CN115197442A - Injectable self-healing hydrogel dressing for treating gastric perforation, preparation method and use - Google Patents

Abstract

The present invention relates to an injectable self-healing hydrogel dressing for the treatment of gastric perforation. The hydrogel is a thermosensitive block of a triblock polymer PTOPT dissolved in a pH 2.5 solution through temperature-induced self-assembly to form a The three-dimensional network structure formed by the micelles of the amino group and the aromatic ring components, and the PEG long chain as a bridge to connect the micelles. The hydrogel possesses an injectable, temperature-sensitive, self-healing, adhesive, antibacterial and biocompatible hydrogel wound dressing PTOPT, which can play a positive and effective therapeutic effect in gastric perforation models. A promising hydrogel dressing.

Description

Injectable self-healing hydrogel dressing for treating gastric perforation, preparation method and use

technical field

The invention relates to the field of biomedical materials, in particular to an injectable self-healing hydrogel dressing for treating gastric perforation, a preparation method and an application.

Background technique

Hydrogels are promising natural extracellular matrix substitutes with exciting promise in medical biomaterials. Injectable hydrogels, in particular, can minimize bioinfestation and pain during treatment when treating wounds where hydrogel cannot be placed directly (eg, in vivo, irregular wounds). At present, researchers have designed and developed injectable hydrogels for wound dressings through physical or chemical methods. However, most hydrogels lack adaptation to some complex biological environments, especially for the more acidic gastric environment. Because most hydrogels will be hydrolyzed under such strong acidic conditions, resulting in hydrogel damage and loss of original therapeutic function, and may even bring about various inflammatory reactions and delay wound healing. lead to death. Therefore, for the clinical treatment of gastric perforation, it is necessary to develop and design injectable hydrogels that can adapt to the complex environment of the stomach.

Among many wound dressings in injectable hydrogels, self-healing hydrogels with self-healing ability can repair themselves after being subjected to external force, which can greatly extend their service life in practical applications. The application of injectable hydrogels with self-healing properties in biomedical materials has become a research hotspot. Therefore, it is necessary to design and develop a bio-adaptive injectable self-healing hydrogel to promote the healing of gastric perforation.

SUMMARY OF THE INVENTION

The purpose of the present invention is to address the current lack of bio-adaptive injectable self-healing hydrogels for gastric perforation treatment.

The purpose of this invention is to realize through the following technical solutions:

A preparation method of an injectable self-healing hydrogel dressing for treating gastric perforation, comprising the following steps:

S1. Synthesis of Pentafluorophenol Acrylate (PFPA)

Mix pentafluorophenol and dichloromethane, add triethylamine and acryloyl chloride dropwise under ice bath conditions, then react at room temperature, filter, concentrate, wash, dry and purify to obtain transparent liquid pentafluorophenol acrylate (PFPA);

S2. Synthesis of 2-((3-oxo-3-(phenethylamino)propyl)amino)ethyl)carbamate (TBC)

Dissolve phenethylamine and tert-butyl N-(2-aminoethyl)carbamate in absolute ethanol, stir vigorously, react, and purify after vacuum drying to obtain an orange oily liquid 2-((3-oxo-3-( phenethylamino)propyl)amino)ethyl)carbamate (TBC);

S3. Synthesis of macromolecular chain transfer agent PEG-CTA

Trithioester, 2-(dodecyl trithiocarbonate base)-2-isobutyric acid (RAFT ₃₆₅ ) and oxalyl chloride were added into there-necked flask, dissolved in anhydrous dichloromethane and reacted, after the reaction finished, The remaining oxalyl chloride and dichloromethane are spin-dried, and then PEG and anhydrous dichloromethane are added to react, and the reaction is precipitated and dried to obtain a pale yellow product PEG-CTA;

S4. Synthesis of triblock polymer Poly(EG-co-PFPA)-b-PEO-b-Poly(EG-co-PFPA) (GPOGP)

PEG-CTA prepared by S3, oligoethylene glycol methacrylate (PEG-MA), PFPA prepared by S1, and azobisisobutyronitrile (AIBN) were dissolved in 1,4-dioxane, and the whole The reaction system was bubbling into nitrogen and reacted; after the reaction was over, a white solid triblock polymer Poly(EG-co-PFPA)-b-PEO-b-Poly(EG-co - PFPA) (GPOGP);

