CN114163667A

CN114163667A - Cross-linked gel for isolation, preparation method and application

Info

Publication number: CN114163667A
Application number: CN202111486538.4A
Authority: CN
Inventors: 沈延臻
Original assignee: Bloomage Biotech Co Ltd
Current assignee: Bloomage Biotech Co Ltd
Priority date: 2021-12-07
Filing date: 2021-12-07
Publication date: 2022-03-11
Anticipated expiration: 2041-12-07
Also published as: CN114163667B

Abstract

The invention discloses a crosslinked gel for isolation, which is prepared by a method comprising the following steps: adding hyaluronic acid or a salt thereof and gelatin into an alkaline solution to obtain a first solution; mixing the first solution with a cross-linking agent to obtain a second solution; and carrying out crosslinking reaction on the second solution, and swelling a crosslinking reaction product to obtain the crosslinked gel for isolation. The crosslinked gel for isolation has excellent form stability and radiation resistance, and is more suitable for isolation protection in radiotherapy; the method has the advantages of convenient operation and reasonable reaction time, and is beneficial to realizing industrialized mass production.

Description

Cross-linked gel for isolation, preparation method and application

Technical Field

The invention relates to the technical field of biomedical treatment, in particular to a crosslinked gel for isolation, a preparation method and application thereof.

Background

Hyaluronic acid, also known as hyaluronic acid, is an acidic mucopolysaccharide. The moisturizing factor is an important basic substance for skin tenderness, is a component of a human body, has a special moisturizing effect, has the weight which is 100 times higher than that of the skin tendering factor, is a substance which is found to have the best moisturizing effect in the nature at present, and is called as an ideal natural moisturizing factor. Because of its excellent biocompatibility, it is widely used in various ophthalmic surgeries, such as crystal implantation, corneal transplantation, and anti-glaucoma surgery. It can also be used for treating arthritis and promoting wound healing.

Gelatin (Gelatin), without a fixed structure and relative molecular weight, is partially degraded by collagen in connective tissues such as animal skin, bone, sarcolemma, fascial, etc. to become white or yellowish, translucent, slightly glossy flakes or particles; the gelatin is a colorless, tasteless, transparent and hard amorphous substance without volatility, can be dissolved in hot water and not dissolved in cold water, but can slowly absorb water, swell and soften, and the gelatin can absorb 5-10 times of water by weight. It is known that gelatin belongs to denatured proteins, has no bioactive triple-helix structure, is a non-immunogenic substance, and related documents show that gelatin injection into rabbits, guinea pigs and dogs fails to produce antibodies. Gelatin is one of the most important natural biopolymer materials, and has been widely used in food, pharmaceutical and chemical industries.

In the radiation treatment process, if a radiation target area is closely connected with a healthy organ, in order to reduce the damage of radiation to the healthy organ and improve the postoperative life quality of a patient, an isolation gel for auxiliary radiation treatment is needed to be used, and a certain volume of space interval is formed between the radiation target area and the healthy organ, so that the radiation dose delivered to the healthy organ in the radiation treatment process is reduced, and the isolation and protection effects on healthy organ tissues are achieved. The barrier gel needs to be stable in the body for a period of time and be completely absorbed by the body.

The common isolation protection gel on the market at present is polyethylene glycol (PEG) isolation gel, and is often used for assisting the radiotherapy of prostate cancer. The product is injected into connective tissue between fascia of prostate and anterior wall of rectum to form a space interval with certain volume, so as to reduce the radiation dose delivered to rectum during prostate cancer radiotherapy, and represents a product such as SpaceOAR isolation gel (Augmenix, Waltham, MA, USA). SpaceOAR hydrogel is divided into two bottles, namely a solid powder polyethylene glycol bottle and a trilysine diluted solution bottle, and the two bottles are required to be uniformly mixed through a Y-shaped connector during use, and then cross-linking reaction occurs immediately after uniform mixing, so that injection is suspended if emergency occurs in the injection process, equipment blockage can be caused, a replacement system is required to be prepared, unnecessary pain is brought to a patient, the operation is complex, the requirement is high, and great examination is also performed on a doctor operator.

