JP7733373B2 - Cervical stenosis prevention device and manufacturing method thereof - Google Patents

Description

The present invention relates to a cervical stenosis prevention device and a method for manufacturing the same.

In recent years, the spread of human papillomavirus and the discontinuation of HPV vaccination have led to a significantly younger age at the onset of cervical cancer, with both the number of cases and the mortality rate on the rise. As a result, cervical conization is performed in cases of severe dysplasia or intraepithelial carcinoma, but this often leads to complications such as (1) severe cervical stenosis after the conization, (2) reduced fertility due to shortening of the cervical canal, and (3) incomplete menstrual flow. In particular, severe cervical stenosis requires a total hysterectomy. Furthermore, because the majority of patients are of childbearing age, couples are increasingly concerned about infertility.

The present inventor has previously developed new therapeutic techniques for tissue regeneration of the skin, esophagus, and tympanic membrane using membranous atelocollagen vitrigel, and new therapeutic techniques for tissue regeneration of the peritoneum using filamentous atelocollagen vitrigel. These new therapeutic techniques for tissue regeneration are techniques that suppress pathological contraction and fibrosis (see, for example, Patent Documents 1 to 3).

International Publication No. 2014/208525 International Publication No. 2017/110776 International Publication No. 2018/211877

Given this background, the development of preventive treatments for stenosis using, for example, atelocollagen vitrigel is anticipated.
The present invention has been made in view of the above circumstances, and provides a highly practical device for preventing cervical stenosis.

The present invention includes the following aspects.
[1] A device for preventing cervical stenosis, comprising: a membranous dried vitrigel body; a composite thread portion having a thread-like core material fixed so as to cover the membranous dried vitrigel body; and a fixing portion for placing the composite thread portion within the cervical canal.
[2] The cervical stenosis prevention device described in [1], wherein the fixing portion has a main portion extending from the middle and multiple branch portions extending from the main portion.
[3] The cervical stenosis prevention device according to claim [1], further comprising a detachable uterine insertion portion for covering the composite thread portion and guiding it to the cervix.
[4] The cervical stenosis prevention device described in [1], wherein the membranous dried vitrigel body has a sewn portion of the thread-like core material.
[5] The cervical stenosis prevention device described in [1], wherein the membranous dried vitrigel is a membranous dried atelocollagen vitrigel.
[6] A method for manufacturing a device for preventing cervical stenosis according to any one of [1] to [5], comprising: step 1 of fixing a filamentous core material in the longitudinal direction of a membranous vitrigel and then drying the same; and step 2 of twisting the dried membranous vitrigel with the filamentous core material fixed thereto while moistening it with an aqueous solution to form a filamentous vitrigel composite.
[7] A method for manufacturing a cervical stenosis prevention device described in [6], in step 1, the thread-like core material is passed through and fixed alternately on the front and back of the membranous vitrigel.
[8] A method for manufacturing a cervical stenosis prevention device described in [6], which includes, after step 2, step 3 of drying the thread-like vitrigel complex to obtain a dried thread-like vitrigel complex.
[9] A method for manufacturing a cervical stenosis prevention device described in [8], which includes, after step 3, step 4 of irradiating the dried thread-like vitrigel complex with ultraviolet light, rehydrating it, and further drying it.
[10] The method for manufacturing a cervical stenosis prevention device described in [6], wherein the hydrogel used to prepare the membranous vitrigel is an atelocollagen gel or a native collagen gel.
[11] The method for manufacturing a cervical stenosis prevention device described in [6], wherein the aqueous solution is atelocollagen sol or native collagen sol.
[12] A method for treating the cervix, comprising the steps of: performing a cervical conization; and inserting and leaving a cervical stenosis prevention device described in any one of [1] to [5] in the remaining cervix after the cervical conization.

The present invention provides a cervical stenosis prevention device with even greater practicality and a method for manufacturing the same.

