Poly-(2-oxazoline) epoxy derivative and application thereof

Abstract

The invention relates to a poly-(2-oxazoline) epoxy derivative and application thereof, and belongs to the technical field of crosslinking. The invention provides a poly-(2-oxazoline) epoxy derivative, which is completely different from existing cross-linking agents such as 1, 4-butanediol diglycidyl ether (BDDE), divinyl sulfone, glycidyl methacrylate and the like in structure, and has the advantages that the structure is simple; the polymer can be used as a cross-linking agent for cross-linking natural high-molecular polymers such as polysaccharide (such as hyaluronic acid) and protein and synthetic high-molecular polymers such as polyethylene glycol and polyvinyl alcohol. Compared with an existing cross-linking agent, the poly-(2-oxazoline) epoxy derivative has the advantages that the poly-(2-oxazoline) epoxy derivative can be easily subjected to a cross-linking reaction with high-molecular polymers such as hyaluronic acid, the prepared cross-linked substances such as sodium hyaluronate gel are more stable and uniform, the performance of the prepared cross-linked substances is easier to regulate and control and the like, and the poly-(2-oxazoline) epoxy derivative has a great application prospect.

Description

Technical Field

[0001] The present invention relates to a poly-(2-oxazoline) epoxy derivative and its application, belonging to the technical field of crosslinking. Background Art

[0002] Hyaluronic acid, also known as hyaluronic acid, is a high-molecular-weight polyanionic polymer and an unbranched glycosaminoglycan. Its disaccharide repeating unit consists of D-glucuronic acid and D-N-acetylglucosamine alternately linked by β-1-4 and β-1-3 glycosidic bonds. Hyaluronic acid exhibits a variety of important physiological functions in the body due to its unique molecular structure and physicochemical properties, such as lubricating joints, regulating the permeability of blood vessel walls, and promoting wound healing. Particularly importantly, hyaluronic acid has a special water retention effect and is the best moisturizing substance found in nature so far, known as the ideal natural moisturizing factor. Moreover, hyaluronic acid is also a good transdermal absorption promoter while moisturizing. Research shows that a large amount of hyaluronic acid is also contained in skin tissues, and the process of human skin maturation and aging also changes with the content and metabolism of hyaluronic acid. Transdermal absorption or injection of hyaluronic acid can improve the nutritional metabolism of skin tissues, making the skin tender, smooth, and having the effects of removing wrinkles, increasing elasticity, and preventing aging.

[0003] However, after non-crosslinked hyaluronic acid (i.e., a hyaluronic acid solution without any modification or modification) is injected into skin tissues, it will be quickly degraded under the combined action of hyaluronidase and reactive oxygen species free radicals (ROS) present in the skin tissues and is usually completely degraded within one week. This makes the half-life of non-crosslinked hyaluronic acid in skin tissues less than two days. Therefore, non-crosslinked hyaluronic acid cannot achieve the therapeutic effect required as a skin filler. The crosslinked hyaluronic acid gel for subcutaneous injection can not only instantly deeply moisturize, increase skin elasticity and tension, help restore the normal oil level balance of the skin, improve dry and loose skin, but also provide a clinical duration of soft tissue filling for 1 year or more for skin tissues. Therefore, currently, crosslinked hyaluronic acid gel is mainly selected as a skin filler for clinical use.

[0004] The crosslinking of hyaluronic acid refers to the intermolecular crosslinking reaction between hyaluronic acid and a crosslinking agent with relevant functional groups, or the intramolecular crosslinking reaction with the crosslinking agent as a catalyst, resulting in a molecular network structure with different degrees of crosslinking, thereby increasing the molecular chain length of hyaluronic acid, increasing the average molecular weight, enhancing the viscoelasticity, relatively weakening the water solubility, and improving the mechanical strength. Among them, due to the leading stability and biodegradability of other crosslinking agents such as divinyl sulfone and 2,7,8-diepoxyoctane, at present, 1,4-butanediol diglycidyl ether (BDDE) is the most commonly used crosslinking agent in hyaluronic acid fillers. However, 1,4-butanediol diglycidyl ether has been found to be mutagenic in Drosophila model organisms, which seriously affects its biosafety. It is urgent to find a hyaluronic acid crosslinking agent with good stability, biodegradability, and higher biosafety. Summary of the Invention

[0005] To solve the above problems, the present invention provides a poly-(2-oxazoline) epoxy derivative, and the poly-(2-oxazoline) epoxy derivative has a structure shown in formula (1):

[0006] Formula (1); Wherein, a is an integer selected from 1 to 200, and c is an integer selected from 0 to 20; R1 is selected from —CH2—, —(CH2) m COOCH2—, —(CH2) m NH—, —NHCO(CH2) m —, —CO(CH2) m — or —(CH2) m CONH—; In R1, is an integer selected from 1 to 10; R2 is selected from NH, O or CH2; R3 is selected from , , or ; In R3, e and f are integers selected from 1 to 100.

