Injector

Abstract

The present disclosure addresses the problem of providing an injector that injects a biomolecule-containing solution into a subject to at least deliver a large proportion of the biomolecule capable of functioning in the subject.　The problem is solved by an injector for injecting a biomolecule-containing solution and a predetermined gas into a subject without using an injection needle, the injector being provided with: a storage unit that stores the biomolecule-containing solution and the predetermined gas; a nozzle unit that is in communication with the storage unit and has an injection port for injecting the biomolecule-containing solution and the gas toward the subject; and a pressurization unit that, when actuated, injects the biomolecule-containing solution and the gas to the subject from the injection port by pressurizing the biomolecule-containing solution and the gas stored in the storage unit.

Description

Technical Field

[0001] The present disclosure relates to an injector.

Background Art

[0002] As injectors for injecting a chemical solution into a living body or the like, there are a needle syringe that performs injection through a needle, a needleless syringe that performs injection without passing through a needle, and a catheter provided with a needle and a drive source for transporting the chemical solution to an injection target. Among these, in a needleless syringe, a configuration may be adopted in which pressure is applied to a storage chamber in which an injection solution is stored by a pressurized gas, a spring, or an electromagnetic force to eject an injection component. For example, a configuration is adopted in which a plurality of nozzle holes are formed inside a syringe body, and a piston driven at the time of injection is arranged corresponding to each nozzle hole (Patent Document 1). With this configuration, an attempt is made to simultaneously inject the injection solution from a plurality of nozzle holes to achieve uniform injection into the target. And a plasmid containing a luciferase gene has been injected into rats, and cell transfer can be achieved with high efficiency. In addition, as a power source for ejecting an injection solution in a needleless syringe, there is a form that uses a pressurized gas. For example, a pressurization form is exemplified in which a large pressure is instantaneously applied at the initial stage of injection and then the pressure is gradually reduced over 40 to 50 msec (Patent Document 2).

[0003] On the other hand, a method of injecting while mixing not only the chemical solution but also air at the time of injection is known. For example, when subcutaneous administration of azacitidine, a therapeutic agent for myelodysplastic syndrome, is performed with a needle syringe, if normal administration is performed without mixing air, there are side effects such as the injection mark turning red, pain at the injection site, and the injection site becoming inflamed, which make the patient uncomfortable. In contrast, it has been reported that when administered while mixing air, contact between the epithelium and the chemical solution is prevented and side effects are reduced (Non-Patent Document 1). Furthermore, when injecting using a needleless syringe, if the drug solution and the patient's skin are in contact beforehand at the outlet of the drug solution chamber, the impact force generated when the drive bar collides with the drug solution is significantly attenuated by the duration of time that is perceived between the drug solution and the patient's skin. Therefore, a technique has been disclosed in which a gas pocket is provided on the outlet side of the drug solution chamber before injecting the drug solution (Patent Document 3). Furthermore, although not a study involving living organisms, an in vitro study has been reported showing that the inclusion of air in the chamber of a needleless syringe allows for efficient introduction of DNA into adherent cell lines. (Patent Document 4) [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2004-358234 [Patent Document 2] U.S. Patent Application Publication No. 2005 / 0010168 [Patent Document 3] Japanese Patent Publication No. 2002-143302 [Patent Document 4] International Publication No. 2020 / 116353 [Non-patent literature]

[0005] [Non-Patent Document 1] Can. Oncol. Nurs. J., 22(4):222-34, 2012 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The problem addressed by this disclosure is to provide an injector that, at the very least, in which a large proportion of biomolecules function within the target when a solution containing biomolecules is injected into the target. [Means for solving the problem]

[0007] One embodiment of this disclosure is, An injector that injects a solution containing biomolecules and a predetermined gas into a target without using a needle, A containment section containing the solution containing the biomolecules and the gas, A nozzle portion communicating with the aforementioned containment portion, having an outlet for injecting the solution containing the biomolecules and the gas toward the injection target, A pressurizing unit that, when in operation, pressurizes the solution containing the biomolecules and the gas contained in the containment unit, thereby injecting the solution containing the biomolecules and the gas from the nozzle toward the injection target, It is an injector equipped with [a specific feature].

