacryloylethylphosphorylcholine-based substance (MPC polymer) or polyethylene glycol is applied to the surface of plastic. By apply | coating the said material to the inner surface of a plastic container, it can suppress that the protein contained in a liquid adsorb | sucks to the inner surface of a container.

Japanese Patent No. 3434891

  However, the elution of the component of the material having the adsorption inhibiting action into the liquid causes the adsorption inhibiting action to deteriorate over time, or the component flows out to the liquid and affects the liquid. Yes. For this reason, when the container is commercialized, it is necessary to confirm that the above components do not elute into the liquid, which requires labor for confirming safety, and the cost of the container may increase. It has become a challenge.

  In addition, as described above, it is known that biopolymers such as proteins lose their functions due to ultraviolet rays. For this reason, in the liquid storage container that stores the biopolymer, it is necessary to minimize the amount of ultraviolet rays irradiated to the inside of the container.

  However, fixing a polymer having an ultraviolet light shielding effect on the inner surface of the container requires a coating operation such as graft polymerization with an electron beam, which is difficult in terms of cost and the like. For this reason, a measure of suppressing the amount of transmitted ultraviolet light by coloring the container may be taken.

  However, when the container is colored, the transparency of the container is lost, causing a problem that the contents of the container cannot be confirmed. In particular, the medium used for cell culture generally contains phenol red in order to confirm its pH, and it is necessary to confirm the quality by the color of the medium. Therefore, the container has transparency. It is necessary to do.

  Furthermore, in order to provide the container with two effects of suppressing the adsorption of biopolymer and shielding light from ultraviolet rays, it is necessary to go through different processes, which is a problem in terms of labor and cost.

  The present invention has been made to solve the above-mentioned problems, and its object is to suppress the adsorption of biopolymers on the inner surface of the container without coating the inner surface of the container and It is in providing the liquid storage container which can suppress the permeation | transmission amount of water.

  A liquid storage container according to an embodiment of the present invention is a liquid storage container for storing a liquid containing a biopolymer, and includes a container body having an inner surface that contacts the liquid containing the biopolymer, The inner surface is formed with a plurality of fine holes that open to the inside of the container main body and can hold a gas therein when the liquid comes into contact with the inner surface of the container main body. It is characterized by including.

  In the liquid container according to the embodiment of the present invention, the opening width of each micropore may be 500 nm to 100 μm, and the aspect ratio of each micropore may be 0.1 to 3.

  In the liquid container according to the embodiment of the present invention, the container body may be made of a transparent or translucent plastic.

  In the liquid container according to the embodiment of the present invention, an angle formed by the inner surface of the container main body and the side surface of each fine hole may be a right angle or an acute angle in a vertical cross section of the container main body.

  In the liquid container according to the embodiment of the present invention, the container body may have a bottom surface, a side surface, and a top surface, and the fine holes may be formed on at least the bottom surface and the side surface of the container body.

  In the liquid container according to the embodiment of the present invention, the fine holes may not be formed in the upper surface of the container body.

  In the liquid container according to the embodiment of the present invention, the container body may be formed of a single layer having the fine holes and including the ultraviolet light shielding agent.

  In the liquid container according to the embodiment of the present invention, the container body is composed of two layers, the outer layer includes the ultraviolet light shielding agent, the inner layer includes the micropores, and the ultraviolet light shielding agent. It does not have to be included.

  In the liquid container according to the embodiment of the present invention, the container body is composed of two layers, the outer layer does not include the ultraviolet light shielding agent, the inner layer includes the micropores and the ultraviolet light shielding agent. But you can.

  In the liquid container according to the embodiment of the present invention, the container main body includes three layers, a central layer includes the ultraviolet light shielding agent, an outer layer does not include the ultraviolet light shielding agent, and an inner layer. May have the fine holes and may not contain the ultraviolet light shielding agent.

