Analgesic polysaccharide-based hydrogel as well as preparation method and application thereof

Abstract

The invention provides analgesic polysaccharide-based hydrogel and a preparation method and application thereof, and belongs to the technical field of biomedical materials.The method comprises the steps that hyaluronic acid is dissolved in water, a catalyst for activating carboxyl is added, a water-soluble long-chain molecule containing amino and a small-molecule analgesic drug are added, and the mixture is stirred to be uniform; a pregabalin-loaded hyaluronic acid-carboxymethyl chitosan polymer is obtained through the action of an amido bond and a hydrogen bond, the polymer is purified, freeze-dried and collected, and the analgesic polysaccharide-based hydrogel is obtained after swelling is conducted again. The preparation method is simple, convenient to operate, low in cost and suitable for large-scale production. Experimental results prove that the analgesic polysaccharide-based hydrogel prepared by the method releases small-molecule analgesic drugs through pH responsiveness, has good biocompatibility and good biological effects in vivo and in vitro, can show good performance of removing ROS in cells, and can be used for preparing the analgesic polysaccharide-based hydrogel. Healing of burn wounds can be promoted, and pain after burns and acute facial pain can be relieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical materials, and particularly relates to an analgesic polysaccharide-based hydrogel, a preparation method thereof, and an application thereof. Background Art

[0002] Patients after burns will suffer severe pain, which can be divided into traumatic pain, neuropathic pain, inflammatory pain, and operative pain according to different sources. During the treatment of burns, traumatic pain, inflammatory pain, and operative pain mostly decrease with the healing of the wound. However, neuropathic pain, especially chronic neuropathic pain, will become a serious sequela of burns. Six point zero one percent of patients still have pain symptoms 5 years after burns, which seriously affects the quality of life and mental state of burn patients and may lead to post-traumatic stress disorder, insomnia, and even suicide. Although there has been quite a lot of research on this, there is still a lack of effective treatment methods to manage short-term or long-term pain caused by burns.

[0003] The treatment concept of modern medicine advocates the transformation from the traditional biomedical model to the "physiological-psychological-social" medical model, which means that the treatment of burn wounds is not only simple wound healing, but also involves wound healing at the physiological level and pain relief at the psychological level. Hydrogel materials have received increasing attention due to their excellent hydrophilicity and biocompatibility. They can cool the burned area to reduce "secondary burns" and relieve the burning pain of patients, which is of great significance for soothing the painful psychology of patients and the healing of skin wounds. However, the current research direction of hydrogel dressings mainly focuses on the engineering regulation of wound repair such as anti-infection, anti-inflammation, promoting angiogenesis, and reducing scar formation, paying less attention to the particularity of burn wounds and ignoring the need to relieve the pain of burn patients. In view of the physiological characteristics of burns, how to effectively design material components to synthesize a bioactive hydrogel dressing that can not only achieve rapid healing of burn wounds but also relieve pain after burns is still an urgent problem to be solved. Summary of the Invention

[0004] To solve the problems of the prior art, the present invention provides an analgesic polysaccharide-based hydrogel, a preparation method thereof, and an application thereof. The analgesic polysaccharide-based hydrogel prepared by this method has good biocompatibility and good biological effects both in vitro and in vivo.

[0005] To achieve the above object, the present invention adopts the following technical solutions: The first object of the present invention is to provide a preparation method of an analgesic polysaccharide-based hydrogel, including: Dissolve hyaluronic acid in water, add a catalyst for activating carboxyl groups, add a water-soluble long-chain molecule containing amino groups and a small molecule analgesic drug, and react to obtain a hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin. Purify, freeze-dry, and collect the hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin, and then obtain an analgesic polysaccharide-based hydrogel after swelling again.

[0006] As a further improvement of the present invention, the catalyst for activating carboxyl groups is 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide.

[0007] As a further improvement of the present invention, the water-soluble long-chain molecule containing amino groups is carboxymethyl chitosan or O-acylated chitosan.

