An injectable self-healing hydrogel dressing, its preparation method and application
By preparing a mildly photothermal NO-releasing injectable self-healing hydrogel dressing, combined with NO donor and thermosensitive polymer, the problems of easy infection and high-temperature damage in postoperative wounds of oral cancer are solved, achieving low-temperature sterilization and rapid healing, which is suitable for the treatment of postoperative wounds of oral cancer.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SICHUAN UNIV
- Filing Date
- 2023-12-11
- Publication Date
- 2026-05-26
AI Technical Summary
Postoperative wounds from oral cancer are prone to infection and difficult to heal. Current photothermal antibacterial therapy causes significant damage to surrounding tissues at high temperatures and has poor bactericidal effect. It is necessary to combine it with other treatment methods to reduce high-temperature damage and promote healing.
A mild photothermal NO-releasing injectable self-healing hydrogel dressing was prepared by loading the NO donor BNN6 onto SiO2@PDA nanoparticles through pp interaction and mixing it with the thermosensitive polymer NAONA to form an injectable self-healing hydrogel. Near-infrared laser irradiation was used to achieve sterilization and promote wound healing.
Hydrogel dressings release NO gas at low temperatures, achieving gentle ablation of bacteria, promoting angiogenesis and tissue regeneration, rapidly healing wounds, reducing the risk of infection, and exhibiting good biocompatibility and adaptability, thus reducing the frequency of dressing changes.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of biomedical materials technology, specifically relating to a mild photothermal releasing NO injectable self-healing hydrogel dressing for postoperative wound healing in oral cancer and its preparation method. Background Technology
[0002] To date, surgery remains the preferred treatment for oral cancer. However, postoperative wounds from oral cancer surgery are susceptible to infection due to the complex oral environment, leading to prolonged recovery and complications such as hematoma, necrosis, and lymphedema. These complications significantly impact appearance and daily life, reducing quality of life and seriously threatening patients' health and safety. Therefore, there is an urgent need to develop a multifunctional postoperative recovery treatment that prevents bacterial infection and promotes wound repair, thereby promoting angiogenesis in the postoperative wound, shortening healing time, and preventing secondary damage.
[0003] In recent years, photothermal antimicrobial therapy (PTAT), which uses photochemical reactions to generate heat under appropriate laser excitation to physically kill bacteria, has attracted much attention due to its ability to precisely kill bacteria while effectively avoiding the development of drug resistance. Previous studies have shown that PTAT alone requires high local temperatures for sterilization, which can cause unnecessary damage to surrounding healthy tissues. Although lowering the temperature of PTAT can significantly improve this problem, its bactericidal effect is still unsatisfactory. Therefore, combining it with other treatment methods to minimize the damage of high temperatures to the tissues surrounding the wound while achieving excellent bactericidal effects is imperative. Recent studies have reported that the combination of PTAT reagents irradiated by near-infrared lasers with gas therapy (such as H2, NO, CO, and H2S) has shown satisfactory antibacterial results. Among these, NO gas molecules, as important intercellular communication substances, play a crucial regulatory role in immune responses and angiogenesis. As an antibacterial agent, it can effectively promote angiogenesis and cell migration to the injured site, greatly enhancing wound healing activity. Hydrogels, with their high structural similarity to the extracellular matrix and their ability to retain large amounts of water, good biocompatibility, and functionally modifiable properties, are promising wound dressing materials. Integrating PTAT reagent and NO donor into hydrogel dressings to achieve excellent bactericidal effects through near-infrared laser irradiation is essential for treating infected wounds. Summary of the Invention
[0004] This invention aims to overcome the challenges of wound infection and slow healing after oral cancer surgery. It develops a mild, photothermal-releasing, injectable, self-healing hydrogel dressing that manages wound infection, promotes angiogenesis, and accelerates wound healing after oral cancer surgery.
[0005] The objective of this invention is achieved through the following technical solution:
[0006] A method for preparing a mild photothermal NO-releasing injectable self-healing hydrogel dressing for postoperative wound healing in oral cancer involves loading the NO donor BNN6 onto SiO2@PDA nanoparticles via PP interaction to obtain SiO2@PDA-BNN6, and then mixing SiO2@PDA-BNN6 with the thermosensitive polymer NAONA in a certain proportion to prepare the hydrogel dressing.
