A fast swelling, enzymatically degradable hydrogel and its preparation method and application

Abstract

The application discloses a kind of fast swelling, enzyme catalytic degradation hydrogel and its preparation method and application, in the present application based on by sucrose molecule connection multi-arm hydrophilic polymer crosslinked hydrogel, and the swelling rate is fast, and the swelling rate is high, and in the environment of sucrose enzyme degradation rate is fast, can be widely used for preparing in enzyme response biodegradable hydrogel carrier and promote weight loss product.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new materials, in particular to a new type of fast swelling, enzyme catalytic degradation hydrogel. BACKGROUND

[0002] Obesity is a worldwide epidemic that seriously affects the health of adults and children. According to the World Health Organization (WHO), the number of obese people has nearly doubled in the past 40 years. Obesity increases the risk of diseases such as cardiovascular disease, type 2 diabetes, hypertension, and cancer, and can also lead to depression and social discrimination. There are many causes of obesity, including lack of exercise and unbalanced nutrition. Therefore, controlling diet and increasing exercise are the basic methods for treating obesity and overweight. However, for most obese people, it is often difficult to implement and maintain dietary habits and exercise for a long time. Therefore, a variety of weight loss drugs have emerged, and the main functions of these drugs include appetite suppression, energy consumption, and intestinal inhibition. However, these weight loss drugs have many side effects, including insomnia, dizziness, headache, mental fatigue, drowsiness, and palpitations. These side effects seriously affect the physical health and normal production and life of patients. Therefore, the development of weight loss auxiliary products with fewer side effects is an important scientific and economic problem.

[0003] In 2014, researchers at the University of Birmingham in the UK first proposed the idea of using hydrogel to make weight loss aids. They developed a kind of edible gel made of seaweed, starch and citrus peel. This gel will swell and fix after contact with gastric acid, making people feel full, reducing appetite, reducing the intake of snacks and meals, and achieving the effect of easy weight loss. In the same year, the American biotechnology company Gelesis developed an oral weight loss drug Gelesis100, which is a kind of biocompatible hydrogel capsule containing thousands of tiny hydrogel particles. After taking the medicine before meals, the capsule is decomposed by water, and the hydrogel particles mix with the food in the stomach, rapidly swelling and causing satiety, so that the patient stops eating. These swollen drug particles will eventually be excreted from the body. Random, double-blind controlled studies have shown that Gelesis100 can make patients lose weight by 2.1%, which is a promising new non-systemic overweight and obesity treatment method with high safety and tolerance. In 2021, Alessandro et al. developed a new cellulose-based superabsorbent hydrogel. This hydrogel can reduce patients' appetite while making up for the insufficient intake of dietary fiber (DFs) in the diet, and is the first to be approved by the United States and Europe as an auxiliary product for weight management. These results show that edible hydrogel has great application prospects in the field of weight loss. However, these hydrogel-based weight loss aids do not have the property of specific degradation and cannot achieve degradation regulated by the biological internal environment. These hydrogels stay in the body for a long time, which can have adverse effects on the patient's gastrointestinal environment. In order to solve this problem, it is of great medical and economic significance to develop a hydrogel weight loss aid with the property of degradation regulated by the biological internal environment. SUMMARY

[0004] In view of the above problems of the prior art, a preparation method and application of a new edible hydrogel with the properties of biological friendliness, rapid swelling and enzyme-catalyzed degradation are provided.

[0005] To solve the above problems, the present application adopts the following scheme: a fast-swelling, enzyme-catalyzed degradable hydrogel, characterized in that the hydrogel is composed of multi-arm hydrophilic polymers connected by sucrose molecules and cross-linked with linear polymers.

[0006] Each arm of the multi-arm super-hydrophilic polymer is connected by a sucrose molecule. That is, the cross-linking point of the hydrogel is a multi-arm hydrophilic polymer connected by a sucrose molecule, preferably a polyethylene glycol connected by a sucrose molecule, i.e. sucrose PEG. This molecule can be decomposed by sucrose enzyme, so the present hydrogel can be rapidly degraded under the action of sucrose enzyme and not degraded in ordinary environment.

