Antioxidant polymer and preparation method thereof, and self-repairing hydrogel and preparation method and application thereof

Abstract

The invention discloses an antioxidant polymer and a preparation method thereof as well as self-repairing hydrogel as well as a preparation method and application thereof, and relates to the technical field of hydrogel dressings. The preparation method of the anti-oxidation polymer comprises the following steps: adding a phenylboronic acid monomer, polyethylene glycol monomethyl ether methacrylate (PEGMA), an initiator, a second solvent and optionally 2-(methacryloyloxy) ethyl-6-methyl-4-ferrocene-2-thio-1, 2, 3, 4, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3, 5-tetramethyl-1, 3, the preparation method comprises the following steps: carrying out free radical copolymerization on raw materials including 1, 2, 3, 4-tetrahydropyrimidine-5-carboxylic ester (FM) to prepare the water-soluble antioxidant polymer. The preparation method comprises the following steps: firstly, synthesizing an antioxidant polymer with ferrocene and phenylboronic acid groups; the invention provides an antioxidant self-repairing hydrogel constructed by dynamic borate bonds. The hydrogel is prepared from common raw materials which are low in cost and easy to obtain, the preparation method is simple and efficient, the gel forming condition is mild, and the hydrogel has high application value.

Description

Technical Field

[0001] This invention relates to the field of hydrogel dressing technology, and more specifically, to an antioxidant polymer and its preparation method, and a self-healing hydrogel and its preparation method and application. Background Technology

[0002] Wound healing is an extremely complex biological process, and the repair of chronic wounds remains a challenge in current wound healing research. With the increasing demand for radiotherapy in cancer treatment, wound repair in radiotherapy patients is a matter of concern. Interfered with by numerous factors such as oxidative stress, immunosuppression, DNA damage, inflammatory effects, and impaired tissue regeneration induced by ionizing radiation, radiation wounds are difficult to heal and highly susceptible to further bacterial infection, ultimately developing into chronic, non-healing wounds.

[0003] Compared to traditional dressings such as gauze, cotton pads, and bandages, self-healing hydrogels are considered ideal dressings for promoting wound healing due to their excellent biocompatibility, ability to spontaneously adapt to irregular wounds, maintenance of a moist wound microenvironment, and similarity to natural tissue. However, common self-healing hydrogels cannot cope with the complex physiological environment of radiation wounds and struggle to integrate antioxidant, antibacterial, and anti-inflammatory effects to achieve effective treatment. Therefore, developing self-healing hydrogel dressings with excellent antioxidant, antibacterial, and anti-inflammatory functions has significant clinical implications and promising application prospects for treating chronic, difficult-to-heal radiation wounds, improving patients' quality of life, and reducing medical costs. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides an antioxidant polymer and its preparation method, as well as a self-healing hydrogel and its preparation method and application. This invention provides an antioxidant self-healing hydrogel constructed from dynamic borate ester bonds. This invention uses inexpensive and readily available common raw materials to prepare the hydrogel; the preparation method is simple and efficient, the gelation conditions are mild, and it has high application value.

[0005] One of the objectives of this invention is to provide an antioxidant polymer.

[0006] The antioxidant polymer of the present invention has the following structural formula:

[0007]

[0008] Where x is 0 or 30-90, y is 30-90, z is 30-90, n is 5-15, m is 1-20, X is one of the halogens, R1 and R2 can be the same or different, and are independently one of the C1-C10 alkyl groups, and R3 is a methyl or hydrogen atom.

[0009] In a preferred embodiment of the present invention:

[0010] x is 30-40, y is 30-40, z is 30-40, n is 8-10, m is 1-5, X is one of F, Cl, Br, I, preferably Cl or Br, and R1 and R2 are each independently one of C1-C3 alkyl groups.

[0011] A second objective of this invention is to provide a method for preparing an antioxidant polymer as described in one objective of this invention.

[0012] The method for preparing the antioxidant polymer of the present invention includes:

[0013] The water-soluble antioxidant polymer is prepared by free radical copolymerization of the raw materials including the phenylboronic acid monomer, polyethylene glycol monomethyl ether methacrylate (PEGMA), an initiator, a second solvent, and optionally 2-(methacryloyloxy)ethyl-6-methyl-4-ferrocene-2-thio-1,2,3,4-tetrahydropyrimidine-5-carboxylic acid ester (FM).

[0014] This invention uses free radical copolymerization to prepare water-soluble antioxidant polymers under mild conditions and with a simple and efficient synthesis process. It simplifies the process and reduces costs while improving yield and efficiency, which is beneficial for mass production.

