Multifunctional photoresponse hydrogel as well as raw materials, preparation method and application thereof

Abstract

The invention relates to a multifunctional photoresponse hydrogel as well as raw materials, a preparation method and application thereof, a natural polymer derivative is obtained by introducing a carbon-carbon double bond and a special functional group on a natural polymer skeleton, and the natural polymer derivative, a cross-linking agent containing multiple sulfydryl groups and a photoinitiator are combined to obtain the multifunctional photoresponse hydrogel. The natural polymer derivative and the cross-linking agent can be subjected to a cross-linking reaction under the action of the photoinitiator after illumination to form the multifunctional photoresponse hydrogel. Through structural design and functional improvement of the photoresponse hydrogel, the hydrogel is endowed with more powerful effects of ultraviolet resistance, inflammation resistance, bacteria resistance, oxidation resistance, repair promotion and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of skin care products, and particularly relates to a multifunctional light-responsive hydrogel, its raw materials, preparation method and application. Background Art

[0002] Hydrogel is a soft material composed of a hydrophilic polymer network, which can absorb and retain a large amount of water while maintaining its three-dimensional structure. Due to its unique biocompatibility, tunable physicochemical properties and characteristics of biomimetic extracellular matrix, hydrogel has been widely used in the fields of biomedicine, tissue engineering, drug delivery, flexible electronics, etc. In recent years, hydrogels have evolved from static materials into "intelligent" materials that can adapt to various stimuli (such as pH value, temperature, chemistry, electricity or light). Among them, light-responsive hydrogels have become a research hotspot of intelligent materials due to their high spatiotemporal precision, non-invasive manipulation and programmability. However, the functions of pure light-responsive hydrogels are relatively single and difficult to meet the requirements of actual multi-faceted applications. Existing light-responsive hydrogels lack structural design and functional modification. In addition to functions such as moisturizing and isolation, it is difficult for hydrogels to meet the special requirements of other applications, such as anti-ultraviolet, promoting tissue regeneration and repair, and antioxidant. Summary of the Invention

[0003] Aiming at the technical problems existing in the above-mentioned prior art, the present invention provides a multifunctional light-responsive hydrogel, its raw materials, preparation method and application. By carrying out structural design and functional improvement on the light-responsive hydrogel, the hydrogel is endowed with more powerful anti-ultraviolet, anti-inflammatory, antibacterial and antioxidant effects.

[0004] In the first aspect of the present invention, a natural polymer derivative is provided, which has the structure shown in Formula I: , in Formula I, is a natural polymer backbone, P 1、 P2 are each independently selected from the dehydroxylated residue, decarboxylated residue, deaminated residue of the natural polymer repeating unit or fragment, R1 is a group containing a carbon-carbon double bond; R2 is any one of an ultraviolet-absorbing small molecule, a small molecule containing a polyphenol structure or a short peptide with a promoting repair function, X and Y are each independently selected from an ether bond, an ester bond, an amide bond, a coupling molecule, and the coupling molecule includes at least two grafting sites of amino and / or hydrazide, and is connected to the carboxyl site on the natural polymer at one end through an amidation reaction and to R1 or R2 at the other end; m and n are each independently selected from integers of 1-10000; The natural polymer includes at least one of sodium hyaluronate, sodium alginate, chitosan, gelatin, collagen, chondroitin sulfate or fibrin; Preferably, the molecular weight of the natural polymer is 2 kDa - 5000 kDa.

[0005] In some embodiments of the present invention, the modification rate of R1 of the natural polymer is 10% to 50%.

[0006] In some embodiments of the present invention, the modification rate of R2 of the natural polymer is 5% to 50%.

[0007] In a second aspect of the present invention, a multifunctional photo-responsive hydrogel is provided, which is prepared from component A, component B and a photoinitiator in a solvent, wherein component A is the above-mentioned natural polymer derivative, and component B is a cross-linking agent containing multiple sulfhydryl groups; Preferably, the concentration of component A is 1 to 5 wt%, the concentration of component B is 1 to 5 wt%, the concentration of the photoinitiator is 0.001 to 1 wt%, and the balance is the solvent; Preferably, the cross-linking agent containing multiple sulfhydryl groups is selected from dithiothreitol, thiolated polyethylene glycol, and sulfhydryl-modified biopolymers; More preferably, the biopolymer is any one of hyaluronic acid, gelatin, collagen, alginic acid, and chitosan.

[0008] Preferably, the solvent is selected from distilled water, physiological saline or buffer solution.

[0009] In some embodiments of the present invention, the group containing a carbon-carbon double bond is selected from vinyl, propenyl, allyloxy, cyclohexenyl, norbornenyl, bicyclo[2.2.2]oct-5-enyl.

[0010] In some embodiments of the present invention, the ultraviolet-absorbing small molecule is a small molecule sunscreen containing a carboxyl group; Preferably, the small molecule sunscreen containing a carboxyl group includes cinnamic acid or a cinnamic acid derivative; the cinnamic acid derivative will undergo a photodimerization reaction to form a cross-linked network under irradiation at a specific wavelength, which can improve the mechanical properties of the photo-responsive hydrogel.

[0011] Preferably, the small molecule sunscreen containing a carboxyl group includes at least one of salicylic acid, a salicylic acid derivative, benzoic acid, a benzoic acid derivative, 2,6-naphthalenedicarboxylic acid, or 1,8-dihydroxy-3-carboxyanthraquinone. These small molecules with strong ultraviolet absorption endow the photo-responsive hydrogel with functions such as anti-ultraviolet, anti-inflammatory, and antioxidant.

[0012] In some embodiments of the present invention, the small molecule containing a polyphenol structure is selected from any one of dopamine, a dopamine derivative, 3,4-dihydroxybenzoic acid, a 3,4-dihydroxybenzoic acid derivative, gallic acid, and a gallic acid derivative. These small molecules containing a polyphenol structure can endow the photo-responsive hydrogel with functions such as antibacterial, antioxidant, and wet tissue adhesion.

[0013] In some embodiments of the present invention, the short peptides with repair-promoting functions include at least one of EGF short peptide, oligopeptide-1, QK peptide, PR1P peptide, RGD peptide, BDNF mimetic peptide or BMP-2-derived peptide. These short peptides with repair-promoting functions can endow the photo-responsive hydrogel with effects such as promoting tissue regeneration and repair.

[0014] In some embodiments of the present invention, the photoinitiator includes at least one of lithium phenyl(2,4,6-trimethylbenzoyl)phosphate (LAP), 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone (I2959), eosin Y, α-ketoglutaric acid, 2,4,6-trimethylbenzoyldiphenylphosphine oxide or 1-hydroxycyclohexyl phenyl ketone.

[0015] In the third aspect of the present invention, a preparation method of the above-mentioned natural polymer derivative having the structure shown in Formula I is provided, and any one of the following preparation methods a-d is selected: a. It is only necessary to sequentially modify R1 and R2 at the hydroxyl, carboxyl or amino sites of the natural polymer; b. Introduce a coupling molecule containing amino and / or hydrazide at the carboxyl site of the natural polymer, and then sequentially modify R1 and R2 on the amino and / or hydrazide; c. Modify R1 at the carboxyl or hydroxyl site of the natural polymer, introduce a coupling agent containing amino at the carboxyl site of the natural polymer derivative modified by R1, and then modify R2 on the amino; d. Modify R2 at the carboxyl or hydroxyl site of the natural polymer, introduce a coupling agent containing amino and / or hydrazide at the carboxyl site of the natural polymer derivative modified by R2, and then modify R1 on the amino or hydrazide; Preferably, the coupling molecule is selected from any one of ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, hexylenediamine, heptylenediamine, octylenediamine, nonylenediamine, decylenediamine, amino-PEG, oxalic dihydrazide, malonic dihydrazide, succinic dihydrazide, glutaric dihydrazide, adipic dihydrazide, pimelic dihydrazide, suberic dihydrazide, azelaic dihydrazide, sebacic dihydrazide.

