Hydrogel for gastric perforation repair, preparation method and application

Abstract

The invention discloses a hydrogel for gastric perforation repair, which belongs to the field of bioadhesives. The technical scheme is as follows: a hydrogel for gastric perforation repair is generated by chemical reaction of compound A and compound B; compound A is a polyethylene glycol derivative A with a terminal active group α; the terminal active group α is succinimidyl succinate; compound B is a polyethylene glycol derivative B with a terminal active group β; the terminal active group β is an amino group; when compound A reacts with compound B, the terminal active group α and the terminal active group β chemically react to form an amide bond. The beneficial effects of the invention are as follows: the hydrogel for gastric perforation repair provided by the invention has a fast gelation speed, can be gelled in situ, is easy to use, has strong adhesion to gastric tissue, has a low swelling rate in simulated gastric fluid and PBS solution, has a strong ability to resist simulated gastric fluid corrosion, has good compression resistance and anti-peristalsis performance, has good biocompatibility, and can be safely degraded.

Description

Technical Field

[0001] The invention relates to the technical field of bioadhesives, and in particular to a hydrogel for repairing gastric perforation. Background Art

[0002] Bioadhesives refer to medical materials that can polymerize in vivo, quickly bond tissues or tissues to non-tissues, and play a certain role in hemostasis and sealing. Hydrogels are promising natural extracellular matrix substitutes and have exciting prospects in medical biomaterials. Injectable hydrogels, in particular, can minimize biological invasion and pain during treatment when treating wounds where hydrogels cannot be placed directly (such as irregular wounds in the body).

[0003] At present, researchers have developed a variety of injectable hydrogels, but most of them lack adaptability to complex biological environments, especially the acidic stomach environment. The stomach is a large hollow organ in the human body, which is constantly moving and has internal pressure (the material needs to resist the pressure and strain of gastric peristalsis). The stomach constantly secretes gastric juice, which is a strong acid solution mixed with digestive enzymes. The requirements for the material are higher, and the organs around the stomach are closely related, so the material should not have obvious adhesion to the surrounding tissues after use.

[0004] A Chinese invention patent with application number CN202210505581.9 discloses an injectable self-healing hydrogel dressing for treating gastric perforation - PTOPT hydrogel. The PTOPT hydrogel has excellent self-healing properties that adapt to the gastric environment, can form a gel in situ in a wet and dynamic human environment, and has good biocompatibility. It can be used to treat gastric perforation. However, the hydrogel dressing needs to be prepared in vitro through a complex preparation process. The raw materials need to be dissolved in dichloromethane, and then trifluoroacetic acid is added to the solution to react at room temperature. After the reaction is completed, the PTOPT polymer is precipitated, purified, and dried to obtain the PTOPT polymer, and then the PTOPT polymer is dissolved in acidic ice water to obtain an injectable hydrogel dressing. The prepared hydrogel dressing needs to be stored at a temperature at least below 22°C, which increases the difficulty of using the hydrogel dressing. Summary of the invention

[0005] In order to solve the above-mentioned problems in the prior art, the present invention provides a hydrogel for gastric perforation repair, which has fast gelation speed, can gel in situ, is easy to use, has strong adhesion, low swelling rate, strong resistance to strong acid corrosion, good compression and anti-peristalsis properties, good biocompatibility, and can be safely degraded.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides a hydrogel for gastric perforation repair, wherein the hydrogel for gastric perforation repair is generated by chemical reaction between compound A and compound B;

[0007] The compound A is a polyethylene glycol derivative A having a terminal active group α; the terminal active group α is succinimidyl succinate;

[0008] The compound B is a polyethylene glycol derivative B having a terminal active group β; the terminal active group β is an amino group;

[0009] When the compound A reacts with the compound B, the terminal active group α and the terminal active group β undergo a chemical reaction to form an amide bond.

[0010] Further, the compound A is any one of formula I, formula II, formula III, and formula IV;

[0011]

[0012] In Formula I, Formula II, Formula III, and Formula IV, SSA is the terminal active group α; the structural formula of SSA is:

[0013]

[0014] The molecular weight of the compound A is 1000-20000.

[0015] Further, the compound B is any one of formula V, formula VI, formula VII, and formula VIII;

[0016]

[0017] The molecular weight of compound B is 1000-20000.

[0018] Furthermore, the hydrogel for gastric perforation repair comprises the following features (1) and (2):

[0019] (1) When tested in simulated gastric fluid with a pH range of 0.9-4, the hydrogel for gastric perforation repair has a swelling rate of <40% and an adhesive strength of ≥30 MPa;

[0020] (2) When tested in a PBS solution with a pH value ranging from 7.2 to 7.4, the swelling rate of the hydrogel for gastric perforation repair is less than 30% and the bonding strength is ≥30 MPa.