S5. Synthesis of Precursor Triblock Polymer Poly(EG-co-TBC)-b-PEO-b-Poly(EG-co-TBC)(PTOPT-Boc)

The TBC prepared by S2 and the triblock polymer GPOGP prepared by S4 were dissolved in tetrahydrofuran, and the reaction system was bubbled and passed into nitrogen to react; after the reaction, precipitation, purification, filtration, and drying were performed to obtain yellowish solid PTOPT-Boc;

S6. Preparation of PTOPT polymer

The precursor triblock polymer PTOPT-Boc is dissolved in dichloromethane, then trifluoroacetic acid is added to the solution, and the reaction is carried out at room temperature. After the reaction is completed, the PTOPT polymer is obtained after precipitation, purification and drying;

S7. Preparation of the hydrogel dressing

Biocompatible injectable self-healing hydrogel dressings were obtained by dissolving PTOPT polymer in acidic ice water.

Specifically, in the S1, pentafluorophenol and dichloromethane are added to the three-necked flask, and then triethylamine and acryloyl chloride are added dropwise for 20 to 60 minutes at -20 to 10 °C; then the ice bath is removed. , react at 20-40 °C for 3-8 hours, use a Buchner funnel to filter to remove triethylamine hydrochloride, concentrate the filtrate, and then wash with HCl solution, saturated NaHCO ₃ and brine; the organic phase is washed with NaSO ₄ or MgSO ₄ carry out drying and dewatering, concentrated, sherwood oil, dichloromethane or n-hexane are used as eluent, the raffinate is purified with column chromatography, the transparent liquid obtained; Wherein the mass ratio of pentafluorophenol and acryloyl chloride is ( 5 to 10): (3 to 5). The amount of dichloromethane added is 50-100 mL; the concentration of HCl is 0.1-1 mol/L.

Specifically, in S2, phenethylamine and tert-butyl N-(2-aminoethyl)carbamate are dissolved in 10-50 mL of absolute ethanol, and vigorously stirred; the mixture is refluxed at 60-80 °C Stir, react for 24-48 hours; dry solvent ethanol in vacuum; then use petroleum ether, dichloromethane, ethyl acetate or methanol as eluent, purify the residue by column chromatography to obtain TBC product; The mass ratio of phenethylamine and tert-butyl N-(2-aminoethyl)carbamate is (2-10):(3-9).

Specifically, in the S3, the mass ratio of RAFT ₃₆₅ , oxalyl chloride and PEG is (1-3): (3-7): (5-20); wherein, the molecular weight of PEG is between 2000-40000; The first and second additions of anhydrous dichloromethane are respectively 5-20 mL and 50-200 mL.

Specifically, in the S4, after the reaction is completed, the solution is added dropwise to diethyl ether or n-hexane for precipitation, and the purification process is repeated twice; the product is filtered and dried under vacuum overnight to obtain a white solid GPOGP; wherein The mass ratio of PEG-CTA, oligoethylene glycol methacrylate (PEG-MA), PFPA, azobisisobutyronitrile (AIBN) and 1,4-dioxane is (1～3):( 2 to 8): (0.5 to 2): (8 to 30).

Specifically, in the S5, after the reaction is completed, the reaction solution is added drop by drop to diethyl ether or n-hexane precipitant for precipitation, and the purification process is repeated twice; the product is filtered and dried under vacuum overnight to obtain a yellowish Solid PTOPT-Boc; wherein, the mass ratio of TBC, GPOGP and tetrahydrofuran is (1-3): (2-10): (20-50).

Specifically, in the S6, the mass ratio of PTOPT-Boc, dichloromethane and trifluoroacetic acid is (1-3): (10-20): (1-2).

Specifically, in described S7, the prepared triblock polymer PTOPT concentration is 50mg/mL～200mg/mL is dissolved in the solution that is configured with pH 2.5 by acetic acid/potassium nitrate or hydrochloric acid, put into the refrigerator refrigerating layer 10 Hydrogel dressings were made in ~30 hours.

An injectable self-healing hydrogel dressing for treating gastric perforation prepared by the method described above. The PTOPT hydrogel of the present invention has good biocompatibility. It can effectively reduce the risk during use.

The prepared hydrogel dressings are used in gastric perforation wound models and other complex wound healing.

