JP2013180121A - Needleless syringe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately feed a target substance for injection to a target site, particularly to a shallow site, in a target area for injection of a living body without via a syringe needle.SOLUTION: A syringe for injecting a target substance for injection to a target area for injection without via a syringe needle includes: a storage part for storing the target substance for injection; and an injection part for pressurizing the target substance for injection stored in the storage part by at least combustion of a primer, injecting the pressurized target substance for injection to the target area for injection, and infiltrating part of the injected target substance for injection into the target site within the target area for injection.

Description

  The present invention relates to a needleless syringe that injects a substance to be injected into an injection target region of a living body without using an injection needle.

  In a needleless syringe that performs injection without going through an injection needle, a configuration in which an injection component is ejected by applying pressure to a storage chamber in which an injection solution is stored by a pressurized gas or a spring may be employed. For example, the needleless syringe described in Patent Document 1 employs a configuration in which a plurality of nozzle holes are formed inside the syringe body, and a piston that is driven at the time of injection is disposed corresponding to each nozzle hole. . With this configuration, an injection solution is simultaneously ejected from a plurality of nozzle holes to achieve uniform injection into the subject.

  Moreover, there exists a form using a pressurized gas as an injection power source of the injection solution in a needleless syringe. For example, in the needleless syringes described in Patent Document 2 and Patent Document 3, a pressurization mode in which a large pressure is instantaneously applied at the initial stage of injection and then the applied pressure is gradually reduced over 40 to 50 msec. Has been.

JP 2004-358234 A US Pat. No. 5,399,163 US Publication No. 2005/0010168

  When an injection is performed on a living body, the component contained in the injection solution and the target site in the injection target area of the living body to which the component is to be fed, particularly the site to be fed recognized in the depth direction, differ depending on the purpose of the injection. This is because the living body injection target area includes various structures such as skin, muscle, and internal organs, and the living tissue constituting these structures has its surface (when the injection is performed, the syringe is a structure) This is because the function varies depending on the depth from the surface touching the surface, and it is difficult to properly exert its effects unless the components in the injection solution reach the target biological tissue (target site). Because it becomes. For example, human skin can be distinguished from the surface side into epidermis, dermis, and subcutaneous tissue in layers. Each layer is composed of keratinocytes, dendritic cells and pigment cells, dermis fibroblasts and collagen cells, and subcutaneous tissue composed of subcutaneous fat and the like in order to perform each function anatomically. And when injecting an injection solution for a predetermined purpose, it is preferable that the predetermined component contained therein is accurately delivered to the target tissue or the like (target site).

  Further, in the injection target region of the living body, the resistance force against the injected injection target substance is not constant, and usually varies depending on the type and location of the living body, or depending on the individual difference. In a general skin structure, the epidermis portion is hard and the inside suddenly softens, so it may be difficult to accurately deliver the pressurized injection target substance to the portion immediately below the epidermis. Accordingly, in the present invention, in view of the above-described problems, it is an object to accurately send an injection target substance to a target site in a target injection region of a living body without using an injection needle, particularly to a shallow site. And

  In order to solve the above problems, the present invention provides a syringe for injecting a substance to be injected into an injection target region of a living body without using an injection needle, and pressurizing the injection target substance by burning an explosive. The injection configuration in which a part of the injection target substance enters the inside of the injection target region is adopted. By providing the needleless syringe with such a configuration, the injection target substance can be suitably delivered to a wide range from a very shallow site to a relatively deep site directly under the surface of the injection target region.

  Specifically, the present invention is a syringe for injecting an injection target substance into an injection target region of a living body without going through an injection needle, the container containing the injection target substance, and at least by burning an ignition agent Pressurizing the injectable substance contained in the container, injecting the pressurized injectable substance to the injection target area, and a part of the injected injectable substance And an injection unit that enters a target site in the injection target region. The igniting agent is an igniting agent included in the igniting means, and refers to an ignition device such as an electric igniter that operates with an igniting current. However, in the needleless syringe of the present invention, the specific configuration of the ignition device is not limited as long as such an ignition agent is used, and a known gas generating agent can be used in combination.