[0016] In the fourth aspect of the present invention, a preparation method of the above-mentioned multifunctional photo-responsive hydrogel is provided, including the following steps: Dissolve component A, component B and the photoinitiator in a solvent to obtain a hydrogel precursor solution: The hydrogel precursor solution undergoes photo-crosslinking under light irradiation to form a hydrogel.

[0017] In the fifth aspect of the present invention, the application of the above-mentioned multifunctional photo-responsive hydrogel is provided, selected from the following applications: The application of the photo-responsive hydrogel in products for promoting tissue regeneration and repair; Application of the light-responsive hydrogel in ultraviolet protection products; Application of the light-responsive hydrogel in antioxidant products; Application of the light-responsive hydrogel in anti-corrosion and bactericidal products.

[0018] The multifunctional light-responsive hydrogel, its raw materials, preparation method and application disclosed in the embodiments of the present invention are based on a natural polymer derivative having the structure shown in Formula I. A carbon-carbon double bond and a special functional group are introduced into its skeleton. The light-responsive hydrogel includes a natural polymer derivative having the structure shown in Formula I (Component A), a cross-linking agent containing multiple mercapto groups (Component B) and a photoinitiator. Under the action of the photoinitiator, Components A and B can undergo a cross-linking reaction to form a hydrogel after being irradiated with light. At this time, the functional groups on the natural polymer derivative having the structure shown in Formula I can enhance its function at the application site, and the cross-linking network can increase the residence time of the functional groups and extend the period for the functional groups to exert their effects. For example, when the functional group is cinnamic acid or a cinnamic acid derivative; the cinnamic acid derivative will undergo a photodimerization reaction to form a cross-linking network under irradiation at a specific wavelength, which can improve the mechanical properties of the light-responsive hydrogel and thus enhance its waterproof performance.

[0019] In summary, by introducing different functional groups into the molecular skeleton of the light-responsive hydrogel, light-responsive intelligent hydrogels with different functions are designed to improve the performance of the light-responsive hydrogel in aspects such as anti-ultraviolet, anti-inflammatory, antibacterial, antioxidant, enhancing tissue adhesion, promoting tissue repair and regeneration, etc., so as to flexibly meet the requirements of different application scenarios. Through special design of the structure of the two-component light-responsive hydrogel, the present invention can introduce functional groups into the molecular skeleton of the hydrogel by a general method, endowing the light-responsive hydrogel with more specific functions, such as more powerful anti-ultraviolet, anti-inflammatory, antibacterial, antioxidant, repair-promoting and other effects, to meet the personalized needs of different application fields.

[0020] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present invention, and are used together with the specification to explain the principles of the present invention; Figure 1 It is a test chart of the tissue adhesion strength of the small molecule-modified light-responsive hydrogel containing polyphenol structure in the embodiments of the present invention; Figure 2 It is a detection chart of the bursting strength of the small molecule-modified light-responsive hydrogel containing polyphenol structure in the embodiment; Figure 3Comparison diagram of the effect of a short peptide-modified light-responsive hydrogel with a promoting repair function on skin repair in the examples. Detailed implementation manners

[0022] The following will clearly and completely describe the concept and technical effects generated by the present invention in combination with the examples to fully understand the purpose, features, and effects of the present invention. Obviously, the described examples are only a part of the examples of the present invention, rather than all the examples. Based on the examples of the present invention, other examples obtained by those skilled in the art without creative efforts shall fall within the scope of protection of the present invention.

[0023] For the experimental methods without specific conditions indicated in the examples, they are usually carried out according to the conventional conditions in the art or according to the conditions recommended by the manufacturer; the raw materials, reagents, etc. used, unless otherwise specified, are all raw materials and reagents that can be obtained from commercial channels such as the conventional market.

[0024] Example 1: Preparation of sodium hyaluronate derivative A1; (1) Weigh 2.0 g of sodium hyaluronate (MW ≈ 400 kDa) and dissolve it in 400 mL of MES solution. Adjust the pH to 4 - 5, add 8.37 g of adipic dihydrazide and 1.05 g of EDC, maintain the pH within the range of 4 - 5, and continuously stir overnight. After the reaction is completed, dialyze with a dialysis bag (MWCO = 10 kDa) in deionized water for three days, and then freeze-dry to obtain hydrazide-functionalized sodium hyaluronate.

[0025] (2) At 40 °C, dissolve 5 g of p-nitrocinnamic acid in 50 mL of N, N'-dimethylformamide (DMF), and then add equimolar amounts of NHS and EDC. React under light protection for 24 h. After the reaction is completed, filter to remove the by-product dicyclohexylurea generated. Pour the filtrate into water for precipitation. After the obtained solid is dried in vacuo, N-succinimidyl p-nitrocinnamate is obtained, and the yield is about 90%.

[0026] (3) Weigh 1.0 g of hydrazide-functionalized sodium hyaluronate and dissolve it in 200 mL of water. Adjust the pH to 7.0, add 4.33 g of norbornene dianhydride and 2.00 g of N-succinimidyl p-nitrocinnamate, stir and react overnight. Then dialyze with a dialysis bag (MWCO = 10 kDa) in deionized water for three days, and freeze-dry to obtain a sodium hyaluronate derivative modified with norbornene and p-nitrocinnamic acid. The yield is about 74%. The norbornene modification rate detected by NMR is about 24%, and the p-nitrocinnamic acid modification rate is 11%.

[0027] Example 2: Preparation of sodium alginate derivative A2; (1) Weigh 2.0 g of sodium alginate (MW ≈ 200 kDa) and dissolve it in 40 mL of 0.1 M NaOH solution. Add 1.7 g of allyl glycidyl ether and stir continuously at 35 °C for 24 h. After the reaction is completed, pour the reaction solution into 250 mL of ice ethanol for precipitation. Filter out the precipitate, redissolve it in water, and then dialyze it in deionized water using a dialysis bag (MWCO = 10 kDa) for three days. Freeze-dry to obtain allyl-functionalized sodium alginate.

[0028] (2) Weigh 2.0 g of allyl-functionalized sodium alginate and dissolve it in 200 mL of MES solution. Add 4.65 g of butanediamine and 2.0 g of EDC, adjust the pH to 4.75, and stir continuously overnight. After the reaction is completed, dialyze it in deionized water using a dialysis bag (MWCO = 10 kDa) for three days. Freeze-dry to obtain sodium alginate functionalized with amino and allyl groups.

[0029] (3) At 40 °C, dissolve 5 g of p-methoxycinnamic acid in 50 mL of N, N'-dimethylformamide (DMF), and then add equimolar amounts of NHS and EDC. React in the dark for 24 h. After the reaction is completed, filter to remove the by-product dicyclohexylurea formed. Pour the filtrate into water for precipitation. After the obtained solid is dried in vacuo, N-succinimidyl p-methoxycinnamate is obtained, with a yield of about 91%.

[0030] (4) Weigh 1.0 g of sodium alginate functionalized with amino and allyl groups and dissolve it in 200 mL of water. Adjust the pH to 7.0, add 2.00 g of N-succinimidyl p-methoxycinnamate, and stir to react overnight. Then dialyze it in deionized water using a dialysis bag (MWCO = 10 kDa) for three days. Freeze-dry to obtain a sodium alginate derivative modified with allyl and p-methoxycinnamic acid, with a yield of about 71%. The allyl modification rate detected by NMR is about 33%, and the p-methoxycinnamic acid modification rate is 9%.

[0031] Example 3: Preparation of sodium hyaluronate derivative A3; (1) Weigh 2.0 g of sodium hyaluronate (MW ≈ 100 kDa) and dissolve it in 200 mL of MES buffer solution. Adjust the pH to 5.5, add 4.4 g of 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride and 1.23 g of norbornene-2-methylamine, and stir continuously at 20 °C for 24 h. After the reaction is completed, pour the reaction solution into 500 mL of ice ethanol for precipitation. Filter out the precipitate, redissolve it in water, and then dialyze it in deionized water using a dialysis bag (MWCO = 10 kDa) for three days. Freeze-dry to obtain norbornene-functionalized sodium hyaluronate.

