Oral care composition, and preparation method therefor and use thereof

Abstract

The present invention relates to the technical field of oral care. Provided are an oral care composition, and a preparation method therefor and the use thereof. The composition comprises: hyaluronic acid or a salt thereof, sodium alginate and a divalent metal salt. The composition has excellent shear stability, and can still maintain the membrane integrity and excellent adhesion after being flushed by a water flow and soaked in saliva during use.

Description

An oral care composition, its preparation method and application

[0001] This application claims priority to Chinese Patent Application No. 202410562949.4, filed on May 8, 2024, entitled "An Oral Care Composition and Its Preparation Method and Application", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of oral care technology, and in particular to an oral care composition, its preparation method, and its application. Background Technology

[0003] Oral diseases are common and frequently occurring illnesses affecting human health. Common oral diseases include dental caries, gingivitis, periodontal disease, dentin hypersensitivity, and oral ulcers. The prevention and treatment of oral diseases has become an important topic for future life science research.

[0004] Hyaluronic acid (HA) is a naturally occurring non-sulfated glycosaminoglycan composed of alternating glucuronic acid and N-acetylglucosamine disaccharide units. It is a linear polysaccharide widely found in the extracellular matrix of organs and tissues throughout the body, including connective tissue, synovial fluid, embryonic mesenchymal stem cells, vitreous humor, and skin. In the oral cavity, hyaluronic acid is a key element in soft tissues such as periodontal tissues, gingiva, and periodontal ligaments, as well as hard tissues such as alveolar bone and cementum. It plays a regulatory role in oral inflammatory responses. Furthermore, hyaluronic acid possesses significant viscoelasticity, which, after forming a film on tissue surfaces, can reduce the penetration of viruses and bacteria into tissues. In both mineralized (e.g., alveolar bone) and non-mineralized tissues, hyaluronic acid, as a key component, participates in a series of stages related to wound healing (inflammation, granulation tissue formation, epithelial formation, and tissue remodeling).

[0005] Sodium alginate is a natural polysaccharide extracted from brown algae, primarily composed of β-D-mannuronic acid and α-L-guluronic acid. Sodium alginate can activate immune cells in the human body and enhance the function of the immune system. In medicine, sodium alginate is often used as a component of wound dressings; its gelling properties help keep wounds moist and promote healing. Furthermore, due to its biodegradability, good compatibility, and high plasticity, sodium alginate is frequently used in sustained-release or controlled-release drug delivery systems.

[0006] Strontium is a metallic element with various applications in oral care and treatment, particularly aimed at addressing tooth sensitivity. Strontium is commonly found as an active ingredient in toothpastes and mouthwashes designed for sensitive teeth. Strontium-based toothpastes contain strontium chloride or strontium acetate. The strontium ions in these products clog the tubules in the dentin that lead to the nerves in the tooth, reducing the ability of external stimuli (such as cold or heat) to stimulate the nerves and cause pain. Besides toothpaste and mouthwash, strontium is also used in some specialized dental products for treating sensitivity. For example, dental professionals may apply strontium-containing products directly to a patient's teeth to help reduce sensitivity. Additionally, some studies suggest that strontium may have beneficial effects on cavities.

[0007] Calcium ions play a very important role in oral care and treatment, mainly in the following aspects: (1) Tooth mineralization: Calcium ions are an important mineral component in tooth structure. Both tooth enamel and dentin contain a large amount of calcium ions, which give teeth sufficient hardness and strength to chew food. (2) Prevention of tooth decay: Providing teeth with calcium ions helps prevent tooth enamel from being eroded by acidic substances, thereby preventing tooth decay. (3) Protection of oral mucosa: Calcium ions can strengthen the oral mucosa, enhance its resistance, and prevent oral infections. (4) Repair of teeth: When teeth are slightly damaged, supplementing with calcium ions can help teeth repair themselves and restore their integrity.

[0008] Zinc is an important trace element with many benefits for human health, including oral health. Here are some of the main functions of zinc ions in oral care: (1) Inhibiting bacterial growth: Zinc ions can inhibit the growth of certain harmful bacteria in the mouth, reducing plaque and tartar formation, thus helping to prevent cavities and periodontal disease. (2) Reducing halitosis: Zinc ions neutralize sulfides in the mouth, effectively reducing halitosis. (3) Promoting wound healing: Zinc ions play an important role in the repair of skin and mucous membranes; therefore, when there are ulcers or wounds in the mouth, zinc ions can help the wounds heal faster. (4) Protecting the oral mucosa: Zinc ions can enhance the barrier function of the oral mucosa, making it more resistant to bacteria and viruses. (5) Promoting taste perception: Zinc ions play an important role in taste perception; zinc deficiency may lead to a decreased sense of taste.

[0009] Stannous ions are a common active ingredient in oral care products. Here are some of the main functions of stannous ions in oral care and treatment: (1) Antibacterial: Stannous ions have been shown to inhibit certain harmful bacteria in the oral cavity, helping to reduce plaque and tartar formation. (2) Prevention of tooth sensitivity: Stannous ions can bind to proteins in the dentinal tubules, forming a protective layer that prevents irritants such as cold, heat, acid, and sweetness from stimulating the dental pulp, thereby reducing tooth sensitivity. (3) Prevention of periodontal disease: Due to its antibacterial and anti-inflammatory effects, stannous ions can help prevent periodontal disease. (4) Relief of gingival bleeding: Stannous ions also have a certain relieving effect on gingival bleeding because they can inhibit plaque formation and reduce the occurrence of gingivitis.

[0010] Gels are a common form of oral care and treatment products that contain and slowly release active ingredients. Gel products are widely used in oral care and treatment due to their convenience and effectiveness. Here are some examples of gels used in oral care and treatment: Gum Gel: This type of gel is typically used to relieve symptoms of gingivitis and periodontitis, such as swollen and bleeding gums. These gels usually contain antibacterial ingredients as well as ingredients that promote oral tissue repair. Teeth Whitening Gel: Used on the surface of teeth to remove stains and improve their brightness. This type of gel usually contains bleaching ingredients such as hydrogen peroxide or sodium bicarbonate. Mouth Ulcer Gel: This type of gel usually contains antibacterial and local anesthetic ingredients to relieve the pain of mouth ulcers and accelerate their healing. Toothpaste Gel: This is a common oral care gel product used to clean teeth and prevent cavities and periodontal disease. Fluoride Gel: This type of gel is often used in professional fluoride treatments performed by dentists to enhance the teeth's resistance to cavities. Fluoride gel can penetrate deep into the tiny cracks on the tooth surface, helping to strengthen tooth enamel and prevent cavities. Tooth Sensitive Gel: This gel contains ingredients that can relieve tooth sensitivity, such as potassium nitrite or stannous ions, which can effectively relieve tooth sensitivity symptoms caused by stimuli such as cold, heat, acid, and sweetness.

[0011] The application of gels in oral care and treatment requires specific physicochemical properties, such as adhesion, stability, biocompatibility, controlled release, and safety, to ensure their effective function and provide a comfortable user experience. Key physicochemical properties include: 1) the gel's stability under shear conditions, maintaining its properties and efficacy during storage and transportation; and 2) its adhesion to both hard and soft tissues in the oral cavity, forming a protective barrier on surfaces such as teeth and gums to resist saliva erosion and continuously release active ingredients.

[0012] Currently, the shear stability and adhesion of strontium ions, calcium ions, zinc ions, and stannous ions in oral gels urgently need to be improved. Summary of the Invention

[0013] The purpose of this application is to provide a multifunctional oral care composition, its preparation method, and its application, which has shear stability, film-forming adhesion to oral tissues and resistance to saliva corrosion, and also has the functions of enamel repair, anti-allergy, anti-gingivitis and periodontitis, and antibacterial properties.

[0014] On one hand, this application provides an oral care composition comprising: hyaluronic acid or a salt thereof, sodium alginate, and a divalent metal salt;

[0015] The composition is obtained by mixing hyaluronic acid or its salt with sodium alginate and then adding a divalent metal salt.

[0016] The structural unit of sodium hyaluronate is (C 14 H 20 NO 11 Na) n , where n is a natural number.

[0017] The structural unit of sodium alginate is (C6H7O6Na). n , where n is a natural number.

[0018] Further, the hyaluronic acid or its salt is selected from one or more of hyaluronic acid, sodium hyaluronate, potassium hyaluronate, calcium hyaluronate, and zinc hyaluronate; optionally, the hyaluronic acid or its salt is sodium hyaluronate; optionally, the molecular weight of the hyaluronic acid or its salt is >200kDa; more preferably, the molecular weight of the sodium hyaluronate is ≥1000kDa.