[0015] In a preferred embodiment of the present invention:

[0016] The concentration of the phenylboronic acid monomer in the second solvent is 0.5–2 mol / L; preferably 1–1.2 mol / L; and / or,

[0017] The molar ratio of the initiator to the phenylboronic acid monomer is (0.005–0.02):1, preferably (0.01–0.015):1; and / or,

[0018] The molar ratio of 2-(methacryloyloxy)ethyl-6-methyl-4-ferrocene-2-thio-1,2,3,4-tetrahydropyrimidine-5-carboxylic acid ester, polyethylene glycol monomethyl ether methacrylate, and phenylboronic acid monomer is 1:(0.3-3):(0.3-3), preferably 1:(1-3):(1-3), and more preferably 1:(1-1.2):(1-1.2).

[0019] In a preferred embodiment of the present invention:

[0020] The structural formula of the phenylboronic acid monomer is:

[0021]

[0022] Where m is 1-20, preferably 1-5;

[0023] X is one of the halogens, preferably one of F, Cl, Br, and I, and more preferably Cl or Br;

[0024] R1 and R2 may be the same or different, and each is independently one of C1-C10 alkyl groups, preferably one of C1-C3 alkyl groups;

[0025] R3 is a methyl or hydrogen atom; and / or,

[0026] The initiator is at least one selected from azobisisobutyronitrile (AIBN), azobisisoheptanenitrile (ABVN), dimethyl azobisisobutyrate, and benzoyl peroxide; and / or,

[0027] The second solvent is at least one of N,N-dimethylformamide, acetonitrile, ethanol, and methanol.

[0028] The monomer FM used in this invention contains an antioxidant ferrocene group and a dihydropyrimidinone structure, which can exert a synergistic antioxidant effect. Compared with the existing single dihydropyrimidinone structure, it has a significantly stronger antioxidant capacity and can be prepared in large quantities through the Biginelli reaction. It is widely available, inexpensive and readily available.

[0029] In a preferred embodiment of the present invention:

[0030] The reaction temperature for the free radical copolymerization is 60–100°C, preferably 60–70°C, and / or the reaction time is 6–24 hours, preferably 20–24 hours.

[0031] In a preferred embodiment of the present invention, the phenylboronic acid monomer is prepared by the following method:

[0032] The phenylboronic acid monomer (BM) is prepared by subjecting the raw materials, including a tertiary amine monomer, halogenated phenylboronic acid and a first solvent, to a quaternization reaction.

[0033] Traditional methods for preparing functional monomers often result in low yields, complex operations, cumbersome post-processing, and high costs. This invention utilizes a one-step quaternization reaction between a tertiary amine monomer and a halogenated phenylboronic acid to obtain a phenylboronic acid monomer containing a phenylboronic acid group. This reaction is highly efficient and requires no purification.

[0034] In a preferred embodiment of the present invention:

[0035] The molar ratio of the tertiary amine monomer to the halogenated phenylboronic acid is 1:(1-2), preferably 1:(1-1.2); and / or,

[0036] The concentration of the halogenated phenylboronic acid in the first solvent is 0.5–2 mol / L; preferably 1–1.2 mol / L.

[0037] In a preferred embodiment of the present invention:

[0038] The tertiary amine monomer is Wherein R1 and R2 may be the same or different, and are each independently one of C1-C10 alkyl groups, preferably one of C1-C3 alkyl groups, and R3 is a methyl group or a hydrogen atom; the tertiary amine monomer may specifically be at least one of dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, diethylaminoethyl methacrylate, diethylaminoethyl methacrylate, dipropylaminoethyl methacrylate, dipropylaminoethyl methacrylate, dibutylaminoethyl methacrylate, dibutylaminoethyl methacrylate, dipentanaminoethyl methacrylate, and dipentanaminoethyl methacrylate; and / or,

[0039] The halogenated phenylboronic acid is Where m is 1-20, preferably 1-5, and X is one of the halogens, preferably one of F, Cl, Br, and I, more preferably Cl or Br; the halogenated phenylboronic acid can specifically be at least one of 4-(bromomethyl)phenylboronic acid, 4-(bromoethyl)phenylboronic acid, 4-(bromopropyl)phenylboronic acid, 4-(bromobutyl)phenylboronic acid, 4-(bromopentyl)phenylboronic acid, 4-(chloromethyl)phenylboronic acid, 4-(chloroethyl)phenylboronic acid, 4-(chloropropyl)phenylboronic acid, 4-(chlorobutyl)phenylboronic acid, and 4-(chloropentyl)phenylboronic acid; and / or,

[0040] The first solvent is at least one of N,N-dimethylformamide, acetonitrile, ethanol, methanol, and tetrahydrofuran.