FIG. 1 is a plan view of a cervical stenosis prevention device 1. FIG. 1 is a plan view of a cervical stenosis prevention device 1. Photographs showing the process of forming through-holes in an atelocollagen vitrigel membrane. 1 is a photograph of an atelocollagen vitrigel membrane having through-holes. This is a photo of FD-1 P70 (Fuji Latex Co., Ltd.). This is a photograph of the tail (nylon thread part) of FD-1 threaded through a vitrigel membrane. Photographs showing the process of obtaining a thread-like atelocollagen vitrigel complex by twisting a dried atelocollagen vitrigel membrane fixed to the tail (nylon thread part) of FD-1 while moistening it with atelocollagen sol. FIG. 1 shows the process of UV irradiation of a dry thread-like atelocollagen vitrigel complex. These are photographs showing the process of UV-irradiated FD-1 with dried vitrigel membrane being placed in PBS, washed, and then hung up again to dry. This is a photograph of dried atelocollagen vitrigel membrane-coated FD-1. 1 is a photograph of a device for preventing cervical stenosis coated with a dried atelocollagen vitrigel membrane produced in Production Example 2. This is a photograph showing conization of the cervix of a miniature crown pig using an electric scalpel. (A) A photograph of the cervix of a miniature crown pig after conization using an electric scalpel. (B) A photograph showing the placement of a cervical stenosis prevention device in the cervix. This is a photograph taken 30 days after placement of the cervical stenosis prevention device. This is a photograph of the intact cervix two weeks after conization. This is a photograph of the cervix two weeks after conization, in which a cervical stenosis prevention device (cvFD-1) was placed. These are photographs of an untreated cervix and a cervix with a cervical stenosis prevention device (cvFD-1) placed two weeks after conization. This is a photograph of the cervix 4 weeks after conization, in which a cervical stenosis prevention device (cvFD-1) was placed. These are stained section images of an untreated cervix and a cervix with a cervical stenosis prevention device (cvFD-1) placed 4 weeks after conization. This is a stained section of the untreated cervix 4 weeks after conization. Additional experiments were conducted with three animals each in the untreated and treated groups, and n = 6 animals were evaluated in each group. The photographs show the untreated cervix and the cervix in which a cervical stenosis prevention device (cvFD-1) was placed.

Below, we will explain in detail the embodiments of the present invention, referring to the drawings where necessary.

<Device to prevent cervical stenosis>
In one embodiment, the present invention provides a device for preventing cervical stenosis, which includes a composite thread portion having a filamentous core material fixed to the composite thread portion so as to cover the core material with a dried vitrigel membranous body, and a fixing portion for placing the composite thread portion in the cervical canal. The device for preventing cervical stenosis of this embodiment is suitable for use as a device for preventing cervical stenosis after cervical conization.

The cervical stenosis prevention device 1 of this embodiment will be described with reference to Figure 1. Figure 1 is a plan view of the cervical stenosis prevention device 1. The cervical stenosis prevention device 1 has a composite thread portion 2 and a fixing portion 3.

By being positioned within the cervix, the composite thread portion 2 prevents cervical stenosis after cervical conization. The composite thread portion 2 has a thread-like core material to which a membranous dried vitrigel body is fixed so as to cover it. The membranous dried vitrigel body covering the thread-like core material is biocompatible, so it does not cause a foreign body reaction or rejection reaction even when positioned within the cervix.

The sol used as a raw material for the hydrogel for producing the membranous vitrigel may be any biocompatible material, and examples thereof include gelling extracellular matrix-derived components, natural polymer compounds such as fibrin, agar, agarose, and cellulose, and synthetic polymer compounds such as polyacrylamide, polyvinyl alcohol, polyethylene oxide, and poly(II-hydroxyethylmethacrylate)/polycaprolactone.
In this specification, "sol" refers to a dispersoid colloidal particle (size: approximately 1 to several hundred nm) in a liquid as a dispersion medium, particularly composed of a polymer compound. More specific examples of sol include aqueous solutions of natural polymer compounds and synthetic polymer compounds. When these polymer compounds are crosslinked by chemical bonding to form a network structure, they transition to a "hydrogel," a semi-solid substance that retains a large amount of water in the network. In other words, "hydrogel" refers to a sol that has been gelled.