[0019] Optionally, the molecular weight of the hyaluronic acid or its salt may be selected from any value among 201kDa, 300kDa, 400kDa, 500kDa, 600kDa, 700kDa, 800kDa, 900kDa, 1000kDa, 1450kDa, 2000kDa, 3000kDa, 4000kDa, 5000kDa, 6000kDa, 7000kDa, 8000kDa, 9000kDa, 10000kDa, and greater than 10000kDa.

[0020] Divalent metal salts include strontium salts, calcium salts, zinc salts, or stannous salts.

[0021] Further, the strontium salt is selected from one or more of strontium nitrate, strontium sulfate, strontium chloride, and strontium acetate; optionally, the strontium salt is strontium acetate.

[0022] Further, the calcium salt is selected from one or more of calcium chloride, calcium borate, calcium acetate, calcium carbonate, calcium phosphate, calcium citrate, calcium lactate, DNA calcium, calcium disodium EDTA, calcium PCA, calcium propionate, calcium pantothenate, calcium pantothenate thioethylamine sulfonate, calcium glycerophosphate, calcium silicate, calcium fluoride, calcium aluminum silicate sodium, calcium pyrophosphate, carrageenan calcium, calcium ascorbate, calcium sodium phosphosilicate, calcium hydrogen phosphate, tricalcium phosphate, calcium aluminum borosilicate, calcium sodium borosilicate, calcium titanium borosilicate, calcium mercaptoacetate, calcium myristate, calcium behenate, calcium carboxymethyl cellulose, calcium aspartate, calcium octenyl succinate starch, calcium stearate, calcium stearoyl lactylate, calcium lauroyl taurate, calcium alginate, calcium phosphoryl oligosaccharide, and calcium gluconate; optionally, the calcium salt is calcium gluconate.

[0023] Further, the zinc salt is selected from one or more of zinc gluconate, zinc lactate, zinc chloride, zinc citrate, zinc sulfate, zinc oxide, zinc acetate, zinc bismaltol oxide, zinc pyrithione, zinc ricinoleate, zinc glycinate, zinc glycyrrhetinate, zinc myristate, zinc undecenoate, zinc salicylate, zinc carbonate, zinc aspartate, zinc cocoyl alcohol polyether sulfate, zinc acetylated methionine, zinc stearate, zinc laurate, and zinc palmitate; optionally, the zinc salt is zinc gluconate and / or zinc chloride.

[0024] Further, the stannous salt is selected from one or more of stannous fluoride, stannous chloride, stannous sulfate, stannous iodide, and stannous furan; optionally, the stannous salt is stannous fluoride.

[0025] Further, the molar ratio of the hyaluronic acid or its salt, sodium alginate and divalent metal salt is 1:(1-11):(0.1-4.5).

[0026] Optionally, the molar ratio of the hyaluronic acid or its salt, sodium alginate and strontium salt is 1:(1-10):(0.5-4.5).

[0027] Optionally, the molar ratio is 1:(2.0-6.5):(1-4); more preferably, the molar ratio is 1:(3-6.5):(1.5-3.5).

[0028] Optionally, the molar ratio of hyaluronic acid or its salt, sodium alginate, and strontium salt may be selected from 1:1:0.5, 1:2.0:1, 1:2.5:1, 1:2.5:1.5, 1:2.5:2, 1:2.5:2.5, 1:2.5:3, 1:2.5:3.5, 1:2.5:4, 1:3:1, 1:3:1.5, 1:3:2, 1:3:2.5, 1:3:3 1:3:3.5, 1:3:4, 1:3.5:1, 1:3.5:1.5, 1:3.5:2, 1:3.5:2.5, 1:3.5:3, 1:3.5:3.5, 1:3.5:4, 1:4:1, 1:4:1.5, 1:4:2, 1:4:2.5, 1:4:3, 1:4:3.5, 1:4:4, 1:4.5:1, 1:4.5: 1.5, 1:4.5:2, 1:4.5:2.5, 1:4.5:3, 1:4.5:3.5, 1:4.5:4, 1:5:1, 1:5:1.5, 1:5:2, 1:5:2.5, 1:5:3, 1:5:3.5, 1:5:4, 1:5.5:1, 1:5.5:1.5, 1:5.5:2, 1:5.5:2.5, 1:5.5:3 1:5.5:3.5, 1:5.5:4, 1:6:1, 1:6:1.5, 1:6:2, 1:6:2.5, 1:6:3, 1:6:3.5, 1:6:4, 1:6.5:1, 1:6.5:1.5, 1:6.5:2, 1:6.5:2.5, 1:6.5:3, 1:6.5:3.5, 1:6.5:4 and any value within this range.

[0029] Optionally, the molar ratio of the hyaluronic acid or its salt, sodium alginate and calcium salt is 1:(2.5-8):(0.2-3.2).

[0030] Optionally, the molar ratio is 1:(3.0-6.5):(0.5-3.0).

[0031] Optionally, the molar ratio of hyaluronic acid or its salt, sodium alginate, and calcium salt may be selected from 1:2.5:0.2, 1:2.5:0.5, 1:2.5:1, 1:2.5:1.5, 1:2.5:2, 1:2.5:2.5, 1:2.5:3, 1:3:0.2, 1:3:0.5, 1:3:1, 1:3:1.5, 1:3:2, 1:3:2.5, 1:3: 3, 1:3.5:0.2, 1:3.5:0.5, 1:3.5:1, 1:3.5:1.5, 1:3.5:2, 1:3.5:2.5, 1:3.5:3, 1:4:0.2, 1:4:0.5, 1:4:1, 1:4:1.5, 1:4:2, 1:4:2.5, 1:4:3, 1:4.5:0.2, 1:4.5:0.5, 1:4. 5:1, 1:4.5:1.5, 1:4.5:2.0, 1:4.5:2.5, 1:4.5:3, 1:5:0.2, 1:5:0.5, 1:5:1, 1:5:1.5, 1:5:2, 1:5:2.5, 1:5:3, 1:5.5:0.2, 1:5.5:0.5, 1:5.5:1, 1:5.5:1.5, 1:5.5:2, 1: 5.5:2.5, 1:5.5:3, 1:6:0.2, 1:6:0.5, 1:6:1, 1:6:1.5, 1:6:2, 1:6:2.5, 1:6:3, 1:6.5:0.2, 1:6.5:0.5, 1:6.5:1, 1:6.5:1.5, 1:6.5:2, 1:6.5:2.5, 1:6.5:3 and any value within this range.

[0032] Further, the molar ratio of the hyaluronic acid or its salt, sodium alginate and zinc salt is 1:(2.5-11):(0.1-2.5); optionally, 1:(2.5-3.5):(1.0-2.0).

[0033] Optionally, the molar ratio of the hyaluronic acid or its salt, sodium alginate and zinc salt may be selected from 1:1:0.1, 1:1:3, 1:1.5:0.1, 1:1.5:3, 1:3:1, 1:3:1.5, 1:3:2, 1:3:2.5, 1:3.5:1, 1:3.5:1.5, 1:3.5:2, 1:3.5:2.5 and any value within this range.

[0034] Further, the molar ratio of the hyaluronic acid or its salt, sodium alginate and stannous salt is 1:(3.5-5.5):(0.5-3.6); optionally, 1:(4.0-5.5):(2.0-3.5).

[0035] Optionally, the molar ratio of the hyaluronic acid or its salt, sodium alginate, and stannous salt may be selected from 1:3.5:1.5, 1:3.5:2, 1:3.5:2.5, 1:3.5:3, 1:3.5:3.5, 1:4:1.5, 1:4:2, 1:4:2.5, 1:4:3, 1:4:3.5, 1:4.5:1.5, 1:4.5:2, 1:4.5:2.5, 1:4.5:3, 1:4.5:3.5, 1:5:1.5, 1:5:2, 1:5:2.5, 1:5:3, 1:5:3.5, 1:5.5:1.5, 1:5.5:2, 1:5.5:2.5, 1:5.5:3, 1:5.5:3.5, and any value within this range.

[0036] The compositions described in this application may also contain excipients, which may include appropriate solvents, oral fluorides, oral whitening ingredients, oral pharmaceutical ingredients, oral desensitizers, antibacterial agents, abrasives, propellants, solubilizers, co-solvents, emulsifiers, colorants, binders, disintegrants, fillers, lubricants, wetting agents, osmotic pressure regulators, stabilizers, flow aids, flavoring agents, preservatives, suspending agents, coating materials, fragrances, anti-adhesion agents, integrators, penetration enhancers, pH adjusters, buffers, plasticizers, surfactants, foaming agents, defoamers, thickeners, encapsulating agents, humectants, absorbents, diluents, flocculants and anti-flocculators, filter aids, release inhibitors, etc.

[0037] The composition can also be compounded with other known active ingredients using conventional methods.

[0038] On the other hand, this application also provides a method for preparing the composition, the method comprising: mixing hyaluronic acid or its salt with sodium alginate, and then adding a divalent metal salt.