[0041] In a preferred embodiment of the present invention:

[0042] The quaternization reaction is carried out at a temperature of 10–100°C, preferably 60–75°C, and / or for a reaction time of 0.5–24 hours, preferably 2–3 hours.

[0043] The third objective of this invention is to provide a self-healing hydrogel.

[0044] The self-healing hydrogel of the present invention comprises a mixture of the following components:

[0045] Solutions of antioxidant polymers as described in one objective of the present invention or solutions of antioxidant polymers prepared by the method as described in another objective of the present invention, polyvinyl alcohol solutions, and optionally antibacterial and anti-inflammatory drugs;

[0046] The mass concentration of the antioxidant polymer solution is 6% to 15%, preferably 8% to 10%;

[0047] The polyvinyl alcohol solution has a mass concentration of 6% to 12%, preferably 8% to 10%.

[0048] The volume ratio of the antioxidant polymer solution to the polyvinyl alcohol solution is 1:(0.5-2), preferably 1:(1-1.2);

[0049] The concentration of the antibacterial and anti-inflammatory drug in the solution of the antioxidant polymer is 0-10 mg / mL, preferably 0.5-4 mg / mL.

[0050] In a preferred embodiment of the present invention:

[0051] The polyvinyl alcohol (PVA) has a degree of polymerization of 500–1700 and / or a degree of alcoholysis of 88–99%; specifically, commonly used polyvinyl alcohols in the art, such as PVA1788, PVA1799, PVA0588, etc., can be used; and / or,

[0052] The solvent for the solution of the antioxidant polymer is at least one of phosphate-buffered saline (PBS), water, and physiological saline; preferably, the pH of the phosphate-buffered saline is 7-8; and / or,

[0053] The solvent for the polyvinyl alcohol solution is at least one of phosphate buffer, water, and physiological saline; preferably, the pH of the phosphate buffer is 7-8; and / or,

[0054] The antibacterial and anti-inflammatory drug is a flavonoid compound, preferably at least one of baicalin (BA), rutin, catechin, quercetin, myricetin, and luteolin, and more preferably baicalin.

[0055] The fourth objective of this invention is to provide a method for preparing a self-healing hydrogel as described in the third objective of this invention.

[0056] The method for preparing the self-healing hydrogel of the present invention includes:

[0057] The antibacterial and anti-inflammatory drug is optionally added to a solution of the antioxidant polymer, and then mixed with the polyvinyl alcohol solution to prepare the self-healing hydrogel.

[0058] Specifically, the following methods can be used:

[0059] By adding flavonoids, a natural small molecule drug with antibacterial and anti-inflammatory effects, such as baicalein (BA), to a solution of antioxidant polymers and then simply mixing it with a solution of polyvinyl alcohol, an antibacterial, anti-inflammatory, antioxidant, and self-repairing hydrogel can be prepared quickly.

[0060] The fifth objective of this invention is to provide an application of a self-healing hydrogel as described in the third objective of this invention or a self-healing hydrogel prepared by the method described in the fourth objective of this invention in the preparation of at least one of antioxidant products, radiation damage protection products, and wound dressing products.

[0061] This invention utilizes safe, inexpensive, and readily available materials to prepare an antibacterial, anti-inflammatory, antioxidant, and self-healing hydrogel. First, an antioxidant polymer containing ferrocene and phenylboronic acid groups was synthesized. This antioxidant polymer contains ferrocene groups, which, due to their highly efficient free radical scavenging ability when uniformly distributed within the hydrogel network, can exert a long-lasting antioxidant effect, clearing excess reactive oxygen species (ROS) at the wound site. Therefore, the hydrogel of this invention exhibits excellent antioxidant properties. Simultaneously, the phenylboronic acid groups on the polymer can form dynamic borate ester bonds with PVA to construct a self-healing hydrogel. Furthermore, they can bind natural flavonoids with antibacterial and anti-inflammatory effects, enabling their responsive release upon ROS stimulation, thus exerting antibacterial and anti-inflammatory effects. Since natural flavonoids such as baicalin have limited solubility and cannot exert antibacterial and anti-inflammatory effects at wound sites, the introduction of polyethylene glycol monomethyl ether methacrylate into the antioxidant polymer of this invention can improve the water solubility of the polymer, thereby enhancing the water solubility of baicalin. Furthermore, it can intelligently bind baicalin through borate ester bonds, so that after the antioxidant gelling polymer is mixed with PVA to form a gel, it can responsively release baicalin under the action of ROS at the wound site to exert antibacterial and anti-inflammatory effects.