  ADVANTAGE OF THE INVENTION According to this invention, while suppressing adsorption | suction of the biopolymer to the inner surface of a container, the amount of permeation | transmission of the ultraviolet-ray of a container can be suppressed.

FIG. 1 is a perspective view showing an overall configuration of a liquid container according to an embodiment of the present invention. FIG. 2 is a plan view showing the inner surface of the container body of the liquid container according to the embodiment of the present invention. FIG. 3 is a cross-sectional view (a cross-sectional view taken along the line II-II in FIG. 2) of the inner surface of the container main body of the liquid container according to the embodiment of the present invention. 4A to 4C are vertical sectional views showing various micropores. FIGS. 5A to 5B are schematic cross-sectional views showing the biopolymer adsorption suppressing action by the micropores. FIGS. 6A to 6B are diagrams showing the ultraviolet light shielding action by the ultraviolet absorber and the ultraviolet scattering agent, respectively. 7A to 7D are schematic cross-sectional views showing various layer configurations of the container body. FIG. 8 is a schematic view showing a manufacturing process in the case of producing a film having a large number of micropores using a roll-to-roll method. FIGS. 9A and 9B are perspective views each showing a case where the container body is composed of two members. FIG. 10 is a graph showing the relationship between the elapsed time since the preparation of the BSA solution and the BSA concentration. FIG. 11 is a graph comparing the BSA concentration between the reference example and the comparative example.

  Embodiments of the present invention will be described below with reference to the drawings. Drawing is an illustration and may exaggerate a characteristic part for explanation, and may differ from an actual thing. In addition, the present invention can be implemented with appropriate modifications without departing from the technical idea. Note that, in the following drawings, the same portions are denoted by the same reference numerals, and some detailed description may be omitted.

(Liquid container)
First, the configuration of a liquid container according to an embodiment of the present invention will be described. 1 to 9 are diagrams showing an embodiment of the present invention.

  As shown in FIG. 1, a liquid container 10 according to the present embodiment contains a liquid L containing a biopolymer (for example, protein, cell, etc.), and a container body having an inner surface 11 a that contacts the liquid L. 11 and a cap 12 attached to the container main body 11.

  Among these, the container main body 11 has a bottom surface 11b, four side surfaces 11c, 11d, 11e, and 11f, and a roof-shaped top surface 11g. The shape of the container body 11 is not limited to this as long as it can accommodate the liquid L. For example, the container body 11 may have a cylindrical shape on the entire side surface or a shape with a flat top surface. The container body 11 may have a shape such as a dish, a bag, or a flask used for cell suspension culture.

  Next, the configuration of the inner surface 11a of the container body 11 will be described with reference to FIGS.

  As shown in FIGS. 2 and 3, a large number (a plurality) of fine holes 20 are formed in the inner surface 11 a of the container body 11. Each fine hole 20 opens toward the inner side (upper side in FIG. 3) of the container main body 11, and has an opening 21 having a planar square shape. The planar shape of each opening 21 may be a polygonal shape such as a circular shape, an elliptical shape, or a triangular shape.

  Each fine hole 20 has a structure capable of holding gas (air) inside when the liquid L contacts the inner surface 11 a of the container body 11. That is, each fine hole 20 has a bottomed rectangular tube shape as a whole, and is an independent space 24 surrounded by a side surface 22 connected to the inner surface 11 a of the container body 11 and a bottom surface 23 connected to the side surface 22. have. In addition, the shape of each micropore 20 is not restricted to a bottomed square tube shape. Various types of bottomed cylindrical shapes can be employed according to the planar shape of the opening 21. For example, each fine hole 20 may be composed of a part of a sphere (see FIG. 4C). In this case, air can be more easily retained in each micropore 20.