[0039] The divalent metal salts include calcium salts, strontium salts, zinc salts, or stannous salts.

[0040] The zinc salt is selected from one or more of zinc gluconate, zinc lactate, zinc chloride, zinc citrate, zinc sulfate, zinc oxide, zinc acetate, zinc bismaltoxygenate, zinc pyrithione, zinc ricinoleate, zinc glycinate, zinc glycyrrhetinate, zinc myristate, zinc undecenoate, zinc salicylate, zinc carbonate, zinc aspartate, zinc cocoyl ether sulfate, zinc acetylated methionine, zinc stearate, zinc laurate, and zinc palmitate; optionally, the zinc salt is zinc gluconate and / or zinc chloride.

[0041] The strontium salt is selected from one or more of strontium nitrate, strontium sulfate, strontium chloride, and strontium acetate; optionally, the strontium salt is strontium acetate.

[0042] The calcium salt is selected from one or more of the following: calcium chloride, calcium borate, calcium acetate, calcium carbonate, calcium phosphate, calcium citrate, calcium lactate, calcium DNA, calcium disodium EDTA, calcium PCA, calcium fluoride, calcium propionate, calcium pantothenate, calcium pantothenate thioethylamine sulfonate, calcium glycerophosphate, calcium silicate, calcium aluminum silicate sodium, calcium pyrophosphate, carrageenan calcium, calcium ascorbate, calcium sodium phosphosilicate, calcium hydrogen phosphate, tricalcium phosphate, calcium aluminum borosilicate, calcium sodium borosilicate, calcium titanium borosilicate, calcium mercaptoacetate, calcium myristate, calcium behenate, calcium carboxymethyl cellulose, calcium aspartate, calcium octenyl succinate starch, calcium stearate, calcium stearoyl lactylate, calcium lauroyl taurate, calcium alginate, calcium phosphoryl oligosaccharide, and calcium gluconate; optionally, the calcium salt is calcium gluconate.

[0043] The stannous salt is selected from one or more of stannous fluoride, stannous chloride, stannous sulfate, stannous iodide, and stannous furan; optionally, the stannous salt is stannous fluoride.

[0044] The hyaluronic acid or its salt is selected from one or more of hyaluronic acid, sodium hyaluronate, potassium hyaluronate, calcium hyaluronate, and zinc hyaluronate; more preferably, the hyaluronic acid or its salt is sodium hyaluronate.

[0045] In one optional embodiment, the preparation method of the composition includes the following steps: mixing an aqueous solution of sodium hyaluronate with an aqueous solution of sodium alginate, and then adding an aqueous solution of calcium gluconate and mixing evenly.

[0046] The sodium hyaluronate aqueous solution can be prepared by mixing sodium hyaluronate and water, the sodium alginate aqueous solution can be prepared by mixing sodium alginate and water, and the calcium gluconate aqueous solution can be prepared by mixing calcium gluconate and water.

[0047] In one optional embodiment, the preparation method of the composition includes the following steps: mixing an aqueous solution of sodium hyaluronate with an aqueous solution of sodium alginate, and then adding an aqueous solution of strontium acetate and mixing evenly.

[0048] The sodium hyaluronate aqueous solution can be prepared by mixing sodium hyaluronate and water, the sodium alginate aqueous solution can be prepared by mixing sodium alginate and water, and the strontium acetate aqueous solution can be prepared by mixing strontium acetate and water.

[0049] In one optional embodiment, the preparation method of the composition includes the following steps: mixing an aqueous solution of sodium hyaluronate with an aqueous solution of sodium alginate, and then adding an aqueous solution of zinc gluconate and mixing evenly.

[0050] The sodium hyaluronate aqueous solution can be prepared by mixing sodium hyaluronate and water, the sodium alginate aqueous solution can be prepared by mixing sodium alginate and water, and the zinc gluconate aqueous solution can be prepared by mixing zinc gluconate and water.

[0051] In one optional embodiment, the preparation method of the composition includes the following steps: mixing an aqueous solution of sodium hyaluronate with an aqueous solution of sodium alginate, and then adding an aqueous solution of stannous fluoride and mixing evenly.

[0052] The sodium hyaluronate aqueous solution can be prepared by mixing sodium hyaluronate and water, the sodium alginate aqueous solution can be prepared by mixing sodium alginate and water, and the stannous fluoride aqueous solution can be prepared by mixing stannous fluoride and water.

[0053] Those skilled in the art can choose conventional methods to mix and homogenize the mixture, as long as the purpose of uniform mixing can be achieved. The specific mixing method has no impact on the final technical effect of the composition of this application, and therefore is not specifically limited here.

[0054] On the other hand, this application also provides an oral care product comprising the composition.

[0055] Optionally, the oral care product is in the form of a gel.

[0056] In one alternative embodiment, the oral care products include toothpaste, desensitizing agents, sustained-release drug gels, dental filling and restoration materials, etc.

[0057] On the other hand, this application also provides the application of the composition or oral care products in oral care; optionally, the oral care includes reducing tooth sensitivity, protecting against tooth erosion, desensitizing care after whitening, orthodontic care and / or improving the comfort and fit of dentures, regulating the oral flora environment, preventing and / or inhibiting dental plaque, preventing caries, anti-gingivitis, inhibiting halitosis, inhibiting tartar, and reducing tooth stains.

[0058] On the other hand, this application also provides the use of the composition in improving gel shear stability and / or resistance to adverse adhesion.

[0059] This application has the following beneficial effects:

[0060] This application provides a hyaluronic acid metal salt gel composition, which has excellent shear stability and can maintain membrane integrity and excellent adhesion even after being rinsed with water and soaked in saliva during use. In addition, the hyaluronic acid metal salt gel has good anti-allergic and antibacterial effects. Attached Figure Description

[0061] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0062] Figure 1(a) shows the SEM image of strontium hyaluronic acid hydrogel. The HAP sheet with gel on the surface was taken out after standing in an incubator at 37°C for 1 hour and rinsed three times with deionized water (A). It was then soaked in artificial saliva at 37°C for 1 hour and rinsed three times with deionized water (B). It was then soaked in artificial saliva at 37°C for 2 hours and rinsed three times with deionized water (C). It was then soaked in artificial saliva at 37°C for 4 hours and rinsed three times with deionized water (D). Finally, it was soaked in artificial saliva at 37°C for 8 hours and rinsed three times with deionized water (E).

[0063] Figure 1(b) shows the SEM images of calcium hyaluronic acid hydrogels, in which the hydrogels were soaked in artificial saliva at 37°C for 1 hour and then rinsed three times with deionized water (B); soaked in artificial saliva at 37°C for 2 hours and then rinsed three times with deionized water (C); soaked in artificial saliva at 37°C for 4 hours and then rinsed three times with deionized water (D); and soaked in artificial saliva at 37°C for 8 hours and then rinsed three times with deionized water (E).

[0064] Figure 1(c) shows the SEM image of zinc hyaluronic acid hydrogel. The HAP sheet with gel on the surface was taken out after standing in an incubator at 37°C for 1 hour and then rinsed three times with deionized water (A). It was then soaked in artificial saliva at 37°C for 1 hour and rinsed three times with deionized water (B). It was then soaked in artificial saliva at 37°C for 2 hours and rinsed three times with deionized water (C). It was then soaked in artificial saliva at 37°C for 4 hours and rinsed three times with deionized water (D). It was then soaked in artificial saliva at 37°C for 8 hours and rinsed three times with deionized water (E).

[0065] Figure 1(d) shows the SEM image of stannous hyaluronic acid hydrogel. The HAP sheet with gel on the surface was taken out after standing in an incubator at 37°C for 1 hour and rinsed three times with deionized water (B). It was then soaked in artificial saliva at 37°C for 1 hour and rinsed three times with deionized water (C). It was then soaked in artificial saliva at 37°C for 2 hours and rinsed three times with deionized water (D). Finally, it was soaked in artificial saliva at 37°C for 4 hours and rinsed three times with deionized water (E).

[0066] Figure 2(a) shows the X-ray photoelectron spectrum of strontium hyaluronic acid hydrogel. The HAP sheet with gel on the surface was taken out after standing in an incubator at 37°C for 1 hour and rinsed three times with deionized water (A). It was then soaked in artificial saliva at 37°C for 1 hour and rinsed three times with deionized water (B). It was then soaked in artificial saliva at 37°C for 2 hours and rinsed three times with deionized water (C). It was then soaked in artificial saliva at 37°C for 4 hours and rinsed three times with deionized water (D). It was then soaked in artificial saliva at 37°C for 8 hours and rinsed three times with deionized water (E).