[0007] In an embodiment of the present invention, the poly-(2-oxazoline) epoxy derivative has a structure shown in formula (2):

[0008] Formula (2); Alternatively, the poly-(2-oxazoline) epoxy derivative has a structure shown in formula (3):

[0009] Formula (3); Alternatively, the poly-(2-oxazoline) epoxy derivative has a structure shown in Formula (4):

[0010] Formula (4); Alternatively, the poly-(2-oxazoline) epoxy derivative has a structure shown in Formula (5):

[0011] Formula (5); wherein, n is an integer selected from 1 to 200.

[0012] The present invention also provides a method for preparing the above poly-(2-oxazoline) epoxy derivative, the method comprising: reacting methyl 3-(4,5-dihydrooxazol-2-yl)propionate (Compound 1) and methyl trifluoromethanesulfonate in a solvent to obtain Compound 2; reacting Compound 2 and potassium hydroxide in a solvent to obtain Compound 3; reacting Compound 3, glycidol, 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide in a solvent to obtain the poly-(2-oxazoline) epoxy derivative shown in Formula (2); Alternatively, the method comprising: reacting methyl 3-(4,5-dihydrooxazol-2-yl)propionate and methyl trifluoromethanesulfonate in a solvent to obtain Compound 2; reacting Compound 2 and potassium hydroxide in a solvent to obtain Compound 3; reacting Compound 3, ethanolamine, 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide in a solvent to obtain Compound 4; reacting Compound 4, potassium hydroxide and epichlorohydrin in a solvent to obtain the poly-(2-oxazoline) epoxy derivative shown in Formula (3); Alternatively, the method comprising: reacting methyl 3-(4,5-dihydrooxazol-2-yl)propionate and methyl trifluoromethanesulfonate in a solvent to obtain Compound 2; reacting Compound 2 and potassium hydroxide in a solvent to obtain Compound 3; reacting Compound 3, ethylenediamine, 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide in a solvent to obtain Compound 5; reacting Compound 5, potassium carbonate, tetrabutylammonium chloride and epichlorohydrin in a solvent to obtain the poly-(2-oxazoline) epoxy derivative shown in Formula (4); Alternatively, the method includes: reacting methyl 3-(4,5-dihydrooxazol-2-yl)propionate with methyl trifluoromethanesulfonate in a solvent to obtain Compound 2; reacting Compound 2 with potassium hydroxide in a solvent to obtain Compound 3; reacting Compound 3, ethylenediamine, 4-dimethylaminopyridine, and N,N'-dicyclohexylcarbodiimide in a solvent to obtain Compound 5; reacting diethylene glycol (Compound 6), 4-dimethylaminopyridine, triethylamine, and tert-butyldimethylsilyl chloride in a solvent to obtain Compound 7; reacting Compound 7, triethylamine, and methanesulfonyl chloride in a solvent to obtain Compound 8; reacting Compound 8, Compound 5, potassium carbonate, and tetrabutylammonium chloride in a solvent to obtain Compound 9; reacting Compound 9 and trifluoroacetic acid in a solvent to obtain Compound 10; reacting Compound 10, potassium hydroxide, and epichlorohydrin in a solvent to obtain the poly-(2-oxazoline) epoxy derivative shown in Formula (4); The methyl 3-(4,5-dihydrooxazol-2-yl)propionate has the structure shown in Formula (6):

[0013] Formula (6); The Compound 2 has the structure shown in Formula (7):

[0014] Formula (7); The Compound 3 has the structure shown in Formula (8):

[0015] Formula (8); The Compound 4 has the structure shown in Formula (9):

[0016] Formula (9); The Compound 5 has the structure shown in Formula (10):

[0017] Formula (10); The Compound 7 has the structure shown in Formula (11):

[0018] Formula (11); The Compound 8 has the structure shown in Formula (12):

[0019] Formula (12); The Compound 9 has the structure shown in Formula (13):

[0020] Formula (13); The compound 10 has a structure shown in Formula (14):

[0021] Formula (14).