The present invention develops a gastric environment-adapted hydrogel (PTOPT) as an in vivo wound dressing. By adapting to physiological conditions, the hydrogel dressing can be easily injected at the target site via supramolecular self-assembly of the ABA triblock copolymer. The formed supramolecular hydrogel can adapt to the gastric environment, obtain rapid self-healing and repair properties through the synergy of hydrophobic and cation-π interactions, reduce the risk of damage during use, and effectively prolong the service life of the material. At the same time, the PTOPT hydrogel dressing can also effectively prevent the accumulation of microorganisms on its surface and has excellent anti-bacterial adhesion properties. And we also measured the cytotoxicity of the hydrogels by CCK-8, and the hydrogels showed minimal toxicity to gastric mucosal cells and L929 cells. Furthermore, 2D/3D cell culture was performed on gastric mucosal cells and L929 cells using the hydrogel, and the data showed that the hydrogel had good biocompatibility. In addition, the PTOPT hydrogel dressing has state-of-the-art advantages compared to conventional gastric perforation treatments, including simplified surgical procedures, reduced postoperative adhesion, and enhanced angiogenesis. The design of our PTOPT hydrogels provides useful insights into the development of bioenvironmentally adapted functional materials for various biomedical applications.

The structural formula of the PFPA prepared by S1 of the present invention is shown in the following formula:

The structural formula of the TBC prepared by S2 of the present invention is shown in the following formula:

The structural formula of the macromolecular chain transfer agent PEG-CTA prepared by S3 of the present invention is shown in the following formula:

The structural formula of the triblock polymer GPOGP with active ester prepared by S4 of the present invention is shown in the following formula

The structural formula of the precursor triblock polymer PTOPT-Boc prepared by S5 of the present invention is shown in the following formula

The structural formula of the target triblock polymer PTOPT prepared by S6 of the present invention is shown in the following formula

The beneficial effects of the present invention are:

(1) The PTOPT hydrogel in the present invention has good temperature sensitivity, and the sol-gel transition temperature of the hydrogel is about 22°C lower than the human body temperature (~37°C). A stable gel can be formed under the induction of human body temperature without the need for other complex external stimuli.

(2) The PTOPT hydrogel in the present invention has attractive injectable properties. When the temperature is lower than 22°C, the hydrogel is in a sol state, and the liquid-like polymer solution can be well injected into the target site through a syringe, and is passed through Body temperature induces stable hydrogels. Furthermore, the shear-thinning behavior of hydrogels suggests that even stabilized hydrogels are attractively injectable, which can minimize bioinfestation and pain during treatment.

(3) The PTOPT hydrogel in the present invention has excellent self-healing properties adapted to the stomach environment. The cation-π interaction between the protonated amino group and the aromatic benzene ring in the hydrogel matches the gastric environment with a pH of 2.5, which enables the hydrogel to self-heal quickly after damage, prolonging the The service life of the material reduces the risk during use.

(4) The PTOPT hydrogel in the present invention has good antibacterial adhesion performance to Escherichia coli (E.coli) and Staphylococcus aureus (S. aureus). It is critical to prevent microorganisms from forming microbial films on the surface of implanted biomaterials. The existence of the PEG segment in the hydrogel will form a strong hydration layer at the wound, which acts as a barrier to bacteria and can effectively prevent bacteria from adhering, which can effectively prevent the immune response or immune response that may be triggered by the microbial membrane. Responses such as inflammation that inhibit the healing process.

(5) The cation-π electrostatic interaction, hydrogen bonding, π-π stacking and hydrophobic interaction occur between the PTOPT hydrogel in the present invention and the tissue surface, and exhibit a good adhesion effect. When the hydrogel is formed in situ on wounds of different shapes, especially in the wet and dynamic human environment, it will be a promising wound dressing.

(6) The PTOPT hydrogel of the present invention has good biocompatibility. In vitro cytotoxicity showed that PTOPT hydrogels were non-toxic and promoted cell growth and proliferation. In addition, PTOPT hydrogel was used for 2D/3D cell culture of mouse fibroblasts (L 929) and rat gastric epithelial cells (GES), indicating that PTOPT hydrogel did not reduce cell proliferation and had good biocompatibility sex.