[0007] Further, the fast-swelling, enzyme-catalyzed degradable hydrogel is characterized in that the linear polymer of the hydrogel is an acrylic acid and single-end double-bond polyethylene glycol copolymer.

[0008] The linear polymer is a single-end double-bond polyethylene glycol (mPEG-ACLT, 2 kDa) and an acrylic acid copolymer. The acrylic acid has good water absorption, the single-end double-bond polyethylene glycol has good polymerization degree and hydrophilicity, and the copolymerization of the two ensures the rapid swelling of the hydrogel.

[0009] The application relates to a preparation method of a rapid-swelling and enzyme-catalytic degradation hydrogel.

[0010] S1, collagen solution preparation: acrylic acid, single-end double-bond polyethylene glycol (mPEG-ACLT, 2 kDa) and sucrose PEG are mixed according to a mass ratio of 200:100:1 to 200:100:10, and then are dissolved in ultrapure water;

[0011] S2, nitrogen is introduced into the mixed solution, and then ultrasonic treatment is carried out, and the step is repeated to remove oxygen in the solution;

[0012] S3, lithium phenyl-2,4,6-trimethylbenzoyl phosphite (LAP) is added into the mixed solution to be dissolved, so that the collagen solution is obtained;

[0013] S4, hydrogel preparation: the collagen solution is injected into a glass mold, and then is irradiated under ultraviolet light (365 nm, 8 W) until the hydrogel is polymerized.

[0014] Preferably, nitrogen is introduced into the mixed solution for 5 minutes, and then ultrasonic treatment is carried out for 5 minutes, and the step is repeated three times to remove oxygen in the solution. The irradiation is carried out under ultraviolet light (365 nm, 8 W) for 2 hours.

[0015] Further, the preparation method of the rapid-swelling and enzyme-catalytic degradation hydrogel is characterized in that the polymerized hydrogel is soaked and cleaned in ultrapure water.

[0016] The application relates to a rapid-swelling and enzyme-catalytic degradation hydrogel.

[0017] The application relates to a rapid-swelling and enzyme-catalytic degradation hydrogel.

[0018] The multi-arm hydrophilic polymer and the linear polymer in the hydrogel have good biocompatibility, so that the hydrogel is edible.

[0019] The multi-arm hydrophilic polymer and the linear polymer in the hydrogel have good biocompatibility, and are certified by the US Food and Drug Administration (FDA), so that the hydrogel is non-toxic.

[0020] The technical effects of the present application are as follows: 1. Compared with traditional hydrogel weight loss auxiliary products, the hydrogel has a degradation regulated by a physiological environment, and can be degraded into a liquid state after a period of time under the action of sucrase, and is discharged from the body without affecting normal physiological functions.

[0021] 2. Compared with traditional weight loss drugs, the hydrogel does not participate in or affect any physiological and chemical reactions in the body, and will not produce side effects.

[0022] 3. The hydrogel realizes an enzyme-regulated degradation process, and can be used to prepare a hydrogel carrier that can be degraded in an enzyme-containing environment. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 Schematic diagram of the design principle of the fast-swelling, enzyme-catalyzed degradation hydrogel.

[0024] Figure 2 Photos of the swelling process of the fast-swelling, enzyme-catalyzed degradation hydrogel.

[0025] Figure 3 Mass change and swelling rate of the swelling process of the fast-swelling, enzyme-catalyzed degradation hydrogel.

[0026] Figure 4 Photos of the degradation process of the fast-swelling, enzyme-catalyzed degradation hydrogel.

[0027] Figure 5 Mass change and degradation rate of the degradation process of the fast-swelling, enzyme-catalyzed degradation hydrogel.

[0028] Figure 6 Cell activity experiment graph of the fast-swelling, enzyme-catalyzed degradation hydrogel.

[0029] Figure 7 Animal model experiment. DETAILED DESCRIPTION

[0030] The present application will be further described in detail below with reference to the accompanying drawings.