[0062] This invention has demonstrated satisfactory cellular safety, low cytotoxicity, excellent self-healing properties, antioxidant properties, antibacterial properties, and the ability to protect cells from oxidative damage after radiation. This biocompatible, antibacterial, anti-inflammatory, antioxidant, and self-healing hydrogel adapts to irregular wound shapes, scavenge excess free radicals at radiation wound sites, and addresses the complex physiological environment of radiation wounds, thereby effectively promoting wound healing. This provides a new strategy for developing novel materials that promote the healing of radiation wounds and chronic wounds. Attached Figure Description

[0063] Figure 1 This is a synthetic route diagram of the antioxidant polymer in Example 1;

[0064] Figure 2 The phenylboronic acid monomer prepared in Example 1 1 H-NMR hydrogen nuclear magnetic spectrum;

[0065] Figure 3 The phenylboronic acid monomer prepared in Example 1 13 C-NMR carbon NMR spectrum;

[0066] Figure 4 Infrared spectra of the antioxidant polymers prepared in Examples 1 and 2, the polymer prepared in Comparative Example 1, and the self-healing hydrogel prepared in Example 3.

[0067] Wherein, PBFM-BA@Gel is the self-healing hydrogel prepared in Example 3, PBFM is the antioxidant polymer prepared in Example 1, PBM is the antioxidant polymer prepared in Example 2, PFM is the polymer prepared in Comparative Example 1, and PVA is polyvinyl alcohol.

[0068] Figure 5 This is a schematic diagram illustrating the formation process of the self-healing hydrogel prepared in Example 3;

[0069] Figure 6 These are photographs of the self-healing process of the self-healing hydrogel prepared in Example 3.

[0070] Figure 7 The graph shows the modulus change of the self-healing hydrogel prepared in Example 3 as strain increases.

[0071] Figure 8 The graph shows the modulus change of the self-healing hydrogel prepared in Example 3 under alternating strain.

[0072] Figure 9 The graph shows the cell safety evaluation results of the self-healing hydrogels prepared in Examples 3-5.

[0073] Wherein, Control is the blank group, PBM@Gel is the self-healing hydrogel prepared in Example 5, PBFM@Gel is the self-healing hydrogel prepared in Example 4, and PBFM-BA@Gel is the self-healing hydrogel prepared in Example 3.

[0074] Figure 10 The self-healing hydrogels prepared in Examples 3-5 are used to remove ABTS. +· Kinetic curves of free radicals;

[0075] Blank is the blank group, PBM@Gel is the self-healing hydrogel prepared in Example 5, PBFM@Gel is the self-healing hydrogel prepared in Example 4, and PBFM-BA@Gel is the self-healing hydrogel prepared in Example 3.

[0076] Figure 11 The graph shows the test results of the responsive release ability of the self-healing hydrogel prepared in Example 3 to scutellarin.

[0077] Figure 12 Comparative photographs of the antibacterial properties of the self-healing hydrogels prepared in Examples 3, 4 and 6;

[0078] In this context, Control represents the blank group, PBFM@Gel represents the self-healing hydrogel prepared in Example 4, PBFM-BA-1@Gel represents the self-healing hydrogel prepared in Example 6, and PBFM-BA@Gel represents the self-healing hydrogel prepared in Example 3.

[0079] Figure 13 The graph shows the antibacterial rate of the self-healing hydrogels prepared in Examples 3, 4 and 6 against Gram-negative bacteria (Escherichia coli).

[0080] In this context, Control represents the blank group, PBFM@Gel represents the self-healing hydrogel prepared in Example 4, PBFM-BA-1@Gel represents the self-healing hydrogel prepared in Example 6, and PBFM-BA@Gel represents the self-healing hydrogel prepared in Example 3.

[0081] Figure 14 The graph shows the antibacterial rate of the self-healing hydrogels prepared in Examples 3, 4 and 6 against Gram-positive bacteria (S. aureus).

[0082] In this context, Control represents the blank group, PBFM@Gel represents the self-healing hydrogel prepared in Example 4, PBFM-BA-1@Gel represents the self-healing hydrogel prepared in Example 6, and PBFM-BA@Gel represents the self-healing hydrogel prepared in Example 3.

[0083] Figure 15 The graph shows the antibacterial rate of the self-healing hydrogels prepared in Examples 3, 4 and 6 against Pseudomonas aeruginosa, a drug-resistant bacterium that commonly causes wounds.

[0084] In this context, Control represents the blank group, PBFM@Gel represents the self-healing hydrogel prepared in Example 4, PBFM-BA-1@Gel represents the self-healing hydrogel prepared in Example 6, and PBFM-BA@Gel represents the self-healing hydrogel prepared in Example 3.

[0085] Figure 16 The graph shows the test results of the ability of the self-healing hydrogels prepared in Examples 3-5 to resist radiation and oxidative damage to cells.