  In the needleless syringe according to the present invention, the injection target substance to be injected into the injection target region of the living body is stored in the storage unit, and at least the ignition agent is combusted with respect to the injection target substance stored in the storage unit. The injection target substance is injected by applying the pressure generated by. This injection target substance contains a component expected to be effective at the target site inside the injection target region. Therefore, as long as at least injection by pressurization through combustion of an igniting agent is possible, the storage state of the injection target substance in the storage part, the injection target substance such as a liquid or gel-like fluid, powder, granular solid, etc. The specific physical form of is not questioned. For example, the injection target substance is a liquid, and even if it is a solid, it may be a gel-like solid as long as fluidity enabling injection is ensured. The injection target substance includes a component to be sent to a target site inside the injection target region of the living body, and the component may exist in a state dissolved in the injection target substance, or the component may be dissolved. Instead, it may be simply mixed. For example, as ingredients to be delivered, there are vaccines for antibody enhancement, proteins for cosmetics, cultured cells for hair regeneration, etc., so that these can be injected into fluids such as liquids and gels. By inclusion, a substance for injection is formed.

  And in the above needleless syringe, the injection part is adopted a configuration in which injection to the injection target region is performed by transmitting at least the pressure generated by the combustion of the ignition agent to the injection target substance, The injection target substance is injected so that a part of the injection target substance enters the injection target area and reaches the target site. It is possible to accurately deliver the injection target substance even to a relatively shallow part in the injection target area by injecting the injection target substance so that a part of the injection target substance enters the target part in the injection target area. This is because the applicant has found that This new knowledge by the present applicant cannot be found in the prior art. By performing such injection of the injection target substance, it becomes possible to provide the needle-free injector with a suitable injection target substance injection performance that does not exist in the prior art.

Here, in the needleless syringe, an injection port through which the injection target substance is injected from the syringe body so that a part of the injection target substance enters the injection target region and can reach the target site. The injection target substance may be injected by the injection unit in a state where the injection target area is pressed against the surface of the injection target area with a predetermined pressing force. In the case of a needleless syringe, injection is performed when the injection target substance ejected from the ejection port enters the inside of the injection target area. Therefore, by injecting the injection target substance in a state where the pressing force to the injection port is set to a predetermined pressing force, a part of the injection target substance is preferably made a target part, particularly a relatively shallow part of the injection target region. It becomes possible to deliver. The predetermined pressing force is appropriately set according to the injection pressure of the injection target substance from the injection port, the hardness of the injection target region (resistance to the injection target substance), and the like. Note that the predetermined pressing force may be constant during a state where the injection is completed from a state before the injection is performed, or may be changed in the middle. By adjusting the pressing force in this way, the energy that the injection target substance pushed out from the nozzle penetrates to the injection target area is adjusted, and in a broad sense, the injection power of the injection target substance by the igniting agent is adjusted. It will also be that.

  Further, in the syringe up to the above, the igniting agent includes explosives containing zirconium and potassium perchlorate, explosives containing titanium hydride and potassium perchlorate, explosives containing titanium and potassium perchlorate, aluminum and perchlorate. Gunpowder containing potassium acid, gunpowder containing aluminum and bismuth oxide, gunpowder containing aluminum and molybdenum oxide, gunpowder containing aluminum and copper oxide, gunpowder containing aluminum and iron oxide, or a plurality of these An explosive consisting of a combination of As a feature of these igniting agents, even if the combustion product is generated in a high temperature state, even if gas is generated, it does not contain a gas component at normal temperature, so that when the combustion product comes into contact with the surface in the combustion chamber, it immediately condenses. Efficient injection into a shallower part of the injection target area of the living body becomes possible.

