Patent Application
20240197952
This application claims the benefit of priority to Korean Patent Application No. 2021-0055086 filed on Apr. 28, 2021, the disclosure of which is incorporated herein by reference in its entirety.
The present invention relates to an embolic hydrogel with adjustable degradation time and a method of preparing the same. More particularly, the present invention relates to an amorphous or spherical embolic hydrogel with precisely adjustable degradation time in a blood vessel and a method of preparing the same.
Rapid advances in imaging diagnostics have made it possible to pinpoint the location of cancer and a blood vessel that supplies blood to the cancer. This allows for precise delivery of various cancer treatments, such as irradiation, surgical removal, and embolization.
Embolization is a treatment that causes necrosis of a tumor by occluding a blood vessel that supplies blood to the tumor. Transcatheter arterial chemoembolization (TACE) is the most commonly performed treatment for liver cancer. TACE involves a combination of physical embolization of an artery that supplies blood to a tumor and chemical treatment with an anti-cancer drug injected through the artery.
Embolization has been used to treat a variety of other indications, such as uterine fibroids, prostate cancer, lung cancer, and kidney cancer. In recent years, it has been reported that embolization may also be used to treat arthritis and frozen shoulder.
Permanent embolization of a blood vessel reduces effectiveness thereof because the original blood vessel cannot be reopened and a new blood vessel is instead created. In order to treat arthritis, frozen shoulder, etc., it is preferable to perform short-term embolization of a blood vessel that supplies nutrients to a nerve that causes pain. This is because only a nerve cell in an inflamed area must be necrotized with minimal effect on other muscles.
The degradation time of a conventional anticancer embolus is too long, measured in days or weeks, and furthermore, time adjustment is not precise. In order to treat arthritis, frozen shoulder, etc., an embolic agent with more precisely adjustable time is needed.
Conventional embolic products include Gelpart, Cali-Gel, and EmboCube, which are amorphous embolic products, and Embosphere, Embozene, and Bead Block, which are spherical embolic products. Each of the conventional embolic products has a long degradation time, and the degradation time thereof cannot be precisely adjusted. Meanwhile, there is a biodegradable embolus, which, however, is amorphous and has a degradation time of two weeks or more, and therefore the biodegradable embolus is not suitable for arthritis or frozen shoulder.
Patent Document 1 is a patent by the applicant of the present invention, which relates to microparticles that can be used as drug-loaded embolic hydrogel microparticles and a method of preparing the same. Patent Document 1 is capable of adjusting the degradation time of an anti-cancer embolic agent when administered in vivo, but the degradation time is in days, like the conventional embolic agent, and therefore Patent Document 1 does not suggest technology capable of adjusting a short time for arthritis or frozen shoulder, etc.
Patent Document 2 relates to gelatin particles having a specific volume swelling rate in the form of a non-porous solid sphere, gelatin particles made by dissolving and retaining a bioactive substance in the gelatin particles, and a device for dispersing the gelatin particles dissolved and impregnated with the bioactive e substance in a syringe with normal saline. Patent Document 2, which has a degradation time in days, does not suggest technology capable of adjusting a short time for arthritis or frozen shoulder, etc., like Patent Document 1.
It is an object of the present invention to provide an embolic hydrogel with adjustable degradation time that can be used for an embolic agent with precisely adjustable degradation time, which is not provided by the conventional embolic agent, and a method of preparing the same. It is another object of the present invention to provide an embolic hydrogel with adjustable degradation time that can be used for an embolic agent with precisely adjustable degradation time and very short degradation time for arthritis or frozen shoulder, etc. and a method of preparing the same.
It is a further object of the present invention to provide an embolic hydrogel having various types of appropriate degradation time for treatment without the use of a cross-linking agent and a method of preparing the same.
In order to accomplish the above objects, the present invention provides an embolic composition including hydrogel microparticles prepared without using a cross-linking agent. The degradation time in vivo of the hydrogel microparticles according to the present invention is adjusted by heat treatment and/or washing. The washing may be performed using a solvent with a δP polar value of 14 or higher.