[0007] Furthermore, its preparation process includes the following steps:
[0008] S1: Synthesis of SiO2@PDA nanoparticles;
[0009] S2: Synthesis of N,N'-disec-butyl-N,N'-dinitroso-1,4-phenylenediamine (BNN6);
[0010] S3: Synthesis of SiO2@PDA-BNN6;
[0011] S4: Synthesis of the macromolecular chain transfer reagent PEG-CTA;
[0012] S5: Synthesis of 6-((3-(6-amino-9-purinyl)propionyl)oxy)hexyl acrylate (AHA);
[0013] S6: The triblock polymer Poly(NIPAM-co-AHA)-b-PEO-b-Poly(NIPAM-co-AHA) (NAONA) was obtained by RAFT polymerization;
[0014] S7: NAONA polymer was mixed with SiO2@PDA-BNN6 in ice water to obtain a bio-adaptive injectable self-healing hydrogel;
[0015] As a further aspect of the present invention, the specific preparation steps of SiO2@PDA in step S1 include:
[0016] Add 5–100 mL of deionized water, 5–25 mL of anhydrous ethanol, and 0.1–5 mL of ammonia to a three-necked flask equipped with a magnetic stirrer and stir at room temperature for 0.5–6 hours. Then, add 0.1–1 g of dopamine hydrochloride to the reaction mixture and stir for 12–48 hours. After the reaction is complete, wash the product three times with water and ethanol by centrifugation. Finally, mix the washed product with 20–80 mL of acetic acid solution (pH = 3) and add it to a hydrothermal reactor. React at 80–200°C for 12–48 hours. After the reaction is complete, wash the product three times with water / ethanol by centrifugation to obtain the final product SiO2@PDA.
[0017] As a further embodiment of the present invention, the mass ratio of deionized water, anhydrous ethanol, ammonia and dopamine hydrochloride is (50 ~ 1000): (50 ~ 200): (1 ~ 50): (1 ~ 10).
[0018] As a further aspect of the present invention, the specific preparation steps of BNN6 in step S2 include:
[0019] 1–5 g of N,N'-di-sec-butyl-1,4-phenylenediamine and 5–40 mL of anhydrous ethanol were sequentially added to a 100 mL three-necked flask equipped with a rotor. Then, under N2 protection, 10–50 mL of potassium nitrite solution (6 mol / L) was added. Next, 5–40 mL of hydrochloric acid solution (6 mol / L) was added to the three-necked flask, and the reaction was carried out at room temperature for 2–8 hours. The precipitate was obtained by centrifugation and washed three times with ethanol and aqueous solution, then freeze-dried in the dark to obtain the product BNN6.
[0020] As a further embodiment of the present invention, the mass ratio of N,N'-disec-butyl-1,4-phenylenediamine, anhydrous ethanol, hydrochloric acid solution and potassium nitrite solution is (1 ~ 5): (5 ~ 40): (5 ~ 40): (10 ~ 50).
[0021] As a further aspect of the present invention, the specific preparation steps of SiO2@PDA-BNN6 in step S3 include:
[0022] 1–25 mg of SiO2@PDA nanoparticles prepared in S1 were suspended in 1–50 mL of deionized water. Then, a BNN6-ethanol solution (0.1–2 mg / mL) prepared in S2 was added to the above solution, and the mixture was stirred in the dark for 12–48 hours. The nanoparticles were then collected by centrifugation and washed three times with deionized water.
[0023] As a further aspect of the present invention, the specific preparation steps of the macromolecular chain transfer reagent PEG-CTA in step S4 include:
[0024] 2–15 g of 2-(dodecyltrithiocarbonyl)-2-isobutyric acid and 5–25 g of oxaloyl chloride were added to a three-necked flask equipped with a stirrer and dissolved in 50–200 mL of anhydrous dichloromethane. After the reaction was complete, the remaining oxaloyl chloride and dichloromethane in the flask were evaporated to dryness. Then, 5–70 g of PEG (molecular weight 1000–30000) was added to continue the reaction. After the reaction was complete, the product was precipitated with a precipitant and dried to obtain a pale yellow product, PEO-CTA. RAFT… 365 The mass ratio of oxaloyl chloride, dichloromethane and PEG is (2 ~ 15): (5 ~ 25): (50 ~ 200): (5 ~ 70).
[0025] As a further embodiment of the present invention, the mass ratio of trithioester 2-(dodecyltrithiocarbonate)-2-isobutyric acid oxaloyl chloride, dichloromethane and PEG is (2 ~ 15): (5 ~ 25): (50 ~ 200): (5 ~ 70).