  In a syringe, it is possible to accurately send an injection target substance to a target site in a target injection region of a living body without using an injection needle, particularly to a shallow site.

It is a figure which shows schematic structure of the needleless syringe which concerns on this invention. It is a figure which shows schematic structure of the initiator (ignition apparatus) with which the syringe shown in FIG. 1 is mounted | worn. 2 is a graph showing a transition of pressure applied to an injection solution by burning of explosives in the needleless syringe shown in FIG. 1. It is a 1st figure which shows the experimental result in the mouse | mouth after injection regarding the injection experiment to the mouse | mouth using the gunpowder type needleless syringe which concerns on this invention. It is the 2nd figure which shows the experimental result in the mouse | mouth after injection regarding the injection experiment to the mouse | mouth using the gunpowder type needleless syringe which concerns on this invention. It is a 3rd figure which shows the experimental result in the mouse | mouth after injection regarding the injection experiment to the mouse | mouth using the gunpowder type needleless syringe which concerns on this invention. It is a figure which shows the experimental result in the mouse | mouth after injection regarding the injection experiment to the mouse | mouth using the spring type needleless syringe which concerns on a prior art. It is the 1st figure which shows the microscope picture of the mouse | mouth structure | tissue after injection regarding the injection experiment to the mouse | mouth using the explosive type needleless syringe which concerns on this invention. It is the 2nd figure which shows the microscope picture of the mouse | mouth structure | tissue after injection regarding the injection experiment to the mouse | mouth using the explosive type needleless syringe which concerns on this invention. It is a figure which shows the 2nd schematic structure of the needleless syringe which concerns on this invention. FIG. 8 is a graph showing a transition of pressure applied to an injection solution by combustion of explosives in the needleless syringe shown in FIG. 7.

  A needleless syringe (hereinafter simply referred to as “syringe”) 1 according to an embodiment of the present invention will be described below with reference to the drawings. The configuration of the following embodiment is an exemplification, and the present invention is not limited to the configuration of this embodiment.

Here, FIG. 1 (a) is a cross-sectional view of the syringe 1, FIG. 1 (b) is a side view of the syringe 1 seen from the initiator (igniter) 20 side, and FIG. It is the side view seen from the nozzle 4 side which inject | emits an injection solution. The syringe 1 has a syringe body 2, and a through-hole 14 extending in the axial direction and having a constant diameter along the axial direction is provided in the central portion of the syringe body 2. One end of the through hole 14 communicates with the combustion chamber 9 having a diameter larger than that of the through hole 14, and the other end reaches the nozzle 4. Furthermore, an initiator 20 is installed on the opposite side of the combustion chamber 9 from the communication location with the through-hole 14 so that the ignition part faces the communication location.

  Here, an example of the initiator 20 will be described with reference to FIG. The initiator 20 is an electric ignition device, and a space for arranging the ignition agent 22 is defined in the cup 21 by a cup 21 whose surface is covered with an insulating cover. And the metal header 24 is arrange | positioned in the space, and the cylindrical charge holder 23 is provided in the upper surface. The charge holder 23 holds the ignition agent 22. A bridge wire 26 that electrically connects one conductive pin 28 and the metal header 24 is wired at the bottom of the ignition agent 22. The two conductive pins 28 are fixed to the metal header 24 via the insulator 25 so that they are insulated from each other when no voltage is applied. Furthermore, the opening of the cup 21 from which the two conductive pins 28 supported by the insulator 25 extend is protected by the resin 27 in a state in which the insulation between the conductive pins 28 is well maintained.

