Oral hydrogels for esophageal mucosal drug delivery, methods of making and use thereof

Abstract

The present application provides an oral hydrogel for esophageal mucosa drug delivery, a preparation method and application thereof, which comprises a first component and a second component, the first component is formed by dispersing polyethylene glycol, polyphenol, sodium alginate and a drug in water, and the second component is formed by dispersing a temperature-sensitive polymer, a tackifier, a water-soluble calcium salt or a water-soluble zinc salt in water; the second component is coated on the surface of the first 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 adhere to the wound surface of the esophageal mucosa after being converted into the gel state, and the second component is converted into a gel state under the condition of body temperature, the second component plays a physical shielding role after being converted into the gel state, avoiding the contact of esophageal mucus and saliva with the first component converted into the gel state. The present application can realize oral administration of the wound protection hydrogel after ESD and reduce the administration frequency, and improve the comfort and compliance of patients.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of biological medicine, and relates to an oral hydrogel for esophageal mucosa drug delivery and a preparation method and application thereof. BACKGROUND

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

[0003] Injectable hydrogels, as an excellent local drug delivery system, have been used for wound coverage and promotion of 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, so that the mucosa at the lesion site is raised, which can prevent damage to the underlying tissue during subsequent incision and dissection operations. After the diseased mucosa is removed by dissection, the residual hydrogel can cover the wound surface, play a protective role for the tissue, prevent infection and perforation, and promote tissue repair, which is conducive to reducing ESD postoperative complications. However, the mucus in the esophagus and the rapid peristalsis of the esophagus can adversely affect the residence time of the hydrogel on the wound surface, and the hydrogel is difficult to provide long-term protection at the wound site, so it is necessary to frequently use the ESD catheter to administer the drug to the esophagus to ensure that the wound is effectively covered by the hydrogel. However, frequent use of the ESD catheter for drug administration can reduce the comfort and compliance of the patient, and also reduce the feasibility of treatment.

[0004] Therefore, it is of great significance to develop an orally administrable hydrogel drug delivery system with rapid adhesion and gelation capacity, to administer the drug-loaded hydrogel through oral administration after ESD, and to make it quickly adhere and gel to stably cover the esophageal wound, so as to prevent postoperative esophageal stenosis and promote tissue repair, improve the comfort and compliance of the patient, reduce the frequency of drug administration, and improve the efficiency of local drug delivery. SUMMARY

[0005] In view of the problem that the existing hydrogel for wound protection after ESD needs to be administered by ESD catheter technology, which reduces the comfort and compliance of patients and the feasibility of treatment, the present application provides an oral hydrogel for esophageal mucosa drug delivery and a preparation method and application thereof, so as to realize rapid adhesion and gelation of the hydrogel components at the esophageal wound site and improve the bonding force of the hydrogel and the esophageal wound, thereby realizing oral administration of the hydrogel for wound protection after ESD, increasing the retention time of the hydrogel at the esophageal wound site, reducing the administration frequency, and improving the comfort and compliance of patients.

[0006] To achieve the above-mentioned application purposes, the technical solutions adopted by the present application are as follows:

[0007] An oral hydrogel for esophageal mucosa drug delivery, which comprises 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, and in the first component, the concentration of polyethylene glycol is 6wt%-20wt%, the concentration of polyphenol is 20wt%-30wt%, and the concentration of sodium alginate is 1wt%-2wt%; the polyethylene glycol and the polyphenol in the first component are combined to form a polyethylene glycol-polyphenol coordination network through intermolecular forces.

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

[0010] The second component is covered on the surface of the first component, the water-soluble calcium salt or the 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, and the first component adheres to the wound of the esophageal mucosa after being converted into a gel state; the second component is converted into a gel state under the condition of body temperature, and the second component plays a physical shielding role after being converted into a gel state to avoid the contact of esophageal mucus and saliva with the first component converted into a gel state.

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

[0012] In the oral hydrogel for esophageal mucosa drug delivery, the molecular weight of the polyethylene glycol is preferably 900-20000 Da.

[0013] In the oral hydrogel for esophageal mucosa drug delivery, the polyphenol is at least one of tannic acid, luteolin, epigallocatechin gallate, gallic acid, quercetin and pyrogallol.