[0086] Wherein, Control represents the non-radiated group, Radiation represents the radiated group, PBM@Gel represents the self-healing hydrogel prepared in Example 5, PBFM@Gel represents the self-healing hydrogel prepared in Example 4, and PBFM-BA@Gel represents the self-healing hydrogel prepared in Example 3. Detailed Implementation

[0087] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0088] Unless otherwise specified, the experimental methods used in the following examples and comparative examples are conventional methods.

[0089] Unless otherwise specified, all materials and reagents used in the following examples and comparative examples are commercially available.

[0090]

Example 1

[0091] The synthetic route of the antioxidant polymer PBFM is as follows: Figure 1 As shown.

[0092] 1. Preparation of phenylboronic acid monomer BM

[0093] The phenylboronic acid monomer BM was synthesized via a quaternization reaction using dimethylaminoethyl methacrylate and 4-(bromomethyl)phenylboronic acid as reactants. Dimethylaminoethyl methacrylate and 4-(bromomethyl)phenylboronic acid were added to tetrahydrofuran at a molar ratio of 1:1 for the quaternization reaction. The concentration of 4-(bromomethyl)phenylboronic acid in tetrahydrofuran was 1 mol / L. The reaction temperature was 70 °C, and the reaction time was 2 hours. The phenylboronic acid monomer BM was obtained by rotary evaporation of the solvent.

[0094] Depend on Figure 2 shown 1 H-NMR spectrum and Figure 3 shown 13 The C-NMR spectrum shows that the phenylboronic acid monomer BM was obtained in this example.

[0095] 2. Preparation of antioxidant polymer PBFM

[0096] The antioxidant polymer PBFM was prepared by free radical copolymerization of phenylboronic acid monomer BM, 2-(methacryloyloxy)ethyl-6-methyl-4-ferrocene-2-thio-1,2,3,4-tetrahydropyrimidine-5-carboxylic acid ester FM, and polyethylene glycol monomethyl ether methacrylate PEGMA (Mn ~ 950 g / mol) in a molar ratio of 1:1:1. Azobisisobutyronitrile (AIBN) was used as the initiator, with a molar ratio of AIBN to BM of 0.005:1. The reaction was carried out in an oil bath at 60°C in N,N-dimethylformamide (DMF) for 24 hours, with the concentration of BM in DMF being 1 mol / L. The reaction mixture was then simply precipitated in diethyl ether to obtain the antioxidant polymer PBFM.

[0097] Depend on Figure 4 The infrared spectrum of the antioxidant polymer PBFM shown can be observed at ~1561 cm⁻¹. -1 Expansion and contraction vibrations from the ferrocene ring skeleton, ~970cm -1The COC stretching vibration peak from PEGMA, and ~650 cm⁻¹ -1 and ~706cm -1 The CH bending vibration peaks originating from the benzene ring of phenylboronic acid. These collectively demonstrate that the antioxidant polymer PBFM was obtained in this embodiment.

[0098]

Example 2

[0099] Preparation of antioxidant polymer PBM: The method of Example 1 was followed, except that 2-(methacryloyloxy)ethyl-6-methyl-4-ferrocene-2-thio-1,2,3,4-tetrahydropyrimidine-5-carboxylic acid ester FM was not added, and the molar ratio of BM to PEGMA was 1:2.

[0100] The antioxidant polymer PBM can be prepared by free radical copolymerization of BM and PEGMA (Mn ~ 950 g / mol) at a molar ratio of 1:2.

[0101] Depend on Figure 4 As shown in the PBM infrared spectrum, compared to PBFM, PBM does not exhibit a peak for ferrocene groups, but retains a peak at ~970 cm⁻¹. -1 The COC stretching vibration peaks from PEGMA, and at ~650 and ~706 cm⁻¹ -1 The CH bending vibration peaks originating from the benzene ring of phenylboronic acid indicate that the antioxidant polymer PBM was obtained in this embodiment.

[0102] Comparative Example 1

[0103] Preparation of polymer PFM: The method of Example 1 was followed, except that BM was not added and the molar ratio of FM and PEGMA was 1:2.

[0104] The control polymer PFM can be prepared by free radical copolymerization of FM and PEGMA (Mn ~ 950 g / mol) at a molar ratio of 1:2.

[0105] Depend on Figure 4 As shown in the PFM infrared spectrum, compared to PBFM, PFM does not have a peak for the benzene ring of phenylboronic acid, but retains a peak at ~1561 cm⁻¹. -1 The stretching vibrations from the ferrocene ring skeleton, and ~970cm -1 The COC stretching vibration peaks from PEGMA. These indicate that the polymer PFM used as a control was obtained in this comparative example.