[0026] As a further aspect of the present invention, the specific preparation steps of AHA in step S5 include:
[0027] 0.1–2 g of adenine, 10–60 mg of 2,6-di-tert-butyl-4-methylphenol, and 10–60 mg of K₂CO₃ were added to 5–50 mL of dimethyl sulfoxide solution and stirred for 1 hour at 50 °C under a nitrogen atmosphere. Then, 1–4 g of 1,6-hexanediol diacrylate was added. After stirring the reaction mixture at 30–60 °C for 2–10 hours, it was poured into 50–200 mL of deionized water, and the mixture was washed with n-hexane to remove excess 1,6-hexanediol diacrylate. The aqueous layer was extracted twice with dichloromethane. The combined extract was dried over Na₂SO₄, filtered, concentrated using a rotary evaporator to remove all solvents, and the residue was purified by column chromatography. The mass ratio of adenine, 2,6-di-tert-butyl-4-methylphenol, K2CO3, dimethyl sulfoxide and 1,6-hexanediol diacrylate is (10 ~ 200): (1 ~ 6): (1 ~ 6): (500 ~ 5000): (100 ~ 400).
[0028] As a further option, the specific preparation steps of the triblock polymer NAONA in step S6 include:
[0029] A certain amount of 0.1–1 g PEG-CTA and 0.5–2 g N-isopropylacrylamide (NIPAM) prepared by S4, and 0.5–2.5 g AHA and 0.002–0.01 g azobisisobutyronitrile (AIBN) prepared by S5 were dissolved in 4–20 mL of 1,4-dioxane. The entire reaction system was bubbled through with nitrogen before the reaction. The reaction was carried out at 60–90 °C for 12–36 hours. After the reaction was complete, the solution was added dropwise to a large amount of diethyl ether or n-hexane to precipitate the product; this purification process was repeated twice. The product was filtered and dried under vacuum overnight to obtain a white solid product. The mass ratio of PEG-CTA, NIPAM, AHA, AIBN, and 1,4-dioxane was (2–15):(3–25):(1–5):(9–50).
[0030] As a further step, the specific preparation steps of the injectable self-healing hydrogel for treating oral cancer in step S7 include:
[0031] The prepared triblock polymer NAONA was dissolved in a PBS solution containing a certain concentration of SiO2@PDA-BNN6 at a certain concentration and placed in the refrigerator for 12 to 36 hours.
[0032] As a further option, the concentration of polymer NAONA is 50 mg / mL to 200 mg / mL.
[0033] As a further option, the concentration of SiO2@PDA-BNN6 is 0.1 mg / mL to 1 mg / mL.
[0034] The present invention also discloses a mild photothermal releasing NO injectable self-healing hydrogel prepared by the above method for promoting wound healing after oral cancer surgery, and discloses its application as a wound dressing.
[0035] Compared with the prior art, the present invention has the following beneficial technical effects:
[0036] The beneficial effects of this invention are:
[0037] (1) The hydrogel dressing of the present invention has good temperature sensitivity and excellent injectability. The sol-gel transition temperature of the hydrogel is about 20°C, which is lower than the human body temperature (~37°C). It can induce the formation of a stable gel at human body temperature without additional stimulation, and has excellent adaptability to wounds.
[0038] (2) The hydrogel dressing in this invention has self-healing properties, which can avoid infection problems caused by material damage during use, extend the service life of the material, reduce the number of dressing changes, and alleviate the patient's pain.
[0039] (3) The hydrogel dressing of the present invention has mild photothermal sterilization properties, releasing NO gas at a relatively low temperature (48°C), thereby achieving sterilization of Escherichia coli and Staphylococcus aureus. E. coli ) and Staphylococcus aureus ( S. aureus The gentle ablation effectively prevents wound infection.
[0040] (4) The hydrogel dressing in this invention has good biocompatibility and blood compatibility, and is an ideal biomaterial.
[0041] (5) The hydrogel dressing of the present invention can accelerate angiogenesis, tissue regeneration, and collagen deposition in the repair of wounds after oral cancer surgery, thereby achieving rapid wound healing.
[0042] Experimental results demonstrate that the mild photothermal NO-releasing injectable self-healing hydrogel dressing of the present invention has a positive and effective effect on postoperative wound management for oral cancer, providing a new option for postoperative wound care in clinical oral cancer surgery. Attached Figure Description
[0043] Figure 1 The results of experiments on the thermosensitive properties, injectability, and self-healing properties of the hydrogel dressing of the present invention are shown.