[0032] (2) Weigh 2.0 g of norbornene-functionalized sodium hyaluronate and dissolve it in 200 mL of MES solution. Add 18.37 g of adipic dihydrazide and 4.05 g of EDC, adjust the pH to 4.75, and continuously stir overnight. After the reaction is completed, dialyze it in deionized water for three days using a dialysis bag (MWCO = 10 kDa), and then freeze-dry to obtain adipic dihydrazide and norbornene-functionalized sodium hyaluronate.

[0033] (3) At 40 °C, dissolve 5 g of cinnamic acid in 50 mL of N, N'-dimethylformamide (DMF), and then add equimolar amounts of NHS and EDC. React in the dark for 24 h. After the reaction is completed, filter to remove the by-product dicyclohexylurea formed. Pour the filtrate into water for precipitation. After the obtained solid is dried in vacuo, N-succinimidyl cinnamate is obtained with a yield of about 91%.

[0034] (4) Weigh 1.0 g of adipic dihydrazide and norbornene-functionalized sodium hyaluronate and dissolve it in 200 mL of water. Adjust the pH to 7.0, add 2.00 g of N-succinimidyl cinnamate, and stir to react overnight. Then dialyze it in deionized water for three days using a dialysis bag (MWCO = 10 kDa), and freeze-dry to obtain a norbornene- and cinnamic acid-modified sodium hyaluronate derivative with a yield of about 82%. The norbornene modification rate is about 27% and the cinnamic acid modification rate is 12% detected by NMR.

[0035] Example 4 Preparation of gelatin derivative A4 Weigh 10.0 g of gelatin (MW ≈ 500 kDa) and dissolve it in 200 mL of 0.5 M NaHCO3 solution at 50 °C. Adjust the pH to 8 - 9, add 10 g of norbornene dianhydride, and continuously stir overnight. After the reaction is completed, dialyze it in deionized water for three days using a dialysis bag (MWCO = 10 kDa), and then freeze-dry to obtain norbornene-functionalized gelatin.

[0036] (2) At 40 °C, dissolve 5 g of o-hydroxybenzoic acid in 50 mL of N, N'-dimethylformamide (DMF), and then add equimolar amounts of NHS and EDC. React in the dark for 24 h. After the reaction is completed, filter to remove the by-product dicyclohexylurea formed. Pour the filtrate into water for precipitation. After the obtained solid is dried in vacuo, recrystallize it with DMF / ethanol to obtain N-succinimidyl o-hydroxybenzoate.

[0037] (3)Weigh 5.0 g of norbornene-functionalized gelatin, dissolve it in 100 mL of water at 50 °C, adjust the pH to 7.0, add 2.00 g of N-succinimidyl o-hydroxybenzoate, stir and react overnight. Then dialyze it in deionized water using a dialysis bag (MWCO = 10 kDa) for three days, and freeze-dry to obtain a gelatin derivative modified with norbornene and o-hydroxybenzoic acid. The yield is about 78%. The norbornene modification rate detected by NMR is about 31%, and the o-hydroxybenzoic acid modification rate is 16%.

[0038] Example 5 Preparation of Collagen Derivative A5 (1)Weigh 2.0 g of bovine-derived collagen (MW ≈ 300 kDa), dissolve it in 50 mL of 0.5 M NaHCO3 solution at 50 °C, adjust the pH to 8 - 9, add 10 g of norbornene dianhydride, and continuously stir overnight. After the reaction, dialyze it in deionized water using a dialysis bag (MWCO = 10 kDa) for three days, and freeze-dry to obtain norbornene-functionalized collagen.

[0039] (2)At 40 °C, dissolve 5 g of 2,6-naphthalenedicarboxylic acid in 50 mL of N,N'-dimethylformamide (DMF), then add equimolar amounts of NHS and EDC, and react in the dark for 24 h. After the reaction, filter to remove the by-product dicyclohexylurea formed, pour the filtrate into water for precipitation, and recrystallize the obtained solid with DMF / ethanol after vacuum drying to obtain N-succinimidyl 2,6-naphthalenedicarboxylate.

[0040] (3)Weigh 1.0 g of norbornene-functionalized gelatin, dissolve it in 50 mL of water at 50 °C, adjust the pH to 7.0, add 2.00 g of N-succinimidyl 2,6-naphthalenedicarboxylate, stir and react overnight. Then dialyze it in deionized water using a dialysis bag (MWCO = 10 kDa) for three days, and freeze-dry to obtain a collagen derivative modified with norbornene and 2,6-naphthalenedicarboxylic acid. The yield is about 72%. The norbornene modification rate detected by NMR is about 24%, and the 2,6-naphthalenedicarboxylic acid modification rate is 11%.

[0041] Example 6 Preparation of Chitosan Derivative A6 (1)Weigh 2.0 g of carboxymethyl chitosan (MW ≈ 200 kDa), dissolve it in 100 mL of 0.5 M NaHCO3 solution, adjust the pH to 8 - 9, add 10 g of norbornene dianhydride, and continuously stir overnight. After the reaction, dialyze it in deionized water using a dialysis bag (MWCO = 10 kDa) for three days, and freeze-dry to obtain norbornene-functionalized chitosan.

[0042] (2) At 40 °C, 5 g of 1,8-dihydroxy-3-carboxyanthraquinone was dissolved in 50 mL of N,N'-dimethylformamide (DMF), and an equimolar amount of NHS and EDC were added. The reaction was carried out in the dark for 24 h. After the reaction was completed, the by-product dicyclohexylurea formed was removed by filtration. The filtrate was poured into water for precipitation. The obtained solid was dried in vacuo and recrystallized from DMF / ethanol to obtain N-succinimidyl 1,8-dihydroxy-3-carboxyanthraquinone ester.

[0043] (3) 1.0 g of norbornene-functionalized chitosan was weighed and dissolved in 100 mL of deionized water. The pH was adjusted to 7.0, and 2.00 g of N-succinimidyl 1,8-dihydroxy-3-carboxyanthraquinone ester was added. The reaction was stirred overnight. Then, dialysis was carried out in deionized water using a dialysis bag (MWCO = 10 kDa) for three days, followed by freeze-drying to obtain a chitosan derivative modified with norbornene and 1,8-dihydroxy-3-carboxyanthraquinone. The yield was approximately 67%. The norbornene modification rate was approximately 30% and the 1,8-dihydroxy-3-carboxyanthraquinone modification rate was 7% as detected by NMR.

[0044] Example 7 Preparation of chondroitin sulfate derivative A7; (1) 2.0 g of chondroitin sulfate was weighed and dissolved in 200 mL of MES buffer solution. The pH was adjusted to 5.5, and 4.4 g of 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride and 1.5 g of 3-cyclohexen-1-amine were added. Stirring was continued at 20 °C for 24 h. After the reaction was completed, the reaction solution was poured into 500 mL of ice ethanol for precipitation. The precipitate was filtered out, redissolved in water, and then dialysis was carried out in deionized water using a dialysis bag (MWCO = 10 kDa) for three days, followed by freeze-drying to obtain 3-cyclohexenyl-functionalized chondroitin sulfate.

[0045] (2) 0.5 g of 3-cyclohexenyl-functionalized chondroitin sulfate was weighed and dissolved in 150 mL of MES solution. 4.24 g of pentanediamine and 2.05 g of EDC were added, and the pH was adjusted to 4.75. Stirring was continued overnight. After the reaction was completed, dialysis was carried out in deionized water using a dialysis bag (MWCO = 10 kDa) for three days, followed by freeze-drying to obtain chondroitin sulfate functionalized with amino and 3-cyclohexene.

[0046] (3) At 40 °C, 5 g of p-methoxysalicylic acid was dissolved in 50 mL of N,N'-dimethylformamide (DMF), and an equimolar amount of NHS and EDC were added. The reaction was carried out in the dark for 24 h. After the reaction was completed, the by-product dicyclohexylurea formed was removed by filtration. The filtrate was poured into water for precipitation. The obtained solid was dried in vacuo and recrystallized from DMF / ethanol to obtain N-succinimidyl p-methoxysalicylate.