[0106]

Example 3

[0107] Preparation of self-healing hydrogel PBFM-BA@Gel:

[0108] The PBFM and PVA (PVA-0588, degree of polymerization 500, degree of alcoholysis 88%) obtained in Example 1 were dissolved in PBS solution (pH ~7.2-7.4) to prepare PBFM solution (mass concentration 8%) and PVA solution (mass concentration 8%), respectively. 4 mg / mL of baicalein (BA) was added to the PBFM solution to prepare PBFM-BA solution; Figure 5 As shown, PBFM-BA solution and polyvinyl alcohol (PVA) solution are mixed in a 1:1 volume ratio, and the antibacterial, anti-inflammatory, antioxidant, and self-healing hydrogel PBFM-BA@Gel can be rapidly prepared within 30 seconds.

[0109] The infrared spectrum of self-healing hydrogels is as follows: Figure 4 As shown, it has a range of ~3350cm -1 The peak of the -OH stretching vibration of PVA in the dynamic bond is ~1561 cm⁻¹. -1 Expansion and contraction vibrations from the ferrocene ring skeleton, ~970cm -1 The COC stretching vibration peak from PEGMA, and ~650 cm⁻¹ -1 and 706cm -1 The CH bending vibration peaks originate from the benzene ring of phenylboronic acid. These indicate that the self-healing hydrogel PBFM-BA@Gel was obtained in this embodiment.

[0110]

Example 4

[0111] Preparation of self-healing hydrogel PBFM@Gel: The method of Example 3 is followed, except that BA is not added.

[0112]

Example 5

[0113] Preparation of self-healing hydrogel PBM@Gel: The method of Example 4 is followed, except that the PBFM prepared in Example 1 is replaced with the PBM prepared in Example 2 to prepare the self-healing hydrogel PBM@Gel.

[0114]

Example 6

[0115] Preparation of self-healing hydrogel PBFM@Gel: The method of Example 3 is followed, except that 2 mg / mL of baicalein (BA) is added to the PBFM solution to prepare PBFM-BA solution, and the self-healing hydrogel PBFM-BA-1@Gel can be prepared.

[0116] The self-healing hydrogels prepared in the above embodiments were subjected to the following performance tests:

[0117] 1. Self-healing performance test

[0118] Qualitative characterization: 0.5 mL of the PBFM-BA@Gel prepared in Example 3 was used to form a 20 mm heart-shaped hydrogel sample. The sample was then divided in half and placed back together. Figure 6 As shown, the two halves completely healed into a single heart shape after 15 minutes. This demonstrates the self-healing properties of the hydrogel.

[0119] Quantitative characterization: Rheological tests (referencing the method in the prior art "An antioxidant self-healing hydrogel for 3D cell cultures") were used to quantitatively evaluate the self-healing ability of the self-healing hydrogel prepared in Example 3.

[0120] like Figure 7 As shown, the elastic modulus G' and storage modulus G” of the self-healing hydrogel remain stable in the linear viscoelastic region under small strains less than 10%. When the strain reaches 321%, G” exceeds G', indicating that the hydrogel network is completely destroyed. Therefore, alternating large strains (400%) that disrupt the hydrogel network structure and small strains (1%) that remain in the linear viscoelastic region are applied to the hydrogel. Figure 8 As shown, the hydrogel (PBFM-BA@Gel) network was completely destroyed under 400% strain, but then rapidly recovered to its original strength under a small strain of 1%. These results demonstrate that the self-healing hydrogel of the present invention has good self-healing capabilities.

[0121] 2. Cell safety testing (refer to the method described in the existing technology "An antioxidant self-healing hydrogel for 3D cell cultures").

[0122] 1 mL of the self-healing hydrogels prepared in Examples 3-5 were immersed in 10 mL of culture medium (RPMI-1640:serum:antibody = 100:10:1) for 24 h to obtain hydrogel extracts. Mouse fibroblasts (L929) were cultured with these extracts, and CCK-8 assays were performed on these cells after 24 hours.

[0123] The results are as follows Figure 9 The cell survival rate after treatment with the self-healing hydrogel is shown. The self-healing hydrogel of the present invention has good cell safety, and the cell survival rate is similar to that of the control group, at around 100%.

[0124] 3. Antioxidant test (refer to the method in the existing technology "An antioxidant self-healing hydrogel for 3D cell cultures")

[0125] The self-healing hydrogels (0.2 mL) prepared in Examples 3-5 were added to ABTS respectively. +· The free radical scavenging ability of the self-healing hydrogel was characterized by a solution (2 mL), with PBS buffer as a blank group. All four groups were operated in parallel.