Description of drawings

Fig. 1(a) Modulus of PTOPT hydrogel as a function of temperature (4℃～45℃); (b) PTOPT hydrogel under three thermal cycles of heating (37℃) and cooling (12℃) Modulus change graph;

Fig. 2 is a sample diagram of a hydrogel dressing PTOPT liquefaction sample injected into 37° C. deionized water in the present invention; (hydrogel stained with Rhodamine B);

Figure 3 (a) Modulus changes with increasing strain (0.1%-1000%) (left) and instantaneous recovery after 1000% strain deformation (right); (b) Dynamics of PTOPT hydrogel at 37°C Strain cycling test (γ=1% or 300%) showed self-healing behavior; (c) demonstrated the self-healing properties of PTOPT hydrogel;

Fig. 4(a) The colony survival pictures of glass slides and PTOPT hydrogel-modified glass slides after co-culture of Escherichia coli and Staphylococcus aureus for 3 hours; (B) Escherichia coli and Staphylococcus aureus adhered on different glass slides Quantitative data attached;

Figure 5 (a) stress-strain curves of PTOPT hydrogel in the present invention to different tissues; (b) adhesion strength of PTOPT hydrogel to different tissues;

Figure 6 (a) Cell viability of L 929 cells incubated with PTOPT hydrogel for 1 day and 7 days; (b) Cell viability of GES cells incubated with PTOPT hydrogel for 1 day and 7 days, the results are shown as mean ± SD (n=6); (c), (d) 2D and 3D cultures of L 929 cells using 15 w/v% hydrogel. Representative live and dead staining of L 929 cells on day 1 after hydrogel incubation. (e), (f) 2D and 3D cultures of GES cells using 15 w/v% hydrogel. Representative live and dead staining of GES cells on day 1 after hydrogel culture.

Figure 7(a) Schematic diagram of gastric perforation treatment; (b) optical photo of gastric perforation treatment; (c) optical photo of stomach after 7 days of gastric perforation treatment; (d) postoperative tissue adhesion; (e) 7 days after gastric perforation treatment H&E staining of stomach. Scale bar: 1000 μm.

Figure 8. Representative immunofluorescence images of (a) CD31 and (b) CD34 staining at wound edges. Brown staining represents blood vessels. The scale bar represents 50 μm. (c) Quantification of CD31 and CD34 staining.

Detailed ways

The technical solutions of the present invention are further described in detail below with reference to the accompanying drawings, but the protection scope of the present invention is not limited to the following.

Example 1

S1: Synthesis of pentafluorophenol acrylate (PFPA): Pentafluorophenol (5.52 g, 30 mmol) and 50 mL of dichloromethane were added to a 100 mL three-necked flask. Triethylamine (3.24 g, 32 mmol) and acryloyl chloride (2.9 g, 32 mmol) were then added dropwise over 30 minutes in an ice bath. Then, the ice bath was removed, and the reaction was carried out at 25°C for 4 hours. Triethylamine hydrochloride was removed by filtration using a Buchner funnel, and the filtrate was concentrated. It was then washed with 0.1 M HCl solution (1 x 75 mL), saturated _NaHCO3 (1 x 75 mL) and brine (1 x 75 mL). The organic phase was dried over _MgSO4 to remove water and concentrated. Using petroleum ether as eluent, the residue was purified by column chromatography to obtain a transparent liquid.

S2: Synthesis of molecule 2-((3-oxo-3-(phenethylamino)propyl)amino)ethyl)carbamate (TBC) containing both amine (cation) and aromatic (π): Phenethylamine (5.25 g, 30 mmol) and tert-butyl N-(2-aminoethyl)carbamate (5.92 g, 37 mmol) were dissolved in 25 mL of absolute ethanol and stirred vigorously. The mixture was stirred under reflux at 80°C and reacted for 48 hours. The solvent ethanol was dried in vacuo. Using EAC and methanol (V:V=10:1, 1 vol.% TEA) as eluent, the residue was purified by column chromatography, and the obtained TBC product was an orange oily liquid.

S3: Synthesis of macromolecular chain transfer agent PEG-CTA: add 1g of trithioester 2-(dodecyltrithiocarbonate group)-2-isobutyric acid (RAFT ₃₆₅ ) and 2ml of oxalyl chloride into a three-necked flask, Dissolve in anhydrous 5 mL of dichloromethane and react. After the reaction was completed, the remaining oxalyl chloride and dichloromethane in the flask were spin-dried. Then add 5 g of PEG (Mn 20000) and 50 mL of anhydrous dichloromethane to react. After the reaction, the product was precipitated with n-hexane as a precipitant and dried to obtain a light yellow product, PEG-CTA.