In view of the above, in order to simplify the injection step of the gel and improve the injection safety, the crosslinking step needs to be transferred to the outside of the body, and therefore, it is necessary to prepare a novel gel which is stable in the body for a certain period of time and is completely absorbed by the human body and is non-toxic. The cohesive property of the hyaluronic acid gel is strong, so that the gel can keep a certain shape in vivo, but the hyaluronic acid gel is easily degraded due to the influence of radiation on the gel, and the retention time in vivo is not long enough; gelatin gel has poor cohesiveness but strong radiation resistance, so that cross-linked hyaluronic acid gelatin gel resistant to radiation degradation is needed, and no report of the product exists at present.

Disclosure of Invention

In order to solve the problems, the invention provides a crosslinked gel for isolation, a preparation method and application.

The specific technical scheme of the invention is as follows:

1. a preparation method of crosslinked gel for isolation comprises the following steps:

adding hyaluronic acid or a salt thereof and gelatin into an alkaline solution to obtain a first solution;

mixing the first solution with a cross-linking agent to obtain a second solution;

and carrying out crosslinking reaction on the second solution, and swelling a crosslinking reaction product to obtain the crosslinked gel for isolation.

2. The production method according to the above-mentioned item 1,

the molecular weight of the hyaluronic acid or the salt thereof is 1000k-4000kDa, preferably 2000k-4000kDa, and more preferably 3000k-4000 kDa.

3. The production method according to the above-mentioned item 1,

the molecular weight of the gelatin is 20k-500kDa, preferably 100k-500kDa, more preferably 200k-400kDa, and the gelatin is preferably any one of animal gelatins.

4. The production method according to the above-mentioned item 1,

the cross-linking agent is an esterified cross-linking agent or an etherified cross-linking agent; wherein the esterified cross-linking agent is preferably carbodiimide or bis/polyepoxide, and the etherified cross-linking agent is preferably divinyl sulfone, 1, 2, 7, 8-diepoxyoctane or 1, 4-butanediol diglycidyl ether;

further preferably, the cross-linking agent accounts for 0.5-5 wt%, preferably 2-3 wt% of the mass of the sum of the mass of the hyaluronic acid or salt thereof and the mass of the gelatin.

5. The production method according to the above-mentioned item 1,

the mass ratio of the hyaluronic acid or the salt thereof to the gelatin is 0.5-10:1, preferably 5-10: 1; preferably, the sum of the contents of hyaluronic acid or a salt thereof and gelatin in the crosslinked gel is 20-50 mg/mL.

6. The production method according to the above-mentioned item 1,

the alkaline solution is selected from one or more of sodium carbonate solution, sodium bicarbonate solution and sodium hydroxide solution;

preferably, the mass percentage concentration of the alkaline solution is 0.1-2 wt%;

further preferably, the crosslinking reaction time is 0.5 to 15h, preferably 8 to 12 h.

7. A crosslinked gel for insulation, which is prepared by the preparation method of any one of claims 1 to 6.

8. A crosslinked isolating gel, wherein the crosslinked isolating gel is prepared by a method comprising the steps of:

9. The crosslinked gel according to the item 8,

10. The crosslinked gel according to item 8, wherein,

11. The crosslinked gel according to the item 8,

further preferably, the amount of the cross-linking agent is 0.5 to 5 wt%, preferably 2 to 3 wt%, of the sum of the mass of the hyaluronic acid or salt thereof and the mass of the gelatin.

12. The crosslinked gel according to the item 8,

the mass ratio of the hyaluronic acid or the salt thereof to the gelatin is 0.5-10:1, preferably 5-10: 1;

preferably, the sum of the contents of the cross-linked hyaluronic acid or a salt thereof and the gelatin in the cross-linked gel is 20 to 50 mg/mL.

