Oral hydrogel for esophageal mucosa drug delivery and preparation method and application thereof

Abstract

The invention provides oral hydrogel for esophageal mucosa drug delivery and a preparation method and application thereof.The oral hydrogel comprises a first component and a second component, the first component is formed by dispersing polyethylene glycol, polyphenol, sodium alginate and drugs in water, and the second component is formed by dispersing polyethylene glycol, polyphenol, sodium alginate and drugs in water; the second component is formed by dispersing a thermo-sensitive polymer, a tackifier, a water-soluble calcium salt or a water-soluble zinc salt in water; the surface of the first component is covered with the second component, the water-soluble calcium salt or the water-soluble zinc salt reacts with the sodium alginate to convert the first component into a gel state, the first component can be adhered to the wound surface of the esophageal mucosa after being converted into the gel state, and the second component is converted into the gel state under the body temperature condition. The second component plays a physical shielding role after being converted into the gel state, so that the esophageal mucus and the saliva are prevented from being in contact with the first component which is converted into the gel state. The oral administration of the ESD postoperative wound protection hydrogel can be realized, the administration frequency is reduced, and the comfort and compliance of a patient are improved.

Description

Technical Field

[0001] The invention belongs to the field of biomedicine and relates to an oral hydrogel for esophageal mucosal drug delivery and a preparation method and application thereof. Background Art

[0002] Endoscopic mucosal dissection (ESD) refers to the complete removal of the diseased mucosa from the deep tissue under the direct vision of the endoscope, so as to achieve the purpose of treating the lesion. ESD has the advantages of being minimally invasive, safe and efficient, and is currently widely used in the treatment of diseases such as esophageal cancer. However, when the resection area exceeds 3 / 4 of the esophageal surface, ESD often leads to esophageal stenosis, with an incidence rate of more than 90%. Esophageal stenosis can cause patients to have difficulty eating and usually requires additional surgery and treatment. Therefore, it is particularly important to prevent esophageal stenosis after ESD and promote the rapid repair of the esophageal mucosa, but there is currently no effective prevention method.

[0003] As an excellent local drug delivery system, injectable hydrogels have been used to cover wounds and promote wound repair after ESD. For example, injectable hydrogels or drug-loaded hydrogels are injected into the submucosal area of ​​the lesion through an ESD catheter to make the mucosa at the lesion site bulge, which can prevent the underlying tissue from being damaged during subsequent incision and stripping operations. After the lesion mucosa is stripped and removed, the residual hydrogel can cover the wound surface, protecting the tissue, preventing infection and perforation, and promoting tissue repair, which is beneficial to reduce postoperative complications of EDS. However, the mucus in the esophagus and the rapid peristalsis of the esophagus will have an adverse effect on the retention time of the hydrogel in the wound. It is difficult for the hydrogel to provide long-term protection at the wound surface. Frequent use of the ESD catheter to administer drugs to the esophagus is required to ensure that the wound is effectively covered by the hydrogel. However, frequent use of the ESD catheter to administer drugs will reduce the patient's comfort and compliance, and will also reduce the feasibility of treatment.

[0004] Therefore, if an orally administrable hydrogel drug delivery system with rapid adhesion and gelation capabilities can be developed, the drug-loaded hydrogel can be administered orally after ESD surgery and made to adhere and gel quickly, stably covering the esophageal wound surface to prevent postoperative esophageal stenosis and promote tissue repair. This will be of great significance for improving patient comfort and compliance, reducing the frequency of administration, and improving the efficiency of local drug delivery. Summary of the invention

[0005] In view of the problem that the existing hydrogels used for post-ESD wound protection need to be administered with the help of ESD catheter technology, which will reduce patient comfort and compliance as well as the feasibility of treatment, the present invention provides an oral hydrogel for esophageal mucosal drug delivery and a preparation method and application thereof, so as to achieve rapid adhesion and gelation of hydrogel components at the esophageal wound surface and improve the binding force between the hydrogel and the esophageal wound surface, thereby realizing the oral administration of the hydrogel for post-ESD wound protection, increasing the retention time of the hydrogel at the esophageal wound surface, reducing the frequency of administration, and improving the comfort and compliance of patients.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows:

[0007] An oral hydrogel for esophageal mucosal drug delivery, the oral hydrogel comprising a first component and a second component;

[0008] The first component is formed by fully dispersing polyethylene glycol, polyphenol, sodium alginate and drugs in water. In the first component, the concentration of polyethylene glycol is 6wt% to 20wt%, the concentration of polyphenol is 20wt% to 30wt%, and the concentration of sodium alginate is 1wt% to 2wt%. The polyethylene glycol and polyphenol in the first component are combined by intermolecular forces to form a polyethylene glycol-polyphenol coordination network.

[0009] The second component is formed by fully dispersing a temperature-sensitive polymer, a thickener, and a water-soluble calcium salt or a water-soluble zinc salt in water. In the second component, the concentration of the temperature-sensitive polymer is 12wt% to 18wt%, the concentration of the thickener is 0.4wt% to 1.1wt%, and the concentration of the water-soluble calcium salt or the water-soluble zinc salt is 2wt% to 7wt%;

[0010] The second component is covered on the surface of the first component, the water-soluble calcium salt or water-soluble zinc salt in the second component reacts with the sodium alginate in the first component to transform the first component into a gel state, and the first component adheres to the wound surface of the esophageal mucosa after being transformed into a gel state, and the second component is transformed into a gel state under body temperature conditions. After being transformed into a gel state, the second component plays a physical shielding role to prevent esophageal mucus and saliva from contacting the first component transformed into a gel state.

[0011] In the above-mentioned technical solution of oral hydrogel for esophageal mucosal drug delivery, the polyphenols in the first component mainly play the role of anti-inflammatory, antioxidant and enhancing the binding force between the first component and the esophageal mucosa. The role of the polyethylene glycol in the first component is mainly to combine with the polyphenols through intermolecular forces including hydrogen bonds, van der Waals forces, etc. to form a polyethylene glycol-polyphenol coordination network. The polyethylene glycol-polyphenol coordination network has good stability and can be used to increase the stability of the hydrogel during use and load drugs, regulate the release performance of drugs, etc.