[0047] (4) Weigh 1.0 g of chondroitin sulfate functionalized with amino and 3-cyclohexene, dissolve it in 100 mL of water, adjust the pH to 7.0, add 1.8 g of N-succinimidyl 4-methoxysalicylate, stir and react overnight. Then, dialyze it in deionized water using a dialysis bag (MWCO = 10 kDa) for three days, and freeze-dry to obtain a chondroitin sulfate derivative modified with 3-cyclohexene and 4-methoxysalicylic acid. The yield is about 78%. The modification rate of 3-cyclohexene detected by NMR is about 22%, and the modification rate of salicylic acid is 10%.

[0048] Example 8: Preparation of sodium hyaluronate derivative A8; (1) Weigh 2.0 g of sodium hyaluronate, dissolve it in 200 mL of MES buffer solution, adjust the pH to 5.5, add 4.4 g of 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride and 1.9 g of bicyclo[2.2.2]oct-5-en-2-ylmethanamine, and continuously stir at 20 °C for 24 h. After the reaction, pour the reaction solution into 500 mL of ice ethanol for precipitation, filter out the precipitate, redissolve it in water, and then dialyze it in deionized water using a dialysis bag (MWCO = 10 kDa) for three days, and freeze-dry to obtain bicyclo[2.2.2]oct-5-en-functionalized sodium hyaluronate.

[0049] (2) Weigh 1.5 g of bicyclo[2.2.2]oct-5-en-functionalized sodium hyaluronate, dissolve it in 150 mL of MES solution, add 4.24 g of hexamethylenediamine and 2.05 g of EDC, adjust the pH to 4.75, and continuously stir overnight. After the reaction, dialyze it in deionized water using a dialysis bag (MWCO = 10 kDa) for three days, and freeze-dry to obtain sodium hyaluronate functionalized with amino and bicyclo[2.2.2]oct-5-ene.

[0050] (3) At 40 °C, dissolve 5 g of salicylic acid in 50 mL of N,N'-dimethylformamide (DMF), add an equimolar amount of NHS and EDC, and react in the dark for 24 h. After the reaction, filter out the by-product dicyclohexylurea formed, pour the filtrate into water for precipitation, and recrystallize the obtained solid with DMF / ethanol after vacuum drying to obtain N-succinimidyl salicylate.

[0051] (4) Weigh 1.0 g of sodium hyaluronate functionalized with amino and bicyclo[2.2.2]oct-5-ene, dissolve it in 100 mL of water, adjust the pH to 7.0, add 1.8 g of N-succinimidyl salicylate, stir and react overnight. Then, dialyze it in deionized water using a dialysis bag (MWCO = 10 kDa) for three days, and freeze-dry to obtain a sodium hyaluronate derivative modified with bicyclo[2.2.2]oct-5-ene and salicylic acid. The yield is about 75%. The modification rate of 3-cyclohexene detected by NMR is about 27%, and the modification rate of salicylic acid is 13%.

[0052] Example 9: Preparation of sodium hyaluronate derivative A9; (1) Weigh 2.0 g of sodium hyaluronate (MW ≈ 800 kDa) and dissolve it in 40 mL of 0.1 M NaOH solution. Add 1.7 g of allyl glycidyl ether and continuously stir at 35 °C for 24 h. After the reaction is completed, pour the reaction solution into 250 mL of ice ethanol for precipitation. Filter out the precipitate, redissolve it in water, and then dialyze it in deionized water for three days using a dialysis bag (MWCO = 10 kDa). Freeze-dry to obtain allyl-functionalized sodium hyaluronate.

[0053] (2) Weigh 2.0 g of allyl-functionalized sodium hyaluronate and dissolve it in 200 mL of MES solution. Add 10.00 g of double-ended amino-terminated polyethylene glycol (H2N-PEG 1000 -NH2) and 2.0 g of EDC. Adjust the pH to 4.75 and continuously stir overnight. After the reaction is completed, dialyze it in deionized water for three days using a dialysis bag (MWCO = 10 kDa). Freeze-dry to obtain amino-functionalized PEG and allyl-functionalized sodium hyaluronate.

[0054] (3) Weigh 1.0 g of amino- and allyl-functionalized sodium hyaluronate and dissolve it in 200 mL of water. Adjust the pH to 7.0, add 2.00 g of N-succinimidyl p-methoxycinnamate, and stir for reaction overnight. Then dialyze it in deionized water for three days using a dialysis bag (MWCO = 10 kDa). Freeze-dry to obtain a sodium hyaluronate derivative modified with allyl and p-methoxycinnamic acid. The yield is about 71%. The allyl modification rate detected by NMR is about 33%, and the p-methoxycinnamic acid modification rate is 9%.

[0055] Example 10: Preparation of hyaluronic acid derivative A10; (1) Weigh 2.0 g of sodium hyaluronate (MW ≈ 50 kDa) and dissolve it in 200 mL of MES buffer solution. Adjust the pH to 5.5, add 4.4 g of 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride and 1.23 g of norbornene-2-methylamine, and continuously stir at 20 °C for 24 h. After the reaction is completed, pour the reaction solution into 500 mL of ice ethanol for precipitation. Filter out the precipitate, redissolve it in water, and then dialyze it in deionized water for three days using a dialysis bag (MWCO = 10 kDa). Freeze-dry to obtain norbornene-functionalized sodium hyaluronate; (2) Weigh 2.0 g of norbornene-functionalized sodium hyaluronate, dissolve it in 200 mL of MES buffer solution, adjust the pH to 5.5, add 4.4 g of 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride and 1.53 g of dopamine, continuously stir at 20 °C for 24 h. After the reaction is completed, pour the reaction solution into 500 mL of ice ethanol for precipitation, filter out the precipitate, redissolve it with water, and then dialyze it in deionized water for three days using a dialysis bag (MWCO = 10 kDa), followed by freeze-drying to obtain norbornene- and dopamine-functionalized sodium hyaluronate with a yield of 69%. The norbornene modification rate measured by NMR is 27%, and the dopamine modification rate is 24%.

[0056] Example 11: Preparation of hyaluronic acid derivative A11; (1) Weigh 2.0 g of sodium hyaluronate (MW ≈ 200 kDa) and dissolve it in 100 mL of 0.5 M NaHCO3 solution, adjust the pH to 8 - 9, add 10 g of norbornene dianhydride, continuously stir overnight. After the reaction is completed, dialyze it in deionized water for three days using a dialysis bag (MWCO = 10 kDa), followed by freeze-drying to obtain norbornene-functionalized sodium hyaluronate.

[0057] (2) Weigh 2.0 g of norbornene-functionalized sodium hyaluronate, dissolve it in 200 mL of MES buffer solution, adjust the pH to 5.5, add 4.4 g of 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride and 1.53 g of dopamine, continuously stir at 20 °C for 24 h. After the reaction is completed, pour the reaction solution into 500 mL of ice ethanol for precipitation, filter out the precipitate, redissolve it with water, and then dialyze it in deionized water for three days using a dialysis bag (MWCO = 10 kDa), followed by freeze-drying to obtain norbornene- and dopamine-functionalized sodium hyaluronate with a yield of 73%. The norbornene modification rate measured by NMR is 28%, and the dopamine modification rate is 17%; Example 12: Preparation of alginic acid derivative A12; (1) Weigh 2.0 g of sodium alginate (MW ≈ 400 kDa) and dissolve it in 400 mL of MES solution, add 7.3 g of heptanediamine and 2.05 g of EDC, adjust the pH to 4.75, continuously stir overnight. After the reaction is completed, dialyze it in deionized water for three days using a dialysis bag (MWCO = 10 kDa), followed by freeze-drying to obtain amino-functionalized sodium alginate.

[0058] (2) At 40 °C, 5 g of 3,4-dihydroxybenzoic acid was dissolved in 50 mL of N,N'-dimethylformamide (DMF), and an equimolar amount of NHS and EDC were added. The reaction was carried out in the dark for 24 h. After the reaction was completed, the by-product dicyclohexylurea formed was removed by filtration. The filtrate was poured into water for precipitation. The obtained solid was dried in vacuo and recrystallized from DMF / ethanol to obtain N-succinimidyl 3,4-dihydroxybenzoate.