13. The crosslinked gel according to the item 8,

14. A radiation therapy barrier protectant comprising the cross-linked gel for barrier prepared by the preparation method of any one of claims 1 to 6 or the cross-linked gel for barrier of any one of claims 8 to 13.

15. Use of the crosslinked gel for radiation therapy isolation prepared by the preparation method of any one of claims 1 to 6 or the crosslinked gel for isolation of any one of claims 8 to 13 in the preparation of radiation therapy isolation shields.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the invention, hyaluronic acid or salt thereof and gelatin are mixed and crosslinked, the two materials have excellent biocompatibility and a large number of active hydroxyl groups, in the crosslinking process, 6-position hydroxyl in a chain of the hyaluronic acid or salt thereof and an epoxy ring in a crosslinking agent (such as 1, 4-butanediol diglycidyl ether, BDDE) undergo nucleophilic reaction to generate stable ether bonds, and meanwhile, hydroxyl in a gelatin chain is linked by the crosslinking agent to form crosslinked gel with a semi-interpenetrating network structure. The gel for isolation provided by the invention fully exerts respective excellent characteristics of two materials, has excellent form stability and radiation resistance, and is more suitable for isolation protection in radiotherapy; the method has the advantages of convenient operation and reasonable reaction time, and is beneficial to realizing industrialized mass production. The use process is simple and convenient, and the injection process is safer.

Detailed Description

The embodiments described below are intended to illustrate the invention in detail, however, it should be understood that the invention can be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

It should be noted that certain terms are used throughout the description and claims to refer to particular components. As one skilled in the art will appreciate, various names may be used to refer to a component. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. The description which follows is a preferred embodiment of the invention, however, the description is given for the purpose of illustrating the general principles of the invention and not for the purpose of limiting the scope of the invention. The scope of the present invention is defined by the appended claims.

The term "kDa" refers to 1000 Da.

The term "Da" refers to the unit of weight average molecular weight of hyaluronic acid and salts thereof or gelatin.

The term "mg/mL" refers to the content of the sum of the mass of hyaluronic acid or a salt thereof and gelatin in the crosslinked gel in the gel.

The invention provides a preparation method of crosslinked gel for isolation, which comprises the following steps:

The "crosslinking agent" is also called a bridging agent, which forms bridges between polymer molecular chains to become an insoluble substance of a three-dimensional structure.

The hyaluronic acid or salt thereof may be one known to those skilled in the art, such as hyaluronic acid, and the hyaluronate salt is preferably a metal hyaluronate salt, such as sodium hyaluronate, potassium hyaluronate, and the like.

The alkaline solution may be an alkaline solution well known to those skilled in the art, such as sodium hydroxide, potassium hydroxide, sodium carbonate solution, etc.;

in some embodiments of the invention, the concentration of the alkaline solution is 0.1-2 wt%, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 09, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0 wt% or any range therebetween.

In some embodiments of the invention, the molecular weight of the hyaluronic acid or salt thereof is 1000k-4000kDa, preferably 2000k-4000kDa, more preferably 3000k-4000 kDa;

for example, the molecular weight of hyaluronic acid or a salt thereof may be 1000kDa, 1100kDa, 1200kDa, 1300kDa, 1400kDa, 1500kDa, 1600kDa, 1700kDa, 1800kDa, 1900kDa, 2000kDa, 2100kDa, 2200kDa, 2300kDa, 2400kDa, 2500kDa, 2600kDa, 2700kDa, 2800kDa, 2900kDa, 3000kDa, 3100kDa, 3200kDa, 3300kDa, 3400kDa, 3500kDa, 3600kDa, 3700kDa, 3800kDa, 3900kDa, 4000kDa, or any range therebetween.

In some embodiments of the invention, the gelatin is any one of animal-derived gelatins, preferably porcine-derived gelatins, and the molecular weight of the gelatin is 20k-500kDa, preferably 100k-500kDa, and more preferably 200k-400 kDa;

for example, the gelatin may have a molecular weight of 20kDa, 50kDa, 100kDa, 150kDa, 200kDa, 250kDa, 300kDa, 350kDa, 400kDa, 450kDa, 500kDa or any range therebetween.

