Vaginal speculum for non-invasive injection of test substance into mouse uterus

Abstract

A vaginal speculum for non-invasive injection of a test substance into the uterus of a mouse according to the present invention comprises: a long cylindrical frame having a cavity; a vaginal insertion part provided at one end of the frame; and a catheter insertion part provided at the other end of the frame, wherein the vaginal insertion part is formed such that one end surface thereof is gradually recessed from the outside toward the center.

Description

Speculum for non-invasive injection of test substance into mouse uterus

[0001] The present invention relates to a speculum for non-invasive intrauterine access in mice, and more specifically, to the development of a mouse speculum that can assist in the blind passage of a catheter or tip into the uterus through the external orifice and cervical lumen.

[0002] Anatomically, the female reproductive system of mice consists of the uterus, cervix, and vagina. The uterus has a bicornuate structure composed of two uterine horns and extends to both sides of the abdomen. The endometrium of the uterus contains uterine glands, which are closely related to the fertilization of germ cells and the successful implantation of the embryo after mating. The cervix is ​​located between the uterus and the vagina and is a rigid cylindrical structure with a very narrow internal lumen. The vagina is the region connecting the cervix to the vulva and is composed of highly expandable tissue.

[0003] The lumen of the cervix is ​​very narrow and opens and closes depending on estrus and pregnancy. During estrus, the cervical lumen opens to receive sperm, while during non-estrus and pregnancy, it closes to act as a protective barrier against infection rising from the vagina. Additionally, the distal end of the mouse cervix is ​​developed with an external uterine opening (ostium uteri externum) that protrudes convexly into the vaginal lumen; this is thought to further reinforce the isolation of the internal uterine environment from the outside. However, this anatomical structure makes the injection of test substances into the uterus difficult.

[0004] Endometrial hypoplasia refers to a condition in which the endometrium is abnormally thin or underdeveloped due to hormonal imbalances (estrogen deficiency), Asherman syndrome, complications after surgery such as endometrial curettage, and congenital factors. Consequently, recurrent miscarriages and infertility may occur due to changes in the endometrium's receptivity to fertilized eggs and difficulties in forming an endometrial environment suitable for implantation. To overcome this endometrial hypoplasia, experiments are currently being conducted worldwide using mouse models created for research such as stem cell injection and organoid transplantation.

[0005] The primary methods used to induce an endometrial deficiency model involve surgical intervention. The most common methods include injecting 95% ethanol into one uterine horn after laparotomy under anesthesia in mice, or injecting 95% ethanol after exposing the anterior tip of the uterine horn through a dorsal skin and muscle incision. However, these methods have disadvantages, such as the need for anesthesia and surgery, variations in the degree of damage depending on the treatment time, and the possibility of secondary diseases. Meanwhile, a non-surgical method involves directly inserting a 22G catheter into the cervix of an anesthetized mouse and injecting 95% ethanol; however, this method also frequently results in genital perforation and trauma caused by the catheter due to the difficulty of navigating the external cervix, which is convex toward the vaginal cavity. In particular, while the injected ethanol should ideally be recovered after damaging only the endometrium, residual ethanol remaining in the uterus may cause outcomes other than the intended damage (such as over-induction of endometrial deficiency and damage to extrauterine areas).

[0006] Speculums or alternatives (straws) are used to inject test substances (stem cells, fertilized eggs, etc.) into the uterus. The purpose of these tools is to expand the vagina after insertion to visualize the location of the external cervix. Subsequently, a catheter or tip is positioned within the cervical lumen to inject the test substance. However, these speculums require a separate light source to view the inside of the vagina; even with a light source, visualizing the inside of the vagina is difficult in small test systems such as mice, and there is still a risk of catheter penetration where the catheter misses the external cervix.

[0007] The object of the present invention is to provide a speculum for non-invasively injecting a test substance into the uterus by passing through the external cervix without damaging the vaginal-cervical junction of a mouse.

[0008] Another objective of the present invention is to provide a speculum that can be stably maintained inserted inside the vagina without any fixation.

[0009] Another objective of the present invention is to provide a speculum having a lumen capable of accommodating a thin catheter or tip that can easily pass through the lumen of the cervix.