[0008] In the aforementioned injector, it is preferable that the volume of the gas contained in the containment section is 20% or more and 60% or less of the volume of the containment section. The injector also preferably uses air as the gas. The injector also preferably contains DNA, which includes genes, as the biomolecule.

[0009] This disclosure also provides a method for injecting a solution containing biomolecules and a predetermined gas into a target object using the injector. [Effects of the Invention]

[0010] This disclosure can at least provide the effect that when a solution containing biomolecules is injected into the target, a large proportion of the biomolecules function within the target. [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows a schematic configuration of an injector according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0012] Each configuration and their combinations in each embodiment are examples, and within the scope not departing from the gist of the present disclosure, addition, omission, substitution, and other changes of the configuration can be made as appropriate. The present disclosure is not limited by the embodiments, but only limited by the scope of the claims.

[0013] One embodiment of the present disclosure is An injector for injecting a solution containing a biomolecule and a predetermined gas into an injection target without passing through a syringe needle, A storage unit that stores the solution containing the biomolecule and the gas, A nozzle unit communicating with the storage unit, the nozzle unit having an ejection port for ejecting the solution containing the biomolecule and the gas toward the injection target, A pressurizing unit that pressurizes the solution containing the biomolecule and the gas stored in the storage unit during operation to eject the solution containing the biomolecule and the gas from the ejection port toward the injection target, An injector comprising

[0014] (Biomolecule) In this embodiment, the biomolecule to be injected into the injection target is not particularly limited as long as it functions in the injection target when injected. Also, the biomolecule may be a natural product or may be artificially synthesized. For example, nucleic acid or its derivative; nucleoside, nucleotide, or their derivative; amino acid, peptide, protein, or their derivative; lipid or its derivative; metal ion; low molecular compound, or its derivative; antibiotic; vitamin or its derivative, etc. can be mentioned. If it is a nucleic acid, it may be DNA or RNA, and they may contain genes. In the examples described later, as the biomolecule, free plasmid DNA containing the luciferase gene is used, and the luciferase gene is used as a reporter gene. The biomolecule to be injected into the injection target functions in the injection target when injected therein, and may be in a free form, fixed to a carrier such as a nanoparticle, or modified, as long as the biomolecule stably exists and has no adverse effects such as destroying the injection target. Its form, including the solvent, is not particularly limited. When the DNA contains a gene, examples include being designed in a form in which the gene is included in an expression cassette or an expression vector. Further, for example, the gene may be arranged under the control of a promoter suitable for the injection target and injection site into which the DNA is injected. That is, known genetic engineering techniques can be used in any aspect. In the examples described later, as the expression vector, pGL4.13[luc2 / SV40]Vector (manufactured by Promega Corporation), a mammalian expression vector, is used. This plasmid vector is known and can be obtained by those skilled in the art. Subcloning of the expression vector and the recombinant vector can be performed according to known methods.

[0015] (Predetermined gas) The injector of this embodiment has a housing portion that contains a predetermined gas. The gas is not particularly limited as long as the biomolecule functions in the injection target when the solution containing the biomolecule is injected into the injection target, the biomolecule stably exists, and there are no adverse effects such as destroying the injection target, and air can be exemplified. The air may be generally used air, and its composition is not particularly limited. For example, a mixed gas of about 80% nitrogen and about 20% oxygen can be mentioned. Also, examples of the gas include nitrogen, oxygen, ozone, carbon dioxide, hydrogen, and carbon monoxide, and a mixed gas of any two or more of these can be exemplified. Also, in a preferred aspect, the gas is a gas that does not contain microorganisms or the like, or a gas in which microorganisms or the like are dead even if they are contained.