In some embodiments of the present invention, the cross-linking agent may be a cross-linking agent known to those skilled in the art, wherein preferably the cross-linking agent is an esterified cross-linking agent or an etherified cross-linking agent; wherein, the esterification crosslinking agent is preferably a polyhydric alcohol, a carbodiimide or a di/poly epoxide, and the etherification crosslinking agent is preferably divinyl sulfone, 1, 2, 7, 8-diepoxyoctane or 1, 4-butanediol diglycidyl ether (BDDE), and more preferably 1, 4-butanediol diglycidyl ether.

In some embodiments of the invention, the cross-linking agent is present in an amount of 0.5 to 5 wt%, preferably 2 to 3 wt%, based on the mass of the hyaluronic acid or salt thereof plus the mass of the gelatin, and may be, for example, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 wt% or any range therebetween.

In some embodiments of the invention, the mass ratio of the hyaluronic acid or salt thereof to the gelatin is 0.5-10:1, preferably 5-10:1, for example 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1, 9.5:1, 10:1 or any range therebetween.

In some embodiments of the present invention, the crosslinking reaction time is 0.5 to 15 hours, preferably 8 to 12 hours, for example, 8 hours, 8.5 hours, 9 hours, 9.5 hours, 10 hours, 10.5 hours, 11 hours, 11.5 hours, 12 hours or any range therebetween.

In some embodiments of the invention, the sum of the contents of the cross-linked hyaluronic acid or salt thereof and the gelatin in the cross-linked gel is 20 to 50mg/mL, for example, may be 20, 25, 30, 35, 40, 45, 50mg/mL or any range therebetween.

The invention provides a crosslinked hyaluronic acid or salt gel thereof for injection, which is prepared by the preparation method.

The invention provides a crosslinked hyaluronic acid or salt gel thereof for injection, which is prepared by the method comprising the following steps:

In some embodiments of the present invention, gelatin is dissolved in an alkaline solution, sodium hyaluronate is added after complete dissolution, a cross-linking agent is added after uniform mixing, the mixture is placed in a water bath for cross-linking reaction after uniform stirring, a cross-linking reaction product is cut after the cross-linking reaction is finished, a phosphate buffer solution is used for dialysis swelling, the obtained gel block is granulated through a 60-mesh screen after swelling to a target weight, so as to obtain cross-linked gel, and then high-pressure steam sterilization is performed.

The gel absorbs water when the dialysis swelling is carried out, and the content of the cross-linked gel is related to the weight of the gel after dialysis swelling. The longer the dialysis time is, the more water is absorbed, and the lower the sum of the contents of the cross-linked hyaluronic acid or a salt thereof and gelatin is, so that the content of the sum of the contents of the cross-linked hyaluronic acid or a salt thereof and gelatin can be controlled by controlling the dialysis time.

The invention provides a radiation treatment isolation protective agent, which comprises the cross-linked gel for isolation prepared by the preparation method or the cross-linked gel for isolation.

The cross-linked gel for isolation is used for isolating a radiation target tissue from a healthy tissue in radiotherapy, and in the process of radiotherapy, if a radiation target area is closely connected with the healthy organ, in order to reduce the damage of radiation to the healthy organ and improve the postoperative life quality of a patient, the isolation gel for auxiliary radiotherapy is required to be used, and a space interval with a certain volume is formed between the radiation target area and the healthy organ so as to reduce the radiation dose delivered to the healthy organ during radiotherapy and play a role in isolating and protecting the healthy organ tissue. The barrier gel needs to be stable in the body for a period of time and be completely absorbed by the body.

The invention also provides the crosslinked gel for radiotherapy isolation prepared by the preparation method or the application of the crosslinked gel for isolation in preparation of radiotherapy isolation protection.