[0012] In the above-mentioned technical solution of the oral hydrogel for esophageal mucosal drug delivery, the molecular weight of the polyethylene glycol is preferably 900 to 20,000 Da.

[0013] In the above-mentioned technical solution of the oral hydrogel for esophageal mucosal drug delivery, the polyphenol is at least one of tannic acid, luteolin, epigallocatechin gallate, gallic acid, quercetin and pyrogallic acid.

[0014] In the above-mentioned technical solution of oral hydrogel for esophageal mucosal drug delivery, the thermosensitive polymer in the second component is mainly used to allow the second component to undergo a sol-gel transition under body temperature conditions, that is, to allow the second component to be transformed into a gel state under body temperature conditions. When the concentration of the thermosensitive polymer aqueous solution is 12wt% to 18wt%, the thermosensitive polymer solution can be transformed from a sol state to a gel state under body temperature conditions. Biocompatible polymers that meet this condition can be used as the thermosensitive polymer in the second component, for example, the thermosensitive polymer in the second component contains an amphiphilic block copolymer with a polyethylene glycol block. Further, feasible temperature-sensitive polymers in the second component include at least one of PCGA-PEG-PCGA [poly(ε-caprolactone-co-glycolic acid)-poly(ethylene glycol)-poly(ε-caprolactone-co-glycolic acid)], PDLLA-PEG-PDLLA (polylactic acid-poly(ethylene glycol)-polylactic acid)], PLGA-PEG-PLGA [polylactic acid-co-glycolic acid-poly(ethylene glycol)-polylactic acid-co-glycolic acid)] and PCL-PEG-PCL [polycaprolactone-poly(ethylene glycol)-polycaprolactone].

[0015] In the above-mentioned technical solution of the oral hydrogel for esophageal mucosal drug delivery, the viscosity enhancer includes at least one of hydroxypropyl cellulose, carboxymethyl cellulose, methyl cellulose, sodium carboxymethyl cellulose, pectin and dextrin.

[0016] In the above-mentioned technical solution of the oral hydrogel for esophageal mucosal drug delivery, the second component is preferably covered on the surface of the first component in a ratio of (0.5-2):1 by volume of the first component to the second component.

[0017] In the technical scheme of the oral hydrogel for esophageal mucosal drug delivery, the drug is a conventional drug used in the prior art to prevent esophageal stenosis after ESD surgery and promote esophageal mucosal repair after ESD surgery. For example, the drug can be an anti-inflammatory drug, an antioxidant drug, an anti-tissue fibrosis drug, and a drug that promotes mucosal repair, etc., and feasible drugs include prednisolone, hydrocortisone, vonoprazan fumarate, triamcinolone acetonide, methylprednisolone sodium succinate, dexamethasone sodium phosphate, fibroblast activation protein inhibitor (FAP inhibitor) and epidermal growth factor (EGF) at least one, but feasible drugs are not limited to the drugs listed above. The concentration of the drug in the first component is determined according to actual application requirements, for example, the concentration of the drug in the first component is generally not more than 5wt%.

[0018] When the above-mentioned oral hydrogel for esophageal mucosal drug delivery is used, the first component is first orally taken, and then the second component is orally taken. The first component is a viscous fluid with relatively high viscosity. After oral administration, it adheres to the surface of the esophagus and covers the wound surface. The second component is mainly used to form a gel. After oral administration, the second component covers the surface of the first component. When the second component contacts the first component, the water-soluble calcium salt or water-soluble zinc salt in the second component reacts rapidly with the sodium alginate in the first component to form a gel-state calcium alginate or zinc alginate, thereby converting the first component into a gel state and quickly fixing it on the esophageal mucosa. Subsequently, the second component gradually converts into a gel state under body temperature conditions. After the second component is converted into a gel state, it covers the surface of the first component that has been converted into a gel state. After the second component is converted into a gel state, the adhesion of the second component to the esophageal mucosa is weak, which can prevent the adhesion of the esophageal mucosa, play a lubricating role and a physical barrier role, reduce the leakage of the drug loaded in the first component converted into a gel state into the esophagus, and make the drug released from the first component converted into a gel state to the wound surface of the esophagus as much as possible.

[0019] The present invention also provides a method for preparing the above-mentioned oral hydrogel for esophageal mucosal drug delivery, comprising the following steps:

[0020] (1) fully dispersing polyethylene glycol, polyphenol, sodium alginate and the drug in water to form a first component;

[0021] (2) fully dispersing the temperature-sensitive polymer, the thickener, and the water-soluble calcium salt or the water-soluble zinc salt in water to form a second component, and controlling the temperature of the second component so that the second component is in a sol state;

[0022] (3) The first component is applied to the esophageal mucosa to cover the wound surface, and the second component is applied to cover the surface of the first component. The water-soluble calcium salt or water-soluble zinc salt in the second component reacts with the sodium alginate in the first component to convert the first component into a gel state. The second component is converted into a gel state under body temperature conditions.

[0023] In the technical solution of the above preparation method, the second component is preferably applied within 1 minute after the first component is applied.

[0024] The present invention takes the formation of the hydrogel of the present invention on the pig esophagus as an example. It is confirmed by experiments that the formed hydrogel has good binding force with the pig esophagus, and the adhesion force of the hydrogel with the pig esophagus can reach 6.5-7.5N. The hydrogel can be stably bound to the pig esophagus by rinsing with a large amount of deionized water and stirring for a long time in PBS buffer at 37°C. The present invention has been confirmed by experiments that the adhesion of the second component transformed into a gel state to the pig esophagus is low, which can avoid the problem of esophageal adhesion caused by direct exposure of the first component transformed into a gel state, and can also avoid the first component transformed into a gel state from contacting with esophageal mucus and saliva, thereby increasing its binding stability with the esophagus. The present invention has also been confirmed by experiments that the hydrogel of the present invention has good cell compatibility when it is not loaded with drugs. In addition, the present invention has also been confirmed by experiments that the drug loaded in the hydrogel of the present invention can be released smoothly. Based on the above performance, the present invention also provides the use of the above-mentioned oral hydrogel for esophageal mucosal drug delivery in the preparation of drugs for preventing esophageal stenosis after ESD surgery or drugs for promoting esophageal mucosal repair after ESD surgery.