[0067] Figure 2(b) shows the X-ray photoelectron spectrum of calcium hyaluronic acid hydrogel. The HAP sheet with gel on the surface was taken out after standing in an incubator at 37°C for 1 hour and then rinsed three times with deionized water (A). It was then soaked in artificial saliva at 37°C for 1 hour and rinsed three times with deionized water (B). It was then soaked in artificial saliva at 37°C for 2 hours and rinsed three times with deionized water (C). It was then soaked in artificial saliva at 37°C for 4 hours and rinsed three times with deionized water (D). It was then soaked in artificial saliva at 37°C for 8 hours and rinsed three times with deionized water (E).

[0068] Figure 2(c) shows the X-ray photoelectron spectrum of zinc hyaluronic acid hydrogel. The HAP sheet with gel on the surface was taken out after standing in an incubator at 37°C for 1 hour and then rinsed three times with deionized water (A), soaked in artificial saliva at 37°C for 1 hour and then rinsed three times with deionized water (B), soaked in artificial saliva at 37°C for 2 hours and then rinsed three times with deionized water (C), soaked in artificial saliva at 37°C for 4 hours and then rinsed three times with deionized water (D), and soaked in artificial saliva at 37°C for 8 hours and then rinsed three times with deionized water (E).

[0069] Figure 2(d) shows the X-ray photoelectron spectrum of stannous hyaluronic acid hydrogel. The HAP sheet with gel on the surface was taken out after standing in an incubator at 37°C for 1 hour and rinsed three times with deionized water (A), soaked in artificial saliva at 37°C for 1 hour and rinsed three times with deionized water (B), soaked in artificial saliva at 37°C for 2 hours and rinsed three times with deionized water (C), and soaked in artificial saliva at 37°C for 4 hours and rinsed three times with deionized water (D).

[0070] Figure 3 shows the SEM images of hyaluronic acid strontium hydrogel for counting dental tubules, including blank sample SEM (a), SEM after artificial saliva treatment (b), and SEM after treatment of Experimental Example 4 (c).

[0071] Figure 4 shows the tubule sealing rate and significance analysis of strontium hyaluronic acid hydrogel;

[0072] Figure 5 shows SEM images of tooth enamel surfaces after 72 hours of artificial saliva immersion, including coated test case 8(A), uncoated test case 8(B), and normal tooth enamel (C).

[0073] Figure 6 shows the tensile stress diagram, where A: pig casing sheets with zinc hyaluronic acid hydrogel on the surface are not soaked in artificial saliva; B: soaked in artificial saliva at 37°C for 30 min; C: soaked in artificial saliva at 37°C for 1 h; D: soaked in artificial saliva at 37°C for 2 h.

[0074] Figure 7 shows OD. 600 The graph shows the relationship between time and experimental example 13, where HA+SA+Zn represents experimental example 13 and HA+SA represents comparative example 31.

[0075] Figure 8 shows SEM images of dentinal tubule sealing experiments using stannous hyaluronic acid hydrogel, with images after artificial saliva treatment (A) and after treatment in Experiment 19 (B).

[0076] Figure 9 shows the tubule closure rate of stannous hyaluronic acid hydrogel, where ***: p<0.001. Detailed Implementation

[0077] To more clearly illustrate the overall concept of this application, a detailed description is provided below with reference to the accompanying drawings and embodiments. Numerous specific details are set forth in the following description to provide a more thorough understanding of this application. However, it will be apparent to those skilled in the art that this application can be implemented without one or more of these details. In other instances, to avoid confusion with this application, some technical features well-known in the art have not been described.

[0078] Unless otherwise specified in the examples, the conditions shall be performed in accordance with the standard conditions or the conditions recommended by the manufacturer.

[0079] Unless otherwise specified, in the following embodiments, reagents or instruments whose manufacturers are not indicated are all conventional products that can be purchased commercially.

[0080] The sources of some of the reagents in the following examples are shown in Table 1.

[0081] Table 1

[0082] In addition, the term "water" as used in this application includes any feasible type of water that can be used in the cosmetics field, such as deionized water, distilled water, ion-exchanged water, double-distilled water, high-purity water, and purified water.

[0083] In the following examples, unless otherwise specified, % means wt%, i.e., weight percentage.

[0084] Example 1

[0085] This embodiment provides a method for preparing strontium hyaluronic acid hydrogel, as follows.

[0086] Experimental Example 1

[0087] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (30mg / mL) evenly, and then add 0.2 parts of strontium acetate aqueous solution (60mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0088] Experimental Example 2

[0089] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (30mg / mL) evenly, and then add 0.15 parts of strontium acetate aqueous solution (60mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0090] Experimental Example 3

[0091] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.3 parts of strontium acetate aqueous solution (60mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0092] Test Example 4

[0093] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.2 parts of strontium acetate aqueous solution (60mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0094] Experimental Example 5

[0095] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (10mg / mL) evenly, and then add 0.3 parts of strontium acetate aqueous solution (60mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0096] Comparative Example 1

[0097] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) thoroughly to prepare a mixture.

[0098] Comparative Example 2

[0099] Add 0.2 parts of strontium acetate aqueous solution (60 mg / mL) to 1 part of sodium alginate aqueous solution (15 mg / mL) to prepare strontium hyaluronic acid hydrogel.

[0100] Comparative Example 3

[0101] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (20mg / mL) evenly, and then add 1 part of strontium acetate aqueous solution (60mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0102] Comparative Example 4

[0103] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (20mg / mL) evenly, and then add 1 part of strontium acetate aqueous solution (100mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0104] Comparative Example 5

[0105] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (30mg / mL) evenly, and then add 1 part of strontium acetate aqueous solution (60mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0106] Comparative Example 6

[0107] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (30mg / mL) evenly, and then add 0.5 parts of strontium acetate aqueous solution (60mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0108] Comparative Example 7

[0109] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (30mg / mL) evenly, and then add 0.4 parts of strontium acetate aqueous solution (60mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0110] Comparative Example 8

[0111] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.4 parts of strontium acetate aqueous solution (60mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0112] Comparative Example 9

[0113] Add 0.3 parts of strontium acetate aqueous solution (60 mg / mL) to 1 part of sodium alginate aqueous solution (15 mg / mL) to prepare strontium hyaluronic acid hydrogel.

[0114] Comparative Example 10

[0115] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (20mg / mL) evenly, and then add 0.5 parts of strontium acetate aqueous solution (60mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0116] Comparative Example 11

[0117] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (30mg / mL) thoroughly to prepare a mixture.

[0118] Comparative Example 12

[0119] Mix 1 part of sodium hyaluronate aqueous solution (molecular weight 200kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.2 parts of strontium acetate aqueous solution (60mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0120] Comparative Example 13

[0121] Mix 1 part of sodium hyaluronate aqueous solution (molecular weight 10kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.2 parts of strontium acetate aqueous solution (60mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0122] Comparative Example 14

[0123] Mix 1 part of sodium hyaluronate aqueous solution (molecular weight 1 kDa, 10 mg / mL) and 1 part of sodium alginate aqueous solution (15 mg / mL) evenly, and then add 0.2 parts of strontium acetate aqueous solution (60 mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0124] Comparative Example 15

[0125] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 0.2 parts of strontium acetate aqueous solution (60mg / mL) evenly, and then add 1 part of sodium alginate aqueous solution (30mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0126] Comparative Example 16

[0127] Mix 1 part sodium alginate aqueous solution (30 mg / mL) and 0.2 parts strontium acetate aqueous solution (60 mg / mL) evenly, and then add 1 part sodium hyaluronate aqueous solution (average molecular weight 1450 kDa, 10 mg / mL) to the above mixed aqueous solution to prepare strontium hyaluronate hydrogel.

[0128] The compositions of the strontium hyaluronic acid hydrogels prepared in Experimental Examples 1-5 and Comparative Examples 1-16 are shown in Table 2.

[0129] Table 2

[0130] Example 2

[0131] This embodiment provides a method for preparing calcium hyaluronic acid hydrogel, as follows.

[0132] Experimental Example 6

[0133] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (20mg / mL) evenly, and then add 0.5 parts of calcium gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare calcium hyaluronate hydrogel.

[0134] Experimental Example 7

[0135] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (20mg / mL) evenly, and then add 0.3 parts of calcium gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare calcium hyaluronate hydrogel.

[0136] Experimental Example 8

[0137] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.5 parts of calcium gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare calcium hyaluronate hydrogel.

[0138] Experimental Example 9

[0139] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.3 parts of calcium gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare calcium hyaluronate hydrogel.

[0140] Experimental Example 10

[0141] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (20mg / mL) evenly, and then add 1 part of calcium gluconate aqueous solution (30mg / mL) to the above mixed aqueous solution to prepare calcium hyaluronate hydrogel.

[0142] Experimental Example 11

[0143] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (20mg / mL) evenly, and then add 1 part of calcium gluconate aqueous solution (5mg / mL) to the above mixed aqueous solution to prepare calcium hyaluronate hydrogel.