  In FIG. 2, the numerous micro holes 20 have the same shape and are arranged in a square lattice at equal intervals in the vertical and horizontal directions when viewed from the plane. Thus, by arranging a large number of micropores 20 in a square lattice shape, the ratio of the openings 21 of the micropores 20 to the inner surface 11a of the container main body 11 is increased, and the inner surface 11a to which biopolymers may adhere. Can be reduced. Specifically, the pitch p of the fine holes 20 is preferably 1 μm to 200 μm (refers to 1 μm or more and 200 μm or less; the same applies hereinafter). Here, the pitch p of the fine holes 20 is a distance from the center to the center of the fine holes 20 adjacent to each other. In addition, when the planar shape of the fine holes 20 is a circle, a large number of fine holes 20 may be arranged in a square triangle shape (finely packed shape).

  The width (diameter) w of the opening 21 of each micropore 20 is 500 nm to 100 μm, and more preferably 5 μm to 50 μm. By setting the width (diameter) w of the opening 21 to 500 nm or more, it becomes negligible that the air in the micropores 20 is eluted into the liquid L, and the air can be reliably held inside the micropores 20. . In addition, since the width (diameter) w of the opening 21 is set to 100 μm or less, it is prevented that it becomes difficult to hold air in the micropore 20 due to the liquid L entering the micropore 20.

  Moreover, in FIG. 3, the aspect ratio of the micropore 20 is 0.1-3, and it is still more preferable to set it as 0.5-3. By setting the aspect ratio of the fine holes 20 to 0.1 or more, air can be easily retained. Moreover, the fine hole 20 can be reliably shape | molded because the aspect-ratio of the fine hole 20 was 3 or less. The aspect ratio of the fine hole 20 is calculated by {(depth d of the fine hole 20) / (width w of the opening 21 of the fine hole 20)}.

  The depth d of the fine hole 20 is set so that the width w of the opening 21 and the aspect ratio of the fine hole 20 satisfy the above-described relationship, and specifically, 50 nm to 300 μm.

  Furthermore, the porosity of the fine holes 20 is preferably 25% or more, and more preferably 50% to 90%. By setting the porosity of the micropores 20 to 25% or more, the area of the portion of the inner surface 11a of the container body 11 to which the biopolymer adheres can be reduced, and the biopolymer with respect to the inner surface 11a of the container body 11 can be reduced. Adsorption can be suppressed. Here, the porosity (%) of the fine holes 20 is the total area of the plurality of openings 21 existing in the region, which occupies the entire area of the region in which the fine holes 20 are provided, and {100 × (fine The total area of the plurality of openings 21 existing in the region where the holes 20 are provided) / (the total area of the region where the micro holes 20 are provided)}.

  4A to 4C, in the vertical cross section perpendicular to the inner surface 11a of the container body 11, the angle θ formed by the inner surface 11a of the container body 11 and the side surface 22 of each fine hole 20 is a right angle. (See FIG. 4A) or an acute angle (see FIGS. 4B and 4C). This makes it difficult for the air contained in the micropores 20 to escape to the outside and makes it easier to hold the air inside the micropores 20, thereby further suppressing the adsorption of the biopolymer to the inner surface 11 a of the container body 11. be able to.

  The fine holes 20 may be formed in the entire area of the inner surface 11a of the container main body 11, but may be formed in a part of the inner surface 11a. ing. For example, the fine holes 20 are formed on the bottom surface 11b and the side surfaces 11c, 11d, 11e, and 11f, which are surfaces with which the liquid L comes into contact, and may not be formed on the top surface 11g. In this case, it is possible to effectively suppress the adsorption of the biopolymer in the portion of the inner surface 11a of the container body 11 that comes into contact with the liquid L. Further, by not forming the micro holes 20 in the upper surface 11g of the container body 11, the liquid L can be easily seen through the upper surface 11g. Or the micropore 20 may be formed only in the bottom face 11b which the liquid L contacts.