Gelling extracellular matrix-derived components include, but are not limited to, collagen (type I, type II, type III, type V, type XI, etc.), basement membrane components reconstituted from mouse EHS tumor extract (including type IV collagen, laminin, heparan sulfate proteoglycan, etc.) (product name: Matrigel), glycosaminoglycans, hyaluronic acid, proteoglycans, gelatin, etc. The desired hydrogel can be produced by selecting the optimal salts and other components for gelation, as well as their concentrations and pH. Furthermore, by combining raw materials, hydrogels that mimic various in vivo tissues can be obtained.

Among these, gelling extracellular matrix-derived components are preferred as sols, with collagen being more preferred. Furthermore, native collagen or atelocollagen are preferred collagen sources, with atelocollagen from which antigenic telopeptides have been removed being even more preferred when transplanting into the body.

The term "vitrigel" refers to a gel in a stable state obtained by vitrifying a conventional hydrogel and then rehydrating it, and has been named "vitrigel (registered trademark)" by the present inventor.
Furthermore, when the term "vitrigel" is used in this specification, the term "(registered trademark)" may be omitted.

The composite thread portion 2 has a filamentous core material, which can improve the breaking strength. Furthermore, by using a non-bioabsorbable filamentous core material, the placement site of the composite thread portion 2 can be confirmed over time even if the vitrigel is digested in the cervical canal.
The filamentous core material is not particularly limited as long as it imparts breaking strength to the composite yarn portion 2, and may be appropriately selected depending on the application. Examples of the filamentous core material include chemical fibers such as nylon yarn, polyester yarn, rayon yarn, and polyglactin yarn; and threads made of natural materials such as silk yarn, cotton yarn, hemp yarn, and wool yarn, with nylon yarn being preferred.
The filamentous core material may be a single yarn, a two-ply yarn made by twisting together the same or two kinds of yarn, or a twisted yarn made by twisting together three or more yarns.

The length of the composite yarn portion 2 is adjusted appropriately depending on the application. For example, it is preferably 1 cm to 100 cm, more preferably 2 cm to 50 cm, and even more preferably 3 cm to 10 cm.
The diameter of the composite yarn portion 2 is adjusted appropriately depending on the application. For example, it is preferably 0.1 mm to 10 mm, more preferably 0.2 mm to 4 mm, and particularly preferably 0.5 mm to 2 mm.

From the viewpoint of improving the bonding strength between the membranous dried vitrigel body and the thread-like core material, it is preferable that the membranous dried vitrigel body have a stitched portion of the thread-like core material. It is more preferable that the membranous dried vitrigel body have multiple stitched portions. The pitch between the stitched portions is preferably constant. The length of the pitch between the stitched portions is preferably 0.5 mm to 10 mm, more preferably 1 mm to 4 mm, and particularly preferably 1 mm to 3 mm.

The composite yarn portion of this embodiment has a helical structure due to being twisted.
The sols used as raw materials for the membranous dried vitrigel body are as described above. Among them, the dried vitrigel body constituting the composite thread portion of this embodiment is preferably an atelocollagen dried vitrigel body because it is a biocompatible material.