[0059] (3) 1.0 g of amino-functionalized sodium alginate was weighed and dissolved in 200 mL of water. The pH was adjusted to 7.0. Then, 4.33 g of norbornene dianhydride and 2.00 g of N-succinimidyl 3,4-dihydroxybenzoate were added successively. The mixture was stirred overnight. Subsequently, it was dialyzed against deionized water for three days using a dialysis bag (MWCO = 10 kDa) and freeze-dried to obtain a sodium alginate derivative modified with norbornene and 3,4-dihydroxybenzoic acid. The yield was approximately 76%. The modification rate of norbornene was measured by NMR to be 25%, and the modification rate of 3,4-dihydroxybenzoic acid was 13%.

[0060] Example 13: Preparation of hyaluronic acid derivative A13; (1) 2.0 g of sodium hyaluronate (MW ≈ 200 kDa) was weighed and dissolved in 40 mL of 0.1 M NaOH solution. 1.7 g of allyl glycidyl ether was added, and the mixture was continuously stirred at 35 °C for 24 h. After the reaction was completed, the reaction solution was poured into 250 mL of ice ethanol for precipitation. The precipitate was filtered out, redissolved in water, and then dialyzed against deionized water for three days using a dialysis bag (MWCO = 10 kDa) and freeze-dried to obtain allyl-functionalized sodium hyaluronate.

[0061] (2) 2.0 g of allyl-functionalized sodium hyaluronate was weighed and dissolved in 200 mL of MES solution. 12.37 g of adipic dihydrazide and 2.0 g of EDC were added, and the pH was adjusted to 4.75. The mixture was continuously stirred overnight. After the reaction was completed, it was dialyzed against deionized water for three days using a dialysis bag (MWCO = 10 kDa) and freeze-dried to obtain a sodium hyaluronate functionalized with hydrazide and allyl.

[0062] (3) At 40 °C, 5 g of gallic acid was dissolved in 50 mL of N,N'-dimethylformamide (DMF), and an equimolar amount of NHS and EDC were added. The reaction was carried out in the dark for 24 h. After the reaction was completed, the by-product dicyclohexylurea formed was removed by filtration. The filtrate was poured into water for precipitation. The obtained solid was dried in vacuo and recrystallized from DMF / ethanol to obtain N-succinimidyl gallate.

[0063] (4) Weigh 1.0 g of hydrazide and allyl-functionalized sodium hyaluronate, dissolve them in 200 mL of water, adjust the pH to 7.0, add 3.00 g of N-succinimidyl gallate, stir and react overnight. Then, dialyze with a dialysis bag (MWCO = 10 kDa) in deionized water for three days, and freeze-dry to obtain a sodium hyaluronate derivative modified with allyl and gallic acid. The yield is about 73%. The allyl modification rate detected by NMR is about 34%, and the gallic acid modification rate is 12%.

[0064] Example 14: Preparation of fibrin derivative A14; (1) Weigh 10.0 g of fibrin (MW ≈ 500 kDa), dissolve it in 200 mL of 0.2 M NaHCO3 solution at 50 °C, adjust the pH to 8 - 9, add 10 g of norbornene dianhydride, and continuously stir overnight. After the reaction, dialyze with a dialysis bag (MWCO = 10 kDa) in deionized water for three days, and freeze-dry to obtain norbornene-functionalized fibrin.

[0065] (2) At 40 °C, dissolve 5 g of 3,4-dihydroxybenzenepropanoic acid in 50 mL of N,N'-dimethylformamide (DMF), then add equimolar amounts of NHS and EDC, and react in the dark for 24 h. After the reaction, filter to remove the by-product dicyclohexylurea formed, pour the filtrate into water for precipitation, and recrystallize the obtained solid from DMF / ethanol after vacuum drying to obtain N-succinimidyl 3,4-dihydroxybenzenepropanoate.

[0066] (3) Weigh 5.0 g of norbornene-functionalized fibrin, heat and dissolve it in 100 mL of water, add 2.00 g of N-succinimidyl 3,4-dihydroxybenzenepropanoate, stir and react overnight. Then, dialyze with a dialysis bag (MWCO = 10 kDa) in deionized water for three days, and freeze-dry to obtain a fibrin derivative modified with norbornene and 3,4-dihydroxybenzenepropanoate. The yield is about 72%, the norbornene modification rate is 39%, and the 3,4-dihydroxybenzenepropanoate modification rate is 21%.

[0067] Example 15: Preparation of gelatin derivative A15; (1) Weigh 10.0 g of gelatin (MW ≈ 500 kDa), dissolve it in 200 mL of 0.2 M NaHCO3 solution at 50 °C, adjust the pH to 8 - 9, add 10 g of norbornene dianhydride, and continuously stir overnight. After the reaction, dialyze with a dialysis bag (MWCO = 10 kDa) in deionized water for three days, and freeze-dry to obtain norbornene-functionalized gelatin.

[0068] (2) At 40 °C, 5 g of 3,4-dihydroxy phenylacetic acid was dissolved in 50 mL of N,N'-dimethylformamide (DMF), and an equimolar amount of NHS and EDC was added. The reaction was carried out in the dark for 24 h. After the reaction was completed, the by-product dicyclohexylurea formed was removed by filtration. The filtrate was poured into water for precipitation. The obtained solid was dried in vacuo and recrystallized from DMF / ethanol to obtain N-succinimidyl 3,4-dihydroxy phenylacetate.

[0069] (3) 5.0 g of norbornene-functionalized gelatin was weighed and heated to dissolve in 100 mL of water. 2.00 g of N-succinimidyl 3,4-dihydroxy phenylacetate was added, and the reaction was stirred overnight. Then, dialysis was carried out in deionized water using a dialysis bag (MWCO = 10 kDa) for three days, followed by freeze-drying to obtain a gelatin derivative modified with norbornene and 3,4-dihydroxy phenylacetic acid. The yield was about 71%. The norbornene modification rate was about 39% measured by NMR, and the 3,4-dihydroxy phenylacetic acid modification rate was 17%.

[0070] Example 16: Preparation of allyl-functionalized sodium hyaluronate a16 and hyaluronic acid derivative A16 (1) 2.0 g of sodium hyaluronate (MW ≈ 200 kDa) was weighed and dissolved in 40 mL of 0.1 M NaOH solution. 2.0 g of allyl glycidyl ether was added, and the reaction was continuously stirred at 35 °C for 24 h. After the reaction was completed, the reaction solution was poured into 250 mL of ice ethanol for precipitation. The precipitate was filtered out, redissolved in water, and then dialyzed in deionized water using a dialysis bag (MWCO = 10 kDa) for three days, followed by freeze-drying to obtain allyl-functionalized sodium hyaluronate a16.

[0071] (2) 1.0 g of allyl-functionalized sodium hyaluronate was weighed and dissolved in 200 mL of water. The pH was adjusted to 7.0, 0.52 g of EDC and 0.52 g of N-hydroxysuccinimide were added, and the reaction was stirred for 30 min. Then, EGF short peptide was added, and the reaction was continuously stirred overnight. Then, dialysis was carried out in deionized water using a dialysis bag (MWCO = 10 kDa) for three days, followed by freeze-drying to obtain a sodium hyaluronate derivative modified with allyl and EGF short peptide. The yield was about 82%. The allyl modification rate was 33% measured by NMR, and the EGF short peptide modification rate was about 9% measured by ultraviolet quantification method.

[0072] Examples 17 - 22: Preparation of hyaluronic acid derivatives A17 - A22 The difference between the preparation methods of Examples 17 - 22 and Example 16 is only that: an equal amount of oligopeptide-1, QK peptide, PR1P peptide, RGD peptide, BDNF mimetic peptide, BMP-2-derived peptide was used to replace the EGF short peptide in turn to obtain hyaluronic acid derivatives A17 - A22.

[0073] The coupling molecules in the above embodiments are equally selected from any one of ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, hexylenediamine, heptylenediamine, octylenediamine, nonylenediamine, decylenediamine, amino-functionalized PEG, oxalic dihydrazide, malonic dihydrazide, succinic dihydrazide, glutaric dihydrazide, adipic dihydrazide, pimelic dihydrazide, suberic dihydrazide, azelaic dihydrazide, and sebacic dihydrazide.