[0021] A method for preparing the hydrogel for gastric perforation repair comprises the following steps:

[0022] Step S1: preparing a mixed solution A containing the compound A as a solute and a mixed solution B containing the compound B as a solute respectively;

[0023] Step S2: Mixing the mixed solution A and the mixed solution B to obtain the hydrogel for gastric perforation repair, wherein the molar ratio of the terminal active group α in the mixed solution A to the terminal active group β in the mixed solution B is 1:10 to 10:1.

[0024] Furthermore, the mixed solution A is prepared by dissolving compound A in solvent A, the solid content of compound A is 3% to 30%, and the solvent A is laboratory pure water or sterile saline;

[0025] The mixed solution B is prepared by dissolving the compound B in a solvent B, the solid content of the compound B is 3% to 30%, and the solvent B is laboratory pure water or sterile physiological saline.

[0026] Furthermore, a double-barrel syringe is used to mix the mixed solution A and the mixed solution B in a manner of synchronously pushing out liquids, the mixed solution A is loaded into one of the syringes of the double-barrel syringe, and the mixed solution B is loaded into the other syringe of the double-barrel syringe.

[0027] A composition for gastric perforation repair, comprising compound A and compound B;

[0028] The compound A is a polyethylene glycol derivative A having a terminal active group α; the terminal active group α is succinimidyl succinate;

[0029] The compound B is a polyethylene glycol derivative B having a terminal active group β; the terminal active group β is an amino group.

[0030] Further, the compound A is any one of formula I, formula II, formula III, and formula IV;

[0031]

[0032] In Formula I, Formula II, Formula III, and Formula IV, SSA is the terminal active group α; the structural formula of SSA is:

[0033]

[0034] The molecular weight of the compound A is 1000-20000.

[0035] Further, the compound B is any one of formula V, formula VI, formula VII, and formula VIII;

[0036]

[0037] The molecular weight of the compound B is 1000-20000.

[0038] A use of the hydrogel for gastric perforation repair, or the hydrogel for gastric perforation repair prepared by the preparation method, or the composition for gastric perforation repair in the preparation of a gastric perforation repair agent.

[0039] The beneficial effects of the present invention are:

[0040] 1. The hydrogel for gastric perforation repair provided by the present invention has a fast gelling speed, can be quickly formed in situ at the site of gastric perforation and quickly adhere to the gastric tissue at the perforation site, and is easy to use;

[0041] 2. The hydrogel for gastric perforation repair provided by the present invention has a low swelling rate in the body, good biocompatibility, and can be safely degraded within a certain period of time;

[0042] 3. The hydrogel for gastric perforation repair provided by the present invention has good compression resistance and anti-peristaltic properties, can resist the intragastric pressure and the strain of gastric peristalsis, and is suitable for gastric perforation repair;

[0043] 4. The hydrogel for gastric perforation repair provided by the present invention does not significantly adhere to surrounding tissues during gastric perforation repair;

[0044] 5. The hydrogel for gastric perforation repair provided by the present invention has extremely strong adhesion compared with fibrin glue. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the reaction of eight-arm-polyethylene glycol succinimidyl succinate with eight-arm-polyethylene glycol amino in Examples 1 and 2 of the present invention to generate a hydrogel for gastric perforation repair;

[0046] Figure 2 This is a stress-strain diagram of the compressive properties of the hydrogel used for gastric perforation repair in Example 1 of the present invention;

[0047] Figure 3 is a strain-time diagram of the compressive properties of the hydrogel used for gastric perforation repair in Example 1 of the present invention;

[0048] Figure 4 This is a state diagram of the hydrogel for gastric perforation repair in Example 1 of the present invention after being immersed in gastric juice for 1 month;

[0049] Figure 5 This is a schematic diagram of the bonding process between the hydrogel used for gastric perforation repair and the surface of pig stomach tissue in Example 2 of the present invention;

[0050] Figure 6 This is a schematic diagram of the connection bond between the hydrogel used for gastric perforation repair and the surface of pig stomach tissue in Example 2 of the present invention;

[0051] Figure 7This is a SEM image of the adhesion between the hydrogel used for gastric perforation repair in Example 2 of the present invention and the surface of pig stomach tissue;

[0052] Figure 8 This is a schematic diagram of the adhesive properties of the hydrogel used for gastric perforation repair in Example 2 of the present invention;