  In the initiator 20 configured as described above, when a voltage is applied between the two conductive pins 28 by the external power source, a current flows through the bridge wire 26, thereby burning the igniting agent 22. At this time, the combustion products resulting from the combustion of the igniting agent 22 are ejected from the opening of the charge holder 23. Therefore, in the present invention, the relative positional relationship of the initiator 20 with respect to the syringe body 2 is designed so that the combustion product of the igniting agent 22 in the initiator 20 flows into the combustion chamber 9. The initiator cap 12 is formed in a hook shape so as to be hooked on the outer surface of the initiator 20 and is fixed to the syringe body 2 with screws. Thereby, the initiator 20 is fixed to the syringe main body 2 by the initiator cap 12, and therefore, the initiator 20 itself can be prevented from dropping from the syringe main body 2 due to the pressure generated when the initiator 20 is ignited.

  The igniting agent 22 used in the syringe 1 is preferably an explosive containing zirconium and potassium perchlorate (ZPP), an explosive containing titanium hydride and potassium perchlorate (THPP), titanium and potassium perchlorate. Gunpowder containing (TiPP), Gunpowder containing aluminum and potassium perchlorate (APP), Gunpowder containing aluminum and bismuth oxide (ABO), Gunpowder containing aluminum and molybdenum oxide (AMO), Gunpowder containing aluminum and copper oxide (ACO) ), Explosives containing aluminum and iron oxide (AFO), or explosives composed of a combination of these explosives. These explosives generate high-temperature and high-pressure plasma at the time of combustion immediately after ignition, but exhibit a characteristic that the generated pressure rapidly decreases because the combustible organisms do not contain gas components when they become room temperature. In addition, you may use explosives other than these as an ignition powder.

Here, nothing is arranged in the combustion chamber 9 shown in FIG. 1, but a gas generating agent that burns with combustion products generated by the combustion of the igniting agent 22 to generate gas is arranged in the combustion chamber 9. You may do it. If the gas generating agent is disposed in the combustion chamber, an example is a single base smokeless explosive composed of 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 that are used in gas generators for airbags and gas generators for seat belt pretensioners. The combined use of such a gas generating agent is different from the case of only the igniting agent 22 described above, and the predetermined gas generated at the time of combustion contains a gas component even at room temperature, so the rate of decrease in generated pressure is small. Furthermore, although the combustion completion time at the time of combustion of the gas generating agent is extremely longer than that of the igniting agent 22, the size, size, shape, and particularly the surface of the gas generating agent when disposed in the combustion chamber 9. By adjusting the shape, it is possible to change the combustion completion time of the gas generating agent. Thus, by adjusting the amount, shape, and arrangement of the gas generating agent, the generated pressure in the combustion chamber 9 can be adjusted as appropriate.

  Next, a metal piston 6 is disposed in the through hole 14 so as to be slidable in the through hole 14 along the axial direction, one end of which is exposed to the combustion chamber 9 side, and the other end is exposed to the other end. The sealing member 7 is integrally attached. Then, the injection liquid ML that is an injection target substance injected by the syringe 1 is accommodated in a space formed in the through hole 14 on the distal end side of the syringe from the sealing member 7. In addition, as shown to Fig.1 (a), the injection liquid ML is not enclosed in the space closed completely, but the syringe front end side is the open state. However, since the inner diameter of the through-hole 14 in which the injection solution ML is accommodated is extremely small and the amount of the injection solution is small, the surface tension of the injection solution ML is thus obtained even if the space for containing the injection solution ML is a semi-closed space. Thus, the state in which the injection solution ML is accommodated in the through hole 14 is preferably maintained. As will be described later, the accommodated injection liquid ML is injected from the nozzle 4 by being pressurized by the initiator 20. Here, the housing part of the syringe according to the present invention is formed by the sealing member 7 and the through hole 14. The sealing member 7 is made of rubber having a surface coated with a thin silicone oil so that the injection liquid ML can smoothly move in the through hole 14 as the piston 6 slides.