[0074] Example 23: Preparation of thiolated hyaluronic acid (HASH) Weigh 2.0 g of sodium hyaluronate (MW ≈ 2000 kDa) and dissolve it in 200 mL of MES buffer. Add 3.06 g of EDC and 0.96 g of N-hydroxysuccinimide. After continuous stirring for 30 min, add 2.0 g of cysteamine hydrochloride, adjust the pH to 4.75, and continuously stir for 24 h. After the reaction is completed, dialyze the reaction solution against water containing HCl (pH ≈ 3.5) using a dialysis bag (MWCO = 10 kDa) for three days, and then lyophilize to obtain thiolated modified hyaluronic acid. The yield is about 87%, and the thiol modification rate measured by NMR is about 30%.

[0075] Example 24: Preparation of photo-responsive hydrogel A1-B Dissolve A1 in water to prepare a 2 wt% solution (solution A), dissolve thiolated modified hyaluronic acid in water to prepare a 2 wt% solution (solution B). After mixing solution A and solution B in a ratio of 1:1, add 0.1% of LAP and mix evenly. Irradiate the solution with light of 405 nm wavelength for 10 - 30 s to form a non-flowing hydrogel. Prepare a gel disc with a diameter of 60 mm and a thickness of 40 mm, place it at the center of the lower plate of the rheometer, apply a pressure of 1 N to the gel block with an upper plate of 60 mm in diameter, and perform a scan in an oscillatory mode at a fixed frequency (f = 1.592 Hz). The elastic modulus of the gel is measured and recorded in Table 1.

[0076] Example 25: Preparation of photo-responsive hydrogel A2-B Dissolve A2 in water to prepare a 2 wt% solution (solution A), dissolve thiolated modified hyaluronic acid in water to prepare a 2 wt% solution (solution B). After mixing solution A and solution B in a ratio of 2:1, add 0.2% of LAP and mix evenly. Irradiate the solution with light of 405 nm wavelength for 10 - 30 s to form a non-flowing hydrogel. The elastic modulus measured by the rheometer is recorded in Table 1.

[0077] Example 26: Preparation of photo-responsive hydrogel A3-B Dissolve A3 in water to prepare a 2 wt% solution (Solution A), dissolve thiolated modified hyaluronic acid in water to prepare a 2 wt% solution (Solution B). After mixing Solution A and Solution B in a 1:1 ratio, add 0.5% of LAP and mix evenly. After the solution is irradiated with light at a wavelength of 405 nm, a non-flowing hydrogel can be formed within 10 - 50 s. The elastic modulus measured by a rheometer is recorded in Table 1.

[0078] Example 27: Preparation of Photo-responsive Hydrogel A4-B Dissolve A4 in water to prepare a 10 wt% solution (Solution A), prepare a 10 wt% aqueous solution of dithiothreitol (DTT) (Solution B). After mixing Solution A and Solution B in a 4:1 ratio, add 0.5% of I2959 and mix evenly. After the solution is irradiated with light at a wavelength of 365 nm, a non-flowing hydrogel can be formed within 10 - 50 s. The elastic modulus measured by a rheometer is recorded in Table 1.

[0079] Example 28: Preparation of Photo-responsive Hydrogel A5-B Dissolve A5 in water to prepare a 10 wt% solution (Solution A), dissolve polyethylene glycol with thiol groups at both ends (HS-PEG-SH, MW = 2000) in water to prepare a 20 wt% aqueous solution (Solution B). After mixing Solution A and Solution B in a 4:1 ratio, add 0.5% of I2959 and mix evenly. After the solution is irradiated with light at a wavelength of 365 nm, a non-flowing hydrogel can be formed within 10 - 50 s. The elastic modulus measured by a rheometer is recorded in Table 1.

[0080] Example 29: Preparation of Photo-responsive Hydrogel A6-B Dissolve A6 in water to prepare a 2 wt% solution (Solution A), dissolve thiolated modified hyaluronic acid in water to prepare a 2 wt% solution (Solution B). After mixing Solution A and Solution B in a 1:1 ratio, add 1% of α-ketoglutaric acid and mix evenly. After the solution is irradiated with light at a wavelength of 365 nm for 30 s, a non-flowing hydrogel can be formed. The elastic modulus measured by a rheometer is recorded in Table 1.

[0081] Example 30: Preparation of Photo-responsive Hydrogel A7-B Dissolve A7 in water to prepare a 2 wt% solution (Solution A), dissolve thiolated modified hyaluronic acid in water to prepare a 2 wt% solution (Solution B). After mixing Solution A and Solution B in a 1:1 ratio, add 1% of α-ketoglutaric acid and mix evenly. After the solution is irradiated with light at a wavelength of 365 nm for 30 s, a non-flowing hydrogel can be formed. The elastic modulus measured by a rheometer is recorded in Table 1.

[0082] Example 31: Preparation of Light-Responsive Hydrogel A8-B Dissolve A8 in water to prepare a 2 wt% solution (Solution A). Dissolve thiolated modified hyaluronic acid in water to prepare a 2 wt% solution (Solution B). After mixing Solution A and Solution B in a 1:1 ratio, add 0.5% of I2959 and mix evenly. The solution is irradiated with light at a wavelength of 365 nm for 20 s to form a non-flowing hydrogel. The elastic modulus measured by a rheometer is recorded in Table 1.

[0083] Example 32: Preparation of Light-Responsive Hydrogel A9-B Dissolve A9 in water to prepare a 2 wt% solution (Solution A). Dissolve thiolated modified hyaluronic acid in water to prepare a 2 wt% solution (Solution B). After mixing Solution A and Solution B in a 1:1 ratio, add 0.1% of LAP and mix evenly. The solution is irradiated with light at a wavelength of 405 nm for 30 s to form a non-flowing hydrogel. The elastic modulus measured by a rheometer is recorded in Table 1.

[0084] Example 33: Preparation of Light-Responsive Hydrogel A10-B Dissolve A10 in water to prepare a 2 wt% solution (Solution A). Dissolve thiolated modified hyaluronic acid in water to prepare a 2 wt% solution (Solution B). After mixing Solution A and Solution B in a 1:1 ratio, add 0.1% of LAP and mix evenly. The solution is irradiated with light at a wavelength of 405 nm for 30 s to form a non-flowing hydrogel. The elastic modulus measured by a rheometer is recorded in Table 1.

[0085] Example 34: Preparation of Light-Responsive Hydrogel A11-B Dissolve A11 in water to prepare a 2 wt% solution (Solution A). Dissolve thiolated modified hyaluronic acid in water to prepare a 2 wt% solution (Solution B). After mixing Solution A and Solution B in a 1:1 ratio, add 0.1% of LAP and mix evenly. The solution is irradiated with light at a wavelength of 405 nm for 30 s to form a non-flowing hydrogel. The elastic modulus measured by a rheometer is recorded in Table 1.

[0086] Example 35: Preparation of Light-Responsive Hydrogel A12-B Dissolve A12 in water to prepare a 2 wt% solution (Solution A). Dissolve thiolated modified hyaluronic acid in water to prepare a 2 wt% solution (Solution B). After mixing Solution A and Solution B in a 1:1 ratio, add 0.1% of LAP and mix evenly. The solution is irradiated with light at a wavelength of 405 nm for 30 s to form a non-flowing hydrogel. The elastic modulus measured by a rheometer is recorded in Table 1.

[0087] Example 36: Preparation of Photo-responsive Hydrogel A13-B Dissolve A13 in water to prepare a 2 wt% solution (Solution A), dissolve thiolated modified hyaluronic acid in water to prepare a 2 wt% solution (Solution B). After mixing Solution A and Solution B in a ratio of 1:1, add 0.1% LAP, mix evenly. The solution is irradiated with light of 405 nm wavelength for 30 s to form a non-flowing hydrogel. The elastic modulus measured by a rheometer is recorded in Table 1.