[0025] The principle of the technical solution of the present invention is mainly as follows:

[0026] The present invention aims to provide a drug-loaded hydrogel for oral administration to prevent esophageal stenosis and promote esophageal wound repair after ESD surgery. In order to achieve oral administration, the most basic problem is to solve the limited retention time of hydrogel or hydrogel precursor on the esophageal mucosa caused by rapid esophageal motility and weak adhesion of esophageal tissue. In order to solve this problem, the present invention fully disperses polyethylene glycol, polyphenols, sodium alginate and drugs in water to form a first component with high viscosity. After oral administration of the first component, the first component relies on its high viscosity to be retained in the esophageal mucosa to cover the wound surface. At the same time, the alginate and polyphenols in the first component rely on their rich hydroxyl groups and phenolic hydroxyl groups to enhance the binding force between the first component and the esophageal mucosal tissue; on this basis, the present invention fully disperses thermosensitive polymers, thickeners, water-soluble calcium salts or water-soluble zinc salts in water to form a second component with slower flow. After oral administration of the second component, the second component relies on its high viscosity to be retained on the surface of the first component and the first component When the first component contacts the second component, the calcium ions or zinc ions in the second component react quickly with the sodium alginate in the first component to form calcium alginate or zinc alginate to transform the first component into a gel state, thereby achieving stable adhesion of the first component transformed into a gel state on the esophageal mucosa. At the same time, the thermosensitive polymer in the second component transforms from a sol state to a gel state under body temperature conditions, thereby achieving fixation of the second component on the surface of the first component. Moreover, the second component transformed into a gel state has low adhesion to the esophageal mucosal tissue, and its coverage on the surface of the first component transformed into a gel state can prevent adhesion of the esophageal mucosa. Furthermore, after the first component is transformed into a gel state, the polyethylene glycol-polyphenol coordination network and the calcium alginate or zinc alginate polymer network therein can effectively load the drug therein, so that the drug is gradually released from the first component transformed into a gel state into the esophageal mucosa, achieving the functions of anti-inflammatory, anti-oxidation, anti-tissue fibrosis or promoting wound tissue repair on the esophageal mucosal wound surface; in addition, the second component transformed into a gel state covers the surface of the first component, which can play the role of a physical barrier. On the one hand, it prevents the first component transformed into a gel state from contacting saliva and esophageal mucus, and prevents the first component transformed into a gel state from being exposed to cause esophageal adhesion. On the other hand, it can reduce the leakage of the drug loaded in the first component transformed into a gel state, so that the drug is released from the first component transformed into a gel state to the wound surface of the esophagus as much as possible. By combining the above technical means, the present invention provides a drug-loaded hydrogel that can be administered orally to prevent esophageal stenosis and promote esophageal wound repair after ESD surgery, which can solve the existing problem of frequent drug administration on the wound after ESD surgery with the help of ESD catheter, and increase patient comfort, compliance and accuracy of drug treatment.

[0027] Compared with the prior art, the technical solution provided by the present invention produces the following beneficial technical effects:

[0028] 1. The present invention provides an oral hydrogel for esophageal mucosal drug delivery, the oral hydrogel comprising a first component and a second component; the first component is formed by fully dispersing polyethylene glycol, polyphenol, sodium alginate and a drug in water, and the second component is formed by fully dispersing a thermosensitive polymer, a viscosity enhancer, a water-soluble calcium salt or a water-soluble zinc salt in water; when in use, the first component is taken orally first, and then the second component is taken orally, the first component is a viscous fluid with relatively high viscosity, which adheres to the surface of the esophagus and covers the wound surface after oral administration, and the second component covers the surface of the first component after oral administration, and the water-soluble calcium salt or water-soluble zinc salt in the second component reacts rapidly with the sodium alginate in the first component to form calcium alginate or zinc alginate in a gel state, thereby rapidly converting the first component into a gel state and fixing it on the esophageal mucosa, and then, the second component converts into a gel state under body temperature conditions and covers the surface of the first component converted into a gel state, playing a shielding role, preventing saliva and esophageal mucus from contacting the first component converted into a gel state, and at the same time preventing esophageal mucosal adhesion and reducing drug leakage. The hydrogel of the present invention can form gel at the esophageal mucosal wound surface by taking the first component and the second component in sequence. The method of use is simple and can solve the problem that the existing hydrogel used for wound protection after ESD surgery needs to be administered with the help of an ESD catheter, which will reduce the patient's comfort and compliance as well as the feasibility of treatment.

[0029] 2. The present invention takes the formation of drug-loaded hydrogel on the pig esophagus as an example. It is confirmed through experiments that when the first component and the second component are applied to the pig esophagus successively to form the hydrogel of the present invention, the formed hydrogel has good binding force with the pig esophagus, and the adhesion force between the hydrogel and the pig esophagus can reach 6.5-7.5N. At the same time, the hydrogel formed on the pig esophagus is rinsed with a large amount of deionized water, and the hydrogel can still be stably bound to the pig esophagus. The pig esophagus formed with the hydrogel is placed in a PBS buffer at 37°C and stirred for 24 hours, and the hydrogel is still stably bound to the pig esophagus. The good binding stability of the hydrogel of the present invention on the esophagus means that its retention time on the esophageal mucosa is relatively long, which is conducive to reducing the frequency of administration and solving the problem that the existing hydrogel used for wound protection after ESD surgery needs to be frequently administered with the help of ESD catheters.

[0030] 3. The present invention takes the formation of a drug-loaded hydrogel on a pig esophagus as an example, and experiments confirm that after the second component is directly combined with the wound surface of the pig esophagus and transformed into a gel state, the adhesion of the second component transformed into a gel state to the pig esophagus is only 0.8 to 1.1 N, which is significantly less than the adhesion of the first component and the drug-loaded hydrogel to the pig esophagus. This shows that the present invention uses the second component transformed into a gel state to cover the first component transformed into a gel state, which can avoid the problem of esophageal adhesion caused by direct exposure of the first component transformed into a gel state, and can also avoid the first component transformed into a gel state from contacting with esophageal mucus and saliva, further increasing its binding stability with the esophagus.