  Such a container body 11 is preferably made of a transparent or translucent plastic material. When the container main body 11 is transparent or translucent, it becomes easy to visually confirm the quality of the liquid L inside the container main body 11. Examples of the plastic material include polyethylene terephthalate, polyethylene, and polypropylene. Furthermore, it is more preferable to use a plastic material that reduces the transmittance of ultraviolet light on the short wavelength side, such as polyethylene terephthalate (PET) or ethylene / vinyl acetate copolymer (EVA). Thereby, it can suppress to a certain extent that the ultraviolet rays are irradiated to the liquid L through the container main body 11. Moreover, although there is no restriction | limiting in particular also in the kind and density | concentration of the additive added to a plastic material, It is preferable to maintain transparency of the grade which can visually recognize the liquid L inside the container main body 11. FIG.

  By providing a large number of micropores 20 on the inner surface 11a of the container body 11 as described above, air (gas) A is held in the numerous micropores 20 when the liquid L containing a biopolymer contacts the inner surface 11a. (See FIGS. 5A and 5B). Since the air A is interposed between the container main body 11 and the liquid L, the substantial contact area between the liquid L and the inner surface 11a of the container main body 11 can be reduced. Thereby, it is suppressed that the biopolymer contained in the liquid L adsorb | sucks to the inner surface 11a of the container main body 11. FIG. In particular, the adsorption of the biopolymer can be suppressed without coating the inner surface 11a of the container body 11 or the like. Therefore, it is not necessary to provide a process for coating the inner surface 11a of the container body 11, and the process for manufacturing the liquid container 10 can be simplified. Further, it is possible to prevent the material coated on the inner surface 11a of the container body 11 from being eluted into the liquid L. Moreover, adsorption of the biopolymer to the inner surface 11a of the container body 11 can be suppressed regardless of the material of the container body 11 and regardless of the size of the biopolymer.

  Although it is desirable that the air A is held in all the numerous micro holes 20, it is considered difficult to hold the air A in all the micro holes 20 in practice. However, when the aspect ratio of the micropore 20 is increased (see FIG. 5B), the number of microscopic holes 20 is larger than that when the aspect ratio of the microhole 20 is decreased (see FIG. 5B). The ratio of the fine holes 20 in which the air A occupying the holes 20 is increased. For this reason, it is thought that it is easier to suppress the adsorption of biopolymers when the aspect ratio of the micropores 20 is increased.

  Moreover, in this embodiment, the plastic material which comprises the container main body 11 contains the ultraviolet light shielding agent. This ultraviolet light shielding agent plays a role of suppressing ultraviolet rays from passing through the container body 11. By including the ultraviolet light shielding agent in the container main body 11, it is possible to prevent the biopolymer contained in the liquid L from being deteriorated by the ultraviolet light or from losing its function. The plastic material containing the ultraviolet light shielding agent can be obtained, for example, by adding the ultraviolet light shielding agent to the plastic material and melt-kneading to disperse the thermally decomposed fine particles of the ultraviolet light shielding agent in the plastic material.

  Examples of the ultraviolet light shielding agent include an ultraviolet absorber (FIG. 6 (a)) and an ultraviolet scattering agent (FIG. 6 (b)). In this case, the container main body 11 may contain one or both of an ultraviolet absorber and an ultraviolet scattering agent.

  When the container main body 11 contains an ultraviolet absorber, as shown in FIG. 6A, the ultraviolet absorber converts the energy of ultraviolet rays into thermal energy, and reduces the amount of ultraviolet rays that pass through the container main body 11. Examples of such ultraviolet absorbers include benzotriazole materials, benzophenone, octyl methoxycinnamate, oxybenzone, and t-butylmethoxydibenzoylmethane. Specific examples include substances listed in “Ministry of Health, Labor and Welfare Notification No. 331, Appendix 4, 2000” and “Polyfile December 2010, page 53”.