[0008] As a further improvement of the present invention, the small molecule analgesic drugs are pregabalin, gabapentin, carbamazepine, oxcarbazepine, celecoxib, diclofenac diethylamine, ibuprofen, curcumin, and capsaicin.

[0009] As a further improvement of the present invention, the molar ratio of hyaluronic acid, catalyst, water-soluble long-chain molecule containing amino groups, and small molecule analgesic drug is 1:(0.001 - 1.000):(0.001 - 1.000):(0.001 - 1.000).

[0010] As a further improvement of the present invention, the temperature of the reaction is 20 - 25°C, the catalytic time of the catalyst is 0.5 - 2 hours, and the final reaction time is 6 hours.

[0011] As a further improvement of the present invention, purifying, freeze-drying, and collecting the hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin includes: dialyzing the hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin with a dialysis bag for 2 - 3 days, freeze-drying the dialyzed polymer, and storing it in an environment of ≤4°C after swelling again.

[0012] The second object of the present invention is that the analgesic polysaccharide-based hydrogel prepared by the described preparation method has important applications in the treatment of skin burn wounds and the relief of facial acute pain.

[0013] In the first aspect, an application of an analgesic polysaccharide-based hydrogel in a dressing for skin tissue burn wounds.

[0014] In the second aspect, an application of an analgesic polysaccharide-based hydrogel in the relief of facial acute pain.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The method of the present invention can prepare an analgesic polysaccharide-based hydrogel for promoting burn wound healing and pain management. By connecting the carboxyl group of hyaluronic acid and the amino group of carboxymethyl chitosan through an amidation reaction, the polymer is purified, freeze-dried and collected, and then swollen again to obtain an analgesic polysaccharide-based hydrogel. A small molecule analgesic drug, pregabalin, is loaded in the hydrogel in the form of hydrogen bonds, thereby synthesizing the analgesic polysaccharide-based hydrogel. The synthesis process of the present invention is green and environmentally friendly, the synthesis raw materials are cheap and affordable, and the yield is high, which is suitable for mass production. Moreover, the experimental results prove that the analgesic polysaccharide-based hydrogel prepared by this method can achieve pH-responsive controlled release of the analgesic drug, has good biocompatibility and good biological effects in vitro and in vivo, can exhibit good performance in scavenging intracellular ROS, can accelerate burn wound healing, and relieve pain after burns. Therefore, this polymer has good application prospects in post-burn tissue repair and pain management. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. The drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a schematic diagram of the synthesis process of the analgesic polysaccharide-based hydrogel prepared by the present invention; Figure 2 It is an FTIR diagram of the analgesic polysaccharide-based hydrogel prepared by the present invention; Figure 3 It is a TEM diagram of the analgesic polysaccharide-based hydrogel prepared by the present invention; Figure 4 It is the drug release behavior of the analgesic polysaccharide-based hydrogel prepared by the present invention at different pH values; Figure 5 It is the cytotoxicity determination of the analgesic polysaccharide-based hydrogel prepared by the present invention on mouse fibroblasts (L929); Figure 6 [[ID=2)4]]It is the result of the in vitro down-regulation of ROS in Raw264.7 cells by the analgesic polysaccharide-based hydrogel prepared by the present invention; Figure 7 It is the result of the in vivo treatment of burn wounds by the analgesic polysaccharide-based hydrogel prepared by the present invention; Figure 8 It is the result of the in vivo relief of pain after burns by the analgesic polysaccharide-based hydrogel prepared by the present invention; Figure 9 It is the result of the in vivo relief of acute facial pain by the analgesic polysaccharide-based hydrogel prepared by the present invention. Detailed implementation manners

[0018] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clear and understandable, the present application will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0019] In the present application, the term "and / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may indicate: A exists alone, A and B exist simultaneously, and B exists alone. Wherein A and B may be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0020] In the present application, "at least one" means one or more, and "a plurality" means two or more. "At least one (item)" or its similar expression below refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, "at least one (item) of a, b, or c", or, "at least one (item) of a, b, and c" can both represent: a, b, c, a-b (that is, a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple respectively.