[0031] 4. The present invention has been confirmed through in vitro drug release experiments that the present invention uses the second component transformed into a gel state to cover the first component transformed into a gel state, which can slow down the release rate of the drug in the early stage of drug release, thereby avoiding unnecessary drug waste.

[0032] 5. The present invention also provides a method for preparing the above-mentioned oral hydrogel for esophageal mucosal drug delivery, which is simple to operate and convenient to apply in practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 These are photos of the gelation of the first component and the second component in Example 1 and Comparative Example 1 when they are in contact in vitro.

[0034] Figure 2 Figures (a) and (b) are photos of the pig esophagus formed with the drug-loaded hydrogel in Example 1 before and after flushing. Figure 2 Figures (c) and (d) are photos of the pig esophagus before and after flushing after adding the second component in Example 1 and placing it in an environment of 37-38°C for 3 minutes.

[0035] Figure 3 This is a photograph of the pig esophagus formed with the drug-loaded hydrogel in Example 1 after being stirred in PBS buffer at 37° C. for 24 hours.

[0036] Figure 4 is the cell compatibility test result of blank hydrogel.

[0037] Figure 5 These are the test results of the adhesion of the first component in Example 6, the second component transformed into a gel state, and the drug-loaded hydrogel to the surface of the pig esophagus.

[0038] Figure 6 This is the drug release curve in Example 7. DETAILED DESCRIPTION

[0039] The oral hydrogel for esophageal mucosal drug delivery provided by the present invention and its preparation method and application are further described by examples below. It is necessary to point out that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. The technical personnel in the relevant field make some non-essential improvements and adjustments to the present invention according to the above invention content for specific implementation, which still falls within the scope of protection of the present invention.

[0040] The thermosensitive polymers PCGA-PEG-PCGA, PDLLA-PEG-PDLLA, PLGA-PEG-PLGA and PCL-PEG-PCL used in the following embodiments and comparative examples can be purchased directly or synthesized by themselves or by entrusting others. The ratio of their blocks satisfies the following conditions: the ratio of the blocks should be such that when the concentration of the above thermosensitive polymers in aqueous solution is 12wt% to 18wt%, the thermosensitive polymer solution can be transformed from a sol state to a gel state under body temperature conditions (e.g., 37 to 38°C).

[0041] Example 1

[0042] In this embodiment, an oral hydrogel for esophageal mucosal drug delivery is prepared in the following steps:

[0043] (1) Add polyethylene glycol with a molecular weight of 1000Da, tannic acid, sodium alginate and triamcinolone acetonide into ultrapure water, stir at a speed of 800rpm for 3h, and fully dissolve or disperse each component in the ultrapure water to obtain a first component. In the first component, the concentration of polyethylene glycol is 6.9wt%, the concentration of tannic acid is 20.7wt%, the concentration of sodium alginate is 2wt%, and the concentration of triamcinolone acetonide is 2.1wt%.

[0044] (2) Add the thermosensitive polymer PCGA-PEG-PCGA, hydroxypropyl cellulose and calcium chloride into ultrapure water, stir at 800 rpm for 2 h, fully dissolve or disperse each component in the ultrapure water, and then drop a small amount of methylene blue aqueous solution to facilitate observation in the subsequent experiment, and fully mix to obtain the second component. In the second component, the concentration of PCGA-PEG-PCGA is 16wt%, the concentration of hydroxypropyl cellulose is 0.8wt%, and the concentration of calcium chloride is 4wt%.

[0045] (3) Take a pig esophagus, peel off part of the mucosa on the surface of the pig esophagus, and form a wound with a diameter of about 2 cm on the pig esophagus mucosa. The temperature of the pig esophagus and the ambient temperature are controlled to be 37-38°C. Use a syringe to add the first component from above the wound surface of the pig esophagus to the wound surface of the pig esophagus, so that the first component adheres to the surface of the esophagus and covers the wound surface. Within 1 minute after the injection of the first component, use a syringe to add the second component from above the wound surface of the pig esophagus to the wound surface of the pig esophagus, so that the second component covers the surface of the first component. At the moment when the second component contacts the first component, the first component is converted into a gel state (the calcium chloride in the second component reacts quickly with the sodium alginate in the first component to form calcium alginate and convert the first component into a gel state). After the second component is added, let it stand for 3 minutes, and the second component is converted into a gel state, that is, a drug-loaded hydrogel is formed on the wound surface of the pig esophagus.

[0046] In this step, the volume ratio of the first component to the second component was controlled to be 1:1. To facilitate subsequent testing, a total of 10 parallel samples were set in this step.

[0047] The adhesion of the drug-loaded hydrogel formed in step (3) of this example to the pig esophagus was tested, and the result was 7.0-7.5N.

[0048] Comparative Example 1

[0049] The operation of this comparative example is substantially the same as that of Example 1, except that the second component does not contain calcium chloride.

[0050] Example 2

[0051] In this example, the gelation of the first component and the second component in Example 1 and Comparative Example 1 when they are in contact in vitro is investigated.

[0052] (1) Take the first component prepared in Example 1 and put it into a glass bottle. Add an equal volume of the second component prepared in Example 1 on top of the first component. Place it in a water bath at a temperature of 37-38°C for 3 minutes. Then tilt the glass bottle and observe the gelation state of the first component and the second component in the glass bottle. The results are as follows: Figure 1 As shown in Figures (a) to (c), Figure (a) is a photograph of the first component, Figure (b) is a photograph of the second component just added on top of the first component, and Figure (c) is a photograph of the glass bottle after being placed in a water bath at 37-38°C for 3 minutes and then taken out and placed at an angle.

[0053] (2) Take the first component prepared in Comparative Example 1 and put it into a glass bottle. Add an equal volume of the second component prepared in Comparative Example 1 on top of the first component. Place it in a water bath at a temperature of 37-38°C for 3 minutes. Then place the glass bottle at an angle and observe the gelation state of the first component and the second component in the glass bottle. The results are as follows: Figure 1As shown in Figures (d) to (f), Figure (d) is a photograph of the first component, Figure (e) is a photograph of the second component just added on top of the first component, and Figure (f) is a photograph of the glass bottle after being placed in a water bath at 37-38°C for 3 minutes and then taken out and placed at an angle.