[0010] Another objective of the present invention is to provide a speculum that can facilitate the passage of a catheter or tip through the external cervix even under blind conditions where there is no light source to illuminate the inside of the vagina.

[0011] The technical problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned technical problems can be clearly understood by those skilled in the art from the description of the present invention.

[0012] A speculum for non-invasive injection of a test substance into a mouse uterus according to the present invention comprises a long cylindrical frame having a hollow space, a vaginal insertion part provided at one end of the frame, and a catheter insertion part provided at the other end of the frame, wherein the vaginal insertion part is characterized in that the surface of the one end is formed to gradually sink inward from the outside toward the center.

[0013] In addition, the vaginal insertion part is characterized by being formed to be rounded and recessed from the outer side of the vaginal insertion part toward the center.

[0014] In addition, the above vaginal insertion part is characterized by being formed in a rounded shape with a radius of curvature of 3 mm.

[0015] In addition, the catheter insertion part is characterized by being formed to be rounded and recessed from the outer side toward the center.

[0016] In addition, the catheter insertion part is characterized by being formed in a rounded shape with a radius of curvature of 2 mm.

[0017] The present invention can provide a speculum that can inject and retrieve a test sample into and from the uterus in a non-invasive manner without a surgical process.

[0018] In addition, the present invention can provide for the improvement of accuracy and reliability of animal experiments using a speculum designed to fit the anatomical structure of a female mouse.

[0019] In addition, the present invention can provide a reduction in the complexity or difficulty of experiments in research related to female mouse genitalia.

[0020] In addition, the present invention can provide a method that allows even an unskilled animal experimenter to easily access the genitals of a female mouse.

[0021] In addition, the present invention can provide a method to alleviate the suffering of experimental animals for compliance with animal experiment ethics.

[0022] FIG. 1 is a drawing showing a speculum for non-invasive injection of a test substance into a mouse uterus according to the first embodiment of the present invention.

[0023] Figure 2 is a drawing showing the top and bottom surfaces of Figure 1.

[0024] Figure 3 is a side view of Figure 1.

[0025] FIG. 4 is a diagram showing the process of inserting a mouse uterine catheter according to the first embodiment of the present invention.

[0026] FIG. 5 is a drawing showing a speculum for non-invasive injection of a test substance into a mouse uterus according to a second embodiment of the present invention.

[0027] Figure 6 is a photograph showing the insertion of the speculum disclosed in Figure 1 into the mouse vagina (a) and the attachment of the RI EZ-tip (b).

[0028] Figure 7 is a photograph of the uterine expansion before and after (a / b) following the insertion of the RI EZ-tip using the speculum disclosed in Figure 1 and the injection of physiological saline.

[0029] Figure 8 shows the process of visual confirmation of the application of the developed speculum after incising the uterine-cervical junction, with photograph (a) showing the speculum stably positioned within the vagina of a mouse containing the external cervix and photograph (b) showing the tip of the RI EZ-tip positioned within the uterus.

[0030]

[0031] The terms used in this specification have been selected to be as widely used general academic terms as possible, taking into account their functions in the present invention, but they may vary depending on the intent of those skilled in the art, case law, the emergence of new technology, etc.

[0032] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0033] Hereinafter, a speculum (1000) for non-invasive injection of a test substance into a mouse uterus according to the present invention will be described in detail with reference to the drawings.

[0034] The present invention provides a speculum (1000) that can assist in the process of receiving a catheter (T) or tip (T) in the external cervix (C) and the cervical lumen after insertion into the vaginal lumen of a mouse.

[0035] FIG. 1 is a drawing showing a speculum for non-invasive injection of a test substance into a mouse uterus according to the first embodiment of the present invention. FIG. 2 is a drawing showing the top and bottom views of FIG. 1. FIG. 3 is a side view of FIG. 1. FIG. 4 is a drawing showing the process of inserting a catheter into a mouse uterus according to the first embodiment of the present invention.

[0036] Referring to FIGS. 1 to 3, a speculum (1000) for non-invasive injection of a test substance into a mouse uterus according to the first embodiment of the present invention may include a frame (100), a vaginal insertion part (200), and a catheter insertion part (300).