[0014] In the oral hydrogel for esophageal mucosa drug delivery, the temperature-sensitive polymer in the second component is mainly used to make the second component undergo sol-gel transition at body temperature, i.e. to make the second component change to gel state at body temperature. When the concentration of the temperature-sensitive polymer aqueous solution is 12wt%-18wt%, the temperature-sensitive polymer solution can change from sol state to gel state at body temperature, and the biocompatible polymer meeting this condition can be used as the temperature-sensitive polymer in the second component, for example, the temperature-sensitive polymer in the second component is an amphiphilic block copolymer containing polyethylene glycol block. Further, the feasible temperature-sensitive polymer in the second component includes at least one of PCGA-PEG-PCGA [poly(ε-caprolactone-hydroxyacetate copolymer)-poly(ethylene glycol)-poly(ε-caprolactone-hydroxyacetate copolymer)], PDLLA-PEG-PDLLA (poly(lactic acid)-poly(ethylene glycol)-poly(lactic acid)), PLGA-PEG-PLGA [poly(lactic acid-hydroxyacetate copolymer)-poly(ethylene glycol)-poly(lactic acid-hydroxyacetate copolymer)] and PCL-PEG-PCL [poly(caprolactone)-poly(ethylene glycol)-poly(caprolactone)].

[0015] In the oral hydrogel for esophageal mucosa 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 oral hydrogel for esophageal mucosa drug delivery, the second component is preferably coated on the surface of the first component according to the volume ratio of the first component to the second component being (0.5-2):1.

[0017] The drug in the oral hydrogel for esophageal mucosa drug delivery is a conventional drug for preventing esophageal stenosis after ESD and promoting esophageal mucosa repair after ESD in the prior art. For example, the drug can be at least one of anti-inflammatory drugs, anti-oxidation drugs, anti-tissue fibrosis drugs, and drugs for promoting mucosa repair, but the feasible drug is not limited to the above-mentioned drugs. The concentration of the drug in the first component is determined according to the actual application requirement, for example, the concentration of the drug in the first component is usually not more than 5 wt%.

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

[0019] The application further provides a preparation method of the oral hydrogel for esophageal mucosa drug delivery, which comprises the following steps:

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

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

[0022] (3) applying the first component to the esophageal mucosa to cover the wound, and applying the second component to 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 converts into a gel state under the condition of body temperature.

[0023] Preferably, the second component is applied within 1 minute after the first component.

[0024] The hydrogel formed on the esophagus of the pig has good binding force with the esophagus of the pig, and the adhesion force between the hydrogel and the esophagus of the pig can reach 6.5-7.5 N. The hydrogel can be stably combined on the esophagus of the pig through a large amount of deionized water flushing and long time continuous stirring in a PBS buffer at 37 DEG C. The second component transformed into a gel state has low adhesion force with the esophagus of the pig, which can avoid the problem that the first component transformed into a gel state is directly exposed and may cause esophageal adhesion, and can also avoid the first component transformed into a gel state contacting with esophageal mucus and saliva, thereby increasing the binding stability with the esophagus. The hydrogel of the present application has good cell compatibility when not loaded with drugs. In addition, the hydrogel of the present application can smoothly release the loaded drugs. Based on the above performance, the application also provides the use of the above oral hydrogel for esophageal mucosa drug delivery in the preparation of drugs for preventing esophageal stenosis after ESD or drugs for promoting esophageal mucosa repair after ESD.

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

[0026] The present application aims to provide a drug-loaded hydrogel for preventing esophageal stenosis and promoting esophageal wound repair after ESD by oral administration. In order to achieve oral administration, the most basic problem to be solved is that the retention time of hydrogel or hydrogel precursor liquid on the esophageal mucosa is limited due to fast esophageal movement and weak esophageal tissue adhesion. In order to solve this problem, the present application fully disperses polyethylene glycol, polyphenol, sodium alginate and drugs in water to form a first component with high viscosity. After oral administration of the first component, the first component is retained at the esophageal mucosa to cover the wound surface due to its high viscosity, and the alginate in the first component enhances the adhesion of the first component to the esophageal mucosa due to its rich hydroxyl and phenolic hydroxyl groups. On this basis, the present application fully disperses a temperature-sensitive polymer, a viscosity enhancer, a water-soluble calcium salt or a water-soluble zinc salt in water to form a second component with slow flow. After oral administration of the second component, the second component is retained on the surface of the first component and covers the first component due to its high viscosity. When the first component contacts the second component, the calcium ions or zinc ions in the second component rapidly react with the sodium alginate in the first component to form calcium alginate or zinc alginate, thereby converting the first component into a gel state, thereby achieving stable adhesion of the first component in the gel state to the esophageal mucosa. At the same time, the temperature-sensitive polymer in the second component changes from sol to gel at body temperature, thereby achieving fixation of the second component on the surface of the first component. Furthermore, the polyethylene glycol-polyphenol coordination network and the calcium alginate or zinc alginate polymer network in the first component after changing into a gel state can effectively load drugs therein, thereby gradually releasing the drugs from the first component in the gel state to the esophageal mucosa, achieving anti-inflammatory, antioxidant, anti-tissue fibrosis or promoting wound tissue repair functions of the esophageal mucosa. In addition, the second component in the gel state covering the surface of the first component can act as a physical barrier, on the one hand, to avoid contact of the first component in the gel state with saliva and esophageal mucus, and on the other hand, to reduce leakage of drugs loaded in the first component in the gel state, so that the drugs are released from the first component in the gel state to the wound surface of the esophagus as much as possible. Through the combination of the above technical means, the present application provides a drug-loaded hydrogel for preventing esophageal stenosis and promoting esophageal wound repair after ESD by oral administration, which can solve the problem of frequent drug administration after ESD by using an ESD catheter, thereby increasing patient comfort, compliance and drug treatment accuracy.