[0054] Depend on Figure 1 As can be seen from Figures (a) to (c) of Example 1, when the first component comes into contact with the second component, the sodium alginate therein reacts with the calcium ions to form a calcium alginate gel, for example, Figure 1 In Figure (c), when the glass bottle is tilted, the material in it does not flow, indicating that the material in the glass bottle has turned into a gel state with poor fluidity. Figure 1 In Figure (c), we can also see that the dye in the second component enters the first component, indicating that the substances in the first component and the second component reacted in Example 1. Figure 1 As can be seen from Figures (d) to (f) of Comparative Example 1, when the second component does not contain calcium ions, the first component and the second component cannot form a gel after contact. Figure 1 In Figure (f), when the glass bottle is tilted, both the yellow first component and the blue second component flow, indicating that they have not turned into a gel state. Figure 1 As can be seen in Figure (f), the first component and the second component maintain their respective colors with a clear boundary, indicating that in Comparative Example 1, the first component and the second component did not react after contact.

[0055] Example 3

[0056] In this example, the porcine esophagus on which the drug-loaded hydrogel was formed in Example 1 and Comparative Example 1 was rinsed with deionized water to examine the stability of the drug-loaded hydrogel on the porcine esophagus.

[0057] (1) The porcine esophagus formed with the drug-loaded hydrogel in Example 1 was placed in an environment of 37-38° C. and continuously rinsed with 3000 mL of deionized water. Figure 2 Figures (a) and (b) are photographs of the pig esophagus formed with the drug-loaded hydrogel in Example 1 before and after flushing.

[0058] (2) Take the pig esophagus to which the second component has been added in Comparative Example 1 and placed in an environment of 37-38° C. for 3 minutes, place it in an environment of 37-38° C., and continuously rinse it with 50 mL of deionized water. Figure 2 Figures (c) and (d) are photos of the pig esophagus before and after flushing after adding the second component in Example 1 and placing it in an environment of 37-38°C for 3 minutes.

[0059] Depend on Figure 2It can be seen that the drug-loaded hydrogel formed at the wound surface of the pig esophagus in Example 1 is stably combined with the pig esophagus, and can still stably exist on the pig esophagus after continuous flushing with 3000mL of deionized water, while in Comparative Example 1, after the second component is added to Comparative Example 1 and placed in an environment of 37-38°C for 3 minutes, the polymer layer on the surface of the pig esophagus is flushed away with only 50mL of deionized water. This shows that the introduction of calcium ions or zinc ions in the second component of the present invention to react with sodium alginate in the first component can effectively increase the adhesion stability of the drug-loaded gel on the surface of the pig esophagus.

[0060] Example 4

[0061] In this example, the porcine esophagus formed on the drug-loaded hydrogel in Example 1 was stirred in a solution at 37° C. to examine the stability of the drug-loaded hydrogel on the porcine esophagus.

[0062] The porcine esophagus formed with the drug-loaded hydrogel in Example 1 was placed in a beaker containing PBS buffer, a magnetic stirrer was added, and the mixture was stirred at 200 rpm for 24 h. During the stirring process, the temperature of the PBS buffer in the beaker was controlled to be 37° C. After stirring for 24 h, the PBS buffer solution was as shown in the following figure. Figure 3 As shown in Figure (a), the pig esophagus formed with the drug-loaded hydrogel was taken out from the PBS buffer and photographed. Figure 3 As shown in Figure (b), Figure 3 It can be seen that after stirring in PBS buffer at 37°C for 24 hours, the drug-loaded hydrogel on the porcine esophagus still exists stably, indicating that the drug-loaded hydrogel has excellent binding stability with the porcine esophagus.

[0063] Example 5

[0064] In this example, the cell compatibility of blank hydrogel was investigated.

[0065] (1) Add polyethylene glycol with a molecular weight of 1000Da, tannic acid and sodium alginate into ultrapure water, stir at 800rpm for 3h, and fully dissolve or disperse each component in the ultrapure water to obtain a first component. In the first component, the concentration of polyethylene glycol is 6.9wt%, the concentration of tannic acid is 20.7wt%, and the concentration of sodium alginate is 2wt%.

[0066] (2) Add the thermosensitive polymer PCGA-PEG-PCGA, hydroxypropyl cellulose and calcium chloride into ultrapure water, stir at 800 rpm for 2 h, fully dissolve or disperse each component in the ultrapure water, and then drop a small amount of methylene blue aqueous solution to facilitate observation in the subsequent experiment, and fully mix to obtain the second component. In the second component, the concentration of PCGA-PEG-PCGA is 16wt%, the concentration of hydroxypropyl cellulose is 0.8wt%, and the concentration of calcium chloride is 4wt%.

[0067] (3) Mix equal volumes of the first component and the second component to obtain a blank hydrogel precursor solution.

[0068] (4) Collect L929 cells in the logarithmic phase, adjust the concentration of the cell suspension, add 100 μL to each well of a 96-well plate, plate the plate to a cell density of 10,000 cells / well, add culture medium and incubate at 5% CO2 and 37°C until the cell monolayer covers the bottom of the well, add blank hydrogel precursor solution and culture medium with a concentration gradient, so that the concentrations of the blank hydrogel precursor solution are 0, 0.24, 0.48, 0.96, 1.92, 3.84, 7.68, 15.36 and 30.72 mg / mL, respectively, set 5 replicate wells for each concentration, add 100 μL to each well, use the blank hydrogel precursor solution with a concentration of 0 mg / mL containing cells as the control well (Control), use the blank hydrogel concentration of 0.24-30.72 mg / mL containing cells as the experimental well, and use the well containing cells and culture medium only as the blank well. Then incubate at 5% CO2 and 37°C for 48 hours. Remove the culture medium, add 100 μL of 5 mg / mL MTT solution to each well, and continue to culture for 4 h. Terminate the culture, carefully remove the culture medium in the well, add 100 μL of dimethyl sulfoxide to each well, shake at low speed on a shaker for 10 min to fully dissolve the crystals, and measure the absorbance of each well at a wavelength of 490 nm using an enzyme-linked immunosorbent assay. Calculate the cell survival rate according to the following formula. The results are as follows: Figure 4 shown.