[0016] In this embodiment, the presence of the gas in the containment unit causes the gas to dissolve into the biomolecule-containing solution as pressure is applied, initiating the injection of the biomolecule-containing solution into the injection target. As the pressure is reduced, some of the gas dissolved in the biomolecule-containing solution returns to its gaseous state, allowing the biomolecule-containing solution to be injected into the injection target while imposing significant shear stress on the target. As a result, it is presumed that the proportion of biomolecules that function in the injection target increases. Furthermore, when the biomolecule-containing solution is injected into cells, it is presumed that this mechanism increases the amount of biomolecule-containing solution injected into the cells by passing through the cell membrane, thereby increasing the proportion of biomolecules that function in the injection target.

[0017] In this case, if the volume of the gas contained in the containment is too large relative to the volume of the containment, the amount of solution containing the biomolecules in the containment will be small. As a result, the injection of the solution containing the biomolecules into the injection target will be completed before all of the gas has dissolved into the solution containing the biomolecules, and it is presumed that the injection target will not be subjected to sufficient shear stress. In other words, it is presumed that a large volume of the gas contained in the containment relative to the volume of the containment does not necessarily mean that the proportion of biomolecules that function in the injection target will be large. On the other hand, if the volume of the gas contained in the containment is too small compared to the volume of the containment, then, as described above, the gas dissolves into the biomolecule-containing solution as pressurization begins, and the injection of the biomolecule-containing solution into the injection target begins. As the pressure decreases, some of the gas that was dissolved in the biomolecule-containing solution returns to its gaseous state, but it is presumed that the amount of gas dissolved in the biomolecule-containing solution is small, resulting in a small shear stress on the injection target. As a result, it is presumed that the proportion of biomolecules that function in the injection target will be small. From these viewpoints, the volume of the gas contained in the containment section is preferably 20% or more, more preferably 30% or more, of the volume of the containment section, while preferably 60% or less, more preferably 50% or less.

[0018] (Functions of biomolecules) Examples of situations where a large proportion of biomolecules function in the target of injection include the following, where DNA as a biomolecule contains genes: When the containment unit does not contain the gas (i.e., the containment unit is filled with a solution containing the biomolecules) and a solution containing DNA is injected into the target to be injected (this is referred to as embodiment C), the expression level of the gene per unit amount of DNA injected into the target to be injected is defined as "expression level C". When the total volume of the DNA-containing solution and the gas is the same as the volume of the DNA-containing solution contained in the containment in embodiment C, and the containment contains the DNA-containing solution and the gas, and when injected into the injection target, the expression level of the gene per unit amount of DNA injected into the injection target is defined as "expression level A". Expression level C < Expression level A This is the case.

[0019] As a method of confirmation, for example, as shown in the examples below, tissue can be collected in a cylindrical shape with an arbitrary radius centered on the injection port after injection, a sample can be prepared by a known biological method, and the expression level of the gene can be confirmed by an expression assay. Depending on the type of gene, a known method can be used as appropriate, but for example, if the gene is a luciferase gene, the amount of luminescence can be assayed using luciferin as a substrate.

[0020] (Target for injection) The target of injection in this embodiment may be one or more selected from the group consisting of, for example, cells, cell sheets, cell aggregates, tissues, organs (such as skin or organs), organ systems, individuals (living organisms), etc., and is not limited. It may be an in vitro system, an in vivo system, or an ex vivo system. The cell aggregate may be a cell aggregate obtained by three-dimensional culture, and the organ (such as skin or organs) may be an organoid.

[0021] Furthermore, when an injection is performed on the target of the injection, the injection may also be performed on a lower level contained within it. That is, for example, when an individual (living organism) is the target of the injection, the injection may be performed on the tissue contained within the individual (living organism), on the cells contained within the individual (living organism), or on both. Also, when a tissue is the target of the injection, the injection may be performed on the cells contained within the tissue, on the intercellular matrix contained within the tissue, or on both.