[0021] It should be understood that in various embodiments of the present application, the magnitude of the serial numbers of the above processes does not mean the order of execution. Some or all steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0022] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "the" and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0023] The weight of the relevant components mentioned in the specification of the embodiments of the present application not only can refer to the specific content of each component, but also can represent the proportional relationship of the weights between the components. Therefore, as long as the content of the relevant components in the specification of the embodiments of the present application is enlarged or reduced in proportion, it is within the scope disclosed in the specification of the embodiments of the present application. Specifically, the mass described in the specification of the embodiments of the present application can be mass units well-known in the chemical industry such as µg, mg, g, kg, etc.

[0024] The first object of the present invention is to provide a preparation method of an analgesic polysaccharide-based hydrogel, including: Dissolve hyaluronic acid in water, add a catalyst for activating carboxyl groups, add a water-soluble long-chain molecule containing amino groups and a small molecule analgesic drug, and react to obtain a hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin. After dialysis, it is freeze-dried and swollen to obtain an analgesic polysaccharide-based hydrogel.

[0025] The method of the present invention can prepare an analgesic polysaccharide-based hydrogel for promoting burn repair and pain management. The carboxyl group of hyaluronic acid and the amino group of carboxymethyl chitosan are connected through an amidation reaction, and then the analgesic drug pregabalin is loaded into the hydrogel in the form of hydrogen bonds, thereby synthesizing an analgesic polysaccharide-based hydrogel. The synthesis process of the present invention is green and environmentally friendly, the synthesis raw materials are cheap and affordable, and the yield is high, which is suitable for mass production. And the experimental results prove that the analgesic polysaccharide-based hydrogel prepared by this method can achieve pH-responsive release of the analgesic drug, has good biocompatibility and good biological effects in vivo and in vitro, can show good performance in scavenging intracellular ROS, can accelerate the healing of burn wounds, relieve pain after burns, so this polymer has good application prospects in the treatment of post-burn tissue repair, pain management and facial acute pain.

[0026] As a specific embodiment, the present invention provides a method for preparing an analgesic polysaccharide-based hydrogel for treating burns, comprising the following steps: 1) Dissolve 1 mol of hyaluronic acid in water, add 0.001 - 1 mol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, react at room temperature for 0.5 - 2 hours, add 0.001 - 1 mol of carboxymethyl chitosan and 0.001 - 1 mol of pregabalin, stir evenly and react at room temperature for 6 hours to obtain a hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin.

[0027] 2) Purify the hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin with a dialysis membrane (3.5 kDa) for 2 - 3 days and then freeze-dry it. Collect the freeze-dried polymer and swell it again in water to obtain an analgesic polysaccharide-based hydrogel.

[0028] In this example, the optional water-soluble long-chain molecule containing amino groups is carboxymethyl chitosan or O-acylated chitosan, and the optional small molecule analgesic drugs are one or more of pregabalin, gabapentin, carbamazepine, oxcarbazepine, celecoxib, diclofenac diethylamine, ibuprofen, curcumin, capsaicin, etc.

[0029] It should be noted that: Pregabalin: The chemical name is (S)-3-aminomethyl-5-methylhexanoic acid, which is a small molecule compound.

[0030] Gabapentin: The chemical formula is C9H 17NO2 is a white to off-white crystalline powder.

[0031] Carbamazepine: Its chemical name is 5H-dibenz[b]azepine-5-carboxamide, which is formed by the fusion of two benzene rings and a seven-membered azacyclic ring.

[0032] Oxcarbazepine: Its chemical name is 10,11-dihydro-10-oxo-5H-dibenz[b,f]azepine-5-carboxamide, and its molecular formula is C 15 H 12 N2O2.

[0033] Celecoxib: The molecular center is a pyrazole ring, containing a tricyanomethyl group, an N-substituted 4-sulfonamidophenyl group, and a 4-methylbenzene.

[0034] Diclofenac diethylamine: Its molecular formula is C 18 H 22 C l2 N2O2, which is a non-selective anti-inflammatory agent.