[0037] The frame (100) is manufactured in the shape of a long cylinder. In order to ensure the expandability of the mouse vagina (V) and stable maintenance after insertion of the speculum (1000) into the vagina (V), it is preferable that the speculum (1000) be formed with a length of 20 mm and an outer diameter of 5 mm. Additionally, it is preferable that the frame (100) be made of a material that can prevent injury to the lumen of the vagina (V) when inserting or removing the vagina (V).

[0038] Additionally, the frame (100) has a hollow (110). Here, the hollow (110) of the frame (100) is preferably formed with a diameter of 1.2 mm so that a CooperSurgical, Inc. RI EZ-tip (T) or a catheter / tip (T) with a corresponding outer diameter can be applied.

[0039] Also, referring to FIG. 4, the vaginal insertion part (200) may be provided at one end of the frame (100). Additionally, the vaginal insertion part (200) may be formed such that the surface of the one end becomes increasingly rounded and recessed from the outside toward the center. More specifically, it is preferable that the vaginal insertion part (200) be formed rounded to have a radius of curvature of 3 mm.

[0040] Here, the vaginal insertion part (200) is inserted into the vagina (V) of the mouse, and the external cervix (C) protruding convexly into the lumen of the mouse vagina (V) is maintained in the vaginal insertion part, thereby allowing the catheter / tip (T) to pass accurately through the external cervix when inserted.

[0041] And, the catheter insertion part (300) may be provided at the other end of the frame (100). Additionally, the catheter insertion part (300) may be formed to be rounded and recessed from the outside toward the center. More specifically, it is preferable that the catheter insertion part (300) be formed rounded to have a radius of curvature of 2 mm.

[0042] Here, the catheter insertion part (300) allows the catheter / tip (T) to be inserted more easily into the hollow (110) along the rounded portion of the catheter insertion part (300).

[0043]

[0044] The following is a detailed description of a speculum for the non-invasive injection of a test substance into a mouse uterus according to the second embodiment of the present invention.

[0045] FIG. 5 is a drawing showing a speculum for non-invasive injection of a test substance into a mouse uterus according to a second embodiment of the present invention.

[0046] Referring to FIG. 5, the second embodiment is identical to the first embodiment in other components, except that the shape and material of the frame (100) and the light source (400) are provided inside the frame (100).

[0047] More specifically, referring to FIG. 5, the outer diameter of the center of the long axis of the frame (100) is formed to be smaller than the outer diameter of both ends according to the shape of the mouse's vagina (V) into which the speculum (1000) is inserted, so that it can be manufactured in the shape of a dumbbell. Accordingly, when the frame (100) is inserted into the vagina (V), the entrance of the vagina (V) is located at the smaller outer diameter of the frame (100), so that it can be better fixed to the lumen of the vagina (V).

[0048] Additionally, the frame (100) may be made of a transparent material and formed with a hollow interior. Accordingly, a light source (400) is positioned inside the frame (100), so that when the frame (100) is inserted into the vagina (V), the interior of the vagina (V) can be more clearly seen through the light source (400). The light source (400) may be a micro-light, a fluorescent material, or any other material commonly used in general industrial fields as long as it enables the realization of the present disclosure.

[0049] In addition, the frame (100) is made of a deformable material so that when the frame (100) is inserted into the vagina (V), it is inserted in a partially deformed state to match the shape of the vagina (V), thereby bending to match various shapes of the vagina (V), which facilitates the vagina (V) insertion process. Here, it is preferable that the frame (100) be made of a material having appropriate elasticity so that it is deformable but maintains a fixed state within the lumen when inserted into the vagina (V). Accordingly, any material commonly used in general industrial fields may be used for the frame (100) as long as the present disclosure can be realized.

[0050]

[0051] The following is a detailed description of an example regarding the non-invasive injection of a test substance into a mouse uterus using a speculum.

[0052] Figure 7 is a photograph showing the insertion of the speculum disclosed in Figure 1 into the mouse vagina (a) and the attachment of the RI EZ-tip (b). Figure 8 is a photograph showing the expansion of the uterus before and after the injection of physiological saline following the insertion of the RI EZ-tip using the speculum disclosed in Figure 1 (a / b). Figure 9 is a photograph showing the process of visual confirmation of the application of the developed speculum after incising the uterine-uterine junction, showing the speculum stably positioned within the mouse vagina containing the external cervix (a) and the tip of the RI EZ-tip positioned within the uterus (b).