S4: Synthesis of triblock polymers with active esters by RAFT polymerization Poly(EG-co-PFPA)-b-PEO-b-Poly(EG-co-PFPA) (GPOGP): PEG-CTA (0.518g, 0.025 mmol), PEG-MA (1.018 g, 9 mmol), PFPA (0.238 g, 1 mmol) and AIBN (0.002 g, 0.0125 mmol) were dissolved in 8 mL of 1,4-dioxane. The entire reaction system was bubbled with nitrogen for 15 minutes, and the reaction was carried out at 70 °C for 12 h. The solution was then added drop by drop to a large amount of ether to precipitate, and the purification process was repeated twice. The product was filtered and dried under vacuum overnight to give a white solid.

S5: Synthesis of precursor triblock polymer Poly(EG-co-TBC)-b-PEO-b-Poly(EG-co-TBC) (PTOPT- Boc): TBC (0.67 g, 2 mmol) and GPOGP (1.54 g) were dissolved in 20 mL of tetrahydrofuran, and the reaction system was bubbled with nitrogen for 20 minutes. The reaction was carried out in an oil bath at 50°C overnight. After the reaction, the reaction solution was added drop by drop to a large amount of ether for precipitation, and the purification process was repeated twice. The product was filtered and dried under vacuum overnight to yield a yellowish solid.

S6: The PTOPT polymer was obtained by hydrolyzing the precursor triblock polymer PTOPT-Boc with trifluoroacetic acid: The precursor triblock polymer PTOPT-Boc was dissolved in 10 ml of dichloromethane, and then 2 mL of trifluoroacetic acid was added to the solution, The reaction was carried out at 25°C for 4 hours. After the reaction is completed, it is purified twice by ether precipitation, and dried in a vacuum drying oven at room temperature overnight to obtain the target product triblock polymer PTOPT.

S7: Dissolve the PTOPT polymer into ice water with pH=2.5 to obtain a biocompatible injectable self-healing hydrogel: The prepared triblock polymer PTOPT was dissolved in 100 mmol of pH 2.5 at a mass fraction of 15% Buffered solution of acetic _acid and 250 mmol KNO. Made in the refrigerator for 12 hours.

The hydrogel wound dressing PTOPT with injectable, temperature-sensitive, self-healing, adhesion, anti-bacterial adhesion and biocompatibility prepared by the method of the invention can play a positive and effective therapeutic effect in gastric perforation model. The following is a detailed analysis of the experimental data.

It can be seen from Figure 1(a) that the prepared PTOPT hydrogel exhibits excellent thermal responsiveness. The storage modulus (G′) and loss modulus (G″) of the hydrogel intersect at 22 °C. Below 22°C, G' is greater than G", and the PTOPT mixture behaves like a sol. When the temperature of the solution exceeds its 22°C, G' crosses G" and exceeds it, and the solution is gel-like. Therefore, when heated to 37°C, the PLOPL solution can become a freestanding gel within 1 minute. This shows that the hydrogel has a well-defined sol-gel transition temperature (TSG). Figure 1(b) shows that the gel-sol-gel transition is completely reversible, and the temperature is lower than the TSG temperature (12°C). , G' is less than G", it is in a sol state, and after the temperature is immediately raised above the TSG temperature (37 °C), G' is less than G", in a gel state. And it can be repeated for several cycles. These data show that the hydrogel has Good temperature sensitive properties.

FIG. 2 shows the injectable properties of the PTOPT hydrogels in Example 1. FIG. Using a 23G × 3/4" syringe, the polymer solution stored below the TSG temperature (4°C) was easily injected into a 37°C water bath and a stable hydrogel was formed immediately.