[0144] Experimental Example 12

[0145] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (30mg / mL) evenly, and then add 0.5 parts of calcium gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare calcium hyaluronate hydrogel.

[0146] Comparative Example 17

[0147] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (20mg / mL) evenly, and then add 1 part of calcium gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare calcium hyaluronate hydrogel.

[0148] Comparative Example 18

[0149] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (20mg / mL) evenly, and then add 1 part of calcium gluconate aqueous solution (100mg / mL) to the above mixed aqueous solution to prepare calcium hyaluronate hydrogel.

[0150] Comparative Example 19

[0151] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 200kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.5 parts of calcium gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare calcium hyaluronate hydrogel.

[0152] Comparative Example 20

[0153] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 10kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.5 parts of calcium gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare calcium hyaluronate hydrogel.

[0154] Comparative Example 21

[0155] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1 kDa, 10 mg / mL) and 1 part of sodium alginate aqueous solution (15 mg / mL) evenly, and then add 0.5 parts of calcium gluconate aqueous solution (40 mg / mL) to the above mixed aqueous solution to prepare calcium hyaluronate hydrogel.

[0156] Comparative Example 22

[0157] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (10mg / mL) evenly, and then add 0.5 parts of calcium gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare calcium hyaluronate hydrogel.

[0158] Comparative Example 23

[0159] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 0.5 parts of calcium gluconate aqueous solution (40mg / mL) evenly to prepare calcium hyaluronate hydrogel.

[0160] Comparative Example 24

[0161] Mix 1 part sodium alginate aqueous solution (15 mg / mL) and 0.5 parts calcium gluconate aqueous solution (40 mg / mL) evenly to prepare a hydrogel.

[0162] Comparative Example 25

[0163] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 0.5 parts of calcium gluconate aqueous solution (40mg / mL) evenly, and then add 1 part of sodium alginate aqueous solution (20mg / mL) to the above mixed aqueous solution to prepare calcium hyaluronate hydrogel.

[0164] Comparative Example 26

[0165] Mix 1 part sodium alginate aqueous solution (20 mg / mL) and 0.5 parts calcium gluconate aqueous solution (40 mg / mL) evenly, then add 1 part sodium hyaluronate aqueous solution (average molecular weight 1450 kDa, 10 mg / mL) to the above mixed aqueous solution to prepare calcium hyaluronate hydrogel.

[0166] The compositions of the calcium hyaluronic acid hydrogels prepared in Experimental Examples 6-12 and Comparative Examples 17-26 are shown in Table 3.

[0167] Table 3

[0168] Example 3

[0169] This embodiment provides a method for preparing zinc hyaluronic acid hydrogel, as follows.

[0170] Experimental Example 13

[0171] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.5 parts of zinc gluconate aqueous solution (40mg / mL) to the above mixture to prepare zinc hyaluronate hydrogel.

[0172] Test Example 14

[0173] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.2 parts of zinc gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare zinc hyaluronate hydrogel.

[0174] Experimental Example 15

[0175] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.1 part of zinc gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare zinc hyaluronate hydrogel.

[0176] Experimental Example 16

[0177] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 2.5 parts of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.5 parts of zinc gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare zinc hyaluronate hydrogel.

[0178] Experimental Example 17

[0179] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 3.5 parts of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.5 parts of zinc gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare zinc hyaluronate hydrogel.

[0180] Experimental Example 18

[0181] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.5 parts of zinc chloride aqueous solution (12mg / mL) to the above mixed aqueous solution to prepare zinc hyaluronate hydrogel.

[0182] Comparative Example 27

[0183] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 1 part of zinc gluconate aqueous solution (30mg / mL) to the above mixed aqueous solution to prepare zinc hyaluronate hydrogel.

[0184] Comparative Example 28

[0185] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (10mg / mL) evenly, and then add 1 part of zinc gluconate aqueous solution (80mg / mL) to the above mixed aqueous solution to prepare zinc hyaluronate hydrogel.

[0186] Comparative Example 29

[0187] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (10mg / mL) evenly, and then add 1 part of zinc gluconate aqueous solution (50mg / mL) to the above mixed aqueous solution to prepare zinc hyaluronate hydrogel.

[0188] Comparative Example 30

[0189] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (5mg / mL) evenly, and then add 1 part of zinc gluconate aqueous solution (50mg / mL) to the above mixed aqueous solution to prepare zinc hyaluronate hydrogel.

[0190] Comparative Example 31

[0191] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) thoroughly to prepare a mixture.

[0192] Comparative Example 32

[0193] Add 0.5 parts of zinc gluconate aqueous solution (40 mg / mL) to 1 part of sodium alginate aqueous solution (15 mg / mL) to prepare a hydrogel.

[0194] Comparative Example 33

[0195] Add 0.2 parts of zinc gluconate aqueous solution (40 mg / mL) to 1 part of sodium alginate aqueous solution (15 mg / mL) to prepare a hydrogel.

[0196] Comparative Example 34

[0197] Add 0.1 part of zinc gluconate aqueous solution (40 mg / mL) to 1 part of sodium alginate aqueous solution (15 mg / mL) to prepare a hydrogel.

[0198] Comparative Example 35

[0199] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 1 part of zinc gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare zinc hyaluronate hydrogel.

[0200] Comparative Example 36

[0201] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 2.5 parts of zinc gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare zinc hyaluronate hydrogel.

[0202] Comparative Example 37

[0203] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 200kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.5 parts of zinc gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare a mixture.

[0204] Comparative Example 38

[0205] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 10kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.5 parts of zinc gluconate aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare a mixture.

[0206] Comparative Example 39

[0207] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1 kDa, 10 mg / mL) and 1 part of sodium alginate aqueous solution (15 mg / mL) evenly, and then add 0.5 parts of zinc gluconate aqueous solution (40 mg / mL) to the above mixed aqueous solution to prepare a mixture.

[0208] Comparative Example 40

[0209] Mix 1 part of zinc hyaluronic acid aqueous solution (average molecular weight 1450kDa, 10mg / mL) evenly, and then add 1 part of sodium alginate aqueous solution (15mg / mL) to the above mixed solution to prepare a mixture.

[0210] Comparative Example 41

[0211] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 0.5 parts of zinc gluconate aqueous solution (40mg / mL) evenly, and then add 1 part of sodium alginate aqueous solution (15mg / mL) to the above mixture to prepare zinc hyaluronate hydrogel.

[0212] Comparative Example 42

[0213] Mix 1 part sodium alginate aqueous solution (15 mg / mL) and 0.5 parts zinc gluconate aqueous solution (40 mg / mL) evenly, then add 1 part sodium hyaluronate aqueous solution (average molecular weight 1450 kDa, 10 mg / mL) to the above mixture to prepare zinc hyaluronate hydrogel.

[0214] The compositions of the zinc hyaluronic acid hydrogels prepared in Experimental Examples 13-18 and Comparative Examples 27-42 are shown in Table 4.

[0215] Table 4

[0216] Experiment Example 4

[0217] This embodiment provides a method for preparing stannous hyaluronic acid hydrogel, as follows.

[0218] Experimental Example 19

[0219] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (25mg / mL) evenly, and then add 0.2 parts of stannous fluoride aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0220] Test Example 20

[0221] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (25mg / mL) evenly, and then add 0.25 parts of stannous fluoride aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0222] Experimental Example 21

[0223] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (25mg / mL) evenly, and then add 0.33 parts of stannous fluoride aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0224] Test Example 22

[0225] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (20mg / mL) evenly, and then add 0.25 parts of stannous fluoride aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0226] Comparative Example 43

[0227] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (30mg / mL) evenly, and then add 0.5 parts of stannous fluoride aqueous solution (30mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0228] Comparative Example 44

[0229] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (30mg / mL) evenly, and then add 0.5 parts of stannous fluoride aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0230] Comparative Example 45

[0231] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (30mg / mL) evenly, and then add 0.4 parts of stannous fluoride aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0232] Comparative Example 26

[0233] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (30mg / mL) evenly, and then add 0.25 parts of stannous fluoride aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0234] Comparative Example 47

[0235] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (30mg / mL) evenly, and then add 0.6 parts of stannous fluoride aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0236] Comparative Example 48

[0237] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (20mg / mL) evenly, and then add 0.5 parts of stannous fluoride aqueous solution (30mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0238] Comparative Example 49

[0239] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (20mg / mL) evenly, and then add 0.5 parts of stannous fluoride aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0240] Comparative Example 50

[0241] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (20mg / mL) evenly, and then add 0.4 parts of stannous fluoride aqueous solution (40mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0242] Comparative Example 51

[0243] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.5 parts of stannous fluoride aqueous solution (30mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0244] Comparative Example 52

[0245] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly, and then add 0.33 parts of stannous fluoride aqueous solution (30mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0246] Comparative Example 53

[0247] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (10mg / mL) evenly, and then add 0.5 parts of stannous fluoride aqueous solution (30mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0248] Comparative Example 54

[0249] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (10mg / mL) evenly, and then add 0.33 parts of stannous fluoride aqueous solution (30mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0250] Comparative Example 55

[0251] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (15mg / mL) evenly to prepare a hydrogel.