The fixing part 3 is for placing the composite thread part 2 in the cervical canal. The fixing part 3 is preferably fixed in the cervical canal by being hooked onto it. Therefore, the fixing part 3 preferably has a main part 4 extending from the center and multiple branch parts 5 extending from the main part 4, and more preferably the multiple branch parts 5 extend semi-radially from the main part 4, and the fixing part 3 is formed in a fishbone shape.
The material of the fixing part 3 is preferably one having flexible elasticity, and examples thereof include elastomer materials such as urethane rubber, nitrile rubber, silicone rubber, silicone resin (e.g., polydimethylsiloxane), fluororubber, acrylic rubber, isoprene rubber, ethylene propylene rubber, chlorosulfonated polyethylene rubber, epichlorohydrin rubber, chloroprene rubber, styrene-butadiene rubber, butadiene rubber, and polyisobutylene rubber; plastics containing polymers such as poly(vinyl chloride), poly(vinyl alcohol), poly(methyl methacrylate), poly(vinyl acetate-co-maleic anhydride), poly(dimethylsiloxane) monomethacrylate, cyclic olefin polymers, fluorocarbon polymers, polystyrene, polypropylene, polyethyleneimine, and polyethylene terephthalate (PET); and copolymers of ethylene vinyl acetate, poly(vinyl acetate-co-maleic anhydride), poly(styrene-co-maleic anhydride), poly(ethylene-co-acrylic acid), or derivatives thereof, with ethylene vinyl acetate being preferred.
From the viewpoint of biocompatibility, the fixing part 3 may be covered with a membranous dried vitrigel body, similar to the composite thread part 2 .

Furthermore, as shown in Figure 2, the cervical stenosis prevention device 1 preferably has a detachable uterine insertion portion 6 that covers the composite thread portion 2 and guides the composite thread portion 2 to the cervix. More specifically, the uterine insertion portion 6 preferably has a thread guide groove in its longitudinal direction that guides the composite thread portion 2. The material of the uterine insertion portion 6 can be the same as that of the fixing portion 3, and ethylene vinyl acetate is preferred.

<Manufacturing method for cervical stenosis prevention device>
In one embodiment, the present invention provides a method for producing the above-mentioned cervical stenosis prevention device of the present invention, comprising step 1 of fixing a filamentous core material in the longitudinal direction of a membranous vitrigel and then drying the membranous vitrigel, and step 2 of twisting the dried membranous vitrigel with the filamentous core material fixed thereto into a filamentous form while wetting it with an aqueous solution to obtain a filamentous vitrigel composite.

<Step 1>
First, the method for producing the hydrogel will be described.
The method for producing a hydrogel includes step A of injecting a sol into a mold, gelling the sol, and then removing the mold to obtain a plate-like hydrogel. It also includes step B of vitrifying the plate-like hydrogel and rehydrating it to obtain a membranous vitrigel.

The plate-shaped hydrogel may have protruding ends to facilitate twisting of the vitrigel membrane to be produced. The plate-shaped hydrogel may also be strip-shaped and may have a narrow width, but is not limited to this and can be adjusted as appropriate. The wider the width of the plate-shaped hydrogel, the thicker the threads produced, and the narrower the width of the plate-shaped hydrogel, the thinner the threads produced. Thus, by adjusting the width of the plate-shaped hydrogel, the thread thickness can be controlled.
Furthermore, the width of the plate-shaped hydrogel does not have to be uniform; it may have an appropriately varying width length, such as a gourd shape, or may have a gradually varying width length, such as a triangular shape.

[Process A]
Step A is a step in which a sol is poured into a mold, the sol is gelled, and then the mold is removed to obtain a plate-like hydrogel.
The mold is not particularly limited as long as it has a hollowed-out shape of the desired plate-like hydrogel, and examples thereof include a PET film.

The sols used as raw materials for the plate-shaped hydrogels can be the same as those described in the section on "Devices for preventing cervical stenosis." Any biocompatible material can be used, such as native collagen or atelocollagen. From the perspective of transplantation into the body, atelocollagen from which antigenic telopeptides have been removed is even more preferable.