[0044] Figure 2 These are the experimental results of the biocompatibility and blood compatibility of the hydrogel dressing of the present invention;
[0045] Figure 3 These are the antibacterial test results of the hydrogel dressing of the present invention. Detailed Implementation
[0046] The present invention will now be clearly and completely described with reference to the accompanying drawings, so that those skilled in the art can fully implement the present invention without the need for creative effort. Example
[0047] A mild photothermal-releasing NO injectable self-healing hydrogel dressing for healing oral cancer wounds includes the following steps:
[0048] Synthesis of SiO2@PDA nanoparticles
[0049] In a three-necked flask equipped with a magnetic stirrer, 40 mL of deionized water, 12 mL of anhydrous ethanol, and 0.5 mL of ammonia were added and stirred at room temperature for 0.5 hours. Then, 0.2 g of dopamine hydrochloride was added to the reaction mixture and stirred for 24 hours. After the reaction was complete, the product was washed three times by centrifugation with water and ethanol. Finally, the washed product was mixed with 40 mL of acetic acid solution (pH = 3) and added to a hydrothermal reactor. The reaction was carried out at 140 °C for 24 hours. After the reaction was complete, the product was washed three times by centrifugation with water / ethanol to obtain the final product SiO2@PDA. The mass ratio of deionized water, anhydrous ethanol, ammonia, and dopamine hydrochloride was 400:120:5:2.
[0050] S2: N, N' -di-sec-butyl- N, N' -Dinitro- 1，4 Synthesis of β-phenylenediamine (BNN6)
[0051] 2 g N, N'- Di-sec-butyl-1,4-phenylenediamine and 18 mL of anhydrous ethanol were sequentially added to a 100 mL three-necked flask equipped with a rotor. Then, under N2 protection, 20 mL of 6 M potassium nitrite solution was added. Next, 20 mL of 6 M hydrochloric acid solution was added to the three-necked flask, and the mixture was stirred for 30 minutes. The reaction was carried out at room temperature for 4 hours. The precipitate was obtained by centrifugation and washed three times with ethanol and aqueous solution. Then, it was freeze-dried in the dark to obtain product BNN6. N, N'- The mass ratio of di-sec-butyl-1,4-phenylenediamine, anhydrous ethanol, hydrochloric acid solution, and potassium nitrite solution is 1:9:10:10.
[0052] S3: Synthesis of SiO2@PDA-BNN6
[0053] The SiO2@PDA nanoparticles (5 mg) prepared by S1 were suspended in 5 mL of deionized water. Then, a BNN6-ethanol solution with a concentration of 2 mg / mL was added to the above solution, and the mixture was stirred in the dark for 24 hours. The nanoparticles were then collected by centrifugation and washed three times with deionized water.
[0054] S4: Synthesis of the macromolecular chain transfer reagent PEG-CTA
[0055] 3 g of trithioester 2-(dodecyl trithiocarbonyl)-2-isobutyric acid (RAFT) 365 10 g of oxaloyl chloride was added to a three-necked flask equipped with a stirrer and dissolved in 10 mL of anhydrous dichloromethane. After the reaction was complete, the remaining oxaloyl chloride and dichloromethane in the flask were evaporated to dryness. Then, 15 g of PEG (…) was added. MnThe mixture (1000 ~ 30000) reacted with 100 mL of anhydrous dichloromethane. After the reaction was complete, precipitate was obtained using diethyl ether as a precipitant, and the product was dried to give a pale yellow product, PEO-CTA. RAFT... 365 The mass ratio of oxaloyl chloride, dichloromethane and PEG is 3:10:110:5.
[0056] Synthesis of S5: 6-((3-(6-amino-9-purinyl)propionyl)oxy)hexyl acrylate (AHA)
[0057] 0.5 g of adenine, 30 mg of 2,6-di-tert-butyl-4-methylphenol, and 20 mg of K₂CO₃ were added to 10 mL of dimethyl sulfoxide solution and stirred at 50 °C under a nitrogen atmosphere for 1 hour. Then, 2 g of 1,6-hexanediol diacrylate was added. After stirring the reaction mixture at 50 °C for 5 hours, it was poured into 100 mL of water, and the mixture was washed with n-hexane to remove excess 1,6-hexanediol diacrylate. The aqueous layer was extracted twice with dichloromethane. The combined extract was dried over Na₂SO₄, filtered, and concentrated using a rotary evaporator to remove all solvents. The residue was purified by column chromatography. The mass ratio of adenine, 2,6-di-tert-butyl-4-methylphenol, K₂CO₃, dimethyl sulfoxide, and 1,6-hexanediol diacrylate was 50:3:2:1000:200.