[0027] Compared with the prior art, the technical scheme provided by the present application has the following beneficial technical effects:

[0028] 1. The present application provides an oral hydrogel for esophageal mucosa 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 drug in water, the second component is formed by fully dispersing a temperature-sensitive polymer, a tackifier, a water-soluble calcium salt or a water-soluble zinc salt in water; in use, the first component is orally taken first, and then the second component is orally taken, the first component is a viscous fluid with high viscosity, which adheres to the surface of the esophagus to cover the wound after oral administration, and the second component covers the surface of the first component after oral administration, the water-soluble calcium salt or water-soluble zinc salt in the second component rapidly reacts with the sodium alginate in the first component to form a calcium alginate or zinc alginate in a gel state, thereby rapidly converting the first component into a gel state to be fixed on the esophageal mucosa, and then the second component is converted into a gel state under the condition of body temperature to cover the surface of the first component converted into a gel state, thereby playing a shielding role to avoid the contact of saliva and esophageal mucus with the first component converted into a gel state, and preventing esophageal mucosa adhesion and reducing drug leakage. The oral hydrogel of the present application can form a gel on the esophageal mucosa wound site by taking the first component and the second component in sequence, the use method is simple, and the problem that the existing hydrogel for wound protection after ESD needs to be administered by ESD catheter, which reduces patient comfort and compliance and the feasibility of treatment, can be solved.

[0029] 2. The present application takes the formation of a drug-loaded hydrogel on the esophagus of a pig as an example, and experiments prove that when the first component and the second component are sequentially applied to form the hydrogel of the present application on the esophagus of a pig, the formed hydrogel has good bonding force with the esophagus of the pig, the adhesion force between the hydrogel and the esophagus of the pig can reach 6.5-7.5 N, and at the same time, the hydrogel formed on the esophagus of the pig can still be stably bonded on the esophagus of the pig after being washed with a large amount of deionized water, and the esophagus of the pig with the formed hydrogel is placed in a PBS buffer at 37℃ and continuously stirred for 24 h, and the hydrogel is still stably bonded on the esophagus of the pig. The good bonding stability of the hydrogel of the present application on the esophagus means that its residence time on the esophageal mucosa is relatively long, which is beneficial to reduce the frequency of drug administration and solve the problem that the existing hydrogel for wound protection after ESD needs to be frequently administered by ESD catheter.

[0030] 3. The present application takes the formation of drug-loaded hydrogel on the esophagus of a pig as an example. The experiment proves that the adhesion of the second component in the gel state to the esophagus of a pig is only 0.8-1.1 N after the second component is directly combined at the wound site of the esophagus of a pig and is converted into the gel state, which is obviously less than the adhesion of the first component and the drug-loaded hydrogel to the esophagus of a pig. This shows that the use of the second component in the gel state to cover the first component in the gel state can avoid the problem of esophageal adhesion caused by the direct exposure of the first component in the gel state, and can also avoid the contact of the first component in the gel state with the mucus and saliva of the esophagus, thereby further increasing the binding stability of the first component in the gel state to the esophagus.

[0031] 4. The present application proves through in-vitro drug release experiments that the use of the second component in the gel state to cover the first component in the gel state can slow down the release rate of the drug in the early stage of drug release, thereby avoiding unnecessary waste of the drug.

[0032] 5. The present application also provides a preparation method of the above-mentioned oral hydrogel for esophageal mucosa drug delivery. The method is simple to operate and convenient to apply in practice. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 Fig. 1 is a photograph of the gelation of the first component and the second component in Example 1 and Comparative Example 1 when they are contacted in vitro.