The cross-linked gel for isolation provided by the invention has an obvious effect, wherein in a mouse experiment, the food intake, the body weight, the mental state and the skin condition of a mouse are observed, and the cross-linked gel for isolation provided by the invention can ensure that the total food intake amount has no obvious change, the mental state of the mouse is good and the skin has no damage. Therefore, the cross-linked gel for isolation provided by the invention has a remarkable effect, fully exerts the respective excellent characteristics of the two materials, has excellent form stability and radiation resistance, and is more suitable for isolation protection in radiotherapy.

The invention is described generally and/or specifically for the materials used in the tests and the test methods, in the following examples,% means wt%, i.e. percent by weight, unless otherwise specified. The reagents or instruments used are not indicated by the manufacturer, and are all conventional reagent products commercially available, wherein Table 1 is a source of raw materials used in the examples.

Table 1 sources of raw materials used in the examples

Example 1

Dissolving 0.4g of gelatin in 10mL of 1 wt% sodium hydroxide solution, wherein the molecular weight of the gelatin is 200kDa, adding 2g of sodium hyaluronate with the molecular weight of 3000kDa after complete dissolution, adding 48mg of 1, 4-butanediol diglycidyl ether with the dosage of 2% of the sum of the mass of the sodium hyaluronate and the gelatin after complete dissolution, fully and uniformly stirring, placing the mixture into a water bath kettle for crosslinking reaction at 30 ℃ for 10 hours, cutting the crosslinking reaction product into small blocks after the crosslinking reaction is finished, placing the small blocks into a phosphate buffer solution (1L of phosphate buffer solution: 9g of sodium chloride, 0.22g of disodium hydrogen phosphate, 0.05g of sodium dihydrogen phosphate and the balance of injection water) for dialysis and swelling, and granulating the obtained gel blocks by a 60-mesh screen to obtain crosslinked gel with the sum of the contents of the crosslinked sodium hyaluronate and the gelatin of 30mg/mL, then sterilizing with high pressure steam at 121 deg.C for 8 min.

Example 2

Example 2 differs from example 1 only in that: the mass ratio of the sodium hyaluronate to the gelatin is 10:1, and the other conditions are the same.

Example 3

Dissolving 1.6g of gelatin in 10mL of 1 wt% sodium hydroxide solution, wherein the molecular weight of the gelatin is 200kDa, adding 0.8g of sodium hyaluronate with the molecular weight of 3000kDa after complete dissolution, adding 48mg of 1, 4-butanediol diglycidyl ether according to the mass ratio of 0.5:1 of sodium hyaluronate to gelatin, wherein the dosage of the 1, 4-butanediol diglycidyl ether is 2% of the sum of the mass of the sodium hyaluronate and the gelatin, fully and uniformly stirring, placing the mixture into a water bath, performing crosslinking reaction at 30 ℃ for 10 hours, cutting the crosslinking reaction product into small blocks after the crosslinking reaction is finished, placing the small blocks into phosphate buffer solution (1L of phosphate buffer solution: 9g of sodium chloride, 0.22g of disodium hydrogen phosphate, 0.05g of sodium dihydrogen phosphate and the balance of injection water) for dialysis, swelling, granulating the obtained gel blocks by using a 60-mesh screen to obtain crosslinked gel with the sum of the contents of the sodium hyaluronate and the gelatin being 30mg/mL, then sterilizing with high pressure steam at 121 deg.C for 8 min.

Example 4

Example 4 differs from example 1 only in that: adding 12mg of 1, 4-butanediol diglycidyl ether, wherein the dosage of the 1, 4-butanediol diglycidyl ether is 0.5 percent of the sum of the mass of the sodium hyaluronate and the mass of the gelatin, and the rest conditions are the same.

Example 5

Example 5 differs from example 1 only in that: adding 120mg of 1, 4-butanediol diglycidyl ether, wherein the dosage of the 1, 4-butanediol diglycidyl ether is 3 percent of the sum of the mass of the sodium hyaluronate and the mass of the gelatin, and the rest conditions are the same.