  Moreover, when the container main body 11 contains an ultraviolet-ray scattering agent, as shown in FIG.6 (b), an ultraviolet-ray scattering agent scatters an ultraviolet-ray outside, and reduces the quantity of the ultraviolet-ray which permeate | transmits the container main body 11. FIG. In the case of using the ultraviolet scattering agent, the temperature of the liquid L accommodated in the container body 11 does not rise, so that the biopolymer in the liquid L does not become unstable. Examples of such ultraviolet light scattering agents include titanium oxide, zinc oxide, chromium oxide and zirconium oxide.

  Next, the layer structure of the container body 11 will be described with reference to FIGS. 7A to 7D, the upper side corresponds to the inner side of the container main body 11, and the lower side corresponds to the outer side of the container main body 11. 7A to 7D, among the layers constituting the container body 11, the layer containing the ultraviolet light shielding agent is indicated by hatching.

  As shown to Fig.7 (a), the container main body 11 may be comprised from the single layer which has the micropore 20 and contains a ultraviolet light shielding agent. In this case, the two effects of suppressing the adsorption of biopolymer and shielding ultraviolet rays can be imparted to the container body 11 by one layer. For this reason, the manufacturing process of the container main body 11 is simplified, and manufacturing cost can be reduced.

  Or as shown in FIG.7 (b), the container main body 11 may be comprised from the two layers 13a and 13b. In this case, the outer layer 13a includes an ultraviolet light shielding agent, and the inner layer 13b includes the fine holes 20 and does not include the ultraviolet light shielding agent. For example, the container body 11 shown in FIG. 7B is obtained by forming the layer 13b provided with the fine holes 20 with a film and sticking the film to the layer 13a containing the ultraviolet light shielding agent. In this case, it is possible to produce the container body 11 in various modes by appropriately changing the layers 13a and 13b.

  Or as shown in FIG.7 (c), the container main body 11 may be comprised from the two layers 14a and 14b. In this case, the outer layer 14a does not contain the ultraviolet light shielding agent, and the inner layer 14b has the fine holes 20 and contains the ultraviolet light shielding agent. For example, the container body 11 shown in FIG. 7C is obtained by forming the layer 14b having the fine holes 20 and containing the ultraviolet light shielding agent with a film and sticking the film to the layer 14a. In FIG. 7C, by preparing the layer 14b in advance, the layer 14b can be attached to a container (layer 14a) having various shapes.

  Or as shown in FIG.7 (d), the container main body 11 may be comprised from the three layers 15a, 15b, and 15c. In this case, the central layer 15 b includes an ultraviolet light shielding agent, and the inner layer 15 c has the fine holes 20. Further, the inner layer 15c and the outer layer 15a do not contain an ultraviolet light shielding agent. For example, the layer 15b may be an adhesive layer, and an ultraviolet light shielding agent may be preliminarily contained in the adhesive constituting the adhesive layer. In this case, the layer 15c may be formed of a film, and the film (layer 15c) may be attached to the layer 15a via an adhesive layer (layer 15b).

  By the way, although the method of producing the container main body 11 is not limited, for example, various molding methods used for plastic molding, such as an injection molding method, a nanoimprint method using ultraviolet rays or heat, a surface preparation method by lithography used in fine processing, and the like are used. be able to. Moreover, since there is no restriction | limiting in the magnitude | size of the container main body 11, it is also possible to use a three-dimensional printer.

  Among these, when using the injection molding method, a large number of fine convex portions corresponding to the fine holes 20 are formed in advance in a region corresponding to the inner surface 11a of the container body 11 of the injection mold, for example, using a precision cutting machine. Keep it. Thereafter, the container body 11 is molded by mounting the injection mold on the injection molding machine and injecting the heated resin into the injection mold from the nozzle of the injection molding machine. At this time, a large number of fine holes 20 are formed in the inner surface 11a of the container body 11 by a large number of fine protrusions provided in the injection mold. In this case, the forming of the container body 11 and the formation of a large number of micro holes 20 in the inner surface 11a of the container body 11 are simultaneously performed in one process, so that the process can be simplified (FIG. 7 ( a)).