[0022] Furthermore, if the target of injection in this embodiment is one or more selected from the group consisting of cells, cell sheets, cell aggregates, tissues, organs (such as skin and organs), or organ systems, it may be one or more selected from the group consisting of cells, cell sheets, cell aggregates, tissues, organs (such as skin and organs), or organ systems in a state in which they exist in an individual (living body), or it may be one or more selected from the group consisting of cells, cell sheets, cell aggregates, tissues, organs (such as skin and organs), or organ systems in a state in which they do not exist in an individual (living body) (for example, in a state in which they have been extracted or separated from an individual (living body), or in a state in which they have been produced outside an individual (living body)).

[0023] Furthermore, the target of injection in this embodiment is stem cell-derived, such as iPS cells (induced pluripotent stem cells). The above may be one or more selected from the group consisting of cells, cell sheets, cell aggregates, tissues, organs (such as skin and organs), and organ systems, and these may be present in an individual (living organism) or not present in an individual (living organism) (for example, in a state where they have been extracted or separated from an individual (living organism), or in a state where they have been produced outside an individual (living organism)). The cell aggregate may be a cell aggregate obtained by three-dimensional culture, and the organ (such as skin and organs) may be an organoid.

[0024] The organism (living organism) is preferably a mammal. The mammal is not particularly limited, but examples include humans and mammals other than humans. Examples of mammals other than humans include mice, rats, guinea pigs, hamsters, cattle, goats, sheep, pigs, monkeys, dogs, cats, etc.

[0025] Furthermore, regardless of which of the above is the target of injection in this embodiment, if the injection is into a cell, the injection may be into the cytoplasm of the cell, into the nucleus of the cell, or into both the cytoplasm and the nucleus of the cell.

[0026] Furthermore, the target of injection in this embodiment is not particularly limited, but preferably it is one or more selected from the group consisting of the intradermal, subcutaneous, and muscular layers within the skin of a mammalian individual (living organism). In this case, a method can be employed in which the solution containing the biomolecules and the gas are injected into the skin by ejecting them from an injector toward the skin surface, and the injection is carried out into one or more selected from the group consisting of the intradermal, subcutaneous, and muscular layers within the skin.

[0027] (syringe) In the injector of this embodiment, "tip side" refers to the side where the nozzle from which a solution containing biomolecules and a predetermined gas are ejected from the injector is located, and "base side" refers to the side of the injector opposite to the tip side. These terms do not limit themselves to any specific location or position.

[0028] In the injector of this embodiment, the drive unit provides injection energy to inject the solution containing the biomolecules and the gas into the target for injection. The "injection" by the injector of this embodiment is achieved by using the injection energy from the drive unit to pressurize the solution containing the biomolecules and the gas contained in the containment section by the pressurizing unit, causing the solution containing the biomolecules and the gas to flow through the flow path in the containment section. The injection energy may be the injection energy used in conventional injectors, and for example, combustion energy such as that of explosives, generation energy such as that of gas generating agents, electrical energy such as that of piezoelectric elements, mechanical energy such as that of springs, or energy that is an appropriate combination of these forms. When using the combustion energy of explosives as injection energy, examples of explosives include any one of the following, or combinations of several of these: explosives containing zirconium and potassium perchlorate (ZPP), explosives containing titanium hydride and potassium perchlorate (THPP), explosives containing titanium and potassium perchlorate (TiPP), explosives containing aluminum and potassium perchlorate (APP), explosives containing aluminum and bismuth oxide (ABO), explosives containing aluminum and molybdenum oxide (AMO), explosives containing aluminum and copper oxide (ACO), and explosives containing aluminum and iron oxide (AFO). A characteristic of these explosives is that although their combustion products are gaseous at high temperatures, they do not contain gaseous components at room temperature, so the combustion products condense immediately after ignition. As a result, in the pressurization process for injecting the biomolecule-containing solution and the gas, the temperature of the combustion products during pressurization can be brought down to near room temperature in a short time after the pressure on the biomolecule-containing solution and the gas reaches its initial peak injection power due to the combustion of the igniter. Furthermore, when utilizing the energy generated by the gas generating agent as injection energy, it is also possible to use single-base smokeless powder (for example, a single-base smokeless powder containing 98% by mass of nitrocellulose, 0.8% by mass of diphenylamine, and 1.2% by mass of potassium sulfate) or various gas generating agents used in airbag gas generators and seat belt pretensioner gas generators.