In particular, the embolic composition according to the present invention may be used for embolization of a joint.
The hydrogel microparticles according to the present invention may be configured such that particles can be produced by thermal denaturation. As a non-limiting example, the hydrogel microparticles may include at least one selected from the biocompatible polymer group consisting of gelatin, collagen, gum, rosin, hyaluronic acid, heparin, dextran, alginic acid, albumin, chitosan, polyglycolide, polylactide, polyhydroxyvalerate, and silk fibroin.
The hydrogel microparticles may be emulsion type microparticles including an organic solvent, and the organic solvent may be at least one selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, hexyl acetate, ethyl formate, dimethyl carbonate, diethyl carbonate, 1, 3-dioxolidin-2-one, cellulose acetate butyrate, medium chain triglyceride (MCT) oil, vegetable oil, wax, and infused oil. In addition, the emulsion may include no separate emulsifier.
The embolic composition according to the present invention may further include an additional drug, and as a non-limiting example, at least one of a local anesthetic, an antibiotic, and a contrast agent may be added.
In another aspect, the present invention provides a method of preparing hydrogel microparticles prepared through step (a) or step (b):
The biocompatible polymer may be at least one selected from the group consisting of gelatin, collagen, gum, rosin, hyaluronic acid, heparin, dextran, alginic acid, albumin, chitosan, polyglycolide, polylactide, polyhydroxyvalerate, and silk fibroin, and the organic solvent may be at least one selected from the group consisting of methyl acetate, ethyl propyl acetate, butyl acetate, isobutyl acetate, isopropyl acetate, hexyl acetate, ethyl formate, dimethyl carbonate, diethyl carbonate, 1, 3-dioxolidin-2-one, cellulose acetate butyrate, medium chain triglyceride (MCT) oil, vegetable oil, wax, and infused oil.
In addition, cold-curing the micro-sized particles prepared in step 2) at room temperature or lower may be added between step 2) of (a) and step 3) of (a).
In addition, crushing the micro-sized microparticles and sieving the crushed microparticles so as to be divided by particle size may be further added between step 4) of (a) and step 5) of (a) or after step 5) of (a), or
As a non-limiting example, the particle size may be divided into 75 μm to less than 150 μm, 150 μm to less than 350 μm, 350 μm to less than 560 μm, 560 μm to less than 710 μm, 710 μm to less than 1000 μm, 1000 μm to less than 1400 μm, and 1400 μm to less than 2000 μm.
The thermal curing may be performed at 100° ° C. to 200° C. for 10 minutes to 24 hours, and the washing may be performed at a temperature of above 0° ° C. to 40° C. or lower. The washing may be performed using a solvent with a 8P polar value of 14 or higher.
The rate of in vivo degradation of the hydrogel microparticles according to the present invention may be adjusted on an hourly and minute basis by the heat treatment and/or washing.
In addition, the present invention provides hydrogel microparticles prepared using the preparation method and an embolic composition including the microparticles.
In addition, the present invention may provide all possible combinations of the above solving means.
As is apparent from the above description, the present invention is capable of providing embolic hydrogel microparticles with adjustable degradation time that can be used for an embolic agent with precisely adjustable degradation time, which is not provided by the conventional embolic agent, and a method of preparing the same.
In the present application, it should be understood that the terms “comprises,” “has,” “includes,” etc., when used in this specification, specify the presence of stated features, numbers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof.
It will be understood that, when a component is referred to as being “connected to” or “coupled to” another component, it may be directly connected to or coupled to the other component, or intervening components may be present. In contrast, when a component is referred to as being “directly connected to” or “directly coupled to” another component, there are no intervening components present. Other terms that describe the relationship between components, such as “between” and “directly between” or “adjacent to” and “directly adjacent to”, must be interpreted in the same manner.
In addition, unless otherwise defined, all terms, including technical and scientific terms, used in this specification have the same meanings as those commonly understood by a person having ordinary skill in the art to which the present invention pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having meanings consistent with their meanings in the context of the relevant art and the present disclosure, and are not to be interpreted in an idealized or overly formal sense unless expressly so defined herein.