[0035] Ibuprofen: Its chemical name is isobutylphenylpropionic acid, and its structure consists of a benzene ring, an isobutyl group, and a propionic acid side chain.

[0036] Curcumin: Its chemical structure is di-feruloyl methane, containing multiple phenolic hydroxyl groups and unsaturated double bonds.

[0037] Capsaicin: It includes capsaicin, dihydrocapsaicin, etc., and its chemical structure contains the basic skeleton of capsaicin.

[0038] The above small molecule analgesic drugs have the following properties: Small molecule characteristics: The molecular weights of all drugs are less than 500 Da (e.g., the molecular weight of pregabalin is 159 Da, and that of celecoxib is 381 Da), which conforms to the characteristics of small molecule drugs being easy to cross the membrane for transport.

[0039] Specific functional groups: Carboxylic acid / ester group: Ibuprofen (propionic acid side chain), diclofenac diethylamine (chlorophenyl group), and curcumin (di-feruloyl methane) all contain carboxylic acid or ester groups, which may be related to their anti-inflammatory activities. Aromatic ring structure: Carbamazepine (dibenzazepine), oxcarbazepine (dibenzazepine), and celecoxib (pyrazole ring + benzene ring) all contain aromatic rings, which may enhance the hydrophobic interaction between the drug and the target.

[0040] Stereoisomerism effect: Pregabalin is the (S)-enantiomer, and its activity is significantly higher than that of the (R)-isomer, reflecting the key influence of the chiral structure on the drug efficacy.

[0041] Among them, pregabalin, gabapentin, carbamazepine, and oxcarbazepine mainly relieve neuropathic pain by regulating the functions of voltage-gated calcium channels or sodium channels to reduce abnormal neuronal discharges. Pregabalin can also increase the chloride current of γ-aminobutyric acid (GABA) receptors and enhance inhibitory neurotransmission. As non-steroidal anti-inflammatory drugs (NSAIDs), celecoxib, diclofenac diethylamine, and ibuprofen reduce prostaglandin synthesis by inhibiting cyclooxygenase (COX) activity, thereby reducing inflammatory responses and pain. Curcumin and capsaicin also exert analgesic effects by inhibiting inflammatory mediators (such as prostaglandins and leukotrienes).

[0042] Furthermore, pregabalin / gabapentin: In addition to analgesia, it also has central effects such as anti-convulsion, anti-anxiety, and sleep improvement, which may be related to the regulation of neurotransmitters such as dopamine and norepinephrine. Curcumin / capsaicin: It has a wide range of pharmacological activities such as antioxidant, anti-inflammatory, and anti-cancer, which is related to the fact that its polyphenol structure can regulate multiple cell signaling pathways.

[0043] As a further preference, the molar ratio of hyaluronic acid, catalyst, water-soluble long-chain molecule containing amino groups, and small molecule analgesic drug is 1:(0.001 - 1.000):(0.001 - 1.000):(0.001 - 1.000), the temperature is 20 - 25°C, the catalytic time of the catalyst is 0.5 - 2 hours, and the final reaction time is 6 hours.

[0044] In the examples, the molar ratio of hyaluronic acid, catalyst, water-soluble long-chain molecule containing amino groups, and small molecule analgesic drug is 1:(0.001 - 1):(0.001 - 1):(0.001 - 1). Further, it is 1:(0.001 - 0.5):(0.001 - 0.5):(0.001 - 0.5), 1:(0.5 - 1.0):(0.5 - 1.0):(0.5 - 1.0), specifically 1:0.001:0.001:0.001, 1:0.1:0.1:0.1, 1:0.2:0.2:0.2, 1:0.4:0.4:0.4, 1:0.5:0.5:0.5, 1:1:1:1, 1:0.1:0.2:0.3, 1:0.5:0.4:0.8, 1:0.4:0.6:0.3, etc., any combination of ratios. The specific dosage can be selected according to actual needs.