[0252] Comparative Example 56

[0253] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 1 part of sodium alginate aqueous solution (30mg / mL) evenly to prepare a hydrogel.

[0254] Comparative Example 57

[0255] Mix 1 part of stannous fluoride aqueous solution (200 mg / mL) and 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450 kDa, 10 mg / mL) evenly to prepare a hydrogel.

[0256] Comparative Example 58

[0257] Mix 1 part sodium alginate aqueous solution (25 mg / mL) and 0.5 parts stannous fluoride aqueous solution (40 mg / mL) evenly to prepare a hydrogel.

[0258] Comparative Example 59

[0259] Mix 1 part of sodium hyaluronate aqueous solution (average molecular weight 1450kDa, 10mg / mL) and 0.2 parts of stannous fluoride aqueous solution (40mg / mL) evenly, and then add 1 part of sodium alginate aqueous solution (25mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0260] Comparative Example 60

[0261] Mix 1 part sodium alginate aqueous solution (25 mg / mL) and 0.2 parts stannous fluoride aqueous solution (40 mg / mL) evenly, and then add 1 part sodium hyaluronate aqueous solution (average molecular weight 1450 kDa, 10 mg / mL) to the above mixed aqueous solution to prepare stannous hyaluronate hydrogel.

[0262] The compositions of the stannous hyaluronic acid hydrogels prepared in Experimental Examples 19-22 and Comparative Examples 43-60 are shown in Table 5.

[0263] Table 5

[0264] Test Example 1: Shear Stability Test

[0265] The shear stability of the hyaluronic acid metal saline gels obtained in Examples 1-4 above was tested. The test method was as follows: after shaking on a shaker for 2 hours (37°C, 200 rpm), the stability of the gel morphology under shear was visually observed.

[0266] The results of the shear stability test of strontium hyaluronic acid hydrogel are shown in Table 6.

[0267] Table 6 Shear Stability of Hyaluronic Acid Strontium Hydrogel

[0268] As shown in Table 6, the strontium hyaluronic acid hydrogels prepared by the methods in Examples 1-4 all exhibit excellent shear stability. The shear stability test results for calcium hyaluronic acid hydrogels are shown in Table 7.

[0269] Table 7 Shear Stability of Calcium Hyaluronic Acid Hydrogel

[0270] As shown in Table 7, the calcium hyaluronic acid hydrogels prepared by the methods in Examples 6-12 all exhibit excellent shear stability. The shear stability test results for zinc hyaluronic acid hydrogels are shown in Table 8.

[0271] Table 8 Shear Stability of Zinc Hyaluronic Acid Hydrogel

[0272] As shown in Table 8, the zinc hyaluronic acid hydrogels prepared by the methods in Examples 13 and 18 exhibit excellent shear stability.

[0273] The results of the shear stability test of stannous hyaluronic acid hydrogel are shown in Table 9.

[0274] Table 9 Shear Stability of Stannous Hyaluronic Acid Hydrogel

[0275] As shown in Table 9, the stannous hyaluronic acid hydrogels prepared by the method in Examples 19-22 exhibit excellent shear stability.

[0276] Test Example 2: Film Formation Experiment and Artificial Saliva Challenge Experiment

[0277] In this experiment, hyaluronic acid metal saline gels prepared by the methods in Experiment Examples 4, 8, 13, and 19 above were used as examples to conduct film formation experiments and artificial saliva challenge experiments to explore whether hyaluronic acid metal saline gels have the ability to resist water rinsing and saliva erosion during actual use.

[0278] Artificial saliva is prepared in accordance with ISO 10271 standard, and its components include: 0.4 g / L NaCl, 0.4 g / L KCl, 0.795 g / L CaCl2·H2O, 1 g / L urea, 0.005 g / L Na2S·2H2O, and 0.78 g / L NaH2PO4·H2O.

[0279] The experimental method included: adding HAP sheets to the hydrogel formed in a 5 mL centrifuge tube, incubating at 37°C for 1 hour, and then rinsing three times with deionized water. Next, the HAP sheets were added to artificial saliva and soaked at 37°C for 1 hour, 2 hours, 4 hours, and 8 hours, respectively, followed by rinsing three times with deionized water. SEM images and X-ray photoelectron spectroscopy were performed on the HAP sheet samples at each stage.

[0280] As shown in the SEM images (Fig. 1(a), Fig. 1(b), Fig. 1(c), and Fig. 1(d)), the films formed by strontium hyaluronic acid hydrogel, calcium hyaluronic acid hydrogel, and zinc hyaluronic acid hydrogel on hydroxyapatite dental slides can resist 8 hours of artificial saliva erosion and maintain good integrity. The film formed by stannous hyaluronic acid hydrogel on hydroxyapatite dental slides can resist 4 hours of artificial saliva erosion and maintain good integrity.

[0281] As clearly seen in X-ray photoelectron spectroscopy (XPS) 2(a), after 1h, 2h, 4h, and 8h of artificial saliva immersion, the film on the surface of the HAP sheet contains the Sr 3d binding energy peak corresponding to strontium. The intensity ratio of the C1s to Sr 3d binding energy peaks in the XPS spectroscopy of the strontium hyaluronic acid gel did not change significantly after 1h, 2h, and 4h of artificial saliva immersion, demonstrating that the strontium hyaluronic acid film helps strontium to form and exist stably and firmly on the HAP sheet, and can withstand water rinsing and saliva immersion. The data are shown in Table 10.

[0282] X-ray photoelectron spectroscopy (XPS) 2(b) clearly shows the Ca 2p binding energy peak corresponding to calcium. After soaking in artificial saliva for 2 h and 4 h, the intensity ratio of the C1s to Ca 2p binding energy peaks in the XPS of the calcium hyaluronic acid gel was even better than at 0 h, and the abundance of Ca was also higher, showing a tendency to accumulate on the membrane. After soaking in artificial saliva for 8 h, the intensity ratio of the C1s to Ca 2p binding energy peaks in the XPS of the calcium hyaluronic acid gel decreased significantly, and the abundance of Ca also decreased significantly, with both values ​​dropping to the levels of 0 h and 1 h, as shown in Table 10.

[0283] X-ray photoelectron spectroscopy (XPS) 2(c) clearly shows the binding energy peak of Zn 2p corresponding to zinc. After soaking in artificial saliva, the intensity ratio of the C1s to Zn 2p binding energy peaks in the XPS of zinc hyaluronic acid gel did not change significantly, proving that the zinc hyaluronic acid film can help zinc to form and exist stably and firmly on the HAP sheet, and can withstand water rinsing and saliva soaking. The data can be found in Table 10.

[0284] X-ray photoelectron spectroscopy (XPS) 2(d) clearly shows the Sn 3d binding energy peak corresponding to tin substantia. After immersion in artificial saliva for 4 hours, the intensity ratio of the C1s to Sn 3d binding energy peaks in the XPS of the tin substantia hydrogel showed no significant change. This demonstrates that the tin substantia hydrogel film can help tin substantia ions to form and exist stably and firmly on the HAP sheet, and can withstand at least 4 hours of immersion and erosion by saliva. The data can be found in Table 10.

[0285] Table 10

[0286] In summary, the hydrogels prepared in the experimental examples can withstand at least 4 hours of immersion and erosion by saliva, and zinc hyaluronic acid can basically resist 8 hours of artificial saliva erosion. The hydrogel film can be stably and firmly formed and exist on HAP sheets.

[0287] In this embodiment, an artificial saliva challenge experiment is used to simulate the saliva-washing environment in the oral cavity. After the gel forms a film in the hard tissues of the oral cavity, it can only effectively exert its therapeutic and preventive effects by resisting saliva erosion.

[0288] Test Example 3: Strontium Hyaluronic Acid Tubulosea Sealing Experiment

[0289] In this embodiment, the strontium hyaluronic acid hydrogel prepared by the method in Experiment Example 4 above was used as an example to conduct a dentinal tubule sealing experiment in order to explore the anti-allergic properties of the strontium hyaluronic acid hydrogel.

[0290] The experimental method included: cutting a 1.5 cm long section from the middle of a bovine tooth root, with a maximum diameter of 8.5 mm. A Deli DL6391B multi-functional cutting and polishing machine was used, fitted with a resin cutting disc and set to speed level 4. After cutting, the labial surface of the root was polished with 120-grit sandpaper to create a flat surface 6 mm wide and long. After cutting and polishing, the root model was stored in a 0.1% thymol solution at 4°C for no more than 3 months. One day before use, the model was removed and stored in deionized water at 4°C.