[0034] Figure 2 Figs. 2(a) and 2(b) are photographs of the esophagus of a pig on which the drug-loaded hydrogel is formed in Example 1 before and after flushing, Figure 2 Figs. 2(c) and 2(d) are photographs of the esophagus of a pig in Comparative Example 1 after the second component is added and placed in an environment of 37-38℃ for 3 min before and after flushing.

[0035] Figure 3 Fig. 3 is a photograph of the esophagus of a pig on which the drug-loaded hydrogel is formed in Example 1 after stirring in PBS buffer at 37℃ for 24 h.

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

[0037] Figure 5 Fig. 5 is the adhesion test result of the first component, the second component in the gel state, and the drug-loaded hydrogel to the surface of the esophagus of a pig in Example 6.

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

[0039] The oral hydrogel for esophageal mucosa drug delivery and the preparation method and application thereof provided by the present application are further described through the following examples. It is necessary to point out that the following examples are only used for further describing the present application and cannot be understood as limiting the protection scope of the present application. The skilled in the art can make some non-essential improvements and adjustments to the specific implementation of the present application according to the above description, which still belongs to the protection scope of the present application.

[0040] The temperature-sensitive polymers PCGA-PEG-PCGA, PDLLA-PEG-PDLLA, PLGA-PEG-PLGA and PCL-PEG-PCL used in the following examples and comparative examples can be directly purchased, or can be synthesized by self or entrustment. The proportion of each block meets the following conditions: the proportion of each block should be such that when the concentration of the above temperature-sensitive polymers in aqueous solution is 12wt%-18wt%, the temperature-sensitive polymer solution can be transformed from sol state to gel state under the condition of body temperature (for example, 37-38℃).

[0041] Example 1

[0042] In this embodiment, the oral hydrogel for esophageal mucosa drug delivery is prepared, and the steps are as follows:

[0043] (1) Polyethylene glycol with a molecular weight of 1000 Da, tannic acid, sodium alginate and triamcinolone acetonide are added to ultrapure water, and stirred at a speed of 800 rpm for 3 h, so that each component is fully dissolved or dispersed 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) The temperature-sensitive polymer PCGA-PEG-PCGA, hydroxypropyl cellulose and calcium chloride are added to ultrapure water, and stirred at a speed of 800 rpm for 2 h, so that each component is fully dissolved or dispersed in the ultrapure water. In order to facilitate observation in the subsequent experimental process, a small amount of methylene blue aqueous solution is added dropwise and mixed thoroughly to obtain a 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 the pig esophagus, stripping the pig esophagus surface of the mucosa, forming a wound diameter of about 2 cm on the pig esophagus mucosa. Control the temperature of the pig esophagus and the ambient temperature is 37-38 ℃, using a syringe to add the first component from the wound of the pig esophagus above the wound of the pig esophagus, so that the first component adheres to the esophagus surface and covers the wound, within 1 min of the first component injection, using a syringe to add the second component from the wound of the pig esophagus above the wound of the pig esophagus, so that the second component covers the surface of the first component, the first component is converted to a gel state at the moment of contact between the second component and the first component (calcium chloride in the second component reacts with sodium alginate in the first component to form calcium alginate and convert the first component to a gel state), after the second component is added, stand for 3 min, the second component is converted to a gel state, that is, a drug-loaded hydrogel is formed on the wound of the pig esophagus.

[0046] In this step, the volume ratio of the first component to the second component is controlled to be 1:1. In order to facilitate subsequent testing, 10 parallel samples are set in this step.

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

[0048] Comparative Example 1

[0049] The operation of this comparative example is basically 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 of Example 1 and Comparative Example 1 when contacted in vitro was 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 above the first component, and place it in a water bath at a temperature of 37-38 ℃ for 3 min, then place the glass bottle obliquely and observe the gelation state of the first component and the second component in the glass bottle. The results are shown in Figs. (a)-(c) of Figure 1 (a) is a photo of the first component, (b) is a photo taken after the second component is added to the first component, and (c) is a photo taken after the glass bottle is placed in a water bath at a temperature of 37-38 ℃ for 3 min and then placed obliquely.