[0031] A novel fast-swelling, enzyme-catalyzed degradation hydrogel is formed by polymerization of a multi-arm superhydrophilic polymer and a linear polymer, wherein each arm of the multi-arm superhydrophilic polymer is bundled and connected by a sucrose molecule as a connecting point, referred to as sucrose PEG. The crosslinking point of the hydrogel is sucrose PEG, which can be decomposed by sucrase, so that the present hydrogel can be rapidly degraded under the action of sucrase and is not degraded in ordinary environments. The linear polymer of the hydrogel is a single-end double-bond polyethylene glycol copolymer with acrylic acid, and the acrylic acid has good water absorption, and the single-end double-bond polyethylene glycol has good polymerization degree, and the copolymerization of the two ensures the fast swelling of the hydrogel. The multi-arm hydrophilic polymer and the linear polymer in the hydrogel both have good biocompatibility, ensuring that the hydrogel is edible.

[0032] A novel method for preparing rapidly swelling and enzyme-catalyzed degradation hydrogels comprises the following steps:

[0033] S1. Collagen solution preparation: Dissolve 200 μL of acrylic acid, 100 mg of single-ended double-bond polyethylene glycol (mPEG-ACLT, 2 kDa), and 1 mg of sucrose PEG in 1 mL of ultrapure water. Purge the mixed solution with nitrogen for 5 minutes, then sonicate for 5 minutes, repeating this process three times to remove oxygen from the solution. Add 0.5 mg of LAP to the mixed solution and dissolve to obtain the collagen solution.

[0034] S2. Hydrogel Preparation: The collagen solution from step S1 was injected into a glass mold and then irradiated under ultraviolet light (365 nm, 8 W) for 2 hours to polymerize into a gel. The polymerized hydrogel was then immersed in ultrapure water for 24 hours to wash away unpolymerized molecules. Finally, the hydrogel was dried in an oven for 24 hours.

[0035] This invention proposes a novel design and preparation method for a bio-friendly, rapidly swelling, enzyme-catalyzed degradation hydrogel. The main idea is to design and develop a rapidly swelling, enzyme-catalyzed degradation hydrogel. The network structure and degradation principle of the hydrogel are as follows: Figure 1 As shown, our design mainly focuses on the unique cross-linking molecules and the rapid water absorption and swelling hydrogel network design. The cross-linking point of this hydrogel is an eight-arm polyethylene glycol molecule linked by sucrose molecules (sucrose PEG). This molecule copolymerizes with single-ended double-bonded polyethylene glycol and acrylic monomers to form a hydrogel. Figure 1 A) ensures rapid swelling of the hydrogel; on the other hand, sucrose PEG can be decomposed under the action of sucrase, at which point the eight-armed polyethylene glycol molecules break, and the hydrogel will rapidly degrade due to the loss of a large number of covalent cross-linking points. Figure 1 (B) This ensures the enzymatic degradation of the hydrogel. Furthermore, the sucrose PEG, single-terminated double-bond polyethylene glycol, and polyacrylic acid used in this hydrogel all possess good biocompatibility, ensuring the hydrogel's edibility.

[0036] The following are examples of performance tests for various aspects of the present invention:

[0037] Example 1: The present invention was tested in terms of rapid swelling.

[0038] Regarding the rapid swelling of the hydrogel, we conducted swelling tests on the hydrogel in PBS buffer and optimized its swelling properties by adjusting the ratio of single-end double-bonded polyethylene glycol, acrylic acid, and sucrose PEG in the hydrogel. Figure 2The mass ratio of the mono-end double bond polyethylene glycol, acrylic acid and sucrose PEG in the hydrogel is 100:200:1. After swelling for two hours, the volume of the hydrogel increases by 40 times, and the average swelling rate is about 20 times per hour; after swelling for 24 hours, the volume of the hydrogel increases by 400 times, and basically reaches the swelling equilibrium, and the average volume swelling rate is 16.7 times per hour. Further, Figure 3 , the weighing experiment results show that, after swelling for two hours, the mass of the hydrogel increases by 40 times; after swelling for 24 hours, the mass of the hydrogel increases by 500 times Figure 3 A). These experimental results show that the swelling speed of the hydrogel is fast, and the swelling proportion is huge Figure 3 B).

[0039] Example 2: Test of the present application in enzyme catalytic degradation.