[0029] In this embodiment of the injector, the pressurizing unit pressurizes the solution containing the biomolecules and the gas contained in the containment unit during operation, thereby injecting the solution containing the biomolecules and the gas from the nozzle toward the target to be injected. The pressurization by the pressurizing section is not particularly limited as long as it does not damage the system, such as by destroying the housing section, and the pressurization conditions of a normal injector can be used. Here, the pressure refers to the pressure inside the containment. The method of measurement is not particularly limited, but for example, when measuring using the injector described in the embodiments below, it can be measured using the method described in the "Method for measuring the pressure inside the containment" section below.

[0030] The injection energy from the drive unit is transmitted to the plunger via the piston, and as the plunger slides within the containment section, the solution containing the biomolecules and the gas contained within the containment section are pushed out along the flow path formed in the nozzle section and finally injected from the nozzle towards the target.

[0031] The containment section may or may not initially contain the solution containing the biomolecules and the gas. If they are not contained, they can be added to the containment section by drawing them in through a nozzle having an injection port. By adopting a configuration that requires a containment operation into the containment section, it becomes possible to inject any desired solution containing biomolecules and gas into the target. Therefore, in the injector of this embodiment, the syringe section and the injector body may be configured to be detachable. Furthermore, although the containment section contains the solution containing the biomolecules and the gas, it is preferable that the solution containing the biomolecules is contained at the tip end of the containment section. In other words, it is preferable that the gas is contained at the base end of the containment section. This also means that it is preferable that the gas is not contained at the tip end of the containment section. For example, the solution containing the biomolecules can be prepared by first drawing the solution into the containment section via a nozzle with an outlet, then drawing the gas into the containment section, and then gently shaking the injector so that the solution containing the biomolecules is contained at the tip end of the containment section. Alternatively, the solution containing the biomolecules can be prepared by first drawing the gas into the containment section via a nozzle with an outlet, and then drawing the solution into the containment section while maintaining the position of the gas so that it is located at the base end of the containment section.

[0032] The injector of this embodiment is a conventional injector that can be used to inject an injection solution into an injection target without using a needle, and can be obtained by containing the solution containing the biomolecules and the gas in the containment section. Examples of such conventional injectors include the injector described in International Publication No. 2019 / 156238, the injector described in International Publication No. 2019 / 156239, the injector described in International Publication No. 2019 / 156237, and the injector described in Japanese Patent No. 5989039.

[0033] Below, with reference to the drawings, a syringe 1 (needleless syringe) will be described as an example of the injector of this embodiment. Note that the configuration of the following embodiment is illustrative and is not limited to the configuration of this embodiment. The terms "tip side" and "base side" will be used to describe the relative positional relationship in the longitudinal direction of syringe 1. The "tip side" refers to the position closer to the tip of syringe 1, i.e., closer to the nozzle 31a, and the "base side" refers to the direction opposite to the "tip side" in the longitudinal direction of syringe 1, i.e., the direction toward the drive unit 7. Furthermore, this example illustrates the use of the combustion energy of gunpowder ignited by an ignition device as injection energy for pressurization, but this embodiment is not limited to this.

[0034] (Components of syringe 1) Figure 1 is a schematic diagram of the syringe 1, and is also a cross-sectional view of the syringe 1 along its longitudinal direction. The syringe 1 is constructed by attaching a syringe assembly 10, which is an integral assembly of a sub-assembly consisting of a syringe section 3 and a plunger 4, and a sub-assembly consisting of a syringe body 6, a piston 5 and a drive unit 7, to a housing (syringe housing) 2.