Example 6

Example 6 differs from example 1 only in that: controlling the sum of the contents of the cross-linked sodium hyaluronate and the gelatin by controlling the dialysis time to obtain the cross-linked gel with the sum of the contents of the cross-linked sodium hyaluronate and the gelatin being 20mg/mL, wherein the rest conditions are the same.

Example 7

Example 7 differs from example 1 only in that: controlling the sum of the contents of the cross-linked sodium hyaluronate and the gelatin by controlling the dialysis time to obtain the cross-linked gel with the sum of the contents of the cross-linked sodium hyaluronate and the gelatin being 50mg/mL, wherein the rest conditions are the same.

Example 8

Example 2 differs from example 1 only in that: the mass ratio of the sodium hyaluronate to the gelatin is 20:1, and the other conditions are the same.

Example 9

Example 9 differs from example 1 only in that: the mass ratio of the sodium hyaluronate to the gelatin is 0.1:1, and the rest conditions are the same.

Example 10

Example 10 differs from example 1 only in that: adding 4.8mg of 1, 4-butanediol diglycidyl ether, wherein the dosage of the 1, 4-butanediol diglycidyl ether is 0.2 percent of the sum of the mass of the sodium hyaluronate and the mass of the gelatin, and the rest conditions are the same.

Example 11

Example 11 differs from example 1 only in that: obtaining the crosslinked gel with the sum of the contents of the crosslinked sodium hyaluronate and the gelatin being 10mg/mL, and the rest conditions are the same.

Example 12

Example 12 differs from example 1 only in that: sodium hyaluronate has a molecular weight of 2000kDa, and the rest conditions are the same.

Example 13

Example 13 differs from example 1 only in that: the molecular weight of sodium hyaluronate is 3600kDa, and the rest conditions are the same.

Example 14

Example 14 differs from example 1 only in that: sodium hyaluronate has a molecular weight of 1500kDa, and the rest conditions are the same.

Example 15

Example 15 differs from example 1 only in that: the molecular weight of sodium hyaluronate is 500kDa, and the rest conditions are the same.

Example 16

Example 16 differs from example 1 only in that: the molecular weight of gelatin is 100kDa, and the rest conditions are the same.

Example 17

Example 17 differs from example 1 only in that: the gelatin has a molecular weight of 10kDa, and the rest of the conditions are the same.

Example 18

Example 18 differs from example 1 only in that: the molecular weight of gelatin is 300kDa, and the rest of the conditions are the same.

Example 19

Example 19 differs from example 1 only in that: the molecular weight of gelatin is 380kDa, and the rest conditions are the same.

Example 20

Example 20 differs from example 1 only in that: 168mg of 1, 4-butanediol diglycidyl ether is added, wherein the dosage of the 1, 4-butanediol diglycidyl ether is 7 percent of the sum of the mass of the sodium hyaluronate and the mass of the gelatin, and the other conditions are the same.

Comparative example 1

Dissolving 2.4g of gelatin in 10mL of 1 wt% sodium hydroxide solution, wherein the molecular weight of the gelatin is 200kDa, adding 48mg of 1, 4-butanediol diglycidyl ether, wherein the dosage of the 1, 4-butanediol diglycidyl ether is 2% of the mass sum of the gelatin, fully and uniformly stirring, putting into a water bath kettle, carrying out crosslinking reaction at 30 ℃ for 10h, cutting a crosslinking reaction product into small blocks after the crosslinking reaction is finished, putting into a phosphate buffer solution (1L of the phosphate buffer solution: 9g of sodium chloride, 0.22g of disodium hydrogen phosphate, 0.05g of sodium dihydrogen phosphate, and the balance of injection water), dialyzing, swelling, granulating the obtained gel block by a 60-mesh screen to obtain crosslinked gel with the content of 30mg/mL, and then carrying out high-pressure steam sterilization at the temperature of 121 ℃ for 8 min.