In step A, when the sol is poured into the mold, if a large amount of sol is poured, a thick plate-like hydrogel is obtained, resulting in a thick thread. On the other hand, if a small amount of sol is poured, a thin plate-like hydrogel is obtained, resulting in a thin thread. In this way, the thread thickness can be controlled by adjusting the amount of sol poured.
The thickness of the plate-like hydrogel is preferably 0.1 mm to 20 mm, more preferably 0.5 mm to 20 mm, and even more preferably 1 mm to 20 mm.
The length of the long side of the hydrogel plate is adjusted appropriately depending on the length of the composite yarn used, and is, for example, preferably 1 cm to 100 cm, more preferably 2 cm to 50 cm, and even more preferably 3 cm to 10 cm.
The length of the short side of the plate-like hydrogel is, for example, preferably 0.5 mm to 20 mm, more preferably 1 mm to 10 mm, and even more preferably 2 mm to 5 mm.

In step A, the temperature at which the sol is kept warm during gelation can be adjusted appropriately depending on the type of sol used. For example, if the sol is a collagen sol, the temperature during gelation should be lower than the denaturation temperature of the collagen, which depends on the animal species of the collagen used. Generally, gelation can be achieved within a few minutes to a few hours by keeping the temperature between 20°C and 37°C.

The plate-shaped hydrogel obtained in step A may also be cut out to obtain strip-shaped hydrogels of the desired width.

[Process B]
Step B is a step of vitrifying the strip-shaped hydrogel having a desired width obtained in step A, and then rehydrating it to obtain a membranous vitrigel.

[Thread-like core material]
Examples of the filamentous core material include those similar to those described in the section entitled "Device for preventing cervical stenosis." There are no particular limitations on the filamentous core material as long as it imparts breaking strength to the composite thread obtained using the manufacturing method of this embodiment, and nylon thread is preferred.
The filamentous core material may be a single yarn, a two-ply yarn made by twisting together the same or two kinds of yarn, or a twisted yarn made by twisting together three or more yarns.

In step 1, a thread-like core material is fixed to the longitudinal direction of the membranous vitrigel. The fixing method is not particularly limited, and may be fixed with an adhesive, or may be physically fixed when twisting the membranous vitrigel dried body in step 2.

From the viewpoint of increasing the bonding strength between the membranous vitrigel and the filamentous core material, it is preferable to pass the filamentous core material alternately through the front and back of the membranous vitrigel to bond them together.
That is, it is preferable to fix the membranous vitrigel by passing the thread-like core material through the membranous vitrigel in a stitching manner with the thread-like core material. By such an operation, the membranous vitrigel and the thread-like core material can be tightly attached to each other.
The position where the thread-shaped core material is fixed is preferably on the central axis that bisects the short side of the membranous vitrigel, and the thread-shaped core material is preferably pierced at equal intervals along the axis to form stitches. The pitch length between stitches is preferably 0.5 mm to 10 mm, more preferably 1 mm to 4 mm, and particularly preferably 1 mm to 3 mm.
The method for passing the filamentous core material through may be to thread the filamentous core material through a needle and sew it, or to open through holes at regular intervals in the membranous vitrigel using a cylindrical or conical blade or the like, and then pass the filamentous core material through. The diameter of the through holes is, for example, preferably 0.01 mm to 5 mm, more preferably 0.1 mm to 3 mm, and particularly preferably 0.3 mm to 1 mm.
Examples of cylindrical blades include medical instruments such as biopsy trephines and injection needles.

Next, in step 1, the membranous vitrigel with the thread-like core material attached is dried.

A variety of drying methods can be used, including air drying, drying in a sealed container (by circulating air within the container to constantly supply dry air), and drying in an environment with silica gel. For example, air drying can be performed by drying for two days in a sterile incubator at 10°C and 40% humidity, or by drying overnight at room temperature in a sterile clean bench.