[0088] Example 37: Preparation of Photo-responsive Hydrogel A14-B Dissolve A14 in water to prepare a 10 wt% solution (Solution A), dissolve thiolated modified hyaluronic acid in water to prepare a 2 wt% solution (Solution B). After mixing Solution A and Solution B in a ratio of 3:1, add 0.1% LAP, mix evenly. The solution is irradiated with light of 405 nm wavelength for 30 s to form a non-flowing hydrogel. The elastic modulus measured by a rheometer is recorded in Table 1.

[0089] Example 38: Preparation of Photo-responsive Hydrogel A15-B Dissolve A15 in water to prepare a 10 wt% solution (Solution A), prepare a 10 wt% aqueous solution of dithiothreitol (DTT) (Solution B). After mixing Solution A and Solution B in a ratio of 4:1, add 0.1% LAP, mix evenly. The solution is irradiated with light of 405 nm wavelength for 30 s to form a non-flowing hydrogel. The elastic modulus measured by a rheometer is recorded in Table 1.

[0090] Example 39: Preparation of Photo-responsive Hydrogels A16-B-1 and A16-B-2 Dissolve a16 and A16 in water to prepare 2 wt% solutions (Solution a and Solution A) respectively, dissolve thiolated modified hyaluronic acid in water to prepare a 2 wt% solution (Solution B). After mixing Solution A and Solution B in a ratio of 1:1, add 0.2% LAP, mix evenly. The solution is irradiated with light of 405 nm wavelength for 20 s to form a non-flowing hydrogel A16-B-1; after mixing Solution a and Solution B in a ratio of 1:1, add 0.2% LAP, mix evenly. The solution is irradiated with light of 405 nm wavelength for 20 s to form a non-flowing hydrogel A16-B-2. The elastic modulus measured by a rheometer is recorded in Table 1.

[0091] Examples 40 - 45: Preparation of Photo-responsive Hydrogels A17-B~A22-B In the method described in Example 39, polymer A16 was sequentially replaced with A17, A18, A19, A20, A21, and A22, and the remaining steps remained unchanged to obtain different combined solutions. After irradiation for 10 - 30 s, immobile hydrogels A17 - B to A22 - B were formed, and the elastic moduli measured by a rheometer were recorded in Table 1.

[0092] Table 1 Composition and gel performance data of photo - responsive hydrogels A1 - B to A22 - B Light-responsive hydrogel Solution A, concentration Solution B, concentration Photoinitiator, concentration Photo-curing time Gel elastic modulus A1-B A1, 1% HASH, 1% LAP, 0.1% 15s 45 kPa A2-B A2, 1.33% HASH, 0.67% LAP, 0.2% 20s 33 kPa A3-B A3, 1% HASH, 1% LAP, 0.5% 15s 47 kPa A4-B A4, 8% DTT, 2% I2959, 0.5% 30s 53 kPa A5-B A5, 8% <![CDATA[SH-PEG 2000 -SH, 4%]]> I2959, 0.5% 30s 46 kPa A6-B A6, 1% HASH, 1% α-Ketoglutaric acid, 1% 30s 40 kPa A7-B A7, 1% HASH, 1% α-Ketoglutaric acid, 1% 30s 45 kPa A8-B A8, 1% HASH, 1% I2959, 0.5% 20s 36 kPa A9-B A9, 1% HASH, 1% LAP, 0.1% 30s 39 kPa A10-B A10, 1% HASH, 1% LAP, 0.1% 30s 47 kPa A11-B A11, 1% HASH, 1% LAP, 0.1% 30s 38 kPa A12-B A12, 1% HASH, 1% LAP, 0.1% 30s 36 kPa A13-B A13, 1% HASH, 1% LAP, 0.1% 30s 38 kPa A14-B A14, 7.5% HASH, 0.5% LAP, 0.1% 30s 38 kPa A15-B A15, 8% DTT, 2% LAP, 0.1% 30s 37 kPa A16-B-1 A16, 1% HASH, 1% LAP, 0.2% 20s 39 kPa A16-B-2 a16, 1% HASH, 1% LAP, 0.2% 20s 41 kPa A17-B A17, 1% HASH, 1% LAP, 0.2% 20s 38 kPa A18-B A18, 1% HASH, 1% LAP, 0.2% 20s 37 kPa A19-B A19, 1% HASH, 1% LAP, 0.2% 20s 40 kPa A20-B A20, 1% HASH, 1% LAP, 0.2% 20s 36kPa A21-B A21, 1% HASH, 1% LAP, 0.2% 20s 34 kPa A22-B A22, 1% HASH, 1% LAP, 0.2% 20s 39 kPa Example 46: The ultraviolet absorbance or transmittance of the photo - responsive hydrogel was measured to evaluate the sunscreen effect. The hydrogel precursor solutions prepared in Examples 24 - 32 were spread on a polymethyl methacrylate plate with a thickness of about 1 mm, and the sun protection factor (sun protection factor 1) of each group of samples was tested using an ultraviolet transmittance analyzer. Then, after irradiating each group of samples with blue light at a wavelength of 405 nm for 60 s and immersing them in water for 20 min, the sun protection factor was measured again (sun protection factor 2) to evaluate the sun protection performance of each group of sunscreen products. A 0.1% DMF solution of p - nitro - cinnamic acid and a 0.1% DMF solution of benzoic acid were used as Comparative Example 1 and Comparative Example 2, respectively. The test results are shown in Table 2, which is a data table for the detection of the sun protection factors of the photo - responsive hydrogels A1 - B to A9 - B prepared in Examples 24 - 32. The data shows that based on the natural polymer derivative with the structure shown in Formula I of the present invention, a carbon - carbon double bond and a sunscreen functional group are introduced into its skeleton. The photo - responsive hydrogel includes a natural polymer derivative with the structure shown in Formula I (component A), a cross - linker containing multiple mercapto groups (component B), and a photo - initiator. Under the action of the photo - initiator, components A and B can undergo a cross - linking reaction to form a hydrogel after irradiation. At this time, the sunscreen functional group on the natural polymer derivative with the structure shown in Formula I can enhance the sunscreen function at the application site. At the same time, for cinnamic acid or cinnamic acid derivatives, cinnamic acid derivatives will undergo a photo - dimerization reaction to form a cross - linked network under irradiation at a specific wavelength, which can improve the mechanical properties of the photo - responsive hydrogel, that is, the cross - linked network can increase the residence time of the sunscreen product and extend the cycle of the sunscreen's efficacy.

[0093] Table 2 Light-responsive hydrogel Sun protection factor 1 Sun protection factor 2 A1-B 1550 1549 A2-B 1674 1658 A3-B 1521 1530 A4-B 1537 1533 A5-B 1602 1592 A6-B 1564 1561 A7-B 1543 1540 A8-B 1582 1574 A9-B 1589 1578 Comparative example 1 1533 1046 Comparative example 2 1572 1083 Example 47: Tissue adhesion strength test and burst pressure test For Examples 33 - 38, after cleaning the fresh pig casings to remove excess fat, cut them into casing pieces of 4 cm × 2 cm in size, and use 502 glue to fix them on a glass slide with dimensions of 6.5 cm × 2.5 cm. Evenly apply 0.2 mL of the hydrogel precursor solution on the adhered casing surface. Then, place another glass slide above this glass slide, and use a 405 nm LED light source to irradiate the casing part for 5 min to cause the hydrogel precursor solution to gel in situ between the two casings. After complete gelling, vertically fix one end of the glass slide, connect the other end to a digital display tensiometer and slowly pull it horizontally, as Figure 1 shown. Record the maximum tensile force when the two casings are separated, and divide it by the contact area of the two casings to obtain the tissue adhesion strength of the hydrogel.