[0069] Cell survival rate = (A S -A b ) / (A C -A b )*100%

[0070] In the above formula, A S is the absorbance of the experimental well, A C is the absorbance of the control well, A b is the absorbance of the blank well.

[0071] Depend on Figure 4 It can be seen that the blank hydrogel in this example has good cell compatibility.

[0072] Example 6

[0073] In this example, the effect of disposing the second component on the surface of the first component on the adhesion is investigated.

[0074] (1) Take a pig esophagus, peel off part of the mucosa on the surface of the pig esophagus, and form a wound with a diameter of about 2 cm on the mucosa of the pig esophagus. The temperature of the pig esophagus and the ambient temperature are controlled to be 37-38° C., and the first component in Example 1 is added to the wound surface of the pig esophagus from above the wound surface of the pig esophagus with a syringe, so that the first component adheres to the surface of the esophagus and covers the wound surface. After the addition is completed, let it stand for 3 minutes.

[0075] (2) Take a pig esophagus, peel off part of the mucosa on the surface of the pig esophagus, and form a wound with a diameter of about 2 cm on the mucosa of the pig esophagus. The temperature of the pig esophagus and the ambient temperature are controlled to be 37-38° C. The second component in Example 1 is added to the wound surface of the pig esophagus from above the wound surface of the pig esophagus with a syringe, so that the second component adheres to the surface of the esophagus and covers the wound surface. After the addition is completed, the second component is allowed to stand for 3 minutes, and then it turns into a gel state.

[0076] (3) Take a pig esophagus, peel off part of the mucosa on the surface of the pig esophagus, and form a wound with a diameter of about 2 cm on the pig esophagus mucosa. The temperature of the pig esophagus and the ambient temperature are controlled to be 37-38°C, and the first component in Example 1 is added to the wound surface of the pig esophagus from above the wound surface of the pig esophagus with a syringe, so that the first component adheres to the surface of the esophagus and covers the wound surface. Within 1 minute after the injection of the first component is completed, the second component in Example 1 is added to the wound surface of the pig esophagus from above the wound surface of the pig esophagus with a syringe, so that the second component covers the surface of the first component. After the second component is added, it is left to stand for 3 minutes to form a drug-loaded hydrogel on the surface of the pig esophagus.

[0077] At 37-38°C, the porcine esophagus prepared in steps (1), (2), and (3) was tested using a universal material machine to test the adhesion of the first component, the second component transformed into a gel state, and the drug-loaded hydrogel to the surface of the porcine esophagus. The results are as follows: Figure 5 As shown. Figure 5 It can be seen that the adhesion of the second component transformed into a gel state to the pig esophagus is only 0.8-1.1N, which is significantly less than the adhesion of the first component and the drug-loaded hydrogel to the pig esophagus. This shows that the second component transformed into a gel state is used to cover the first component transformed into a gel state, which can avoid the problem of esophageal adhesion caused by direct exposure of the first component transformed into a gel state. On the other hand, it also shows that the present invention has excellent bonding stability by directly bonding with the esophageal wound surface by the first component transformed into a gel state.

[0078] Example 7

[0079] In this example, the effect of disposing the second component on the surface of the first component on the drug release was investigated.

[0080] (1) The first component prepared in Example 1 was placed in a glass bottle, and an equal volume of the second component prepared in Example 1 was added on top of the first component. The mixture was placed in a water bath at a temperature of 37-38° C. for 3 minutes to obtain sample AB. Sample AB contained 300 mg of the drug.

[0081] (2) The first component prepared in Example 1 was placed in a glass bottle and placed in a water bath at a temperature of 37-38° C. for 3 min to obtain sample A, which contained 300 mg of the drug.

[0082] (3) The small cup method was used for drug dissolution and release. The dissolution medium was normal saline with a volume of 150 mL. Sample A and sample AB were placed in dialysis bags with a molecular weight cutoff of 1000 Da for drug release. The release medium was aspirated at release times of 0.17 h, 0.33 h, 0.5 h, 0.67 h, 0.83 h, 1 h, 1.5 h, 2 h, 2.5 h, 3.5 h, 4.5 h, 6.5 h, 8.5 h, 12 h, 24 h, 36 h and 48 h to test drug concentration. An equal amount of normal saline was added. The drug release curves were shown in FIG. Figure 6 As shown, Figure 6 Curve A in represents sample A, and curve AB represents sample AB.

[0083] Depend on Figure 6 It can be seen that within the first 25 minutes of drug release, the drug release rate in sample A is faster than that in sample AB. As the release time increases, the second component transformed into a gel state swells, which accelerates the drug release rate in sample AB. This shows that the present invention sets the second component on the surface of the first component and transforms it into a gel state, which can slow down the drug release rate in the early stage of drug release.

[0084] Example 8

[0085] In this embodiment, an oral hydrogel for esophageal mucosal drug delivery is prepared in the following steps:

[0086] (1) Add polyethylene glycol with a molecular weight of 1000Da, tannic acid, sodium alginate and epidermal growth factor (EGF) into ultrapure water, stir at a speed of 200rpm for 3h, and fully dissolve or disperse each component in the ultrapure water to obtain a first component. In the first component, the concentration of polyethylene glycol is 7.0wt%, the concentration of tannic acid is 21.1wt%, the concentration of sodium alginate is 2wt%, and the concentration of EGF is 0.00007wt%.

[0087] (2) Adding the thermosensitive polymer PCGA-PEG-PCGA, hydroxypropyl cellulose and calcium chloride into ultrapure water, stirring at 200 rpm for 2 h, fully dissolving or dispersing each component in the ultrapure water, and obtaining a second component. In the second component, the concentration of PCGA-PEG-PCGA is 16 wt%, the concentration of hydroxypropyl cellulose is 0.8 wt%, and the concentration of calcium chloride is 4 wt%.

[0088] (3) The operation of this step is the same as step (3) of Example 1, except that the volume ratio of the first component to the second component is controlled to be 0.5:1. A total of 5 parallel samples are set.

[0089] The adhesion of the drug-loaded hydrogel formed in step (3) of this example to the pig esophagus was tested, and the result was 7.0-7.5N.