[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 above the first component, and place it in a water bath at a temperature of 37-38 ℃ for 3 min, then place the glass bottle obliquely and observe the gelation state of the first component and the second component in the glass bottle. The results are shown in Figs. (a)-(c) of Figure 1As shown in Figures (d) to (f), Figure (d) is a photo of the first component, Figure (e) is a photo of the second component just after it is added on top of the first component, and Figure (f) is a photo of the glass bottle after it is 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), in Example 1, when the first component comes into contact with the second component, the sodium alginate therein reacts with calcium ions to form calcium alginate gel, for example, Figure 1 In Figure (c), the material in the glass bottle did not flow when the glass bottle was tilted, indicating that the material in the glass bottle had turned into a gel state with poor fluidity. Figure 1 In Figure (c), we can also see the phenomenon that the dye in the second component enters the first component, which shows 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 transformed into a gel state. Figure 1 As can be seen in Figure (f), the first component and the second component maintain their respective colors and have a clear boundary, indicating that in Comparative Example 1, the first component and the second component do 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) Take the pig esophagus formed with the drug-loaded hydrogel in Example 1, place it in an environment of 37-38°C, and continuously rinse it with 3000 mL of deionized water. 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.

[0058] (2) Take the pig esophagus to which the second component in Comparative Example 1 has been added 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 2As can be seen, the drug-loaded hydrogel formed at the wound surface of the porcine esophagus in Example 1 adhered stably to the porcine esophagus and remained stable on the porcine esophagus even after continuous rinsing with 3000 mL of deionized water. In contrast, in Comparative Example 1, after adding the second component and placing the hydrogel at 37-38°C for 3 minutes, the polymer layer on the porcine esophagus surface was flushed away with only 50 mL of deionized water. This indicates that the introduction of calcium or zinc ions in the second component of the present invention to react with the sodium alginate in the first component can effectively increase the adhesion stability of the drug-loaded gel on the surface of the porcine 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 investigate the stability of the drug-loaded hydrogel on the porcine esophagus.

[0062] The pig esophagus formed with the drug-loaded hydrogel in Example 1 was placed in a beaker containing PBS buffer, and a magnetic stirrer was added. 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 at 37°C. After stirring for 24 h, the PBS buffer solution was obtained as shown in the following figure. Figure 3 As shown in Figure (a), the pig esophagus with 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) Polyethylene glycol (1000 Da), tannic acid, and sodium alginate were added to ultrapure water and stirred at 800 rpm for 3 h to fully dissolve or disperse the components in the ultrapure water, thereby obtaining a first component. The first component had a polyethylene glycol concentration of 6.9 wt%, a tannic acid concentration of 20.7 wt%, and a sodium alginate concentration of 2 wt%.

[0066] (2) The thermosensitive polymer PCGA-PEG-PCGA, hydroxypropyl cellulose, and calcium chloride were added to ultrapure water and stirred at 800 rpm for 2 h to fully dissolve or disperse the components in the ultrapure water. To facilitate observation during subsequent experiments, a small amount of methylene blue aqueous solution was added dropwise and thoroughly mixed to obtain a second component. The concentration of PCGA-PEG-PCGA in the second component was 16 wt %, the concentration of hydroxypropyl cellulose was 0.8 wt %, and the concentration of calcium chloride was 4 wt %.

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

[0068] (4) L929 cells in the logarithmic phase were collected, the cell suspension concentration was adjusted, and 100 μL was added to each well of a 96-well plate. The cells were plated to a density of 10,000 cells / well. Culture medium was added and the plate was incubated at 5% CO2 and 37°C until the cell monolayer covered the bottom of the well. A concentration gradient of blank hydrogel precursor solution and culture medium was added to make the concentrations of the blank hydrogel precursor solution 0, 0.24, 0.48, 0.96, 1.92, 3.84, 7.68, 15.36, and 30.72 mg / mL, respectively. Five replicate wells were set for each concentration, and 100 μL was added to each well. The wells containing cells with a blank hydrogel precursor concentration of 0 mg / mL were used as control wells (Control), the wells containing cells with blank hydrogel concentrations of 0.24 to 30.72 mg / mL were used as experimental wells, and the wells containing cells and culture medium only were used as blank wells. The plate was then incubated at 5% CO2 and 37°C for 48 h. Remove the culture medium and add 100 μL of 5 mg / mL MTT solution to each well. Continue incubation for 4 hours. Terminate the culture, carefully aspirate the culture medium in the wells, add 100 μL of dimethyl sulfoxide to each well, shake at low speed on a shaker for 10 minutes 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 viability according to the following formula: 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 was investigated.

[0074] (1) Take the 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 both controlled at 37-38°C, and the first component in Example 1 is added from above the wound of the pig esophagus to the wound of the pig esophagus by using a syringe, so that the first component adheres to the surface of the esophagus and covers the wound. After the addition is completed, it is left for 3 min.