[0053] Fig. 9 This is a diagram of the immersion test of pig stomach in Example 2 of the present invention;

[0054] Fig.10 This is a test diagram of a pig stomach subjected to a bursting water pressure test in Example 2 of the present invention;

[0055] Fig.11 Biocompatibility test of the hydrogel used for gastric perforation repair in Example 1 of the present invention with gastric and intestinal cell lines Figure I ;

[0056] Fig.12 Biocompatibility test of the hydrogel used for gastric perforation repair in Example 1 of the present invention with gastric and intestinal cell lines Figure II ;

[0057] Fig.13 The swelling curves of the hydrogel used for gastric perforation repair in Example 1 of the present invention in PBS solution, porcine gastric juice, and human gastric juice;

[0058] Fig.14 This is the degradation curve of the hydrogel used for gastric perforation repair in Example 1 of the present invention in PBS solution, porcine gastric juice, and human gastric juice;

[0059] Fig.15 This is a fluorescence imaging image of the hydrogel used for gastric perforation repair in Example 1 of the present invention in the abdominal cavity of a rat;

[0060] Fig.16 This is a diagram showing the use results of the pig stomach perforation site in Example 2 of the present invention. DETAILED DESCRIPTION

[0061] In order to clearly illustrate the technical features of this solution, this solution is described below through a specific implementation method.

[0062] Example 1

[0063] Weigh 0.075 g of eight-arm-polyethylene glycol succinimidyl succinate (Formula IV, where SSA, i.e., the complete expression of the succinimidyl succinate group, is shown in Formula IX) and dissolve it in 0.5 ml of laboratory pure water or sterile saline to prepare a mixed solution A; weigh 0.075 g of eight-arm-polyethylene glycol amino (Formula VIII) and dissolve it in 0.5 ml of laboratory pure water or sterile saline to prepare a mixed solution B;

[0064]

[0065] Take a double-barreled syringe, load mixed solution A into one of the syringe barrels of the double-barreled syringe, and load mixed solution B into the other syringe barrel, then directly mix mixed solution A and mixed solution B, and after 5 seconds, a hydrogel for gastric perforation repair is formed. The reaction process is shown in Figure 1 ; Figure 1 In the invention, PEG-SSA is compound A or a mixed solution A prepared from compound A, PEG-NH2 is compound B or a mixed solution B prepared from compound B, the terminal active group α of eight-arm-polyethylene glycol succinimidyl succinate is an active ester, and the terminal active group β of eight-arm-polyethylene glycol amino is an amino group. The active ester forms an amide bond with the amino group to form a hydrogel for gastric perforation repair.

[0066] The compression properties of the hydrogel for gastric perforation repair were tested using a universal tensile machine, wherein: Figure 2 The stress-strain curve shows that the compressive strength of the hydrogel used for gastric perforation repair can reach nearly 1.2 MPa, and the high compressive strength can resist the intragastric pressure when used; Figure 3 The graph is a strain-time curve, which records the compression state of the hydrogel used for gastric perforation repair within a time range of 0 to 3500 seconds. It can be seen that the hydrogel used for gastric perforation repair exhibits a very stable and reliable anti-cyclic compression performance under a stress state of 10% strain. The anti-cyclic compression performance decreases slightly with the increase of strain. Under a stress state of no more than 30% strain, the anti-cyclic compression performance is relatively stable, which can resist the strain force of gastric peristalsis and meet the requirements of gastric perforation repair.

[0067] The hydrogel for gastric perforation repair can still be preserved intact after being immersed in gastric juice for 1 month. Figure 4 It can be seen that the hydrogel used for gastric perforation repair has extremely strong acid corrosion resistance and meets the requirements for gastric perforation repair.

[0068] Example 2

[0069] Weigh 0.075 g of eight-arm-polyethylene glycol succinimidyl succinate and dissolve it in 0.5 ml of sterile pure water for experiments to prepare mixed solution A; weigh 0.075 g of eight-arm-polyethylene glycol amino and dissolve it in 0.5 ml of sterile pure water for experiments to prepare mixed solution B;