FIG. 3 shows the self-healing properties of the PTOPT hydrogel in Example 1. FIG. As shown in Fig. 3(a), in the strain range of 0.1% to 10%, G' and G" are basically unchanged, and G' is greater than G", showing gel properties. When the strain is increased to 25%, G′ intersects with G″, which is the critical strain of the hydrogel. Further increasing the strain, G″ is larger than G′, showing a sol-like property, because when the strain exceeds the critical strain When the polymer chains are broken, the three-dimensional network of the hydrogel is destroyed. However, after the 3D network of the hydrogel is destroyed under the condition of large strain (γ=1000%), immediately applying a small strain (γ=1%), G′ and G″ will rapidly self-recover to their initial values (self-recovery within 3 min). The efficiency reaches 100%). It shows that the mechanical properties of the hydrogel specimens recover rapidly after removing the large strain. In addition, a continuous step-strain change between 300% and 1% was performed to evaluate the healing ability of the hydrogel. As shown in Figure 3(b), when a large failure strain of 300% was applied for 50 seconds, the G″ of the hydrogel was larger than G’, indicating that the hydrogel network was destroyed and a gel-sol transition occurred. However, the G' of the hydrogel rapidly recovered to its initial value after a few seconds at a lower strain (γ = 1%), suggesting that the ruptured hydrogel network can be activated by reversible cation-π interactions reconstruction. In addition, the self-healing properties of the hydrogels can also be observed macroscopically. As shown in Fig. 3(c), a circular hydrogel was cut into two semi-circles, and then the two semi-circles were placed together. After contacting for 3 minutes without external stimulation, the two semi-circles self-healed as A whole and able to support its own weight.

FIG. 4 shows the antibacterial adhesion properties of PTOPT hydrogels in Example 1. FIG. As shown in Figure 4(a), the number of colonies of Escherichia coli and Staphylococcus aureus on the blank glass slide is much higher than that on the glass slide modified with hydrogel, which indicates that the bacteria easily adhere to the glass slide surface and formed a microbial film, while the glass slides modified with PTOPT hydrogel exhibited good antibacterial adhesion properties. This indicates that bacteria can easily adhere to the surface of the glass sheet and form a microbial film, while the glass sheet modified with PTOPT hydrogel has excellent anti-adhesion properties, which can effectively prevent the formation of microbial film. As shown in Fig. 4(b), the quantitative data of the colonies showed that there were far fewer bacteria on the hydrogel-modified glass slides, indicating its excellent antibacterial adhesion properties. This is due to the existence of the PEG segment in the hydrogel, which can form a strong hydration layer on the glass sheet, which acts as a barrier to bacteria and can effectively prevent bacteria from adhering.

Figure 5 shows the performance of PTOPT hydrogels in Example 1 for tissue adhesion. As shown in Figure 5(a) and (b), it can be seen that the adhesion strength of the hydrogel to pig intestine, pig stomach, pig skin and pig heart is 15.3, 2.8, 20.5 and 3.3 kPa in turn, which indicates that the hydrogel has more The tissue has good adhesive strength. The adhesion properties of hydrogels to various tissues benefit from the ordered cation-π sequence in the molecular structure of hydrogels. The hydrogel adhesion mechanism diagram is shown in Figure 3-8. The cation-π-mediated electrostatic interaction, hydrogen bonding, π-π stacking and hydrophobic interaction occur between the hydrogel and the tissue surface, and the display exhibits good adhesion. Effect. These results suggest that the hydrogel will be a promising wound dressing when it is formed in situ on wounds of different shapes, especially in the wet and dynamic human environment.

FIG. 6 shows the biocompatibility of PTOPT hydrogels in Example 1. FIG. It can be seen from Figure 6(a) and (b) that within a certain concentration range, the viability of L 929 cells and GES cells is almost stable, and all activities are maintained at about 90% or above. In vitro cytotoxicity showed that PTOPT hydrogels were nontoxic and promoted cell growth and proliferation. Furthermore, we examined the cytocompatibility of PTOPT hydrogels by using them for 2D/3D cell culture of L929 cells and GES cells. Cells without any treatment served as normal controls. As shown in Figures 6(c), (d), (e) and (f), after 24 hours of culture, very few dead cells were observed in both the 2D culture group and the 3D group. There was no significant difference in the evaluation of viable cell density between the normal group and the hydrogel group, indicating that the PTOPT hydrogel did not reduce cell proliferation and had good biocompatibility.

Figure 7 shows the use of PTOPT hydrogel in Example 1 for the treatment of gastric perforation. An in vivo rat gastric perforation model was constructed as shown in Figure 7(a) to demonstrate that PTOPT hydrogel can be used as a sealant for the treatment of gastrointestinal perforation. Following the above method, a 5 mm perforation was made in the gastric antrum, as shown in Figure 7(b). On the 7th postoperative day, macroscopic images from the incision of the harvested gastric tissue showed that the wound area treated with PTOPT hydrogel was significantly reduced, indicating a good wound healing effect, as shown in Figure 7(c). We also took a representative macroscopic image for intraperitoneal adhesions. There was almost no intraperitoneal adhesions treated with PTOPT hydrogel, as shown in Fig. 7(d). H&E staining showed that the PTOPT hydrogel treatment almost healed, as shown in Figure 7(e).