  Further, for example, a film (layers 13b and 14b) having a large number of micropores 20 is formed in advance by a nanoimprint method or a lithography surface preparation method, and the film is injection-molded by being sandwiched in an injection mold (not shown). Thus, the film may be integrated with the layers (layers 13a and 14a) constituting the outer shape of the container body 11 (in-mold molding method). In this case, mass production of the container main body 11 becomes easier by manufacturing a film having a large number of fine holes 20 using a so-called roll-to-roll system (see FIG. 8). Note that the ultraviolet light shielding agent may be included in the layer 13a constituting the outer shape of the container body 11 (see FIG. 7B), or may be included in the film (layer 14b) (FIG. 7C). )reference).

  Further, a film (layers 13b, 14b, 15c) having a large number of micropores 20 is formed in advance by, for example, a nanoimprint method or a lithography surface preparation method, and the film is a layer (layer) that forms the outer shape of the container body 11. 13a, 14a, 15a). Even in this case, mass production of the container main body 11 becomes easier by manufacturing a film having a large number of fine holes 20 using a so-called roll-to-roll system (see FIG. 8). The ultraviolet light shielding agent may be included in the layer 13a constituting the outer shape of the container body 11 (see FIG. 7B) or may be included in the film (layer 14b) (FIG. 7C). )), And may be included in an adhesive layer (layer 15b) for bonding the two (see FIG. 7D).

  In addition, when sticking the film (layer 13b, 14b, 15c) which has many micropores 20 to the layer (layer 13a, 14a, 15a) which comprises the external shape of the container main body 11, FIG. 9 (a) (b) For example, the container body 11 may be composed of two members 16a and 16b. In this case, after the films (layers 13b, 14b, 15c) are attached to the layers (layers 13a, 14a, 15a) constituting the outer shape of the container body 11, these members 16a, 16b are attached using an ultrasonic welding method or the like. You may connect mutually. 9A shows a case where the members 16a and 16b constituting the container main body 11 have substantially symmetrical shapes, and FIG. 9A shows the case where the member 16a constituting the container main body 11 is a lid. It shows a case where the member 16b is made of a bottom portion.

  As described above, according to the present embodiment, the inner surface 11a of the container body 11 is opened to the inside of the container body 11, and when the liquid L is in contact with the inner surface 11a of the container body 11, a plurality of gases can be held therein. Fine holes 20 are formed, and the container body 11 contains an ultraviolet light shielding agent. Thereby, without coating the inner surface 11 a of the container body 11, it is possible to suppress the biopolymer from adsorbing to the container body 11 and to suppress the amount of ultraviolet light transmitted through the container body 11. This prevents the amount of the biopolymer contained in the liquid L from decreasing and prevents the biopolymer from being decomposed by the ultraviolet light transmitted through the container body 11 and losing its function. Can do. As a result, the period for storing the liquid L containing the biopolymer in the liquid container 10 can be extended. Further, since the inner surface 11a of the container body 11 is not coated, it is possible to prevent the components of the coating agent from being eluted into the liquid L and affecting the liquid L.

<Biopolymer adsorption suppression effect by micropores>
Next, the biopolymer adsorption suppression effect by the micropores will be described as a reference example.

<Reference Example 1>
A square lattice-like groove pattern (concave portion) was formed on the surface of a 6.35 mm thick, 50 mm square metal plate (made by BeCu) using a machine cutting device (manufactured by FANUC, ROBONANO). A planar square-shaped convex portion was formed between the concave portions. In addition, each convex part becomes a micropore when it transfers to the resin side so that it may mention later. The width w _b of the recess was 5 μm. The depth d _{a of the} recess was 5 μm. The ratio of the width _{w b} of width _{w a} and the recess 81 of the convex portion was 1: 1.