[0045] In the examples, the hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin also needs to be post-treated after synthesis. The treatment method is: after the reaction is completed, the polymer is dialyzed with a dialysis bag for 2 - 3 days, and the dialyzed hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin is freeze-dried, and then stored in a 4°C refrigerator after re-swelling.

[0046] The second object of the present invention is to provide an analgesic polysaccharide-based hydrogel prepared by the above method, which has a simple synthesis method and low cost. The analgesic polysaccharide-based hydrogel prepared by the described preparation method has important applications in the treatment of skin burn wounds and drugs for relieving acute facial pain.

[0047] The present invention is committed to preparing an analgesic polysaccharide-based hydrogel with good biocompatibility, which can promote tissue repair after burns and relieve pain after burns. The pain after burns seriously affects the quality of life and mental state of burn patients. Therefore, in the present invention, the molecular skeleton of the polysaccharide-based hydrogel is constructed through an amidation reaction, and then a small molecule analgesic drug is loaded into the hydrogel through hydrogen bonds to obtain an analgesic polysaccharide-based hydrogel. The analgesic polysaccharide-based hydrogel prepared by this method has good biocompatibility and good biological effects in vivo and in vitro, can exhibit good performance in scavenging intracellular ROS, and promote the healing of skin burn wounds and the relief of pain after burns. Therefore, this polymer has good application prospects in burn wound dressings and the treatment of acute facial pain.

[0048] To better understand the present invention, the present invention will be described in detail below in conjunction with specific embodiments, but the content of the present invention is not limited to the following embodiments.

[0049] Example 1 1) Dissolve 1 mol of hyaluronic acid in water, add 0.2 mol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, react at room temperature for 1 hour, add 1 mol of carboxymethyl chitosan and 0.04 mol of pregabalin, stir evenly and react at room temperature for 6 hours to obtain a pregabalin-loaded hyaluronic acid-carboxymethyl chitosan polymer.

[0050] 2) Purify the pregabalin-loaded hyaluronic acid-carboxymethyl chitosan polymer with a dialysis membrane (3.5 kDa) for 3 days and then freeze-dry it. Collect the freeze-dried polymer and swell it again in water to obtain the analgesic polysaccharide-based hydrogel.

[0051] The analgesic polysaccharide-based hydrogel prepared by the present invention exhibits good biocompatibility and also exhibits good performance in scavenging intracellular ROS. It is a wound dressing for burn wound repair and pain management after burns. The experimental data of Example 1 will be analyzed in detail below.

[0052] Figure 1It is a schematic diagram of the synthesis process and structure of the analgesic polysaccharide-based hydrogel synthesized in the present invention. The carboxyl group of HA was activated using the catalyst EDC / NHS, and the molecular skeleton of the hydrogel was constructed through chemical cross-linking of the amino group of CMCS and the carboxyl group of HA, and the analgesic drug PGB was loaded in the form of hydrogen bonds, thus successfully preparing the CHP hydrogel.

[0053] Figure 2 It is the FTIR diagram of the analgesic polysaccharide-based hydrogel. The CHP hydrogel was successfully synthesized by establishing hydrogen bonds and amide bonds. In the CHP hydrogel, the absorption peak reaching the maximum at 1586 cm -1 indicates the formation of the amide I band of C=O. The absorption peak near 1468 cm -1 has a weak vibration, revealing the formation of the amide II band of C-N-H. The absorption peak at 1251 cm -1 is the C-N absorption peak located near 1240 cm -1 proving that C-N forms the amide III band in the CHP hydrogel. The absorption peaks of CMCS and HA at 3370 cm -1 and 3366 cm -1 originate from the amino and hydroxyl groups in the structure. The absorption peaks of the amino and hydroxyl groups of CHP shift to the lower band at 3288 cm -1 respectively. At the same time, the C=O absorption peak of PGB at 1642 cm -1 shifts to the lower band at 1586 cm -1 , indicating that due to electrostatic interaction, hydrogen bonding may occur among PGB, CMCS and HA, resulting in the red shift of the absorption peaks of other bonds.