  Furthermore, a holder 5 in which a nozzle 4 for injecting the injection liquid ML is formed is provided on the distal end side (right side in FIG. 1) of the syringe 1. The holder 5 is fixed to the end surface of the syringe body 2 with a gasket 3 interposed therebetween via a holder cap 13. The holder cap 13 is formed in a hook shape so as to be hooked to the holder 5, and is fixed to the syringe body 2 with screws. Thereby, the holder 5 is prevented from dropping from the syringe main body 2 due to the pressure applied to the injection liquid ML when the injection liquid ML is ejected. One nozzle 4 is formed at the center of the holder 5 as shown in FIG.

  In the syringe 1 configured as described above, the combustion product is filled in the combustion chamber 9 by the igniting agent 22 in the initiator 20, and the pressure is applied to the injection liquid ML accommodated in the through hole 14 via the piston 6. Add As a result, the injection liquid ML is pushed out toward the distal end side of the syringe 1 with the sealing member 7 and is ejected toward the injection target through the nozzle 4. Since pressure is applied to the injected injection liquid ML, it can penetrate the surface of the injection target object and reach the inside of the injection liquid, thereby achieving the purpose of injection in the syringe 1.

  Here, for an injection target region such as a skin structure of a living body, for example, a substance to be injected according to a therapeutic purpose for the skin, and a position in the skin structure where it is desired to be injected (site in the depth direction, In other words, the target site) corresponds individually, but in particular, it is difficult to accurately deliver a desired substance by injection to the target site existing in a shallow position. Therefore, in the syringe 1 according to the present invention, by adjusting various conditions related to injection of the injection solution so that a part of the injection solution enters the target site of the injection target region, the reaching depth is relatively shallow. Made it possible to As described above, substances to be injected into the skin structure (injection target substance) vary depending on the treatment purpose, and therefore, in the following description, the injection target substance is generically referred to as “injection solution”. However, this is not intended to limit the content or form of the injected substance. In the injection target substance, the component to be delivered to the skin structure may or may not be dissolved, and the injection target substance can be injected from the nozzle 4 to the skin structure by pressurization. If it exists, the specific form is not ask | required and various forms, such as a liquid and a gel form, are employable.

<Pressurizing conditions>
In the syringe 1 shown in FIG. 1, as described above, the applied pressure generated when the igniting agent 22 included in the initiator 20 is ignited and burnt becomes a driving source for injection of the injection liquid ML. In this embodiment, a living mouse is injected with an injection solution containing a predetermined injection target substance. Therefore, 35 mg of ZPP (zirconium / potassium perchlorate mixture) is used as the ignition agent 22. Note that the transition of pressure generated in the combustion chamber 9 by the combustion of the ignition agent 22 is as shown in FIG. At the time of ignition (elapsed time of 0 sec), a pressure of over 20 MPa is instantaneously generated, and immediately after that, the pressure suddenly drops, but gradually decreases from 0.02 to 0.05 sec, and changes around 5 MPa. Thus, when only the igniting agent 22 is used as a drive source for injection injection, there is a feature that although there is a steep pressure generation at the time of ignition, the pressure gradually decreases thereafter. At this time, the volume of the combustion chamber 9 in the syringe 1 is 0.5 cc. FIG. 3 shows the pressure transition when operating at room temperature.