Comparative example 2

Dissolving 2.4g of sodium hyaluronate into 10mL of 1 wt% sodium hydroxide solution, adding 48mg of 1, 4-butanediol diglycidyl ether, wherein the amount of the 1, 4-butanediol diglycidyl ether is 2% of the mass sum of the sodium hyaluronate, fully and uniformly stirring, placing into a water bath kettle for crosslinking reaction at 30 ℃ for 10h, cutting the crosslinked reaction product into small blocks after the crosslinking reaction is finished, placing into a phosphate buffer solution (1L of the phosphate buffer solution: 9g of sodium chloride, 0.22g of disodium hydrogen phosphate, 0.05g of sodium dihydrogen phosphate, and the balance of injection water) for dialysis and swelling, granulating the obtained gel block through a 60-mesh screen to obtain crosslinked gel with the content of 30mg/mL, and then carrying out high-pressure steam sterilization at the temperature of 121 ℃ for 8 min.

TABLE 2 raw material usage tables used in examples 1 to 20 and comparative examples 1 to 2

Experimental example 1 determination of postoperative protection of crosslinked gel to particle implantation

The crosslinked gels obtained in examples 1 to 20 were respectively numbered as gels 1 to 20, and the crosslinked gels obtained in comparative examples 1 to 2 were respectively numbered as gels 21 to 22.

After implantation of radioactive 125I particles in mice, the effect of gels 1-22 in reducing the toxicity of the 125I particles implanted into the skin was examined.

Test animals: Balb/C mice

Grouping tests: 69 mice were randomly divided into 23 groups of 3 mice each, which were respectively a control group, 1 group, 2 groups, 3 groups, 4 groups, 5 groups, 6 groups, 7 groups, 8 groups, 9 groups, 10 groups, 11 groups, 12 groups, 13 groups, 14 groups, 15 groups, 16 groups, 17 groups, 18 groups, 19 groups, 20 groups, 21 groups, 22 groups by a computer random number method, gel 1 was used for 1 group of mice, gel 2 was used for 2 groups of mice, … was repeated, and gel 22 was used for 22 groups of mice. The control group was implanted with 1 empty-shelled particle (blank control), and the other 22 groups were implanted with 1 active 125I particle of 0.6mCi, respectively. Injecting gel 1.0ml between skin and particles while implanting radioactive particles, wherein the group number is the same as the test sample number, and the blank control group is not injected with crosslinked gel.

Feeding animals: the experimental animals after the implantation of the particles are fed in cages under standard conditions.

Observation and indexes are as follows: general observations were made on the test animals.

Food intake (food and water): the total food intake was calculated by subtracting the remaining food amount from the daily food intake. The 5 th, 10 th, 30 th, 90 th 90 … 150 th day after operation was recorded by observation from before operation.

Weight: the 5 th, 10 th, 30 th, 90 th 90 … 150 th day after operation was recorded by observation from before operation.

Mental state: subjective evaluation by the same observer, scored as good, normal, slightly poor, cachexia, and death. The 5 th, 10 th, 30 th, 90 th 90 … 150 th day after operation was recorded by observation from before operation.

Skin damage: the mice were observed for skin lesions such as color change, hair loss, ulcer formation, etc. And skin damage between different groups.

And (4) observing the remaining gel: each group of 1 animal was sacrificed randomly at 90 and 150 days post-surgery, respectively, and the gel was observed for remaining.

The test results are summarized: see table 3.