<Step 2>
In step 2, the dried membranous vitrigel body to which the thread-like core material is fixed is twisted into a thread shape while being moistened with an aqueous solution to obtain a thread-like vitrigel composite.
The aqueous solution is not particularly limited, and examples include sterile water, physiological saline, PBS, atelocollagen sol, native collagen sol, etc., and when transplanted into a living body, atelocollagen sol from which antigenic telopeptides have been removed is preferred. Coating with atelocollagen sol or native collagen sol can increase the strength of the thread. Furthermore, this procedure can also bring the membranous vitrigel and the thread-like core material into close contact.

<Step 3>
After step 2, it is preferable to dry the thread-like vitrigel complex to obtain a dried thread-like vitrigel complex. A preferable drying method is the same as that in step 1.

<Step 4>
After step 3, it is preferable to irradiate the dried thread-like vitrigel complex with ultraviolet light, then rehydrate it, and further dry it.
By irradiating with ultraviolet light, cross-linking structures are formed between and within the collagen molecules that make up the vitrigel and the collagen coating, thereby increasing the strength of the composite thread. This operation also allows the membranous vitrigel and the thread-like core material to adhere to each other.
The irradiation energy of the ultraviolet light may be adjusted appropriately depending on the composition and content of the membranous dried vitrigel material. The irradiation energy of the ultraviolet light may be, for example, 0.1 mJ/ ^cm2 to 6000 mJ/ ^cm2 , for example, 10 mJ/ ^cm2 to 4000 mJ/ ^cm2 , or for example, 20 mJ/ ^cm2 to 2000 mJ/ ^cm2 .
Aqueous solutions used for rehydration include sterilized water, physiological saline, PBS, and the like.
After rehydration, the thread-like vitrigel composite is dried and revitrified.

According to the manufacturing method of the cervical stenosis prevention device of this embodiment, the breaking strength of the thread-like atelocollagen vitrigel can be improved, and therefore the obtained composite thread portion can be suitably used even in hard tissues of the cervix.
Furthermore, when the obtained composite thread portion is inserted and left in place in tissue, the dried membranous vitrigel is gradually digested in vivo, but the thread-like core material remains undigested, or the thread-like core material is digested more slowly than atelocollagen vitrigel, so the placement site of the composite thread portion can be confirmed over time.
Furthermore, by using a thread-like core material, vitrigel can be used only in the area of the thread-like core material where it is needed, thereby saving expensive vitrigel.

[Cervix treatment method]
The method for treating the cervix of this embodiment includes a step of performing a cervical conization and a step of inserting and placing the cervical stenosis prevention device of this embodiment into the remaining uterus after the cervical conization. According to this embodiment, by placing the area where the vitrigel is in close contact into the remaining cervix to be treated, postoperative cervical stenosis can be easily prevented.
Furthermore, according to this embodiment, the cervical stenosis prevention device can be easily removed after healing.

The present invention will be explained below using examples, but the present invention is not limited to the following examples.

[Production Example 1] Production of a dried porcine atelocollagen vitrigel membrane (1) Polyethylene vinyl (85 mm × 85 mm square) and a wall mold (acrylic cylinder; inner diameter 60 mm, outer diameter 64 mm, height 15 mm) were sterilized with 70% ethanol and then dried in a clean bench.
(2) Polyethylene vinyl was laid on a 100 x 100 mm Petri dish (AS ONE Cat. No. 2-4727-01), and the wall mold was placed on top of it.

(3) Preparation of Collagen Sol: On ice, 13 mL of serum-free culture medium (DMEM GIBCO Cat. No.: 11885-084 + 20 mM HEPES GIBCO Cat. No.: 15630-080 + 100 units/mL Penicillin 100 μg/mL Streptomycin GIBCO Cat. No.: 15140-148) was dispensed into a 50 mL conical tube (Falcon Cat. No.: 352070), followed by 13 mL of porcine atelocollagen solution (collagen concentration 1%, Kanto Chemical). The mixture was pipetted three times to prepare a uniform collagen sol. 7 mL of sol was poured into three wall molds. This process was repeated to prepare six molds, which were then left on the bench for approximately 30 minutes.