Fig. 8 shows the situation of PTOPT hydrogel in Example 1 used to treat angiogenesis around gastric perforation wounds. We assessed the fluorescence intensity at the wound edge by IF staining for CD31 and CD34, markers of endothelial cells and angiogenesis. As shown in Figure 8, in the results of CD31 and CD34, the intensity of positively stained capillaries in the PTOPT hydrogel group was significantly higher than that in the suture group (P<0.01) and the incision group (P<0.05).

The experimental results prove that the hydrogel wound dressing PTOPT, which has injectable, temperature-sensitive, self-healing, adhesive, anti-bacterial adhesion and biocompatibility prepared by the method of the present invention, can play a positive and effective role in gastric perforation model. the therapeutic effect. The results of postoperative tissue adhesion, granulation tissue growth, and angiogenesis around the wound were further evaluated. The hydrogel showed a good therapeutic effect. In addition, these hydrogels have stable rheological properties, modulus close to human soft tissue, good adhesion properties, self-healing properties, anti-bacterial adhesion, biocompatibility, etc. Therefore, the hydrogel dressing PTOPT has a good application prospect in the treatment of gastric perforation healing.

The above are only preferred embodiments of the present invention, and it should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as the exclusion of other embodiments, but can be used in various other combinations, modifications and replacements, and can be within the scope of the concepts described herein. However, modifications and changes made by those skilled in the art do not depart from the spirit and scope of the present invention, and should all fall within the protection scope of the appended claims of the present invention.

Claims (10)