  After preparing a sheet-like polymethyl methacrylate (PMMA) base material (manufactured by Mitsubishi Rayon Co., Ltd.) having a thickness of 2 mm and heating the base material at 150 ° C. for softening, the base plate is brought into contact with the base material. And pressurized at 10 MPa. The contact angle of the PMMA base material with respect to water was 66.0 °. The base material was cooled while being pressurized, and then the original plate was peeled off to obtain a structure having a shape in which the convex portions and the concave portions of the original plate were inverted.

  The above structure was immersed in Alexa488-labeled anti-rabbit IgG antibody (Molecular Probes) (dilution ratio 1/100 with PBS) for 1 hour, and then the structure was phosphorous containing 0.05% Tween 20 (Wako Pure Chemical Industries). Washing was performed by repeating immersion for 1 minute in acid buffer (PBS) three times to sufficiently remove unadsorbed antibody (protein). The obtained structure was excited with light having a wavelength of 488 nm by a single scan of a confocal microscope (manufactured by Carl Zeiss), and the fluorescence intensity in the wavelength region of 520 nm was measured. It was confirmed that the amount of protein adsorbed was less than 40% compared to the case where no micropores were produced.

<Amount of UV irradiation that causes protein degradation>
Next, as a reference example, an analysis performed to estimate the amount of ultraviolet irradiation that causes protein degradation will be described.

<Reference Example 2>
Bovine serum albumin (BSA; Wako Pure Chemical Industries, Ltd.) was dissolved in Hank's salt buffer (Sigma), and the concentration was adjusted to about 12 μg / ml. Each 2 ml of this solution was placed in a 3.5 cm Petri dish (Becton Dickinson), six of which were prepared, placed in a safety cabinet (Panasonic Healthcare) and irradiated with ultraviolet light. After 0 hour (immediately after production), 1 hour, 4 hours, 12 hours, 18 hours, and 24 hours, 1 ml of the solution was collected. The samples were stored frozen in a -20 ° C freezer until measurement.

  Standard dilution series with concentrations of 0 μg / ml, 0.7 μg / ml, 1.3 μg / ml, 2.5 μg / ml, 5 μg / ml, 10 μg / ml, and 20 μg / ml are prepared using the above buffer and BSA. did. Next, 20 μl of Bio-rad Protein Assay Dye Reagent Concentrate (BIO RAD) was placed in each well in a 96-well plate (Becton Dickinson). Next, 180 μl of each of the standard dilution series and the ultraviolet irradiation sample was added to cause color development reaction. The absorbance at a wavelength of 620 nm was measured for these luminescence intensities with a plate reader (TECAN), and a calibration curve was prepared with a standard dilution series, and then the BSA concentration of each ultraviolet irradiation sample was estimated.

  The result is as shown in FIG. From this, it was considered that the decomposition of BSA by ultraviolet rays occurred at 24 hours after irradiation.

Next, the ultraviolet ray irradiation amount in the clean bench was measured using a UV irradiometer UIT-250 (USHIO INC.) In a range including a wavelength region that damages the protein. As a result, the irradiation dose was 0.3 mW / cm ² .

Therefore, the total ultraviolet irradiation energy received by irradiation for 24 hours was estimated to be about 26 J / cm ² . It is considered that the protein is denatured when receiving ultraviolet rays of this level.

Here, when stored indoors, the ratio of outdoor ultraviolet energy to the room that is considered to be most affected is about 10%. According to the “Ultraviolet Environment and Health Manual Ministry of the Environment 2008”, the amount of UV-B outdoors in Japan is about 10 to ²⁰ kJ / m ² per day. Based on this calculation, considering that the amount of UV-A (wavelength 315 to 400 nm) and the amount of UV-B (wavelength 280 to 315 nm) reaching the ground surface is approximately 99: 1, it is received indoors in one day. transmitting ultraviolet energy is estimated to be 10~20J / cm ^2. The energy of the white fluorescent lamp in the ultraviolet wavelength region is estimated to be approximately 1 to 7 μW / cm ² , but this value is sufficiently weak compared with the transmitted light ultraviolet energy and can be ignored.