[0054] Figure 3 It is the TEM diagram of the analgesic polysaccharide-based hydrogel prepared in the present invention. At the microscopic scale of 200 μm, the freeze-dried morphology of the analgesic polysaccharide-based hydrogel polymer presents a porous structure with a pore diameter of 80 - 110 μm. This porous structure is not only beneficial to the delivery of oxygen, nutrients and drugs, but also can store a large amount of water molecules to keep the wound surface moist, which is conducive to the repair of burn wounds.

[0055] Figure 4Drug release behavior of the analgesic polysaccharide-based hydrogel prepared in this invention at different pH values. PBS buffers with pH 5.5 and 7.4 were used to simulate the wound microenvironment and normal tissue environment respectively. The results showed that in the PBS solution, with the gradual degradation of the hydrogel matrix, PGB loaded in the three-dimensional network structure through hydrogen bonding showed a continuous release characteristic. Quantitative analysis showed that the release concentration of PGB reached 2 mg / mL after incubation for 9 h under the condition of pH = 7.4, and still showed an upward trend at 72 h, confirming that the CHP hydrogel could achieve continuous drug release within the standard dressing change cycle of 72 h. At the same time, the release amount of PGB under acidic conditions (pH = 5.5) was more than that under neutral conditions, which meant that the analgesic polysaccharide-based hydrogel could release the analgesic drug pregabalin in a pH-responsive controlled release manner.

[0056] Figure 5 Cytotoxicity determination of the analgesic polysaccharide-based hydrogel prepared in this invention on mouse fibroblasts (L929). The hydrogel leaching solution was co-incubated with L929 for 24 h respectively, and the relative percentage of cell viability in each group was calculated. When the highest concentration of the CHP hydrogel reached 20 mg / mL, the viability of L929 cells was relatively inhibited, which was 95.11 ± 2.19% of the cell viability in the NC group. These results all indicated that the CHP hydrogel had good compatibility with L929 cells and could be used as a medical wound dressing.

[0057] Figure 6 Results of the in vitro down-regulation of intracellular ROS by the analgesic polysaccharide-based hydrogel prepared in this invention. Compared with the NC group, Raw264.7 cells treated with LPS showed strong green fluorescence, which proved that a large amount of ROS that could not be cleared in time could be generated in Raw264.7 cells after LPS induction. After intervention with the CHP hydrogel, the level of endogenous ROS in cells showed a significant downward trend. This proved that the CHP hydrogel showed strong ability to scavenge intracellular ROS.

[0058] Figure 7 Results of the in vivo treatment of burn wounds by the analgesic polysaccharide-based hydrogel prepared in this invention. On the third day after burn, the wound area of mice in the simple burn group (Burn group) was the largest, and the surrounding tissues showed a white blister-like appearance. On the seventh day, the relative wound areas of the three groups of mice were all smaller than those on the third day, especially the wound area of mice in the CHP hydrogel group was the smallest. On the fourteenth day, only small scabs remained on the burn wounds of the CHP hydrogel group, and hair grew around the wounds, while the burn wounds of mice in the Burn group were still not completely closed.

[0059] Figure 8The results of the in vivo alleviation of post - burn pain by the analgesic polysaccharide - based hydrogel prepared in this invention. In the Burn group, mechanical hyperalgesia immediately appeared in the left paw of mice after burn modeling. Specifically, a mechanical stimulus with a 0.5 g von Frey filament could trigger a positive response in mice, and this hyperalgesia persisted until the 42nd day after burn before barely returning to normal. In the CHP hydrogel group, mice only showed mild hyperalgesia in the second week. Meanwhile, in the CH hydrogel group, no significant hyperalgesia appeared in the early stage of burn, which proved that the hydrogel material had a certain analgesic effect. However, the mechanical hyperalgesia in the CHP hydrogel group of mice did not return to the normal value until the 42nd day. The above results indicate that the pain of burned mice can be effectively alleviated after treatment with CHP hydrogel.