1. a preparation method of the injectable self-healing hydrogel dressing for the treatment of gastric perforation, is characterized in that: comprise the steps: S1. Synthesis of Pentafluorophenol Acrylate (PFPA) Mix pentafluorophenol and dichloromethane, add triethylamine and acryloyl chloride dropwise under ice bath conditions, then react at room temperature, filter, concentrate, wash, dry and purify to obtain transparent liquid pentafluorophenol acrylate (PFPA); S2. Synthesis of 2-((3-oxo-3-(phenethylamino)propyl)amino)ethyl)carbamate (TBC) Dissolve phenethylamine and tert-butyl N-(2-aminoethyl)carbamate in absolute ethanol, stir vigorously, react, and purify after vacuum drying to obtain an orange oily liquid 2-((3-oxo-3-( phenethylamino)propyl)amino)ethyl)carbamate (TBC); S3. Synthesis of macromolecular chain transfer agent PEG-CTA Trithioester, 2-(dodecyl trithiocarbonate base)-2-isobutyric acid (RAFT ₃₆₅ ) and oxalyl chloride were added into there-necked flask, dissolved in anhydrous dichloromethane and reacted, after the reaction finished, Remaining oxalyl chloride and dichloromethane are spin-dried, then add polyethylene glycol (PEG) and anhydrous dichloromethane to react, and after the reaction finishes, precipitation and drying to obtain pale yellow product PEG-CTA; S4. Synthesis of triblock polymer Poly(EG-co-PFPA)-b-PEO-b-Poly(EG-co-PFPA)(GPOGP) PEG-CTA prepared by S3, oligoethylene glycol methacrylate (PEG-MA), PFPA prepared by S1, and azobisisobutyronitrile (AIBN) were dissolved in 1,4-dioxane, and the whole The reaction system was bubbling into nitrogen and reacted; after the reaction was over, a white solid triblock polymer Poly(EG-co-PFPA)-b-PEO-b-Poly(EG-co - PFPA) (GPOGP); S5. Synthesis of the precursor triblock polymer Poly(EO-co-TBC)-b-PEO-b-Poly(EO-co-TBC)(PTOPT-Boc); The TBC prepared by S2 and the triblock polymer GPOGP prepared by S4 were dissolved in tetrahydrofuran, and the reaction system was bubbled and passed into nitrogen to react; after the reaction, precipitation, purification, filtration, and drying were performed to obtain yellowish solid PTOPT-Boc; S6. Preparation of PTOPT polymer The precursor triblock polymer PTOPT-Boc is dissolved in dichloromethane, then trifluoroacetic acid is added to the solution, and the reaction is carried out at room temperature. After the reaction is completed, the PTOPT polymer is obtained after precipitation, purification and drying; S7. Preparation of the hydrogel dressing Biocompatible injectable self-healing hydrogel dressings were obtained by dissolving PTOPT polymer in acidic ice water. 2. the preparation method of a kind of injectable self-healing hydrogel dressing for the treatment of gastric perforation according to claim 1, is characterized in that: in described S1, in the there-necked flask, add pentafluorophenol and methylene dichloride , then add triethylamine and acryloyl chloride dropwise for 20 to 60 minutes at -20 to 10 °C; then remove the ice bath, react at 20 to 40 °C for 3 to 8 hours, and use a Buchner funnel to filter to remove triethylamine Amine hydrochloride, the filtrate was concentrated, then washed with HCl solution, saturated NaHCO ₃ and brine; the organic phase was dried with NaSO ₄ or MgSO ₄ to remove water, concentrated, petroleum ether, dichloromethane or n-hexane as eluent, The residual liquid is purified by column chromatography to obtain a transparent liquid, wherein the mass ratio of pentafluorophenol and acryloyl chloride is (5-10):(3-5). 3. the preparation method of a kind of injectable self-healing hydrogel dressing for the treatment of gastric perforation according to claim 1, is characterized in that: in described S2, by phenylethylamine and N-(2-aminoethyl (base) tert-butyl carbamate is dissolved in 10-50 mL of absolute ethanol, and vigorously stirred; the mixture is stirred at 60-80 ° C under reflux, and the reaction is carried out for 24-48 hours; the solvent ethanol is dried in vacuum; Methane, ethyl acetate or methanol are used as eluents, and the residue is purified by column chromatography to obtain the TBC product; wherein the mass ratio of phenethylamine and N-(2-aminoethyl) tert-butyl carbamate It is (2～10):(3～9). 4. the preparation method of a kind of injectable self-healing hydrogel dressing for the treatment of gastric perforation according to claim 1, is characterized in that: in described S3, RAFT ₃₆₅ , the mass ratio of oxalyl chloride and PEG is ( 1 to 3): (3 to 7): (5 to 20). 5. the preparation method of a kind of injectable self-healing hydrogel dressing for the treatment of gastric perforation according to claim 1, is characterized in that: in described S4, after the reaction finishes, the solution is added dropwise to ether Or precipitation in n-hexane, and the purification process was repeated twice; the product was filtered and dried under vacuum overnight to obtain a white solid GPOGP; wherein PEG-CTA, oligoethylene glycol methacrylate (PEG-MA), PFPA, The mass ratio of azobisisobutyronitrile (AIBN) and 1,4-dioxane was (1-3):(2-8):(0.5-2):(8-30). 6. the preparation method of a kind of injectable self-healing hydrogel dressing for the treatment of gastric perforation according to claim 1, is characterized in that: in described S5, after the reaction finishes, the reaction solution is added drop by drop to Precipitation in ether or n-hexane precipitant, and the purification process was repeated twice; the product was filtered and dried under vacuum overnight to obtain a yellowish solid PTOPT-Boc; wherein, the mass ratio of TBC, GPOGP and tetrahydrofuran was (1～3): (2-10): (20-50). 7. the preparation method of a kind of injectable self-healing hydrogel dressing for the treatment of gastric perforation according to claim 1, is characterized in that: in described S6, PTOPT-Boc, dichloromethane and trifluoroacetic acid The mass ratio is (1-3):(10-20):(1-2). 8. the preparation method of a kind of injectable self-healing hydrogel dressing for the treatment of gastric perforation according to claim 1, is characterized in that: in described S7, the triblock polymer PTOPT concentration of the preparation is 50mg /mL～200mg/mL is dissolved in a solution with a pH of 2.5 prepared from acetic acid/potassium nitrate or hydrochloric acid, and placed in a refrigerator for 10 to 30 hours to prepare a hydrogel dressing. 9. An injectable self-healing hydrogel dressing for the treatment of gastric perforation, characterized in that: a kind of injectable self-healing water for the treatment of gastric perforation prepared by the method according to any one of claims 1 to 8 Gel dressing. 10. The use of an injectable self-healing hydrogel dressing for the treatment of gastric perforation according to claim 9, wherein the hydrogel dressing is used in gastric perforation wound model and other complex wound healing .

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