[0075] (2) Take the 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 both controlled at 37-38°C, and the second component in Example 1 is added from above the wound of the pig esophagus to the wound of the pig esophagus by using a syringe, so that the second component adheres to the surface of the esophagus and covers the wound. After the addition is completed, it is left for 3 min, and the second component is converted into a gel state.

[0076] (3) Take the 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 both controlled at 37-38°C, and the first component in Example 1 is added from above the wound of the pig esophagus to the wound of the pig esophagus by using a syringe, so that the first component adheres to the surface of the esophagus and covers the wound. Within 1 min after the injection of the first component is completed, the second component in Example 1 is added from above the wound of the pig esophagus to the wound of the pig esophagus by using a syringe, so that the second component covers the surface of the first component. After the addition of the second component is completed, it is left for 3 min, and a drug-loaded hydrogel is formed on the surface of the pig esophagus.

[0077] Under the condition of 37-38°C, the pig esophagus prepared in steps (1), (2), and (3) is tested by using a universal material machine, and the adhesion of the first component, the second component converted into a gel state, and the drug-loaded hydrogel to the surface of the pig esophagus is tested, and the results are shown in Table 1. Figure 5 Figure 5 As can be seen from Table 1, the adhesion of the second component converted into a gel state to the pig esophagus is only 0.8-1.1 N, which is obviously smaller than the adhesion of the first component and the drug-loaded hydrogel to the pig esophagus. This indicates that, on the one hand, the second component converted into a gel state covering the first component converted into a gel state can avoid the problem that the first component converted into a gel state is directly exposed and may cause esophageal adhesion, and on the other hand, it also indicates that the first component converted into a gel state directly combined with the wound of the esophagus has excellent combination stability.

[0078] Example 7

[0079] In this example, the influence of the second component arranged on the surface of the first component on the drug release is investigated.

[0080] ​(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 above the first component, and place it in a water bath at a temperature of 37-38℃ for 3 min to obtain sample AB, which contains 300 mg of the drug.

[0081] (2) Take the first component prepared in Example 1 and put it into a glass bottle, and place it in a water bath at a temperature of 37-38℃ for 3 min to obtain sample A, which contains 300 mg of the drug.

[0082] (3) The drug dissolution release is carried out using the small cup method, the dissolution medium is physiological saline with a volume of 150 mL, and the samples A and AB are placed in dialysis bags with a molecular weight cut-off of 1000 Da for drug release. The release medium is sampled at 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, respectively, to test the drug concentration, and an equal amount of physiological saline is added. The drug release curve is shown in Figure 6 Figure 6 Curve A in the above figure represents sample A, and curve AB represents sample AB.

[0083] As can be seen from Figure 6 , the drug release rate in sample A is faster than that in sample AB within the first 25 min of drug release. With the increase of release time, the second component which has been converted into a gel state swells, which makes the drug release rate in sample AB faster. This shows that the second component arranged on the surface of the first component and converted into a gel state 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 mucosa drug delivery is prepared, and the steps are as follows:

[0086] (1) Add polyethylene glycol with a molecular weight of 1000 Da, tannic acid, sodium alginate and epidermal growth factor (EGF) into ultrapure water, stir at a speed of 200 rpm for 3 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 7.0 wt%, the concentration of tannic acid is 21.1 wt%, the concentration of sodium alginate is 2 wt%, and the concentration of EGF is 0.00007 wt%.

[0087] ​(2) The temperature-sensitive polymer PCGA-PEG-PCGA, hydroxypropyl cellulose and calcium chloride were added into ultrapure water, and stirred at a speed of 200 rpm for 2 h to fully dissolve or disperse the components in the ultrapure water to obtain the second component. In the second component, the concentration of PCGA-PEG-PCGA was 16 wt%, the concentration of hydroxypropyl cellulose was 0.8 wt%, and the concentration of calcium chloride was 4 wt%.

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

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

[0090] Example 9

[0091] In this example, an oral hydrogel for esophageal mucosa drug delivery was prepared, and the steps were as follows:

[0092] (1) Polyethylene glycol with a molecular weight of 1000 Da, tannic acid, sodium alginate and triamcinolone acetonide were added into ultrapure water, and stirred at a speed of 500 rpm for 3 h to fully dissolve or disperse the components in the ultrapure water to obtain the first component. In the first component, the concentration of polyethylene glycol was 6.9 wt%, the concentration of tannic acid was 20.7 wt%, the concentration of sodium alginate was 2 wt%, and the concentration of triamcinolone acetonide was 2.1 wt%.