[0060] Figure 9 The results of the in vivo alleviation of acute facial pain by the analgesic polysaccharide - based hydrogel prepared in this invention. After local injection of capsaicin, the pain in the jaw and face of mice in the capsaicin group was obvious, and behaviors such as restlessness, hyperactivity, scratching, and grooming of mice could be clearly observed. The wiping behavior of the front paws of mice in the capsaicin group increased significantly to 87.00 ± 3.87 times, showing a significant statistical difference from that of mice in the NC group. The scratching times of the front paws of mice in the CHP hydrogel group decreased significantly to 17.80 ± 2.36 times, showing a statistical difference from that of mice in the capsaicin group. The results prove that the CHP hydrogel has a significant analgesic effect on the acute facial pain of mice induced by capsaicin.

[0061] Therefore, it can be concluded that the analgesic polysaccharide - based hydrogel of this invention has the possibility to be applied in the treatment of skin burn wound dressings and acute facial pain, and the effect is obvious. Therefore, this hydrogel has a good application prospect in the treatment of burn wound dressings and acute facial pain.

[0062] Example 2 1) Dissolve 1 mol of hyaluronic acid in water, add 0.6 mol of 1 - (3 - dimethylaminopropyl) - 3 - ethylcarbodiimide hydrochloride and N - hydroxysuccinimide, react at room temperature for 0.7 hours, add 0.5 mol of carboxymethyl chitosan and 0.05 mol of pregabalin, stir evenly and then react at room temperature for 6 hours to obtain a pregabalin - loaded hyaluronic acid - carboxymethyl chitosan polymer.

[0063] 2) Purify the pregabalin - loaded hyaluronic acid - carboxymethyl chitosan polymer with a dialysis membrane (3.5 kDa) for 2 days and then freeze - dry it. Collect the freeze - dried polymer and swell it in water again to obtain the analgesic polysaccharide - based hydrogel.

[0064] Example 3 1) Dissolve 1 mol of hyaluronic acid in water, add 0.1 mol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, react at room temperature for 1.3 hours, add 1 mol of carboxymethyl chitosan and 0.1 mol of pregabalin, stir evenly and then react at room temperature for 6 hours to obtain a hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin.

[0065] 2) Purify the hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin with a dialysis membrane (3.5 kDa) for 2 days and then freeze-dry it. Collect the freeze-dried polymer and swell it again in water to obtain an analgesic polysaccharide-based hydrogel.

[0066] Example 4 1) Dissolve 1 mol of hyaluronic acid in water, add 0.18 mol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, react at room temperature for 2 hours, add 0.7 mol of carboxymethyl chitosan and 0.55 mol of pregabalin, stir evenly and then react at room temperature for 6 hours to obtain a hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin.

[0067] 2) Purify the hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin with a dialysis membrane (3.5 kDa) for 2 days and then freeze-dry it (in a 2°C refrigerator). Collect the freeze-dried polymer and swell it again in water to obtain an analgesic polysaccharide-based hydrogel.

[0068] Example 5 1) Dissolve 1 mol of hyaluronic acid in water, add 0.375 mol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, react at room temperature for 1.5 hours, add 0.9 mol of carboxymethyl chitosan and 0.22 mol of pregabalin, stir evenly and then react at room temperature for 6 hours to obtain a hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin.

[0069] 2) Purify the hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin with a dialysis membrane (3.5 kDa) for 2 days and then freeze-dry it (in a 4°C refrigerator). Collect the freeze-dried polymer and swell it again in water to obtain an analgesic polysaccharide-based hydrogel.

[0070] The analgesic polysaccharide-based hydrogel prepared in the present invention has a simple preparation process, environmentally friendly raw materials, low cost, and can exhibit good performance in scavenging intracellular ROS, and has good application prospects in post-burn wound repair and pain management and the relief of facial acute pain.