[0126] The results are as follows Figure 10 As shown, compared to the blank group, the ABTS processed by PBM@Gel... +· The absorbance of the solution at 734 nm decreased from ~0.8 A to ~0.4 A within 60 minutes, and PBFM-BA@Gel and PBFM@Gel exhibited superior free radical scavenging ability in the treated ABTS. +· The absorbance of the solution at 734 nm decreased from ~0.8 A to below 0.1 A within 10 minutes, indicating that the self-healing hydrogel with ferrocene groups has a better antioxidant effect.

[0127] 4. Responsive release test (refer to the method in the existing technology A ROS / glucose stimulated-responsive ADSCs-derived exosomes-release hydrogel system for diabetic wound healing)

[0128] The self-healing hydrogel PBFM-BA@Gel prepared in Example 3 was immersed in PBS solution and PBS solution with added hydrogen peroxide (1 mM), respectively. The concentration of baicalein (BA) in the solution at 276 nm at different times was detected by ultraviolet absorption spectroscopy.

[0129] Test results are as follows Figure 11 As shown, the hydrogel encapsulates baicalenin through dynamic bonds, enabling it to release baicalenin in response to ROS stimulation, achieving an equilibrium release rate of approximately 87% within 12 hours.

[0130] 5. Antibacterial ability test (refer to the method in existing technology Hydrogel dressings with intrinsic antibiofilm and antioxidative dual functionalities accelerate infected diabetic wound healing)

[0131] The ability of the self-healing hydrogels prepared in Examples 3, 4, and 6 to inhibit Gram-negative bacteria (Escherichia coli), Gram-positive bacteria (S. aureus), and drug-resistant Pseudomonas aeruginosa, a common bacterium in wounds, was evaluated. The inhibition rates of the self-healing hydrogels against the three bacteria were calculated by counting the bacteria after co-culturing them with self-healing hydrogels of different BA concentrations.

[0132] Test results are as follows Figure 12-15 As shown, the self-healing hydrogel exhibits good antibacterial activity against both Gram-negative and Gram-positive bacteria. It also demonstrates good antibacterial effect against *Pseudomonas aeruginosa*, a drug-resistant wound bacterium. The antibacterial activity of the self-healing hydrogel increases with increasing BA content; the PBFM-BA@Gel in Example 3 achieves a 100% inhibition rate.

[0133] 6. Cellular resistance to radiation and oxidative damage experiments

[0134] One mL of the self-healing hydrogel prepared in Examples 3-5 was immersed in 10 mL of culture medium (RPMI-1640:serum:antibody = 100:10:1) for 24 h to obtain hydrogel extracts. These extracts were then used to replace the culture medium for mouse fibroblasts (L929). After 6 h, the cells were irradiated with 4 Gy of X-rays, and the reactive oxygen species (ROS) levels were measured 1 h after irradiation using DCFH-DA fluorescence staining. The test results are as follows: Figure 16 As shown, compared with the blank irradiated cells, the fluorescence intensity of cells in the PBM@Gel group, PBFM@Gel group and PBFM-BA@Gel group was significantly reduced. The fluorescence intensity of the PBFM-BA@Gel group was the weakest, and the ROS level was the lowest, which was similar to the ROS level of the unirradiated cells. This indicates that the self-healing hydrogel of the present invention has a good effect on resisting oxidative damage to cells after radiation and can be used for the treatment of radiation wounds.

Claims

1. An antioxidant polymer, characterized in that... The structural formula of the antioxidant polymer is: Where x is 0 or 30-90, y is 30-90, z is 30-90, n is 5-15, m is 1-20, X is one of the halogens, R1 and R2 can be the same or different, and are independently one of the C1-C10 alkyl groups, and R3 is a methyl or hydrogen atom.

2. The antioxidant polymer according to claim 1, characterized in that: x is 30-40, y is 30-40, z is 30-40, n is 8-10, m is 1-5, X is one of F, Cl, Br, I, preferably Cl or Br, and R1 and R2 are each independently one of C1-C3 alkyl groups.

3. A method for preparing the antioxidant polymer as described in claim 1 or 2, characterized in that... The method includes: The antioxidant polymer is prepared by free radical copolymerization of raw materials including the phenylboronic acid monomer, polyethylene glycol monomethyl ether methacrylate, initiator, second solvent and optionally 2-(methacryloyloxy)ethyl-6-methyl-4-ferrocene-2-thio-1,2,3,4-tetrahydropyrimidine-5-carboxylic acid ester.