[0035] As described above, the syringe assembly 10 is configured to be detachable from the housing 2. The housing 32 formed between the syringe part 3 and the plunger 4 in the syringe assembly 10 is filled with a solution containing biomolecules and a predetermined gas, and the syringe assembly 10 is a disposable unit that is used each time the solution containing biomolecules and the gas are injected. On the other hand, the housing 2 contains a battery 9 that supplies power to the igniter 71 included in the drive unit 7 of the syringe assembly 10. Power from the battery 9 is supplied via wiring between the electrode on the housing 2 side and the electrode on the drive unit 7 side of the syringe assembly 10 when the user presses a button 8 provided on the housing 2. The shape and position of the electrodes on the housing 2 side and the electrode on the drive unit 7 side of the syringe assembly 10 are designed so that they automatically make contact when the syringe assembly 10 is attached to the housing 2. The housing 2 is a unit that can be used repeatedly as long as there is enough power remaining in the battery 9 to supply power to the drive unit 7. In addition, if the battery 9 in housing 2 runs out of power, only the battery 9 may be replaced, and housing 2 may continue to be used.

[0036] Next, the details of the syringe assembly 10 will be described. First, the sub-assembly including the syringe section 3 and the plunger 4 will be described. The syringe section 3 has a containment section 32 formed inside, which is a space capable of containing the solution containing the biomolecules and the gas. More specifically, as shown in Figure 1, the plunger 4 is slidably arranged along the inner wall surface extending in the axial direction of the syringe section 3, and the containment section 32 is defined by the inner wall surface of the syringe section 3 and the plunger 4. The syringe section 3 also has a nozzle section 31 that communicates with the containment section 32, and an outlet 31a is formed on the tip side of the nozzle section 31. The cross-sectional area of ​​the flow path of the nozzle section 31 gradually decreases from the containment section 32 side to the outlet 31a side, and it is a flow path for guiding the solution containing biomolecules and a predetermined gas filled in the containment section 32 to the outlet 31a. In the example shown in Figure 1, the shape of the tip side of the plunger 4 is roughly the same as the shape of the nozzle section 31.

[0037] Next, the subassembly including the syringe body 6, piston 5, and drive unit 7 will be described. The piston 5 is made of metal, for example, and is pressurized by the combustion products (combustion gas) generated by the igniter 71 of the drive unit 7, and is configured to slide through a through hole formed inside the syringe body 6. The syringe body 6 is a generally cylindrical member, and the piston 5 is slidably housed along its axially extending inner wall surface. The piston 5 may also be made of resin, in which case metal may be used in combination with resin in parts where heat resistance and pressure resistance are required. Also, as shown in Figure 1, the piston 5 is integrally connected to the plunger 4.

[0038] Next, the drive unit 7 will be described. As shown in Figure 1, the drive unit 7 is fixed to the base end side with respect to the through hole in the syringe body 6. The drive unit 7 has an igniter 71, which is an electric igniter. The igniter 71 is positioned to face the inside of the through hole in the syringe body 6, and contains an igniter. Various types of explosives can be used as the igniter, as shown above. The igniter can also be contained in an explosive cup made of a suitable thin metal, for example.

[0039] In the syringe 1 configured as described above, the volume of gas contained in the containment section 32 is adjusted to be, for example, 20% to 60% of the volume of the containment section 32.