[0070] Take a double-barreled syringe, load mixed solution A in one of the syringe barrels of the double-barreled syringe, and load mixed solution B in the other syringe barrel, then inject mixed solution A and mixed solution B into the perforated part of the pig stomach at the same time, the pig stomach is filled with simulated gastric juice, the simulated gastric juice includes strong acid and protease, and the pH value of the simulated gastric juice ranges from 0.9 to 4. During the injection process, the pig stomach is immersed in a PBS solution with a pH value range of 7.2 to 7.4, and the simulated gastric juice in the pig stomach flows out from the perforated part, and the mixed solution A and the mixed solution B form a hydrogel for gastric perforation repair, and the hydrogel for gastric perforation repair is bonded to the surface of the pig stomach tissue, that is, in the component of the hydrogel for gastric perforation repair, the terminal active group α of the eight-arm-polyethylene glycol succinimide succinate that has not undergone an amidation reaction with the amino group of the terminal active group of the eight-arm-polyethylene glycol amino group undergoes an amidation reaction with the amino group on the surface of the pig stomach tissue, thereby achieving rapid adhesion of the hydrogel for gastric perforation repair to the surface of the pig stomach tissue, see Figure 5-7 After the eight-arm-polyethylene glycol succinimidyl succinate in the mixed solution A is fully in contact with the eight-arm-polyethylene glycol amino in the mixed solution B, gelation is formed within 5 seconds to form a hydrogel for gastric perforation repair. The hydrogel has strong adhesion and is not disturbed by the intragastric environment (pressure, strong acid and protease, etc.). After 2 minutes, normal saline is sprayed on the injection site. The surface of the hydrogel for gastric perforation repair can be rinsed with normal saline to remove the unreacted terminal active group α. The terminal active group α can be quickly hydrolyzed and inactivated when it comes into contact with water.

[0071] The adhesion performance of the hydrogel used for gastric perforation repair in Example 2 to the pig stomach was tested. Another pig stomach with a perforation and filled with simulated gastric fluid was taken and immersed in a PBS solution. Fibrin glue was bonded to the perforation site, and the simulated gastric fluid in the pig stomach gushed out from the perforation site. After 3-5 minutes or when the fibrin glue and the pig stomach tissue were completely bonded, the adhesion performance of the fibrin glue and the pig stomach tissue was tested. Figure 8 This is a comparison chart of the adhesion performance of the hydrogel and fibrin glue in Example 2 to the porcine stomach, respectively. Since the adhesion parts of the hydrogel and fibrin glue in Example 2 to the porcine stomach are respectively in PBS solution on one side and in simulated gastric fluid on the other side, the test results can simultaneously reflect the adhesion performance in PBS solution and in simulated gastric fluid. It can be seen from the figure that the adhesion strength of the fibrin glue is 12.5 KPa, and the adhesion strength of the hydrogel used for gastric perforation repair is 33.5 KPa, that is, the adhesion strength of the hydrogel in Example 2 is nearly 3 times that of the fibrin glue. It can be seen that in PBS solution and in simulated gastric fluid, the hydrogel used for gastric perforation repair has extremely strong adhesion, which meets the application requirements of gastric perforation.

[0072] The pig stomach in which the hydrogel of Example 2 of the present invention is formed at the perforated site is filled with strong acid and protease, and the filling is marked with red dye. Then, the pig stomach is immersed in PBS solution. PBS solution, the full name of which is phosphate buffered saline. The ion concentration in PBS solution is similar to that in human intracellular fluid, see Fig. 9 After 8 hours, no red liquid exudation was observed, indicating that the hydrogel for gastric perforation repair had a good initial repair effect on pig gastric perforation.

[0073] Burst hydraulic pressure test of porcine stomachs injected with hydrogels for gastric perforation repair at the perforation site, see Fig.10 When the perfusion water pressure was 0.019 MPa, the pig stomach still did not explode, indicating that the hydrogel for gastric perforation repair and the pig stomach repaired with the hydrogel for gastric perforation repair have good compressive properties and meet the compressive requirements of the stomach for perforation repair materials.

[0074] Fig.11 , 12 For the biocompatibility of the hydrogel used for gastric perforation repair in Example 1 with gastric and intestinal cell lines, see Fig.11 , gastric cell lines (gastric GES-1) and intestinal cell lines (Caco-1) were co-cultured with the hydrogel for gastric perforation repair, and no obvious cytotoxic effect was observed; see Fig.12 Flow cytometry experiments proved that the hydrogel used for gastric perforation repair did not cause unsafe immune inflammatory response after co-culture.

[0075] from Fig.13 It can be seen that the swelling weight gain of the hydrogel used for gastric perforation repair in Example 1 of the present invention in PBS solution, porcine gastric juice, and human gastric juice within 10 days is only about 30% at most. Both porcine gastric juice and human gastric juice are simulated gastric juice. Among them, the swelling weight gain in human gastric juice within 10 days is 32.2%, which is lower than 35%. The swelling weight gain in porcine gastric juice and PBS solution within 10 days is 23.2% and 23.1%, respectively, which are lower than 25%. It can be seen that the hydrogel can maintain the stability of shape and structure during gastric repair, and has a certain ability to absorb and store water to ensure stable performance, has good biocompatibility, can be well compatible with biological tissues, and reduce inflammatory reactions and rejection reactions. In addition, the moderate swelling rate also enhances the adhesion between the hydrogel and the tissue, so that it can better fit the biological surface, improve the therapeutic effect, and meet the application requirements of gastric perforation repair.