Under such pressurizing conditions with the initiator 20, injection experiments (Experiments 1-3) with the syringe 1 were performed. In addition, in order to obtain reference results for comparison of experimental results, injection experiments using spring-type needle-free injection according to the prior art (reference experiments 1 to 3), injection experiments using needle injection (reference experiment) 4-6) was performed.
<Other experimental conditions>
(About injection solution)
As an injection solution to be injected (that is, as an injection solution accommodated in the through-hole 14 of the syringe 1), 27 μL of a plasmid encoding luciferase or LacZ was used. When luciferase or the like reaches a predetermined site (relatively shallow site just under the epidermis) of the mouse skin structure and diffuses there, gene expression can be confirmed visually from the outside or by microscopic observation of the injection site.
(Pressing condition)
In this embodiment, when the syringe 1 is injected into the mouse living body, the injection is performed with the injection port of the nozzle 4 being pressed against the mouse living body, that is, the initiator 20 is ignited. This pressing force of the injection port is a load applied so that the injection port is completely covered with the mouse body and perpendicular to the surface of the mouse body, and is a parameter that affects the behavior of the injected injection solution. One is considered. The table below summarizes the conditions of each experiment including the pressing force. Table 1 shows the conditions of Experiments 1 to 3, Table 2 shows the conditions of Reference Experiments 1 to 3, and Table 3 shows the conditions of Reference Experiments 4 to 6. The pressing force is such that a scale (such as an electronic balance) on which a mouse to be injected is placed is pressed against the nozzle 4 of the fixed syringe 1 using a jack, and the scale indicated by the balance at that time is used as the pressing force. .

<Experimental result>
Next, experimental results according to the above experimental conditions are shown below. First, Table 4 below shows measured values of luciferase activity (relative luminescence amount: RLU / Protein) in mice injected with luciferase. In the case of a mouse, the amount of luminescence by luciferase becomes significant when luciferase diffuses to a site directly under the epidermis.
The injection penetration rate in Table 4 above indicates the ratio of the amount of injection solution that has entered the target site of the mouse body by injection relative to the amount of injection solution (27 μL) loaded on the syringe side. Specifically, the injection penetration rate was calculated by measuring the amount of injection solution that was not injected into the target site of the mouse body. At this time, it is assumed that the amount excluding the amount that has not reached the target site of the mouse from the loaded amount has reached the target site of the mouse. In Experiment 2 and Experiment 3 described above, only a part of the injection solution loaded in the syringe 1 is injected into the living body of the mouse under the condition that the pressurizing force shown in FIG. That's right.
Moreover, the active part visual recognition magnitude | size in the said Table 4 is a magnitude | size which can be visually recognized about the location where the luciferase activity has arisen, About Experiments 1-3, the photograph of the active location is shown to FIG. 4A, FIG. 4B, Each is shown in FIG. 4C. For Reference Experiment 1, a photograph of the active site is shown in FIG. The other reference experiments were basically of the same visual size as the reference experiment 1, so that the description of the photos of the respective active sites was omitted by describing that fact in Table 4 above. In addition, in order to make it possible to grasp the size of the photograph of each active location, the active location is surrounded by a dotted line, and a ruler having a scale of 1 mm is arranged in the active location.

According to the above experimental results, as shown in Experiments 2 and 3, so that part of the injection solution loaded in the syringe 1 enters the target site of the mouse body, that is, the injection penetration rate is 100%. When the ignition agent 22 is burned in the initiator 20 so as not to become a state, the luciferase activity can be clearly and easily grasped from the outside. This means that luciferase activity is expressed at a site (target site) directly under the epidermis of mice according to the injections in Experiments 2 and 3. On the other hand, in the case where the injection penetration rate is 100% (Experiment 1 and each reference experiment), it is difficult to confirm the luciferase activity directly under the epidermis of the mouse.

Furthermore, an injection experiment (Experiment 4 and Experiment 5) was performed on the living body of the mouse using the syringe 1 under the conditions shown in Table 5 below, and the tissue piece (frozen section) after 48 hours had been subjected to X-gal staining and The micrographs of the tissue pieces when stained with E are shown in FIGS. 6A and 6B, respectively.

The injection penetration rates of Experiment 4 and Experiment 5 performed under the above conditions were 50% and 100%, respectively. Looking at FIG. 6A, which shows a micrograph of a tissue fragment with an injection penetration rate of 50%, a gene expression site by LacZ (highly expressed in the figure) is located immediately below the epidermis (target site) surrounded by a dotted line in the figure. Can be found widely. This means that the injection solution containing LacZ ejected by the syringe 1 stayed at the site directly under the epidermis without entering the deep part of the mouse body and diffused there. On the other hand, looking at FIG. 6B showing a micrograph of a tissue piece with an injection penetration rate of 100%, unlike FIG. 6A, a gene expression site by LacZ is found in a site directly under the epidermis surrounded by a dotted line in the figure. I can't. In this case, it is considered that the injected injection solution has reached the deep part of the mouse living body outside the field of view of the micrograph.