[0093] (2) The temperature-sensitive polymer PDLLA-PEG-PDLLA, hydroxypropyl cellulose and calcium chloride were added into ultrapure water, and stirred at a speed of 500 rpm for 2 h to fully dissolve or disperse the components in the ultrapure water to obtain the second component. In the second component, the concentration of PDLLA-PEG-PDLLA was 12.5 wt%, the concentration of hydroxypropyl cellulose was 0.7 wt%, and the concentration of calcium chloride was 4 wt%.

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

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

[0096] Example 10

[0097] In this example, an oral hydrogel for esophageal mucosa drug delivery was prepared, and the steps were as follows:

[0098] (1) polyethylene glycol with a molecular weight of 20000 Da, epigallocatechin gallate (EGCG), sodium alginate and dexamethasone sodium phosphate were added into ultrapure water, stirred at a speed of 800 rpm for 4 h, and each component was fully dissolved or dispersed in the ultrapure water to obtain a first component. In the first component, the concentration of polyethylene glycol was 6 wt%, the concentration of EGCG was 30 wt%, the concentration of sodium alginate was 2 wt%, and the concentration of dexamethasone sodium phosphate was 3 wt%.

[0099] (2) The temperature-sensitive polymer PLGA-PEG-PLGA, carboxymethyl cellulose and zinc chloride were added into ultrapure water, stirred at a speed of 800 rpm for 3 h, and each component was fully dissolved or dispersed in the ultrapure water to obtain a second component. In the second component, the concentration of PLGA-PEG-PLGA was 18 wt%, the concentration of carboxymethyl cellulose was 0.4 wt%, and the concentration of zinc chloride was 5 wt%.

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

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

[0102] Example 11

[0103] In this example, an oral hydrogel for esophageal mucosal drug delivery was prepared, and the steps were as follows:

[0104] (1) polyethylene glycol with a molecular weight of 900 Da, gallic acid, sodium alginate and hydrocortisone were added into ultrapure water, stirred at a speed of 600 rpm for 4 h, and each component was fully dissolved or dispersed in the ultrapure water to obtain a first component. In the first component, the concentration of polyethylene glycol was 20 wt%, the concentration of gallic acid was 20 wt%, the concentration of sodium alginate was 1 wt%, and the concentration of hydrocortisone was 1 wt%.

[0105] (2) The temperature-sensitive polymer PCL-PEG-PCL, methyl cellulose and calcium chloride were added into ultrapure water, stirred at a speed of 600 rpm for 3 h, and each component was fully dissolved or dispersed in the ultrapure water to obtain a second component. In the second component, the concentration of PCL-PEG-PCL was 12 wt%, the concentration of methyl cellulose was 1.1 wt%, and the concentration of calcium chloride was 2 wt%.

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

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

[0108] Example 12

[0109] In this example, an oral hydrogel for esophageal mucosa drug delivery was prepared, and the steps were as follows:

[0110] (1) Polyethylene glycol with a molecular weight of 5000 Da, quercetin, sodium alginate, and fibroblast activation protein inhibitor (FAP inhibitor) were added to ultrapure water, stirred at a speed of 500 rpm for 4 h, and each component was fully dissolved or dispersed in the ultrapure water to obtain a first component. In the first component, the concentration of polyethylene glycol was 15 wt%, the concentration of quercetin was 22 wt%, the concentration of sodium alginate was 1.5 wt%, and the concentration of FAP inhibitor was 0.1 wt%.

[0111] (2) The temperature-sensitive polymer PCGA-PEG-PCGA, sodium carboxymethyl cellulose, and calcium chloride were added to ultrapure water, stirred at a speed of 500 rpm for 3 h, and each component was fully dissolved or dispersed in the ultrapure water to obtain a second component. In the second component, the concentration of PCGA-PEG-PCGA was 14 wt%, the concentration of sodium carboxymethyl cellulose was 0.8 wt%, and the concentration of calcium chloride was 4 wt%.

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

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

[0114] Example 13

[0115] In this example, an oral hydrogel for esophageal mucosa drug delivery was prepared, and the steps were as follows:

[0116] (1) Polyethylene glycol with a molecular weight of 8000 Da, luteolin, sodium alginate, and methylprednisolone sodium succinate were added to ultrapure water, stirred at a speed of 500 rpm for 4 h, and each component was fully dissolved or dispersed in the ultrapure water to obtain a first component. In the first component, the concentration of polyethylene glycol was 13 wt%, the concentration of luteolin was 25 wt%, the concentration of sodium alginate was 2 wt%, and the concentration of methylprednisolone sodium succinate was 1.2 wt%.