[0071] The hyaluronic acid used in the present invention is one of the important components of the extracellular matrix. It has simple degradation components in vivo, can provide a suitable environment for cell proliferation and migration, has the function of scavenging free radicals, low cost, and high reaction activity. The carboxymethyl chitosan used not only has good biocompatibility, biodegradability, low toxicity, antimicrobial activity, and low immunogenicity, but also has improved water solubility. Pregabalin used in the present invention is an alkylated analogue of γ-aminobutyric acid, which is loaded in the hydrogel in the form of hydrogen bonds and released locally at the burn wound, thereby effectively relieving the neuropathic pain after burns. Moreover, the release amount of pregabalin is regulated by the environmental pH, and the release concentration of pregabalin under acidic conditions (pH = 5.5) is greater than that under neutral conditions (pH = 7.4).

[0072] The analgesic polysaccharide-based hydrogel for treating burns prepared in the present invention has a simple preparation process, a green synthesis process, and can be mass-produced. The prepared analgesic polysaccharide-based hydrogel has the ability to scavenge intracellular ROS. The solvent used in the preparation of the analgesic polysaccharide-based hydrogel is deionized water, and there is no organic solvent in the preparation process.

[0073] In summary, the present invention provides an analgesic polysaccharide-based hydrogel dressing for treating burns. By using hyaluronic acid, a catalyst for activating carboxyl groups, a long-chain hydrophilic macromolecule containing amino groups, and a small molecule analgesic drug as monomers, the analgesic polysaccharide-based hydrogel is successfully prepared by forming amide bonds and hydrogen bonds. The preparation method of the present invention is simple, convenient to operate, and low in cost, and is suitable for large-scale production.

[0074] The above content is only to illustrate the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A preparation method of an analgesic polysaccharide-based hydrogel, characterized in that, Comprising: Dissolve hyaluronic acid in water, add a catalyst for activating carboxyl groups, then add a water-soluble long-chain molecule containing amino groups and a small molecule analgesic drug, react to obtain a hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin, and then after dialysis, lyophilize and swell to obtain an analgesic polysaccharide-based hydrogel.

2. The preparation method of the analgesic polysaccharide-based hydrogel according to claim 1, wherein The catalyst for activating carboxyl groups is 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide.

3. The preparation method of the analgesic polysaccharide-based hydrogel according to claim 1, characterized in that, The water-soluble long-chain molecule containing amino groups is carboxymethyl chitosan or O-acylated chitosan.

4. The preparation method of the analgesic polysaccharide-based hydrogel according to claim 1, wherein The small molecule analgesic drug is one or more of pregabalin, gabapentin, carbamazepine, oxcarbazepine, celecoxib, diclofenac diethylamine, ibuprofen, curcumin, capsaicin.

5. The preparation method of the analgesic polysaccharide-based hydrogel according to claim 1, wherein, The molar ratio of the hyaluronic acid, the catalyst for activating carboxyl groups, the water-soluble long-chain molecule containing amino groups and the small molecule analgesic drug is 1:(0.001 - 1.000):(0.001 - 1.000):(0.001 - 1.000).

6. The preparation method of the analgesic polysaccharide-based hydrogel for treating burns according to claim 1, characterized in that, The temperature of the reaction is 20 - 25 °C, the catalytic time of the catalyst for activating carboxyl groups is 0.5 - 2 hours, and the reaction time after catalysis is 6 hours.

7. The preparation method of the analgesic polysaccharide-based hydrogel according to claim 1, wherein, The hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin is collected by purification and lyophilization; Lyophilizing and swelling after dialysis includes: dialyzing the hyaluronic acid-carboxymethyl chitosan polymer loaded with pregabalin with a dialysis bag for 2 - 3 days, freeze-drying the dialyzed polymer, and storing it in an environment of ≤4 °C after re-swelling.

8. An analgesic polysaccharide-based hydrogel, characterized in that, Prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the analgesic polysaccharide-based hydrogel prepared by the preparation method according to any one of claims 1 to 7, characterized in that, Use in the preparation of a dressing for skin burn wounds.

10. Use of the analgesic polysaccharide-based hydrogel prepared by the preparation method according to any one of claims 1 to 7, characterized in that, Use in the preparation of a drug for facial acute pain.

Images