[0094] After cleaning the fresh pig casings, cut them into casing pieces of 4 × 4 cm. Cover the bursting pressure test device with the casing, make a circular hole with a diameter of 2 mm on the casing, cover 0.5 mL of the hydrogel precursor solution at the incision, and irradiate it with 405 nm blue light for 60 s to form a hydrogel in situ at the puncture site. The thickness of the hydrogel is about 4.4 mm, and measure the bursting pressure after gelling. Fill the device with water, and the peak pressure before pressure loss measured by the pressure gauge is the bursting pressure, as Figure 2 shown. Taking the commercially available sample Fibrin Glue (manufacturer Baxter, model TISSEEL) as a comparison, all measurements are repeated three times. The tissue adhesion force and bursting pressure of the hydrogel are shown in Table 3, which is the data table of the tissue adhesion test and bursting pressure test for the photo-responsive hydrogels A10 - B to A15 - B prepared in Examples 33 - 38. The data shows that based on the natural polymer derivative with the structure shown in Formula I of the present invention, a carbon-carbon double bond and a small molecule functional group containing a polyphenol structure are introduced into its backbone. The photo-responsive hydrogel includes a natural polymer derivative with the structure shown in Formula I (Component A), a cross-linking agent containing multiple mercapto groups (Component B), and a photo-initiator. The two components A and B can, under the action of the photo-initiator, undergo a cross-linking reaction to form a hydrogel after light irradiation. Its performance in terms of tissue adhesion strength and bursting pressure has been improved compared to the comparative examples, making it more advantageous for applications in antibacterial, antioxidant, wet tissue adhesion and other products. In other words, the small molecule functional group containing a polyphenol structure on the natural polymer derivative with the structure shown in Formula I can enhance the antibacterial, antioxidant, wet tissue adhesion and other effects at the application site.

[0095] Table 3 Light-responsive hydrogel Tissue adhesion strength (kPa) Bursting pressure (kPa) A10-B 23.7 28.1 A11-B 24.3 27.5 A12-B 25.2 29.8 A13-B 32.1 38.8 A14-B 33.8 39.3 A15-B 21.7 30.3 Fibrin Glue 17.5 22.4 Example 48: Test on promoting skin repair by hydrogel Use surgical scissors to create a 1.5 cm × 1.5 cm skin defect on the back of mature female SD rats to establish a skin defect model on the back of rats. Cover the wound surface with 0.5 mL of the hydrogel precursor solutions of A16-B-1 and A16-B-2 (without EGF short peptide modification) in Example 39 respectively, and irradiate with 405 nm blue light for 60 s to form a hydrogel in situ at the defect site. After 2 weeks of treatment and observation, the wound closure rate of the mice in the combination-16 group reached 91%, the wound closure rate of the blank control group of mice without treating the wound was 46%, and the wound closure rate of the positive control group of mice covered with the combination-16-2 hydrogel was 65%. As Figure 3 shown, the results show that the hydrogel A16-B-1 modified with EGF short peptide has an obvious effect of promoting tissue repair. It shows that the small molecule functional group containing polyphenol structure on the natural polymer derivative with the structure shown in Formula I can enhance its function at the application site.

[0096] Example 49 Hydrogel Promoting Skin Repair Test Use surgical scissors to create a 1.5 cm × 1.5 cm skin defect on the back of mature female SD rats to establish a skin defect model on the back of rats. Cover the wound surface with 0.5 mL of the hydrogel precursor solutions of A20-B in Example 42 and A16-B-2 (without EGF short peptide modification) in Example 39 respectively, and irradiate with 405 nm blue light for 60 s to form a hydrogel in situ at the defect site. After 2 weeks of treatment and observation, the wound closure rate of the mice in the A20-B group reached 84%, the wound closure rate of the blank control group of mice without treating the wound was 46%, and the wound closure rate of the positive control group of mice covered with A16-B-2 was 65% (as Figure 3 shown), the results show that the hydrogel modified with RGD peptide has an obvious effect of promoting tissue. It further proves that the small molecule functional group containing polyphenol structure on the natural polymer derivative with the structure shown in Formula I can enhance its function at the application site.

[0097] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0098] The above-described embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. A natural polymer derivative, characterized in that, It has the structure shown in Formula I: ， In formula I, is a natural polymer backbone, P 1、 P2 are each independently selected from the dehydroxylation residues, decarboxylation residues, and deamination residues of natural polymer repeating units or fragments. R1 is a group containing a carbon-carbon double bond; R2 is any one of small ultraviolet-absorbing molecules, small molecules containing polyphenol structures, or short peptides with a repair-promoting function. X and Y are each independently selected from an ether bond, an ester bond, an amide bond, and a coupling molecule. The coupling molecule includes at least two grafting sites, amino groups and / or hydrazides, and is connected to the carboxyl site on the natural polymer at one end through an amidation reaction and connected to R1 or R2 at the other end; m and n are each independently selected from integers from 1 to 10,000; The natural polymer includes at least one of sodium hyaluronate, sodium alginate, chitosan, gelatin, collagen, chondroitin sulfate, or fibrin.

2. The natural polymer derivative according to claim 1, characterized in that, The group containing a carbon-carbon double bond is selected from vinyl, propenyl, allyloxy, cyclohexenyl, norbornenyl, bicyclo[2.2.2]oct-5-enyl.

3. The natural polymer derivative according to claim 1, characterized in that, The ultraviolet-absorbing small molecule includes at least one of cinnamic acid, cinnamic acid derivatives, salicylic acid, salicylic acid derivatives, benzoic acid, benzoic acid derivatives, 2,6-naphthalenedicarboxylic acid, or 1,8-dihydroxy-3-carboxyanthraquinone.

4. The natural polymer derivative according to claim 1, wherein The small molecule containing a polyphenol structure includes at least one of dopamine, dopamine derivatives, 3,4-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid derivatives, gallic acid, or gallic acid derivatives.

5. The natural polymer derivative according to claim 1, characterized in that, The short peptide with a function of promoting repair includes at least one of EGF short peptide, oligopeptide-1, QK peptide, PR1P peptide, RGD peptide, BDNF mimetic peptide, or BMP-2-derived peptide.

6. A method for preparing the natural polymer derivative according to claim 1, characterized in that, Select any one of the following preparation methods a-d: a. It is only necessary to sequentially modify R1 and R2 at the hydroxyl, carboxyl, or amino site of the natural polymer; b. Introduce a coupling molecule containing an amino group and / or hydrazide at the carboxyl site of the natural polymer, and then sequentially modify R1 and R2 on the amino group and / or hydrazide; c. Modify R1 at the carboxyl or hydroxyl site of the natural polymer, introduce a coupling agent containing an amino group at the carboxyl site of the natural polymer derivative modified by R1, and then modify R2 on the amino group; d. Modify R2 at the carboxyl or hydroxyl site of the natural polymer, introduce a coupling agent containing an amino group and / or hydrazide at the carboxyl site of the natural polymer derivative modified by R2, and then modify R1 on the amino group or hydrazide.

7. A multifunctional light-responsive hydrogel, characterized in that, It is prepared from component A, component B, and a photoinitiator in a solvent, where component A is the natural polymer derivative described in claim 1, and component B is a crosslinking agent containing multiple thiol groups; Among them, the concentration of component A is 1-5 wt%, the concentration of component B is 1-5 wt%, the concentration of the photoinitiator is 0.001-1 wt%, and the rest is the solvent; The crosslinking agent containing multiple thiol groups is selected from any one of dithiothreitol, thiolated polyethylene glycol, or thiol-modified hyaluronic acid, gelatin, collagen, alginic acid, chitosan.

8. The multifunctional light-responsive hydrogel according to claim 7, wherein The photoinitiator includes at least one of lithium phenyl(2,4,6-trimethylbenzoyl)phosphate (LAP), 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone (I2959), eosin Y, α-ketoglutaric acid, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, or 1-hydroxycyclohexyl phenyl ketone.

9. The preparation method of the multifunctional light-responsive hydrogel according to claim 7, wherein, It includes the following steps: Dissolve component A, component B, and the photoinitiator in a solvent to obtain a hydrogel precursor solution: The hydrogel precursor solution undergoes photocrosslinking under light source irradiation to form a hydrogel.

10. The application of the multifunctional light-responsive hydrogel according to claim 7, characterized in that, It is selected from the following applications: The application of the photo-responsive hydrogel in ultraviolet protection products; The application of the photo-responsive hydrogel in products for promoting tissue regeneration and repair; The application of the photo-responsive hydrogel in antioxidant products; The application of the photo-responsive hydrogel in antiseptic and bactericidal products.

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