The washing method is influenced by the ratio of microspheres to a washing solution, washing intensity, and washing time.
50 g of the microspheres according to Example 1 were mixed with 1.5 L of 15° C. distilled water, and stirring was performed at 200 rpm for 30 minutes to wash the microspheres. After 30 minutes, the swollen microspheres were completely settled, supernatant was removed, 1.5 L of 15° C. distilled water was added, and stirring was performed again at 200 rpm for 30 minutes to wash the microspheres. The washing process was performed until the supernatant was completely transparent. In the case of Example 1, washing was performed a total of 3 times.
In the following other examples or comparative example, washing was performed in the same manner as described above.
The washing solution was checked, and it was found that microspheres swelled in solvents with a OP polar value of 14 or higher.
Identical to Example 1 except that the last step 5), among the preparation steps of Example 1, was not performed.
The heat treatment temperature and time in step 4) of Example 1 were changed to 120° C. and 3 hours, respectively. After heat treatment, the microparticles are divided into four parts and washed in distilled water at 4° C. (Example 2), 10° C. (Example 3), 20° C. (Example 4), and 27° C. (Example 5), respectively. After distilled water washing, the microparticles are washed with acetone and dried under vacuum to obtain final spherical hydrogel microparticles.
The heat treatment temperature and time in step 4) of Example 1 were changed as shown in Table 4 below.
The spherical hydrogel microparticles prepared according to Example 1 and the amorphous hydrogel microparticles prepared according to Example 3 were observed using a microscope (see
In addition, the spherical hydrogel microparticles prepared according to Example 1 and the amorphous hydrogel microparticles prepared according to Example 13 were immersed in distilled water for 20 minutes to swell, and were observed using the microscope (see
As can be seen from
As can be seen from
The particle size distribution of the spherical hydrogel microparticles prepared according to Example 1 was measured using a particle size analyzer.
It can be seen that the spherical hydrogel microparticles according to Example 1 of the present invention have a very narrow degree of particle distribution with an average size of about 300 μm. In addition, the particle size distribution is a desirable size for embolization.
Eluates were observed for Example 1 and Comparative Example 1.
The elution test was performed by adding 30 ml of a 1×PBS solution to 2 g of microparticles to sufficiently swell the microparticles and eluting the same in a 37° C. shaking water bath for 24 hours.
A cytotoxicity test (ISO10993-5), an endotoxin test (ISO10993-11), and a pyrogenic test (ISO10993-11) were performed for each of Example 1 and Comparative Example 1.
Table 1 and
In Table 1 below, a cell viability of 80% or more is required to pass; in Table 2, an endotoxin value of 20 EU/device or more is required to pass; and in Table 3, if fever of 0.5° C. or more is generated, this is not a pass.
In all three toxicity tests, Comparative Example 1 was a Fail and Example 1 was a Pass.
The microparticles of Examples 2 to 5 were sieved to collect only microparticles of 100 to 300 μm in size, were introduced into 1× phosphate-buffered saline (PBS), and were observed for degradation time in a constant temperature water bath at 37ºC, which is similar to the human body temperature. The results of the degradation time are shown in
The microparticles of Examples 6 to 12 were sieved to collect only microparticles of 100 to 300 μm in size, were introduced into 1× phosphate-buffered saline (PBS), and were observed for degradation time in a constant temperature water bath at 37° C., which is similar to the human body temperature. The results of the degradation time are shown in Table 4. Experiment 5 shows that the degradation time can be finely adjusted by changing the washing temperature after the same heat treatment. Experiment 6 clearly shows that the degradation time of the microparticles in large units can be adjusted by changing the heat treatment temperature and the heat treatment time.
It can be seen from Experiments 5 and 6 that, when designing the degradation time of microparticles, it is possible to set the degradation time in large units (days or hours) by adjusting the heat treatment temperature and time first and then to adjust the time in minutes by adjusting the washing temperature.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0055086 | Apr 2021 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/006131 | 4/28/2022 | WO |