[0040] In the aspect of enzyme catalytic degradation of the hydrogel, we carried out degradation test of the hydrogel in PBS buffer (pH=4, 37°C) containing 3 mg / mL sucrose enzyme, and used the change of the hydrogel in PBS buffer as a control. We adjusted the ratio of the mono-end double bond polyethylene glycol, acrylic acid and sucrose PEG in the hydrogel during the experiment, and optimized the degradation properties of the hydrogel. As Figure 4 shown, the present hydrogel is completely degraded in the sucrose enzyme solution within 72 hours, and the volume of the present hydrogel remains the swelling equilibrium in PBS. The change of the mass of the present hydrogel with time Figure 5 A) can further demonstrate the conclusion. As shown in the figure, the average degradation rate of the present hydrogel in the sucrose enzyme solution is 0.002~0.012 mL h-1, that is, the degradation rate is about 1.4% per hour Figure 5 B). These experimental results show that the hydrogel in the present application has a very fast degradation rate in the environment of sucrose enzyme, and has a certain stability in ordinary aqueous solution.

[0041] Example 3: Test of the present application in cytotoxicity.

[0042] In the aspect of biocompatibility of the hydrogel, as Figure 6 shown, we carried out cell activity test of the hydrogel. After culturing human mesenchymal stem cells (hMSC) on the surface of the present hydrogel for 48 hours, the cells were stained with live and dead cell staining. The live and dead cell staining photos show Figure 6 A) that more than 94% of the hMSC cells can survive on the surface of the hydrogel, and the survival rate is similar to that in the culture medium Figure 6 B). This shows that the present hydrogel has good biocompatibility and no cytotoxicity.

[0043] Example 4: Test of the present application in biological safety

[0044] In order to demonstrate the biosafety of the hydrogel material in the present application in vivo, the applicant conducted animal model experiments, as shown in the following. Figure 7 As shown in the following, the toxicity test and degradation test of the hydrogel material implanted subcutaneously on the back of mice were conducted, and it can be found from hematoxylin-eosin (HE) staining that the inflammatory response caused by the hydrogel material in the present application is very weak, and the material gradually degrades in vivo over time. Figure 7 As shown in the following, the inflammatory response caused by the hydrogel material in the present application is very weak, and the material gradually degrades in vivo over time. Figure 7 As shown in the following, the inflammatory response caused by the hydrogel material in the present application is very weak, and the material gradually degrades in vivo over time.

[0045] The above merely describes preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a rapidly swelling, enzyme-catalyzed degradation hydrogel, characterized in that, The steps are as follows: S1. Collagen solution preparation: Acrylic acid, single-end double-bond polyethylene glycol and sucrose PEG are mixed in a mass ratio of 200:100:1 to 200:100:10, and then dissolved in ultrapure water; S2. Introduce nitrogen gas into the mixed solution, then sonicate. Repeat this step to remove oxygen from the solution. S3. Add lithium phenyl-2,4,6-trimethylbenzoyl phosphite (LAP) to the mixed solution and dissolve to obtain collagen solution; S4. Hydrogel preparation: Inject the collagen solution into a glass mold and then irradiate it under ultraviolet light until it polymerizes into a hydrogel. The structural formula of sucrose PEG in S1 is as follows:

2. The method for preparing a rapidly swelling, enzyme-catalyzed degradation hydrogel according to claim 1, characterized in that, The polymerized hydrogel was soaked in ultrapure water to clean the unpolymerized molecules; then the hydrogel was placed in an oven to dry.

3. The application of a hydrogel prepared by the method for rapid swelling and enzyme-catalyzed degradation of hydrogel according to claim 1, characterized in that, The hydrogel prepared according to the rapid swelling and enzyme-catalyzed degradation hydrogel preparation method is used to prepare enzyme-responsive degradation hydrogels and drug carriers.

4. The application of a hydrogel prepared by the rapid swelling and enzyme-catalyzed degradation method of claim 1, characterized in that, The hydrogel prepared according to the aforementioned rapid swelling and enzyme-catalyzed degradation method is used to prepare products that promote weight loss.

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