4. The method according to claim 3, characterized in that: The concentration of the phenylboronic acid monomer in the second solvent is 0.5–2 mol / L; preferably 1–1.2 mol / L; and / or, The molar ratio of the initiator to the phenylboronic acid monomer is (0.005–0.02):1, preferably (0.01–0.015):1; and / or, The molar ratio of 2-(methacryloyloxy)ethyl-6-methyl-4-ferrocene-2-thio-1,2,3,4-tetrahydropyrimidine-5-carboxylic acid ester, polyethylene glycol monomethyl ether methacrylate, and phenylboronic acid monomer is 1:(0.3-3):(0.3-3), preferably 1:(1-3):(1-3), and more preferably 1:(1-1.2):(1-1.2).

5. The method according to claim 3, characterized in that: The structural formula of the phenylboronic acid monomer is: Where m is 1-20, preferably 1-5; X is one of the halogens, preferably one of F, Cl, Br, and I, and more preferably Cl or Br; R1 and R2 may be the same or different, and each is independently one of C1-C10 alkyl groups, preferably one of C1-C3 alkyl groups; R3 is a methyl or hydrogen atom; and / or, The initiator is at least one selected from azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, and benzoyl peroxide; and / or, The second solvent is at least one of N,N-dimethylformamide, acetonitrile, ethanol, and methanol.

6. The method according to claim 3, characterized in that: The reaction temperature for the free radical copolymerization is 60–100°C, preferably 60–70°C, and / or the reaction time is 6–24 hours, preferably 20–24 hours.

7. The method according to any one of claims 3-5, characterized in that... The phenylboronic acid monomer is prepared by the following method: The phenylboronic acid monomer is prepared by subjecting the raw materials, including a tertiary amine monomer, halogenated phenylboronic acid and a first solvent, to a quaternization reaction.

8. The method according to claim 7, characterized in that: The molar ratio of the tertiary amine monomer to the halogenated phenylboronic acid is 1:(1-2), preferably 1:(1-1.2); and / or, The concentration of the halogenated phenylboronic acid in the first solvent is 0.5–2 mol / L; preferably 1–1.2 mol / L.

9. The method according to claim 7, characterized in that: The tertiary amine monomer is Wherein R1 and R2 may be the same or different, and are each independently one of C1-C10 alkyl groups, preferably one of C1-C3 alkyl groups, and R3 is a methyl group or a hydrogen atom; and / or, The halogenated phenylboronic acid is Where m is 1-20, preferably 1-5, and X is one of the halogens, preferably one of F, Cl, Br, and I, more preferably Cl or Br; and / or, The first solvent is at least one of N,N-dimethylformamide, acetonitrile, ethanol, methanol, and tetrahydrofuran.

10. The method according to claim 7, characterized in that: The quaternization reaction is carried out at a temperature of 10–100°C, preferably 60–75°C, and / or for a reaction time of 0.5–24 hours, preferably 2–3 hours.

11. A self-healing hydrogel, characterized in that... The self-healing hydrogel comprises a mixture of the following components: Solutions of antioxidant polymers as described in claim 1 or 2, or antioxidant polymers prepared by the method as described in any one of claims 3-10, polyvinyl alcohol solutions, and optionally antibacterial and anti-inflammatory drugs; The mass concentration of the antioxidant polymer solution is 6% to 15%, preferably 8% to 10%; The mass concentration of the polyvinyl alcohol solution is 6% to 12%, preferably 8% to 10%; The volume ratio of the antioxidant polymer solution to the polyvinyl alcohol solution is 1:(0.5-2), preferably 1:(1-1.2); The concentration of the antibacterial and anti-inflammatory drug in the solution of the antioxidant polymer is 0-10 mg / mL, preferably 0.5-4 mg / mL.

12. The self-healing hydrogel according to claim 11, characterized in that: The degree of polymerization of the polyvinyl alcohol is 500–1700, and / or the degree of alcoholysis is 88–99%; and / or, The solvent for the solution of the antioxidant polymer is at least one selected from phosphate buffer, water, and physiological saline; preferably, the pH of the phosphate buffer is 7-8; and / or, The solvent for the polyvinyl alcohol solution is at least one of phosphate buffer, water, and physiological saline; preferably, the pH of the phosphate buffer is 7-8; and / or, The antibacterial and anti-inflammatory drug is a flavonoid compound, preferably at least one of scutellarin, rutin, catechin, quercetin, myricetin, and luteolin, and more preferably scutellarin.

13. A method for preparing a self-healing hydrogel as described in claim 11 or 12, characterized in that... The method includes: The antibacterial and anti-inflammatory drug is optionally added to a solution of the antioxidant polymer, and then mixed with the polyvinyl alcohol solution to prepare the self-healing hydrogel.

14. The application of a self-healing hydrogel as described in claim 11 or 12, or a self-healing hydrogel prepared by the method as described in claim 13, in the preparation of at least one of antioxidant products, radiation damage protection products, and wound dressing products.

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