[0040] Next, the operation of the syringe 1 with the above configuration will be explained. As shown in Figure 1, with the syringe assembly 10 attached to the housing 2, a solution containing biomolecules and a predetermined gas are drawn in from the nozzle 31a of the nozzle section 31. This allows the solution containing biomolecules and the predetermined gas to be filled into the containment section 32. From this state, for example, when the nozzle 31a of the syringe 1 is brought into contact with the object to be injected, the user presses the button 8 provided on the housing 2. This acts as a trigger, supplying operating power from the battery 9 to the igniter 71 of the drive unit 7, and the igniter 71 is activated. When the igniter 71 is activated, the igniter is ignited and burns, generating combustion products (flames, combustion gases, etc.). As a result, for example, the gunpowder cup of the igniter 71 ruptures, and the combustion gas of the igniter is released into the through hole in the syringe body 6. As a result, the pressure inside the through-hole of the syringe body 6 increases rapidly, pushing the piston 5 toward the tip of the syringe body 6. Consequently, the piston 5 slides toward the tip along the inner wall surface of the through-hole in the syringe body 6. As described above, since the plunger 4 is integrally connected to the piston 5, the plunger 4 also slides along the inner wall surface of the syringe part 3 in conjunction with the piston 5. That is, as the plunger 4 is pushed toward the nozzle part 31 located toward the tip of the syringe part 3, the volume of the containment part 32, which contains the biomolecule-containing solution and a predetermined gas, decreases and is rapidly pressurized. As a result, the biomolecule-containing solution and the predetermined gas filled in the containment part 32 are pushed toward the nozzle part 31 and injected at high pressure from the injection port 31a. This allows the biomolecule-containing solution and the predetermined gas to be injected into the target.

[0041] Furthermore, although no additional explosive components are placed inside the syringe body 6 shown in Figure 1, a gas generating agent that burns and generates gas through combustion products produced by the combustion of explosives in the igniter 71 can be placed inside the igniter 71 or in the through-hole of the syringe body 6 in order to adjust the pressure transition between the solution containing the biomolecules and the gas via the piston 5. The configuration of placing a gas generating agent inside the igniter 71 is already a known technology, as disclosed in International Publication No. 01-031282 and Japanese Patent Application Publication No. 2003-25950, etc. Another example of a gas generating agent is a single-base smokeless powder containing 98% by mass of nitrocellulose, 0.8% by mass of diphenylamine, and 1.2% by mass of potassium sulfate. It is also possible to use various gas generating agents used in gas generators for airbags and seat belt pretensioners. By adjusting the dimensions, size, shape, and especially the surface shape of the gas generating agent when it is placed in the through-hole, it is possible to change the combustion completion time of the gas generating agent. This makes it possible to change the pressure transition between the solution containing biomolecules and the gas to a desired transition, that is, a transition that allows the solution containing biomolecules and the gas to appropriately reach the injection target. In this embodiment, the gas generating agent used as needed is also included in the drive unit 7. In this embodiment, the "pressurization unit" is composed of a plunger 4 and a piston 5.

[0042] Another embodiment of the present disclosure is a method of injecting a solution containing biomolecules and a predetermined gas into an injection target using the injector of the above embodiment. The injector, the target of injection, and the solution containing biomolecules in this embodiment shall be described in accordance with the above-described embodiment. [Examples]

[0043] Examples are described below, but none of these examples should be interpreted as being limited in meaning.

[0044] [Example 1] As the plasmid, we prepared pGL4.13[luc2 / SV40]Vector (Promega), amplified the required amount, and used a concentration of 1 μg / μL. The plasmid solution was drawn up into the injector's containment section (volume: 100 μL) in quantities of 100 μL, 80 μL, 70 μL, 50 μL, 40 μL, or 30 μL from the nozzle of the injector. Then, except when 100 μL of the plasmid solution was drawn up, the plunger was raised to the 100 μL mark without drawing up any more plasmid solution, and the injector was filled with normal laboratory air. That is, the volume of air contained in the containment section was 0%, 20%, 30%, 50%, 60%, and 70% of the volume of the containment section, respectively (hereinafter, the volume of air contained in the containment section relative to the volume of the containment section may be referred to as the "air abundance"), and the amount of plasmid injected was 100 μg, 80 μg, 70 μg, 50 μg, 40 μg, and 30 μg, respectively. Furthermore, the air in the containment section during injection is contained towards the proximal end, while the plasmid solution is contained towards the proximal end.