[0090] Example 9

[0091] In this embodiment, an oral hydrogel for esophageal mucosal drug delivery is prepared in the following steps:

[0092] (1) Adding polyethylene glycol with a molecular weight of 1000Da, tannic acid, sodium alginate and triamcinolone acetonide into ultrapure water, stirring at a speed of 500rpm for 3h, fully dissolving or dispersing each component in the ultrapure water, and obtaining a first component. In the first component, the concentration of polyethylene glycol is 6.9wt%, the concentration of tannic acid is 20.7wt%, the concentration of sodium alginate is 2wt%, and the concentration of triamcinolone acetonide is 2.1wt%.

[0093] (2) Add the thermosensitive polymer PDLLA-PEG-PDLLA, hydroxypropyl cellulose and calcium chloride into ultrapure water, stir at 500 rpm for 2 h, and fully dissolve or disperse each component in the ultrapure water to obtain a second component. In the second component, the concentration of PDLLA-PEG-PDLLA is 12.5 wt%, the concentration of hydroxypropyl cellulose is 0.7 wt%, and the concentration of calcium chloride is 4 wt%.

[0094] (3) The operation of this step is the same as step (3) of Example 1, except that the volume ratio of the first component to the second component is controlled to be 2:1, and 5 parallel samples are set.

[0095] The adhesion of the drug-loaded hydrogel formed in step (3) of this example to the pig esophagus was tested, and the result was 7.0-7.5N.

[0096] Example 10

[0097] In this embodiment, an oral hydrogel for esophageal mucosal drug delivery is prepared in the following steps:

[0098] (1) Add polyethylene glycol with a molecular weight of 20,000 Da, epigallocatechin gallate (EGCG), sodium alginate and dexamethasone sodium phosphate into ultrapure water, stir at 800 rpm for 4 h, and fully dissolve or disperse each component in the ultrapure water to obtain a first component. In the first component, the concentration of polyethylene glycol is 6 wt%, the concentration of EGCG is 30 wt%, the concentration of sodium alginate is 2 wt%, and the concentration of dexamethasone sodium phosphate is 3 wt%.

[0099] (2) Adding the thermosensitive polymer PLGA-PEG-PLGA, carboxymethyl cellulose and zinc chloride into ultrapure water, stirring at 800 rpm for 3 h, fully dissolving or dispersing each component in the ultrapure water, and obtaining a second component. In the second component, the concentration of PLGA-PEG-PLGA is 18 wt%, the concentration of carboxymethyl cellulose is 0.4 wt%, and the concentration of zinc chloride is 5 wt%.

[0100] (3) The operation of this step is the same as step (3) of Example 1, except that 5 parallel samples are set up.

[0101] The adhesion of the drug-loaded hydrogel formed in step (3) of this example to the pig esophagus was tested, and the result was 7.0-7.5N.

[0102] Embodiment 11

[0103] In this embodiment, an oral hydrogel for esophageal mucosal drug delivery is prepared in the following steps:

[0104] (1) Add polyethylene glycol with a molecular weight of 900 Da, gallic acid, sodium alginate and hydrocortisone into ultrapure water, stir at a speed of 600 rpm for 4 hours, and fully dissolve or disperse each component in the ultrapure water to obtain a first component. In the first component, the concentration of polyethylene glycol is 20wt%, the concentration of gallic acid is 20wt%, the concentration of sodium alginate is 1wt%, and the concentration of hydrocortisone is 1wt%.

[0105] (2) Adding the thermosensitive polymer PCL-PEG-PCL, methylcellulose and calcium chloride into ultrapure water, stirring at 600 rpm for 3 h, fully dissolving or dispersing each component in the ultrapure water, and obtaining a second component. In the second component, the concentration of PCL-PEG-PCL is 12 wt%, the concentration of methylcellulose is 1.1 wt%, and the concentration of calcium chloride is 2 wt%.

[0106] (3) The operation of this step is the same as that of Example 1, except that the volume ratio of the first component to the second component is controlled to be 0.8:1. A total of 5 parallel samples are set.

[0107] The adhesion of the drug-loaded hydrogel formed in step (3) of this example to the pig esophagus was tested, and the result was 6.5-7.0N.

[0108] Example 12

[0109] In this embodiment, an oral hydrogel for esophageal mucosal drug delivery is prepared in the following steps:

[0110] (1) Add polyethylene glycol with a molecular weight of 5000Da, quercetin, sodium alginate and fibroblast activation protein inhibitor (FAP inhibitor) into ultrapure water, stir at a speed of 500rpm for 4 hours, and fully dissolve or disperse each component in the ultrapure water to obtain a first component. In the first component, the concentration of polyethylene glycol is 15wt%, the concentration of quercetin is 22wt%, the concentration of sodium alginate is 1.5wt%, and the concentration of FAP inhibitor is 0.1wt%.

[0111] (2) Adding the thermosensitive polymer PCGA-PEG-PCGA, sodium carboxymethyl cellulose and calcium chloride into ultrapure water, stirring at a speed of 500 rpm for 3 hours, and fully dissolving or dispersing each component in the ultrapure water to obtain a second component. In the second component, the concentration of PCGA-PEG-PCGA is 14wt%, the concentration of sodium carboxymethyl cellulose is 0.8wt%, and the concentration of calcium chloride is 4wt%.

[0112] (3) The operation of this step is the same as step (3) of Example 1, except that the volume ratio of the first component to the second component is controlled to be 1.2:1, and 5 parallel samples are set.

[0113] The adhesion of the drug-loaded hydrogel formed in step (3) of this example to the pig esophagus was tested, and the result was 7.0-7.5N.

[0114] Example 13

[0115] In this embodiment, an oral hydrogel for esophageal mucosal drug delivery is prepared in the following steps:

[0116] (1) Add polyethylene glycol with a molecular weight of 8000Da, luteolin, sodium alginate and methylprednisolone sodium succinate into ultrapure water, stir at a speed of 500rpm for 4h, and fully dissolve or disperse each component in the ultrapure water to obtain a first component. In the first component, the concentration of polyethylene glycol is 13wt%, the concentration of luteolin is 25wt%, the concentration of sodium alginate is 2wt%, and the concentration of methylprednisolone sodium succinate is 1.2wt%.