[0076] Fig.14The weight change of the hydrogel used for gastric perforation repair in Example 1 of the present invention in PBS solution, porcine gastric juice and human gastric juice as time increases. Similarly, porcine gastric juice and human gastric juice are both simulated gastric juice. It can be seen that the weight of the hydrogel increases slightly within 1-2 weeks. At this time, the hydrogel absorbs water and swells to a certain extent, which can ensure the adhesion between the tissue and better fit the biological surface to achieve the repair effect. The weight of the hydrogel begins to decrease after 2 weeks, and the weight decreases to 25% to 50% after 4 weeks. The weight decreases the most in human gastric juice, the weight decreases to 30%, the weight decreases to 33% in porcine gastric juice, and the weight decreases to 45% in PBS solution, which reduces long-term contact with biological tissues, thereby reducing potential risks. At the same time, it further illustrates that the hydrogel has good biocompatibility, can coexist harmoniously with biological tissues, and reduce inflammatory reactions and rejection reactions.

[0077] Fig.15 This is a fluorescent imaging image of the hydrogel used for gastric perforation repair in Example 1 in the abdominal cavity of a rat. It can be seen that the hydrogel used for gastric perforation repair is stable in shape in the abdominal cavity of a rat within 24 hours, is mostly degraded after 3 weeks, and is completely degraded after 4 weeks.

[0078] Fig.16 The diagrams are result diagrams of the use of the pig stomach perforation site in Example 2 of the present invention. The first figure from the left is a photo of the pig stomach perforation part taken with a laparoscope, and the gastric juice gushing out can be clearly seen; the second figure from the left is a gastric perforation repair performed under laparoscopy using the hydrogel for gastric perforation repair of the present invention; the third figure from the left is a laparoscopic exploration and repair effect of a pig stomach repaired with the hydrogel for gastric perforation repair at 4 weeks, and no gastric juice gushed out at this time; the last figure from the left is a gastroscopic exploration and repair effect diagram of a pig stomach repaired with the hydrogel for gastric perforation repair at 4 weeks, and it can be observed from the inside of the stomach that the perforation site has been repaired.

[0079] The system embodiment described above is merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art may understand and implement it without creative work.

[0080] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for reducing the swelling rate of a hydrogel, prolonging the degradation time of the hydrogel, and making the hydrogel suitable for gastric perforation repair, characterized in that: The hydrogel comprises the following features (1) and (2): (1) When tested in simulated gastric fluid with a pH range of 0.9-4, the hydrogel for gastric perforation repair has a swelling rate of <40% and an adhesive strength of ≥30 MPa; (2) When tested in a PBS solution with a pH range of 7.2-7.4, the hydrogel for gastric perforation repair has a swelling rate of <30% and an adhesive strength of ≥30 MPa; The method comprises chemically reacting compound A with compound B to generate a hydrogel for gastric perforation repair; The compound A is of formula IV: The structural formula of SSA is: The molecular weight of the compound A is 1000-20000; The compound B is of formula VIII: The molecular weight of the compound B is 1000-20000; When compound A reacts with compound B, the terminal active group of compound A reacts chemically with the terminal active group of compound B to form an amide bond.

2. The method according to claim 1, characterized in that The following steps are involved: Step S1: preparing a mixed solution A containing the compound A as a solute and a mixed solution B containing the compound B as a solute respectively; Step S2: Mixing the mixed solution A and the mixed solution B to obtain the hydrogel for gastric perforation repair, wherein the molar ratio of the terminal active groups in the mixed solution A to the terminal active groups in the mixed solution B is 1:10 to 10:

1.

3. The method according to claim 2, characterized in that The mixed solution A is prepared by dissolving compound A in solvent A, the solid content of compound A is 3% to 30%, and the solvent A is laboratory pure water or sterile saline; The mixed solution B is prepared by dissolving the compound B in a solvent B, the solid content of the compound B is 3% to 30%, and the solvent B is laboratory pure water or sterile physiological saline.

4. Use of the hydrogel prepared by the method according to any one of claims 1 to 3 in preparing a gastric perforation repair agent.

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