[0045] Here, the injector was used as a device for injecting the substance into the abdomen of the test animal, as described later, and is the injector shown in Figure 1. In this example, 35 mg of ZPP was used as the igniter, and 40 mg of single-base smokeless powder (containing 98% by mass of nitrocellulose, 0.8% by mass of diphenylamine, and 1.2% by mass of potassium sulfate) was used as the gas generating agent. Furthermore, the time from the start of pressurization until the pressure reaches the maximum pressure, and the measurement of this maximum pressure, utilized conventional techniques. Specifically, as described in the measurement method of Japanese Patent Publication No. 2005-21640, the injection force was distributed and applied to the diaphragm of a load cell located downstream of the nozzle, and the output from the load cell was collected by a data acquisition device via a detection amplifier and stored as the injection force (N) for each period of time. The injection pressure was calculated by dividing the injected pressure by the area of ​​the injection port 31a of the injector. The measured internal pressure of the containment section is equivalent to the injection pressure, and the injection pressure can be used as the pressure inside the containment section. As a result, for example, when the volume of air contained in the containment section is 0% of the volume of the containment section, the time from the start of pressurization to the pressure reaching the maximum pressure was 0.55 milliseconds, and the maximum pressure was 10.3 MPa.

[0046] Domestic pigs (Specific Pathogen Free, SPF) were used as test animals and were anesthetized beforehand. After shaving, the aforementioned injectable substance from the injector was injected into the abdomen. Following the injection, the animals were kept for approximately 24 hours, and then euthanized by hemostasis under anesthesia. The injection site was excised using a biopsy trephine φ8.0 mm (Kai Corporation) and collected in a 2.0 mL tube. 1 mL of Passive Lysis 5× Buffer (Promega), diluted 5 times with MilliQ water, was added to each excision site until a skin fragment of approximately 1 mm was obtained. The samples were minced using a sapiens. After freezing on dry ice and thawing at room temperature once each, the skin fragments were separated by centrifugation at 20380G for 2 minutes, yielding a supernatant containing protein extract. A Luciferase Assay System (Promega) was used for luciferase measurement. That is, 100 μL of substrate solution was mixed with 20 μL of the protein extract, and the luminescence (RLU) was measured using a Lumitester C (Kikkoman).

[0047] Because the amount of plasmid injected into the abdomen differs depending on the conditions described above, the expression efficiency was calculated as the expression level per 1 μg of plasmid and expressed as a relative value compared to the case with 0% air presence. The results are shown in Table 1.

[0048] [Table 1]

[0049] These results confirmed that when the air content is between 20% and 60%, the expression efficiency of luciferase significantly improves.

[0050] [Reference example 1] In addition, the following comparative experiment was conducted separately. Specifically, the procedure was the same as in Example 1, except that the same amount of TE buffer (Nacalai Tesque) was used instead of air. As a result, it was confirmed that the plasmid concentration did not affect the expression efficiency per 1 μg of plasmid. [Explanation of symbols]

[0051] 1...Syringe 2. Housing 3. Syringe section 4. Plunger 5. Piston 6...Syringe body 7. Drive unit 8 buttons 9. Battery 10...Syringe assembly 31..Nozzle section 31a...Ejection port 32.....Detention Unit 71...Igniter

Claims

1. An injector that injects a solution containing biomolecules and a predetermined gas into a target without using a needle, A containment section containing the solution containing the biomolecules and the gas, A nozzle portion communicating with the aforementioned containment portion, having an outlet for injecting the solution containing the biomolecules and the gas toward the injection target, A pressurizing unit that, when in operation, pressurizes the solution containing the biomolecules and the gas contained in the containment unit, thereby injecting the solution containing the biomolecules and the gas from the nozzle toward the injection target, Equipped with, The volume of the gas contained in the containment section is 30% or more and 60% or less of the volume of the containment section. syringe.

2. The injector according to claim 1, wherein the gas is air.

3. The injector according to claim 1 or 2, wherein the biomolecule is DNA containing a gene.

4. A method for injecting a solution containing biomolecules and a predetermined gas into an injection target (excluding humans) using an injector according to any one of claims 1 to 3.

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