(4) Gelation The sample prepared in (3) was placed in a 5% CO ₂ incubator set at 37° C. for 2 hours to allow gelation.
(5) After 2 hours, the gel was released from the wall mold using a syringe needle, and then the wall mold was left attached and placed in an air dryer in a constant temperature and humidity chamber set at 10°C and 40% RH.
(6) After confirming that the vitrigel membrane was dry, the procedure of (3) was carried out, and 7 mL of sol was added and layered on top of the dry vitrigel membrane.
(7) The steps (4), (5), and (6) were repeated a total of eight times. For the eighth time, after gelation, the wall surface mold was removed and the mixture was placed in an air dryer in a constant temperature and humidity chamber set at 10°C and 40% RH.

(8) Rehydration: First, 20 mL of PBS (SIGMA D8537) was placed in a 60 mm diameter Petri dish (Falcon Cat. No.: 351007), and the dried gel was floated on it to gradually rehydrate. After obtaining a vitrigel membrane, the gel was submerged. While immersed in PBS, the gel was washed four times for 20 minutes while shaking. After rehydration, the rehydrated vitrigel membrane was placed on a vinyl sheet placed on the bottom of the Petri dish, ensuring that air did not enter, and then vitrified at 10°C and 40% RH.

[Production Example 2] Preparation of a cervical stenosis prevention device coated with a dried porcine atelocollagen vitrigel membrane (1) The dried vitrigel membrane prepared in Production Example 1 was rehydrated with PBS and cut in half.
(2) A 27G injection needle was inserted approximately 3.5 mm from the edge of the cut surface to leave a needle mark. The 27G injection needle was then inserted again at an interval of 2 mm to leave a needle mark. This procedure was repeated until approximately 27 needle marks were left (see Figure 3).
(3) The row of holes was cut to a width of 1 mm, and cut 1 mm from both sides to make a 3 mm width. Approximately 2 mm was cut so that both ends (circumferential portions) were straight. Approximately 27 needle marks were left on the vitrigel membrane measuring approximately 3 mm x 55 mm (see Figure 4), and this was placed in PBS.
(4) The inserter of the FD-1 P70 (Fuji Latex Co., Ltd.) was removed (see Figure 5), and the tail (nylon thread part) of the FD-1 was threaded through the holed vitrigel membrane in PBS. This was done in a stitching motion, with the thread threading alternately from the top and bottom, creating a zigzag pattern. The vitrigel membrane was threaded until it met the main body of the FD-1, and the FD-1 was unfolded and placed on a vinyl sheet to dry (see Figure 6).
(5) The dried FD-1 with the vitrigel membrane was hung with the body facing up, and the collagen sol prepared on ice was applied to a finger to rehydrate it. Once it had dried slightly, it was twisted so that the surrounding vitrigel membrane was tightly attached to the thread. A clip was attached to the tip of the tail to act as a weight, and it was left to dry on the bench (see Figure 7).
(6) The product was removed from the hanging position, and the main body was covered with aluminum foil and irradiated twice (from two directions) with UV rays of 800 mJ/ ^cm2 (see Figure 8).
(7) The UV-irradiated FD-1 with the dried vitrigel membrane was washed in PBS and then hung to dry again (see FIG. 9).
(8) The dried atelocollagen vitrigel membrane-coated FD-1 (see Figure 10) was set in an inserter, placed in a container, and then stored in a bag. Five dried atelocollagen vitrigel membrane-coated cervical stenosis prevention devices (collagen density 10 mg/cm ² ) were successfully produced (see Figure 11).

[Example 1] Treatment method after cervical conization On the day of surgery, conization was performed on the left and right cervix (bicornuate uterus) of crown-type miniature pigs (10 months old, weighing 19.3 kg-22.4 kg) using an electric scalpel (see Figures 12 and 13(A)), and then the atelocollagen vitrigel membrane-coated cervical stenosis prevention device produced in Production Example 2 was inserted into the cervical canal and fixed (see Figure 13(B)).