[0291] Before the experiment, the tooth roots were opened to create tubules. The slides were immersed in 0.5M EDTA (pH=7.5) solution and stirred at 75 rpm for 2 min. After rinsing with deionized water, the slides were patted dry with a paper towel. The slides were held in a petri dish with tweezers. A micro-toothbrush was used to apply 0.5M EDTA solution to the model surface for 2 min. The model was then rinsed with deionized water for 5 s and patted dry with a paper towel. A mixture of 500 μL of strontium hyaluronic acid hydrogel and an equal volume of artificial saliva was applied to the cut surface with a micro-toothbrush. The artificial saliva group used only 500 μL of artificial saliva, while the control group used 500 μL of water. The mixture was repeatedly applied to the cut surface for 10 min, and SEM images were generated (Figure 3). The tubules were counted using ImageJ software, and significance analysis was performed (Figure 4). The analysis results are shown in Table 11.

[0292] Table 11

[0293] As shown in Figures 3 and 4 and Table 11, compared with artificial saliva, strontium hyaluronic acid gel can significantly block dentinal tubules, with a blocking rate of up to 88%, proving that it has a good anti-allergic effect.

[0294] Test Example 4: Hyaluronic Acid Calcium Hydrogel-Induced Enamel Growth Experiment

[0295] (1) Experimental method:

[0296] a) To simulate early caries damage, tooth enamel samples were etched with H3PO4 (37wt%) for 10 min.

[0297] b) Then sonicate in deionized water for 20 minutes to ensure removal of any residual contaminants and air dry.

[0298] c) Divide the area on the enamel into two, apply gingival protectant to one half, and after it has cured under natural light, apply 100 μL of test case 8 to the other half of the enamel.

[0299] d) After standing for 15 minutes, remove the gingival protectant, soak the sample in artificial saliva, and place it in a 37°C constant temperature oven for 72 hours before taking it out.

[0300] e) Place the sample in deionized water and sonicate for 20 minutes to remove surface gel residue, then air dry, spray with gold, and observe the cross-sectional morphology of the enamel.

[0301] in conclusion:

[0302] Figure 5 shows SEM images of the enamel surfaces of samples from Test Example 8 (treated with and untreated with Test Example 8) after 72 hours of immersion in artificial saliva. The images clearly show that after treatment with Test Example 8, the acid-etched enamel surface became smooth, similar to normal enamel, while the surface without treatment remained grooved. This indicates that, under the protection of the calcium hyaluronic acid film, phosphate ions in artificial saliva can slowly penetrate into the enamel surface, slowly combine with calcium on the calcium hyaluronic acid film, and grow on the enamel surface.

[0303] Test Example 5: Oral Mucosal Adhesion Test and Artificial Saliva Challenge Experiment

[0304] In this embodiment, the zinc hyaluronic acid hydrogel prepared by the method in Experiment Example 13 above was used to conduct oral mucosal adhesion tests and artificial saliva challenge experiments to explore the adhesion ability of the zinc hyaluronic acid hydrogel to the mucosa before and after saliva immersion during actual use.

[0305] Artificial saliva is prepared in accordance with ISO 10271 standard, and its components include: 0.4 g / L NaCl, 0.4 g / L KCl, 0.795 g / L CaCl2·H2O, 1 g / L urea, 0.005 g / L Na2S·2H2O, and 0.78 g / L NaH2PO4·H2O.

[0306] The experiment used pig intestines to simulate the oral mucosa and examined the adhesion of the gel to the mucosa, as follows:

[0307] Group without artificial saliva soaking: Cut pig casings into strips 3cm wide and wrap them around one end of a metal sheet, securing the back with adhesive tape (prepare two). Evenly apply the gel precursor solution (200μL each of sodium hyaluronate (10mg / mL) and sodium alginate (15mg / mL) mixed) to the surface of the first pig casing. After adding 100μL of zinc gluconate (40mg / mL), quickly attach the second metal sheet with the pig casing to the first sheet. After waiting 2 minutes for the gel to fully form, clamp both ends of the metal sheet to a fixture and stretch it at 100mm / min until the two metal sheets are completely separated. Repeat the experiment 5 times and measure the tensile stress.

[0308] Artificial saliva soaking group: Pig casings were cut into 3cm wide strips and wrapped around one end of an iron sheet, securing the back with adhesive tape (two strips were prepared). The precursor solution for the gel (200μL each of sodium hyaluronate (10mg / mL) and sodium alginate (15mg / mL) mixed evenly) was evenly applied to the surface of the first pig casing. After adding 100μL of zinc gluconate (40mg / mL), the second iron sheet with the pig casing attached was quickly attached to the first sheet. After 2 minutes of complete gel formation, the iron sheet was immersed in artificial saliva at 37℃ for 30 minutes, 1 hour, or 2 hours. Once the set soaking time was complete, the iron sheet was removed, and both ends were clamped onto a fixture. The sheet was then stretched at a speed of 100mm / min until the two iron sheets were completely separated. The experiment was repeated 5 times, and the tensile stress was measured.

[0309] The tensile stress test results are shown in Figure 6 and Table 12.

[0310] Table 12

[0311] As shown in Figure 6 and Table 12, the zinc hyaluronic acid hydrogel (Example 13) gradually broke down with increasing immersion time in artificial saliva. The tensile stress diagram indicates that the zinc hyaluronic acid hydrogel remained stable on the oral mucosa for 30 minutes. The oral mucosa adhesion test was used to demonstrate the material's adhesion to the oral mucosa and its ability to resist saliva erosion. The longer the material remains stable on the oral mucosa, the longer its effect lasts. The experiment demonstrates that the zinc hyaluronic acid hydrogel can effectively provide membrane protection for oral soft tissues within 30 minutes, during which zinc may also exert antibacterial effects on the oral soft tissues through the membrane.

[0312] Test Example 6: Bacterial Growth Curve Experiment

[0313] In this embodiment, a bacterial growth curve experiment was conducted on zinc hyaluronic acid hydrogel.

[0314] The experimental method included: adding 250 μL of Streptococcus mutans solution (10 6CFU / mL (Top Biotech) was mixed with 250 μL PBS, a sodium hyaluronate / sodium alginate mixture (prepared using the method of Comparative Example 31), and a zinc hyaluronate hydrogel (prepared using the method of Experimental Example 13), respectively. The mixtures were placed at 37°C and continuously shaken for 4 h (200 rpm). Each mixture was then transferred to a 15 mL centrifuge tube containing 10 mL of BHI medium and incubated in a shaker. Equal volumes of samples were taken at 0 h, 3 h, 6 h, 9 h, 12 h, 18 h, 24 h, and 30 h to measure their OD values. 600 As shown in Table 13, the OD is plotted accordingly. 600 The curve showing the relationship between time and growth is the bacterial growth curve (Figure 7).

[0315] Table 13 Note: *: t-test p < 0.05 between Experimental Example 13 and Comparative Example 31; **: t-test p < 0.05 between Experimental Example 13 and Comparative Example 31 < 0.01; ***: t-test between Experimental Example 13 and Comparative Example 31, p<0.001; ****: t-test between Experimental Example 13 and Comparative Example 31, p<0.0001; *****: t-test between Experimental Example 13 and Comparative Example 31, p<0.00001; $: t-test between Experimental Example 13 and PBS, p<0.05; $$: t-test between Experimental Example 13 and PBS, p<0.01; $$$: t-test between Experimental Example 13 and PBS, p<0.001; $$$$: t-test between Experimental Example 13 and PBS, p<0.0001; $$$$: t-test between Experimental Example 13 and PBS, p<0.00001.

[0316] As shown in Table 13 and Figure 7, compared with the PBS blank, Experimental Example 13 showed significantly stronger antibacterial activity from 6 to 18 hours. Compared with Comparative Example 31 without zinc, Experimental Example 13 showed significantly stronger antibacterial activity from 9 to 18 hours. However, there was essentially no significant difference in antibacterial activity between Comparative Example 31 and the PBS blank; in fact, at 12 hours of incubation, the antibacterial activity of Comparative Example 31 was significantly worse than that of the PBS blank.

[0317] Test Example 7: Bacterial Colony Counting Experiment

[0318] In this embodiment, a bacterial colony count experiment was conducted on zinc hyaluronic acid hydrogel to further verify its antibacterial effect.