[0117] (2) The temperature-sensitive polymer PCGA-PEG-PCGA, pectin and calcium chloride were added into ultrapure water, and stirred at a speed of 500 rpm for 3 h, so that each component was fully dissolved or dispersed in the ultrapure water to obtain a second component. In the second component, the concentration of PCGA-PEG-PCGA was 14 wt%, the concentration of pectin was 0.5 wt%, and the concentration of calcium chloride was 6 wt%.

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

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

[0120] Example 14

[0121] In this example, an oral hydrogel for esophageal mucosa drug delivery was prepared, and the steps were as follows:

[0122] (1) Polyethylene glycol with a molecular weight of 1000 Da, pyrogallic acid, sodium alginate and triamcinolone acetonide were added into ultrapure water, and stirred at a speed of 500 rpm for 4 h, so that each component was fully dissolved or dispersed in the ultrapure water to obtain a first component. In the first component, the concentration of polyethylene glycol was 12 wt%, the concentration of pyrogallic acid was 20 wt%, the concentration of sodium alginate was 2 wt%, and the concentration of triamcinolone acetonide was 2.1 wt%.

[0123] (2) The temperature-sensitive polymer PDLLA-PEG-PDLLA, dextrin and calcium chloride were added into ultrapure water, and stirred at a speed of 500 rpm for 3 h, so that each component was fully dissolved or dispersed in the ultrapure water to obtain a second component. In the second component, the concentration of PDLLA-PEG-PDLLA was 15 wt%, the concentration of dextrin was 0.8 wt%, and the concentration of calcium chloride was 7 wt%.

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

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

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 a drug in water, in the first component, the concentration of polyethylene glycol is 6wt%-20wt%, the concentration of polyphenol is 20wt%-30wt%, and the concentration of sodium alginate is 1wt%-2wt%; the polyethylene glycol and the polyphenol in the first component are combined to form a polyethylene glycol-polyphenol coordination network through intermolecular forces; The second component is formed by fully dispersing a temperature-sensitive polymer, a tackifier, 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%-18wt%, the concentration of the tackifier is 0.4wt%-1.1wt%, and the concentration of the water-soluble calcium salt or the water-soluble zinc salt is 2wt%-7wt%; The second component is applied to the surface of the first component, the water-soluble calcium salt or the 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 first component adheres to the wound surface of the esophageal mucosa after being converted into the gel state, and the second component is converted into a gel state under the condition of body temperature, thereby playing a physical shielding role to avoid the contact of esophageal mucus and saliva with the first component converted into the gel state.

2. The oral hydrogel for esophageal mucosal drug delivery according to claim 1, wherein, The molecular weight of the polyethylene glycol is 900-20,000 Da.

3. The oral hydrogel for esophageal mucosal drug delivery according to claim 1, wherein, 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, wherein, The temperature-sensitive polymer is an amphiphilic block copolymer containing a polyethylene glycol block, and the aqueous solution of the temperature-sensitive polymer can be converted into a gel state under the condition of body temperature.

5. The oral hydrogel for esophageal mucosal drug delivery according to claim 4, wherein, 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, wherein, The tackifier 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, wherein, The second component is applied to the surface of the first component at 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, wherein, The drug includes at least one of hydrocortisone, hydrocortisone, fumaderm, triamcinolone acetonide, methylprednisolone sodium succinate, dexamethasone sodium phosphate, fibroblast activation protein inhibitor and epidermal growth factor.

9. A process for the preparation of an oral hydrogel for esophageal mucosal drug delivery as claimed in any of claims 1 to 8, characterized in that, The method comprises the following steps: (1) fully dispersing polyethylene glycol, polyphenol, sodium alginate and a drug in water to form a first component; (2) fully dispersing a temperature-sensitive polymer, a tackifier and a water-soluble calcium salt or a water-soluble zinc salt in water to form a second component, and controlling the temperature of the second component to make the second component in a sol state; (3) applying the first component to the esophageal mucosa to cover the wound surface, and applying the second component to the surface of the first component within 1 min after applying the first component, the water-soluble calcium salt or the 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, and the second component is converted into a gel state under the condition of body temperature.

10. Use of the oral hydrogel for esophageal mucosal drug delivery according to any one of claims 1 to 8 for the preparation of a medicament for the prevention of esophageal stricture after ESD or a medicament for the promotion of esophageal mucosal repair after ESD.

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