[0058] S6: Triblock polymer Poly(NIPAM-) was obtained via RAFT polymerization. co -AHA)- b -PEO- b -Poly(NIPAM- co -AHA) (NAONA);
[0059] A certain amount of PEG-CTA prepared in S4, N-isopropylacrylamide (NIPAM), AHA prepared in S5, and azobisisobutyronitrile (AIBN) were dissolved in 1,4-dioxane. The entire reaction system was bubbled through nitrogen gas before the reaction. The reaction temperature was 70℃, and the reaction time was 2436 hours. After the reaction was complete, the solution was added dropwise to a large amount of diethyl ether to precipitate the product; this purification process was repeated twice. The product was filtered and dried under vacuum overnight to obtain a white solid. The mass ratio of PEG-CTA, NIPAM, AHA, AIBN, and 1,4-dioxane was 500:1000:2:5000.
[0060] S7: NAONA polymer and SiO2@PDA-BNN6 were mixed in ice water to obtain a bio-adaptive injectable self-healing hydrogel.
[0061] The prepared triblock polymer NAONA (150 mg / mL) was dissolved in a PBS solution containing SiO2@PDA-BNN6 (0.3 mg / mL) and placed in the refrigerator for 24 hours.
[0062] like Figure 1 , 2 As shown in Figure 3, the mild photothermal NO-releasing injectable self-healing hydrogel dressing prepared by this invention for postoperative wound healing in oral cancer surgery exhibits excellent temperature sensitivity, injectability, and self-healing properties. It demonstrates excellent adaptability to complex postoperative wounds, and its outstanding cell and blood compatibility proves its suitability as an ideal biomaterial. Furthermore, it releases NO gas under mild photothermal conditions, achieving excellent bactericidal efficiency and effectively managing postoperative wound infection.
[0063] The preferred embodiments of the present invention have been described above. It should be noted that the present invention is not limited to the specific embodiments described above. The devices and structures not described in detail should be understood to be implemented in the ordinary way in the art. Any simple modifications, equivalent changes and modifications made by any person skilled in the art to the above embodiments based on the technical essence of the present invention without departing from the scope of the technical solution of the present invention shall still fall within the protection scope of the technical solution of the present invention.
Claims
1. A method for preparing a mild photothermal-releasing NO injectable self-healing hydrogel dressing for postoperative wound healing in oral cancer surgery, characterized in that, Includes the following steps: S1: Synthesis of SiO2@PDA nanoparticles; S2: N , N' -di-sec-butyl- N , N' Synthesis of 1,4-nitroso-1,4-phenylenediamine (BNN6); S3: Synthesis of SiO2@PDA-BNN6: The SiO2@PDA nanoparticles prepared in S1 were suspended in deionized water, and then BNN6-ethanol solution was added and stirred in the dark; the nanoparticles were collected by centrifugation and washed with deionized water; S4: Synthesis of the macromolecular chain transfer reagent PEO-CTA; S5: Synthesis of 6-((3-(6-amino-9-purinyl)propionyl)oxy)hexyl acrylate (AHA): Adenine, 2,6-di-tert-butyl-4-methylphenol, and K2CO3 were added to a dimethyl sulfoxide solution and stirred under a nitrogen atmosphere; then 1,6-hexanediol diacrylate was added; after the reaction, the solution was poured into water, and excess 1,6-hexanediol diacrylate was removed by washing with n-hexane. The aqueous layer was extracted with dichloromethane, and the collected organic layer was dried with Na2SO4, filtered, and concentrated by rotary evaporation to remove all solvents. The residue was purified by column chromatography. The mass ratio of adenine, 2,6-di-tert-butyl-4-methylphenol, K2CO3, dimethyl sulfoxide and 1,6-hexanediol diacrylate is (10 ~ 200): (1 ~ 6): (1 ~ 6): (500 ~ 5000): (100 ~ 400). S6: A triblock polymer Poly(NIPAM-co-AHA)-b-PEO-b-Poly(NIPAM-co-AHA) (NAONA) was obtained by RAFT polymerization: a certain amount of PEO-CTA prepared in S4, N-isopropylacrylamide (NIPAM), AHA prepared in S5, and azobisisobutyronitrile (AIBN) were dissolved in 1,4-dioxane. The entire reaction system was bubbled with nitrogen gas before the reaction. After the reaction was completed, the solution was added drop by drop to a large amount of diethyl ether or n-hexane precipitant to precipitate. The purification process was repeated twice. The product was filtered and dried under vacuum overnight to obtain a white solid. The mass ratio of PEO-CTA, NIPAM, AHA, AIBN and 1,4-dioxane is (2 ~ 15): (3 ~ 25): (1 ~ 5): (9 ~ 50). S7: NAONA polymer and SiO2@PDA-BNN6 were mixed in ice water to obtain a bio-adaptive injectable self-healing hydrogel.