Based on the above experimental results, at least in the syringe 1, the injection penetration rate does not become 100%, that is, so that a part of the injection solution loaded in the syringe 1 enters the target site of the mouse body. By performing the injection, it can be said that the penetration depth of the injection solution inside the mouse living body can be suitably adjusted to a relatively shallow site. In particular, as shown in Experiments 2, 3, and 4, by making the pressing force of the injection port of the syringe 1 relatively small (in this example, about 17 g), the penetration rate of the injection solution at the time of injection is 100%. Therefore, it is possible to realize the diffusion of the injection solution in a relatively shallow region.

<Other examples>
In the embodiments described above, the injection target is an example related to a mouse, but a living body other than the mouse may be the injection target. For example, a rabbit larger than a mouse can be mentioned. In this case, in order to increase the injection effect, the structure of the syringe 1 may be different from the structure shown in FIG. 1 as shown in FIG. In the syringe 1 shown in FIG. 8, the inner diameter of the through-hole 14 is made larger than the structure shown in FIG. 1 so that the amount of injection solution that can be loaded on the syringe side is increased. Therefore, since it becomes difficult to store the injection solution using the surface tension, a configuration in which the injection solution ML is stored in a closed space between the sealing member 7 and the sealing member 8 is employed.

  Then, when the holder 5 is attached to the syringe body 2, a recess 10 that can accommodate the sealing member 8 is formed at a location facing the sealing member 8. The recess 10 has substantially the same diameter as the sealing member 8 and has a depth slightly longer than the length of the sealing member 8. Thereby, when pressure is applied to the piston 6 and the injection liquid ML moves to the distal end side of the syringe 1 together with the sealing members 7 and 8, the sealing member 8 can be accommodated in the recess 10. When the sealing member 8 is accommodated in the recess 10, the pressurized injection solution ML is released. Therefore, the flow path 11 is formed at a portion of the holder 5 that contacts the syringe body 2 so that the released injection liquid ML is guided to the nozzle 4. Thereby, the released injection liquid ML is ejected from the nozzle 4 to the injection target through the flow path 11. Moreover, it can avoid that injection | pouring of the injection liquid ML is inhibited by the sealing member 8 because the recessed part 10 has the depth which accommodates the sealing member 8. FIG.

  Moreover, the syringe 1 shown in FIG. 8 is provided with a plurality of nozzles 4 (for example, three nozzles). In this case, it is preferable that the nozzles are arranged at equal intervals around the central axis of the syringe 1. When a plurality of nozzles are formed, a flow path corresponding to each nozzle is formed so that the injection solution released to each nozzle is fed. The diameter of the nozzle 4 is appropriately set in consideration of the injection target, the injection pressure applied to the injection liquid ML, the physical properties (viscosity) of the injection liquid, and the like.

Further, in the syringe 1 shown in FIG. 8, a gas generating agent 30 is disposed in the combustion chamber 9. The gas generating agent 30 is a single base propellant, and the component ratio is as follows.
Nitrocellulose: 98.1% by weight
Diphenylamine: 0.8% by weight
Potassium sulfate: 1.1% by weight
Graphite (external split): Trace amount

In this embodiment, 55 mg of ZPP is used as the igniting agent 22 in the initiator 20 and 10 mg of the gas generating agent 30 having the above component ratio is used. The pressure transition in the combustion chamber 9 at that time is shown in FIG. Is shown by a solid line. In addition, the dotted line shown in FIG. 9 is a pressure transition in the syringe 1 shown in FIG. 3, and is included in FIG. 9 for comparison. Thus, by using the gas generating agent 30, it becomes possible to set the pressurizing force between 0.01 to 0.05 sec after ignition of the igniting agent 22 high.