[0117] (2) Adding the thermosensitive polymer PCGA-PEG-PCGA, pectin and calcium chloride into ultrapure water, stirring at 500 rpm for 3 h, fully dissolving or dispersing each component in the ultrapure water, and obtaining a second component. In the second component, the concentration of PCGA-PEG-PCGA is 14 wt%, the concentration of pectin is 0.5 wt%, and the concentration of calcium chloride is 6 wt%.

[0118] (3) The operation of this step is the same as step (3) of Example 1, except that the volume ratio of the first component to the second component is controlled to be 1.5:1, and 5 parallel samples are set.

[0119] The adhesion of the drug-loaded hydrogel formed in step (3) of this example to the pig esophagus was tested, and the result was 7.0-7.5N.

[0120] Embodiment 14

[0121] In this embodiment, an oral hydrogel for esophageal mucosal drug delivery is prepared in the following steps:

[0122] (1) Add polyethylene glycol with a molecular weight of 1000Da, pyrogallic acid, sodium alginate and triamcinolone acetonide into ultrapure water, stir at a speed of 500rpm for 4h, and fully dissolve or disperse each component in the ultrapure water to obtain a first component. In the first component, the concentration of polyethylene glycol is 12wt%, the concentration of pyrogallic acid is 20wt%, the concentration of sodium alginate is 2wt%, and the concentration of triamcinolone acetonide is 2.1wt%.

[0123] (2) Add the thermosensitive polymer PDLLA-PEG-PDLLA, dextrin and calcium chloride into ultrapure water, stir at 500 rpm for 3 h, and fully dissolve or disperse each component in the ultrapure water to obtain a second component. In the second component, the concentration of PDLLA-PEG-PDLLA is 15 wt%, the concentration of dextrin is 0.8 wt%, and the concentration of calcium chloride is 7 wt%.

[0124] (3) The operation of this step is the same as step (3) of Example 1, except that 5 parallel samples are set up.

[0125] The adhesion of the drug-loaded hydrogel formed in step (3) of this example to the pig esophagus was tested, and the result was 7.0-7.5N.

Claims

1. An oral hydrogel for esophageal mucosal drug delivery, characterized in that: The oral hydrogel comprises a first component and a second component; The first component is formed by fully dispersing polyethylene glycol, polyphenol, sodium alginate and drugs in water. In the first component, the concentration of polyethylene glycol is 6wt% to 20wt%, the concentration of polyphenol is 20wt% to 30wt%, and the concentration of sodium alginate is 1wt% to 2wt%. The polyethylene glycol and polyphenol in the first component are combined by intermolecular forces to form a polyethylene glycol-polyphenol coordination network. The second component is formed by fully dispersing a temperature-sensitive polymer, a thickener, and a water-soluble calcium salt or a water-soluble zinc salt in water. In the second component, the concentration of the temperature-sensitive polymer is 12wt% to 18wt%, the concentration of the thickener is 0.4wt% to 1.1wt%, and the concentration of the water-soluble calcium salt or the water-soluble zinc salt is 2wt% to 7wt%; The second component is covered on the surface of the first component, the water-soluble calcium salt or water-soluble zinc salt in the second component reacts with the sodium alginate in the first component to transform the first component into a gel state, and the first component adheres to the wound surface of the esophageal mucosa after being transformed into a gel state, and the second component is transformed into a gel state under body temperature conditions. After being transformed into a gel state, the second component plays a physical shielding role to prevent esophageal mucus and saliva from contacting the first component transformed into a gel state.

2. The oral hydrogel for esophageal mucosal drug delivery according to claim 1, characterized in that: The molecular weight of polyethylene glycol is 900 to 20,000 Da.

3. The oral hydrogel for esophageal mucosal drug delivery according to claim 1, characterized in that: The polyphenol is at least one of tannic acid, luteolin, epigallocatechin gallate, gallic acid, quercetin and pyrogallic acid.

4. The oral hydrogel for esophageal mucosal drug delivery according to claim 1, characterized in that: The temperature-sensitive polymer is an amphiphilic block copolymer containing polyethylene glycol blocks, and the temperature-sensitive polymer aqueous solution can be transformed into a gel state under body temperature conditions.

5. The oral hydrogel for esophageal mucosal drug delivery according to claim 4, characterized in that: The temperature-sensitive polymer includes at least one of PCGA-PEG-PCGA, PDLLA-PEG-PDLLA, PLGA-PEG-PLGA and PCL-PEG-PCL.

6. The oral hydrogel for esophageal mucosal drug delivery according to any one of claims 1 to 5, characterized in that: The viscosity enhancer includes at least one of hydroxypropyl cellulose, carboxymethyl cellulose, methyl cellulose, sodium carboxymethyl cellulose, pectin and dextrin.

7. The oral hydrogel for esophageal mucosal drug delivery according to any one of claims 1 to 5, characterized in that: The second component is covered on the surface of the first component according to a volume ratio of the first component to the second component of (0.5-2):

1.

8. The oral hydrogel for esophageal mucosal drug delivery according to any one of claims 1 to 5, characterized in that: The drug comprises at least one of prednisolone, hydrocortisone, vonoprazan fumarate, triamcinolone acetonide, methylprednisolone sodium succinate, dexamethasone sodium phosphate, fibroblast activation protein inhibitor and epidermal growth factor.

9. The method for preparing the oral hydrogel for esophageal mucosal drug delivery according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) fully dispersing polyethylene glycol, polyphenol, sodium alginate and the drug in water to form a first component; (2) fully dispersing the temperature-sensitive polymer, the thickener, and the water-soluble calcium salt or the water-soluble zinc salt in water to form a second component, and controlling the temperature of the second component so that the second component is in a sol state; (3) The first component is applied to the esophageal mucosa to cover the wound surface. Within 1 minute after the first component is applied, the second component is applied to cover the surface of the first component. The water-soluble calcium salt or water-soluble zinc salt in the second component reacts with the sodium alginate in the first component to convert the first component into a gel state. The second component is converted into a gel state under body temperature conditions.

10. Use of the oral hydrogel for esophageal mucosal drug delivery according to any one of claims 1 to 8 in the preparation of a drug for preventing esophageal stenosis after ESD or a drug for promoting esophageal mucosal repair after ESD.

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