2. The method for preparing a mild photothermal releasing NO injectable self-healing hydrogel dressing for postoperative wound healing in oral cancer surgery according to claim 1, characterized in that: The specific preparation steps of SiO2@PDA nanoparticles in step S1 include: adding 5-100 mL of deionized water, 5-25 mL of anhydrous ethanol, and 0.1-5 mL of ammonia water to a three-necked flask equipped with a magnetic stirrer and stirring at room temperature for 0.5-6 hours; then, adding 0.1-1 g of dopamine hydrochloride to the reaction solution and stirring for 12-48 hours; after the reaction, washing the product with water and ethanol by centrifugation 1-9 times; finally, mixing the washed product with 20-80 mL of acetic acid solution and adding it to a hydrothermal reactor; reacting at 80-200°C for 12-48 hours; after the reaction, washing with water / ethanol by centrifugation 1-9 times to obtain the final product SiO2@PDA; wherein, the mass ratio of deionized water, anhydrous ethanol, ammonia water, and dopamine hydrochloride is (50-1000):(50-200):(1-50):(1-10).
3. The method for preparing a mild photothermal-releasing NO injectable self-healing hydrogel dressing for postoperative wound healing in oral cancer surgery according to claim 1, characterized in that, The specific preparation steps of BNN6 in step S2 include: taking 1~5 g of... N, N' -Di-sec-butyl-1,4-phenylenediamine and 5-40 mL of anhydrous ethanol were sequentially added to a 100 mL three-necked flask equipped with a rotor, followed by the addition of 10-50 mL of 6 M potassium nitrite solution under N2 protection; then, 5-40 mL of 6 M hydrochloric acid solution was added to the three-necked flask, and the mixture was stirred for 10-120 minutes. The reaction was carried out at room temperature for 2-8 hours; the precipitate was obtained by centrifugation and washed 1-9 times with ethanol and aqueous solution, and then freeze-dried in the dark to obtain product BNN6; wherein, the deionization... N, N' The mass ratio of di-sec-butyl-1,4-phenylenediamine, anhydrous ethanol, hydrochloric acid solution and potassium nitrite solution is (1 ~ 5): (5 ~ 40): (5 ~ 40): (10 ~ 50).
4. The method for preparing a mild photothermal releasing NO injectable self-healing hydrogel dressing for postoperative wound healing in oral cancer, as described in claim 1, is characterized in that: The specific preparation steps of the macromolecular chain transfer reagent PEO-CTA in step S4 include: adding 2-15 g of trithioester 2-(dodecyltrithiocarbonate)-2-isobutyric acid (RAFT365) and 5-25 g of oxaloyl chloride to a three-necked flask equipped with a stirrer, and dissolving them in 5-50 mL of anhydrous dichloromethane; after the reaction is completed, evaporating the remaining oxaloyl chloride and dichloromethane in the flask to dryness; then adding 5-70 g of PEG and 45-150 mL of anhydrous dichloromethane to react; after the reaction is completed, precipitating with diethyl ether or n-hexane as a precipitant, drying, and obtaining the pale yellow product PEO-CTA; wherein the mass ratio of RAFT365, oxaloyl chloride, dichloromethane and PEG is (2-15):(5-25):(50-200):(5-70).
5. The method for preparing a mild photothermal-releasing NO injectable self-healing hydrogel dressing for postoperative wound healing in oral cancer surgery according to claim 1, characterized in that, The specific preparation steps of the injectable self-healing hydrogel for treating oral cancer in step S7 include: dissolving the prepared triblock polymer NAONA in a PBS solution containing SiO2@PDA-BNN6 and placing it in the refrigerator for 12 to 36 hours.
6. A mild photothermal-releasing NO injectable self-healing hydrogel dressing for postoperative wound healing in oral cancer surgery, characterized in that: A mild photothermal NO-releasing injectable self-healing hydrogel dressing for postoperative wound healing in oral cancer is prepared by the method described in any one of claims 1 to 5.