In animals in which the atelocollagen vitrigel membrane-coated cervical stenosis prevention device was inserted into the cervix, cervical stenosis did not occur, and the effect was maintained up to week 4 (see Figure 14). On the other hand, in the untreated group, stenosis and occlusion of the cervix occurred (see Figures 15-18).
Furthermore, stained section images showed that new fibrous septa were formed in the cervical canal in the untreated group, resulting in cervical occlusion. Furthermore, relatively thick fibrosis was observed under the epithelium in the cervical canal, but in the animals with the atelocollagen vitrigel membrane-coated cervical stenosis prevention device inserted, no fibrous septa were formed in the cervical canal, and the degree of fibrosis tended to be reduced (see Figures 19 and 20).

[Example 2] Treatment method after cervical conization As a follow-up experiment to Example 1, an experiment was conducted with an untreated group (3 animals) and a treated group (3 animals), with n = 6 animals in each group evaluated. The results are shown in Figure 21. In the untreated group, 4 animals showed cervical cul-de-sac and 1 animal showed cervical stenosis. On the other hand, in the treated group, none of the 6 animals showed cervical cul-de-sac or stenosis.
In conclusion, the atelocollagen vitrigel membrane-coated cervical stenosis prevention device was found to be effective in preventing cervical stenosis and closure after uterine conization.

The present invention makes it possible to provide a cervical stenosis prevention device with even greater practicality.

Claims (11)

a composite thread part having a thread-like core material fixed to the membranous dried vitrigel body so as to cover the core material; and a fixing part for placing the composite thread part in the cervical canal ,
A device for preventing cervical stenosis , wherein the membranous dried vitrigel body has a plurality of stitches of the thread-like core material, and the thread-like core material extends through the membranous dried vitrigel body at a plurality of points . The cervical stenosis prevention device according to claim 1, wherein the fixation portion has a main portion extending from the center and multiple branch portions extending from the main portion. The cervical stenosis prevention device according to claim 1, further comprising a detachable uterine insertion portion for covering the composite thread portion and guiding it into the cervix. The device for preventing cervical stenosis according to claim 1, wherein the pitch length between the stitches of the plurality of stitches is 0.5 mm to 10 mm . The cervical stenosis prevention device according to claim 1, wherein the dried vitrigel membrane is a dried atelocollagen vitrigel membrane. A method for manufacturing the cervical stenosis prevention device according to claim 1,
Step 1: Fixing a thread-like core material in the longitudinal direction of a membranous vitrigel and then drying the same;
a step 2 of twisting the dried membranous vitrigel body to which the thread-like core material has been fixed while moistening it with an aqueous solution to form a thread-like vitrigel composite;
In the step 1, the filamentous core material is passed through and fixed to the front and back of the membranous vitrigel alternately at multiple locations . 7. The method for manufacturing a cervical stenosis prevention device according to claim 6 , wherein in step 1, the pitch between the plurality of stitches formed by penetrating the filamentous core material alternately on the front and back of the membranous vitrigel at a plurality of locations is 0.5 mm to 10 mm . The method for manufacturing a cervical stenosis prevention device according to claim 6, further comprising, after step 2, step 3 of drying the thread-like vitrigel composite to obtain a dried thread-like vitrigel composite. The method for manufacturing a cervical stenosis prevention device according to claim 8, further comprising step 4, after step 3, of irradiating the dried thread-like vitrigel complex with ultraviolet light, rehydrating it, and then drying it. The method for manufacturing a cervical stenosis prevention device according to claim 6, wherein the hydrogel used to prepare the membranous vitrigel is an atelocollagen gel or a native collagen gel. The method for manufacturing a cervical stenosis prevention device according to claim 6, wherein the aqueous solution is atelocollagen sol or native collagen sol.