[0319] The experimental methods included assessing the activity of the Streptococcus mutans biofilm on the surface of hydroxyapatite dental slides and its inhibitory effect on the samples by bacterial colony count (CFU). Untreated hydroxyapatite dental slides and those coated with experimental example 13 or comparative example 31 were placed in 1 mL of 10...6 The HAP (hydroxyapatite) dental slides were cultured in CFU / mL bacterial solution at 37℃ under anaerobic conditions for 6 h, 12 h, and 24 h, respectively. After culturing, the HAP surface was rinsed three times with PBS to remove any adhering bacteria. The slides were then transferred to centrifuge tubes containing 1 mL of PBS and sonicated for 15 min to collect the bacteria. The bacterial solution was serially diluted 10-fold to 1200-fold using PBS, and then spread onto BHI solid agar plates. After incubating the agar plates at 37℃ for 2 days, the bacterial count was calculated. The results are shown in Table 14.

[0320] As shown in Table 14, the experimental results revealed that after 6h, 12h, and 24h of incubation, the antibacterial effect of experimental group 13 was significantly greater than that of the control group. This demonstrates that experimental group 13 also exhibits a significantly greater antibacterial effect than control group 31 on hydroxyapatite.

[0321] Table 14 Note: **: t-test p < 0.01 between Experimental Example 13 and Comparative Example 31; ***: t-test p < 0.001 between Experimental Example 13 and Comparative Example 31.

[0322] Test Example 8: Bacterial Colony Counting Experiment

[0323] In this test case, stannous hyaluronic acid hydrogel was used to detect its antibacterial and anti-caries effects.

[0324] (1) Experimental method:

[0325] The viability of the *Streptococcus mutans* biofilm on the HAP surface and the inhibitory effect on the samples were assessed by bacterial colony count (CFU). HAP and HAP coated with the control group (50 μL sodium hyaluronate + 50 μL sodium alginate) (e.g., Comparative Example 1) and Experimental Example 19 (50 μL sodium hyaluronate + 50 μL sodium alginate + 10 μL stannous fluoride) were respectively placed in 1 mL of 10 6 The HAP was cultured in CFU / mL bacterial solution at 37℃ under anaerobic conditions for 6 h, 12 h, and 24 h, respectively. After culturing, the HAP surface was rinsed three times with PBS to remove unattached bacteria. The HAP was then transferred to centrifuge tubes containing 1 mL PBS and collected by sonication for 10 min. The bacteria were then serially diluted 10-fold with PBS (6 h to 10). 3 Diluted to 10 times, 12 hours later 4 Dilute to 10 times, 24 hours later 5 The bacterial culture was diluted (times), and then spread on BHI solid agar plates. After incubating the agar plates at 37°C for 2 days, the bacterial count was calculated. The results are shown in Table 15.

[0326] (2) Conclusion:

[0327] The experimental results showed that after 6h, 12h, and 24h of incubation, the antibacterial effect of Experimental Example 19 was significantly better than that of the control group, achieving 100% antibacterial activity and demonstrating extremely excellent antibacterial effect. This proves that on hydroxyapatite, Example 19 has a significantly better antibacterial effect than the control group, and also shows excellent long-lasting anti-caries effect.

[0328] Table 15

[0329] Table 15. Inhibition rate of *Streptococcus mutans* on the surface of Experiment 19 and the control group. Experiment 19 compared to the control group: **: p < 0.01; ***: p < 0.001

[0330] Test Example 9: Dental tubule sealing experiment using stannous hyaluronic acid hydrogel

[0331] (1) Experimental method:

[0332] A 1.5cm section of the root of a bovine tooth was cut from the middle. The widest part of the root was 8.5mm in diameter. A Deli DL6391B multi-functional cutting and polishing machine was used, with the resin cutting disc installed and the speed set to level 4. After cutting, the labial surface of the root was polished with 120-grit sandpaper to create a flat surface 6mm wide and long. The root model was then stored in a 0.1% thymol solution at 4°C for no more than 3 months. The day before use, the model slices were removed and stored in deionized water at 4°C.

[0333] The slides were immersed in 0.5M EDTA (pH=7.5) solution and stirred at 75 rpm for 2 min. After rinsing with deionized water, the slides were patted dry with a paper towel. The slides were then held in a petri dish with tweezers. A micro-toothbrush was used to apply 0.5M EDTA solution to the model surface for 2 min. The model was then rinsed with deionized water for 5 seconds and patted dry with a paper towel. A micro-toothbrush was then used to apply 500 μL of a mixture of Experiment 19 and artificial saliva (500 μL of artificial saliva was applied to the artificial saliva group) repeatedly to the slide surface for 10 min. The dentinal tubules were counted and significance analyzed using ImageJ software. The results are shown in Table 16, Figure 8, and Figure 9.

[0334] (2) Conclusion:

[0335] Compared to artificial saliva, Experiment 19 can significantly block dentinal tubules, with a blockage rate of 97%, and has excellent anti-allergic effects.

[0336] Table 16

[0337] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. An oral care composition, characterized in that, The composition comprises: hyaluronic acid or a salt thereof, sodium alginate, and a divalent metal salt; The composition is obtained by mixing hyaluronic acid or its salt with sodium alginate and then adding a divalent metal salt.

2. The composition according to claim 1, characterized in that, The molar ratio of the hyaluronic acid or its salt, sodium alginate and divalent metal salt is 1:(1-11):(0.1-4.5).

3. The composition according to claim 1, characterized in that, The divalent metal salt includes one or more of calcium salts, strontium salts, zinc salts, or stannous salts.

4. The composition according to claim 3, characterized in that, The zinc salt is selected from one or more of zinc gluconate, zinc lactate, zinc chloride, zinc citrate, zinc sulfate, zinc oxide, zinc acetate, zinc bismaltoxygenate, zinc pyrithione, zinc ricinoleate, zinc glycinate, zinc glycyrrhetinate, zinc myristate, zinc undecenoate, zinc salicylate, zinc carbonate, zinc aspartate, zinc cocoyl ether sulfate, zinc acetylated methionine, zinc stearate, zinc laurate, and zinc palmitate; optionally, the zinc salt is zinc gluconate and / or zinc chloride. The strontium salt is selected from one or more of strontium nitrate, strontium sulfate, strontium chloride, and strontium acetate; optionally, the strontium salt is strontium acetate. The calcium salt is selected from one or more of the following: calcium chloride, calcium borate, calcium acetate, calcium carbonate, calcium phosphate, calcium citrate, calcium lactate, calcium DNA, calcium disodium EDTA, calcium PCA, calcium fluoride, calcium propionate, calcium pantothenate, calcium pantothenate thioethylamine sulfonate, calcium glycerophosphate, calcium silicate, calcium aluminum silicate sodium, calcium pyrophosphate, carrageenan calcium, calcium ascorbate, calcium sodium phosphosilicate, calcium hydrogen phosphate, tricalcium phosphate, calcium aluminum borosilicate, calcium sodium borosilicate, calcium titanium borosilicate, calcium mercaptoacetate, calcium myristate, calcium behenate, calcium carboxymethyl cellulose, calcium aspartate, calcium octenyl succinate starch, calcium stearate, calcium stearoyl lactylate, calcium lauroyl taurate, calcium alginate, calcium phosphoryl oligosaccharide, and calcium gluconate; optionally, the calcium salt is calcium gluconate. The stannous salt is selected from one or more of stannous fluoride, stannous chloride, stannous sulfate, stannous iodide, and stannous furan; optionally, the stannous salt is stannous fluoride.

5. The composition according to claim 3, characterized in that, The molar ratio of the hyaluronic acid or its salt, sodium alginate and strontium salt is 1:(1-10):(0.5-4.5); optionally, 1:(2.0-6.5):(1-4).

6. The composition according to claim 3, characterized in that, The molar ratio of the hyaluronic acid or its salt, sodium alginate and calcium salt is 1:(2.5-8):(0.2-3.2); optionally, 1:(3.0-6.5):(0.5-3.0).

7. The composition according to claim 3, characterized in that, The molar ratio of the hyaluronic acid or its salt, sodium alginate and zinc salt is 1:(2.5-11):(0.1-2.5); optionally, 1:(2.5-3.5):(1.0-2.0).

8. The composition according to claim 3, characterized in that, The molar ratio of the hyaluronic acid or its salt, sodium alginate and stannous salt is 1:(3.5-5.5):(0.5-3.6); optionally, 1:(4.0-5.5):(2.0-3.5).

9. The composition according to any one of claims 1-8, characterized in that, The hyaluronic acid or its salt is selected from one or more of hyaluronic acid, sodium hyaluronate, potassium hyaluronate, calcium hyaluronate, and zinc hyaluronate; optionally, the hyaluronic acid or its salt is sodium hyaluronate; optionally, the molecular weight of the hyaluronic acid or its salt is >200kDa; more preferably, the molecular weight of the sodium hyaluronate is >1000kDa.

10. An oral care product comprising the composition of any one of claims 1-9.

11. The use of the composition as described in any one of claims 1-9 or the oral care product as described in claim 10 in oral care.

12. The use of the composition according to any one of claims 1-9 in improving gel shear stability and / or resistance to adverse adhesion.

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