And, as a result of conducting the same quality injection experiment as that of mice under such pressure conditions, compared to needled syringes, needleless syringes were used and the injection penetration rate was 100%. Injecting while adjusting the pressing force of the injection port so that a part of the loaded injection solution enters the target part of the rabbit living body, so that it can be injected into a relatively shallow part of the rabbit living body. The liquid could be diffused, and it was confirmed that the activity of the injection solution exceeded that of the needle syringe in that portion. Further, the present applicant has confirmed that the syringe 1 shown in FIG. 8 is effective for injection into pigs and rats in addition to rabbits.

<Other examples>
According to the syringe 1 according to the present invention, in addition to the case where the above-mentioned injection solution is injected into the skin structure, for example, in the field of regenerative medicine, cells to be injected or scaffold cells / scaffolds with cultured cells and stem cells Etc. can be seeded. For example, as disclosed in JP-A-2008-206477, cells that can be appropriately determined by those skilled in the art depending on the site to be transplanted and the purpose of recellularization, such as endothelial cells, endothelial precursor cells, bone marrow cells, and prebones Blast cells, chondrocytes, fibroblasts, skin cells, muscle cells, liver cells, kidney cells, intestinal cells, stem cells, and any other cells considered in the field of regenerative medicine can be injected with the syringe 1. .

  Furthermore, the syringe 1 according to the present invention can also be used for delivery of DNA or the like to cells, scaffold tissue, scaffolds, etc. as described in JP-T-2007-525192. In this case, it can be said that the use of the syringe 1 according to the present invention is more preferable than the case of delivery using a needle because the influence on the cells, the scaffold tissue, the scaffold and the like can be suppressed.

  Furthermore, the syringe 1 according to the present invention is suitable also when various genes, tumor suppressor cells, lipid envelopes, etc. are directly delivered to a target tissue or when an antigen gene is administered to enhance immunity against a pathogen. Used for. In addition, in the field of various disease treatments (fields described in JP2008-508881, JP2010-503616, etc.), immunomedicine (fields described in JP2005-523679, etc.), etc. The syringe 1 can be used, and the field in which the syringe 1 can be used is not intentionally limited.

DESCRIPTION OF SYMBOLS 1 ... Syringe 2 ... Syringe body 4 ... Nozzle 5 ... Holder 6 ... Piston 7, 8 ... Sealing member 9 ... Combustion chamber 10. ...... Recess 11 ... Flow path 20 ... Initiator 22 ... Ignition agent 30 ... Gas generating agent

Claims (3)

A syringe for injecting an injection target substance into an injection target region of a living body without going through an injection needle,
A storage section for storing the injectable substance;
Pressurize at least the injection target substance accommodated in the accommodating part by burning the ignition agent, and inject the pressurized injection target substance to the injection target region, and the injected injection purpose An injection part for allowing a part of the substance to enter a target site in the injection target region,
Needleless syringe. An injection port through which the injection target substance is ejected from the syringe body has a predetermined pressing force on the surface of the injection target area so that a part of the injection target substance can enter the target site in the injection target area. In the pressed state, the injection target substance is injected by the injection unit.
The needleless syringe according to claim 1. The igniting agent includes explosives including zirconium and potassium perchlorate, explosives including titanium hydride and potassium perchlorate, explosives including titanium and potassium perchlorate, explosives including aluminum and potassium perchlorate, aluminum and oxidation. An explosive containing bismuth, an explosive containing aluminum and molybdenum oxide, an explosive containing aluminum and copper oxide, an explosive containing aluminum and iron oxide, or an explosive comprising a plurality of combinations thereof.
The needleless syringe according to claim 1 or 2.