[0053]

[0054] Example 1. Confirmation of non-invasive intrauterine access to mice via speculum and vaginal injection of test material

[0055] Referring to FIG. 7, Example 1 was performed to verify the accuracy of non-invasive intrauterine access to a mouse using a speculum (1000). First, the mouse was anesthetized by aspiration of 2% isoflurane and then positioned in a dorsal recumbency. The labia were grasped with tweezers and the vulva was spread open, and the speculum (1000) was carefully inserted as far as possible into the vagina (V). Afterward, a point 3 cm from the tip of the RI EZ-tip (T) was marked and connected to a 1 ml syringe equipped with a 23 G needle. Physiological saline was aspirated using the syringe and then carefully inserted through the internal passage at the bottom of the speculum (1000). After confirming that the 3 cm mark had entered the speculum (1000), 50-100 μl of physiological saline was injected.

[0056] When checking for leakage and reflux of physiological saline through the vagina (V) and vulva after injection, no related symptoms were found. Additionally, it was confirmed that the injected physiological saline was recovered when retrieved from the uterus using a syringe.

[0057]

[0058] Example 2. Visual confirmation of intrauterine access of the RI EZ-tip via speculum and injection of the test substance in mice

[0059] Example 2 was performed to visually confirm the accuracy of non-invasive access to the mouse uterus (U) and the injection of the test substance through a speculum (1000). First, the mouse was euthanized by CO2 exposure in a high-concentration CO2 chamber. After restraining the limbs, an incision was made, and the application of the speculum (1000) and the insertion of the RI EZ-tip (T) were carried out in the same manner as in Example 1.

[0060] Afterwards, referring to Fig. 8, the mouse uterus (U) located on the dorsal abdominal wall was bluntly separated and exposed outside the abdominal cavity, and then 50-100 μl of physiological saline was injected through the inserted RI EZ-tip (T), and the expansion of the uterus (U) was visually checked.

[0061] In addition, referring to Fig. 9, the uterine-uterine junction was incised and it was confirmed that the tip of the RI EZ-tip (T) was stably positioned inside the mouse uterus (U).

[0062] As described above, the main technical concept of the present invention is to provide a speculum (1000) for the non-invasive injection of a test substance into the uterus of a mouse. Furthermore, the embodiments described above with reference to the drawings are merely partial embodiments, and the scope of the present invention should be determined based on the patent claims. In addition, the scope of the present invention extends to various equivalent embodiments that can be derived.

[0063] [Explanation of the symbol]

[0064] 1000: Speculum for non-invasive injection of a test substance into the mouse uterus according to the present invention

[0065] T : Catheter / Tip

[0066] C : External cervix

[0067] V : Quality

[0068] U : Uterus

[0069] 100 : Frame

[0070] 110 : Communist China

[0071] 200 : Vaginal insertion part

[0072] 300 : Catheter insertion site

[0073] 400 : Light source

Claims

1. A long cylindrical frame having a hollow interior; A vaginal insertion part provided at one end of the above frame; and It includes a catheter insertion part provided at the other end of the above frame; and The above vaginal insertion portion is characterized by being formed such that the one end surface gradually becomes sunken from the outside toward the center, for non-invasive injection of a test substance into a mouse uterus.

2. In Paragraph 1, The above vaginal insertion part is, A speculum for non-invasive injection of a test substance into a mouse uterus, characterized by being formed such that the vaginal insertion portion becomes rounded and indented from the outer side toward the center.

3. In Paragraph 2, A speculum for non-invasive injection of a test substance into a mouse uterus, characterized in that the above-mentioned vaginal insertion part is formed roundly to have a radius of curvature of 3 mm.

4. In Paragraph 1, A speculum for non-invasive injection of a test substance into a mouse uterus, characterized in that the catheter insertion portion is formed to be rounded and indented from the outer side toward the center.

5. In Paragraph 1, A speculum for non-invasive injection of a test substance into a mouse uterus, characterized in that the catheter insertion portion is formed roundly to have a radius of curvature of 2 mm.

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