TABLE 3 isolation protection effect test results

As can be seen from Table 3, the combined effect of the groups 1-20 is better than that of the groups 21 and 22 by observing and recording the food intake, mental state and skin injury of the mice at 5, 10, 30, 90 and 150 days after operation, i.e., the isolating crosslinked gels obtained in the examples 1-20 are better than those of the comparative examples 1-2 in isolating effect, especially the results recorded at 30, 90 and 150 days, such as mental state and skin injury. The reason is that the isolating crosslinked gel of comparative example 1 to which no hyaluronic acid or a salt thereof is added and the isolating crosslinked gel of comparative example 2 to which no gelatin is added, i.e., the isolating crosslinked gel obtained by adding hyaluronic acid or a salt thereof and gelatin at the same time, has a superior isolating protective effect to the case of adding only one of them. Both hyaluronic acid or salt thereof and gelatin have excellent biocompatibility and a large number of active hydroxyl groups, in the crosslinking process, 6-position hydroxyl in the chain of hyaluronic acid or salt thereof and an epoxy ring in a crosslinking agent (such as 1, 4-butanediol diglycidyl ether, BDDE) undergo nucleophilic reaction to generate stable ether bonds, and meanwhile, hydroxyl in a gelatin chain is linked by the crosslinking agent to form a crosslinked gel with a semi-interpenetrating network structure, which shows that the two polymers synergistically exert the effect of isolation protection. In addition, the hyaluronic acid or salt gel thereof has excellent cohesiveness and gelatination property, can keep stable form under the action of a certain external force, is sensitive to irradiation, is easy to degrade after long-term irradiation, has strong irradiation resistance of gelatin, maintains strong form stability of mixed gel formed by crosslinking hyaluronic acid or salt thereof and gelatin, and can play a role of structural nodes in the irradiation degradation process to improve the irradiation resistance of the gel.

Preferably, in examples 1 to 20, the barrier effect of examples 1 to 7 is superior to that of examples 8 to 11, wherein it can be seen from comparing example 1 with example 8 that the barrier effect is slightly inferior when the gelatin content is low because the gelatin content is too low and an interpenetrating network structure effective for enhancing the crosslinking strength is not formed; comparing example 1 with example 9, it can be seen that when the gelatin content is higher, the isolation protection effect is slightly poor because the gelatin content is higher, which causes poor gel cohesion, is not easy to recover after deformation, and fails to achieve an obvious isolation protection effect; by comparing example 1 with example 10, it can be seen that when the amount of the cross-linking agent is low, the barrier effect is slightly poor because the amount of the cross-linking agent is insufficient, the degree of cross-linking is insufficient, and an interpenetrating network structure effective for enhancing the cross-linking strength is not formed; by comparing example 1 with example 11, it can be seen that the barrier effect is slightly poor when the gel content is low, because the gel content is too low and the gel is thin to fail to provide effective support.

TABLE 4 summary of the remaining crosslinked gel results

The isolating cross-linked gel is mainly used for radiotherapy isolating protection by injecting the synthetic gel into a gap between a target part and an organ needing protection in a physical spacing mode, increasing the distance between the two organs, and aiming at reducing the radiation to the organ needing protection and reducing the possible chronic toxic reaction of the organ to be protected after the radiotherapy is finished. In order to stabilize the gel existing between the target site and the organ to be protected, it is required that the isolated crosslinked gel has certain crosslinking stability, radiation resistance and cohesion, and the gel is prevented from being displaced during the treatment. The gel is generally stable for a period of time (typically more than 3 months) and can be completely degraded in vivo after the radiotherapy has been completed.

Comparative example 1 may have much gel remained because comparative example 1 is a pure gelatin crosslinked gel which has a strong radiation resistance and thus much remains, but pure gelatin has a poor gelling ability. In addition, in comparative example 2, the remaining gel was large, but the protective effect was inferior to that of example 1, because the radiation damaged part of the molecular chains of hyaluronic acid or its salt, making the gel looser and the supporting effect worse.

The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.

Claims

2. The production method according to claim 1,

3. The production method according to claim 1,

4. The production method according to claim 1,

5. A crosslinked gel for insulation, which is prepared by the preparation method of any one of claims 1 to 4.

6. A crosslinked isolating gel, wherein the crosslinked isolating gel is prepared by a method comprising the steps of:

7. The crosslinked gel of claim 6,

8. The crosslinked gel of claim 6,

9. A radiation therapy barrier protective agent, which comprises the cross-linked gel for barrier prepared by the preparation method of any one of claims 1 to 4 or the cross-linked gel for barrier of any one of claims 5 to 8.

10. Use of the crosslinked gel for radiation therapy isolation prepared by the preparation method of any one of claims 1 to 4 or the crosslinked gel for isolation of any one of claims 5 to 8 in the preparation of radiation therapy isolation shields.