  From this, it is estimated that an ultraviolet cut rate of 91.3 to 95.7% or more is necessary to allow the protein to have one month without being damaged.

  The addition amount of the ultraviolet absorber required to achieve the above-described ultraviolet cut rate is examined. For example, according to the case where the substance disclosed in Japanese Patent Application Laid-Open No. 2009-209343 is used, it is sufficient that it is added at a ratio of 0.001% with respect to the weight of the resin constituting the container as a weight ratio. Conceivable. In addition, since this ratio is dependent on a substance, it is not necessarily restricted to this value. Moreover, since the ultraviolet cut rate increases as the amount of the ultraviolet absorber added increases, it is considered that there is no upper limit to the value. Furthermore, it is possible to use not only a single material but also a material to which a plurality of additives are added.

  Increasing the amount of the UV absorber added adds to the container manufacturing cost, so it is necessary to estimate the optimum amount for the required storage period and the substance to be used in each case.

<Analysis of the cause of the decrease in BSA>
Next, the following analysis was performed in order to confirm whether or not the decrease in BSA seen in the above Reference Example was due to adhesion to Petri dishes.

  A Petri dish sample containing BSA was prepared in the same manner as in the above Reference Example, and left for 24 hours in a room temperature environment. This is a comparative example.

  The BSA concentration was obtained by measuring the absorbance of the comparative example by the same process as in the reference example.

  The result is as shown in FIG. In addition, the reference example here is a product that has been subjected to ultraviolet irradiation for 24 hours. Since no decrease in BSA concentration was observed in the comparative example, it was suggested that the decrease in BSA seen in the reference example was decomposition due to ultraviolet rays.

DESCRIPTION OF SYMBOLS 10 Liquid container 11 Container main body 11a Surface 11b Bottom surface 11c-11f Side surface 11g Upper surface 12 Cap 13a-13b Layer 14a-14b Layer 15a-15c Layer 20 Micropore 21 Opening 22 Side surface 23 Bottom surface 24 Space

Claims (10)

A liquid storage container for storing a liquid containing a biopolymer,
A container body having an inner surface in contact with a liquid containing the biopolymer;
The inner surface of the container body is formed with a plurality of micropores that open to the inside of the container body and can hold gas while the liquid is in contact with the inner surface of the container body. ,
The container main body contains an ultraviolet light shielding agent.   The liquid container according to claim 1, wherein the opening width of each micropore is 500 nm to 100 µm, and the aspect ratio of each micropore is 0.1 to 3.   The liquid container according to claim 1, wherein the container body is made of a transparent or translucent plastic.   4. The liquid container according to claim 1, wherein an angle formed between the inner surface of the container body and a side surface of each micropore is a right angle or an acute angle in a vertical cross section of the container body. .   The said container main body has a bottom face, a side surface, and an upper surface, The said micropore is formed in the said bottom face and the said side surface of the said container main body, The any one of Claim 1 thru | or 4 characterized by the above-mentioned. The liquid container described.   The liquid container according to claim 5, wherein the fine hole is not formed in the upper surface of the container body.   The liquid container according to any one of claims 1 to 6, wherein the container body is composed of a single layer having the fine holes and containing the ultraviolet light shielding agent.   The container body is composed of two layers, an outer layer includes the ultraviolet light shielding agent, an inner layer includes the micropores and does not include the ultraviolet light shielding agent. The liquid container according to any one of the above.   The said container main body is comprised from two layers, an outer layer does not contain a ultraviolet-ray light-shielding agent, and an inner layer has the said micropore and contains an ultraviolet-ray light-shielding agent. A liquid container according to claim 1.   The container body is composed of three layers, a central layer includes the ultraviolet light shielding agent, an outer layer does not include the ultraviolet light shielding agent, an inner layer has the micropores, and the ultraviolet light shielding agent. The liquid container according to claim 1, which is not included.

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