[0022] The present invention also provides an application of the above poly-(2-oxazoline) epoxy derivative in the preparation of a crosslinking agent, a crosslinked product or a skin filler.

[0023] The present invention also provides a crosslinking agent, and the components of the crosslinking agent include the above poly-(2-oxazoline) epoxy derivative.

[0024] The present invention also provides a crosslinked product, which is obtained by crosslinking a high molecular polymer under the action of the above poly-(2-oxazoline) epoxy derivative.

[0025] In one embodiment of the present invention, the high molecular polymer is selected from one or more of natural high molecular polymers and synthetic high molecular polymers.

[0026] In one embodiment of the present invention, the natural high molecular polymer is selected from one or more of starch and its derivatives, chitosan and its derivatives, chitin and its derivatives, cellulose and its derivatives, pectin and its derivatives, gelatin and its derivatives, arabic gum and its derivatives, casein and its derivatives, chitin and its derivatives, fibroin and its derivatives, albumin and its derivatives, casein and its derivatives, hyaluronic acid and its derivatives, glycogen and its derivatives, sericin and its derivatives, gellan gum and its derivatives, xanthan gum and its derivatives, guar gum and its derivatives, dextran and its derivatives, chitosan oligosaccharide and its derivatives, inulin and its derivatives, glucan and its derivatives, mannan oligosaccharide and its derivatives, mannan and its derivatives, galactan and its derivatives, chondroitin sulfate and its derivatives, dermatan sulfate and its derivatives, heparin and its derivatives, heparan sulfate and its derivatives, agar and its derivatives.

[0027] In one embodiment of the present invention, the hyaluronic acid derivative is a hyaluronate; the hyaluronate is selected from one or more of sodium hyaluronate, potassium hyaluronate, calcium hyaluronate, magnesium hyaluronate, zinc hyaluronate, cobalt hyaluronate and tetrabutylammonium hyaluronate.

[0028] In one embodiment of the present invention, the hyaluronic acid derivative is sodium hyaluronate; the molecular weight of the sodium hyaluronate is 50,000 to 3,000,000 Daltons (specifically, such as 50,000, 100,000, 500,000, 1,000,000, 1,500,000, 2,000,000, 2,500,000 or 3,000,000 Daltons).

[0029] In one embodiment of the present invention, the molecular weight of the sodium hyaluronate is 300,000 to 1,500,000 Daltons.

[0030] In one embodiment of the present invention, the synthetic polymer is selected from one or more of polyvinylpyrrolidone and its derivatives, polyethylene glycol and its derivatives, polyethylene oxide and its derivatives, polyvinyl alcohol and its derivatives, polyvinyl acetate and its derivatives, polylactic acid and its derivatives, polyglycolic acid and its derivatives, polyacrylic acid and its derivatives, polyacrylamide and its derivatives, polytetrahydrofuran and its derivatives, poly(epoxybutane) and its derivatives, poly(oxetane) and its derivatives, poly(maleic anhydride) and its derivatives, poly(methyl methacrylate) and its derivatives, polypropylene glycol and its derivatives, polycaprolactone and its derivatives.

[0031] In one embodiment of the present invention, the crosslinked product is sodium hyaluronate crosslinked with the above poly-(2-oxazoline) epoxy derivative.

[0032] In one embodiment of the present invention, the preparation method of the crosslinked product includes: dissolving hyaluronic acid and the above poly-(2-oxazoline) epoxy derivative in a solvent and then carrying out a crosslinking reaction to obtain a hyaluronic acid gel.

[0033] In one embodiment of the present invention, in the crosslinked product, the molar ratio of hyaluronic acid to the above poly-(2-oxazoline) epoxy derivative is 0.01~1:1 (specifically, such as 0.01:1, 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1 or 1.0:1).

[0034] The present invention also provides a skin filler, and the components of the skin filler include the above crosslinked product.

[0035] The technical solution of the present invention has the following advantages: 1. The present invention provides a poly-(2-oxazoline) epoxy derivative. This poly-(2-oxazoline) epoxy derivative is completely different in structure from the existing crosslinking agents such as 1,4-butanediol diglycidyl ether (BDDE), divinyl sulfone, and glycidyl methacrylate, and can be used as a crosslinking agent for crosslinking natural polymers such as polysaccharides (such as hyaluronic acid) and proteins, as well as synthetic polymers such as polyethylene glycol and polyvinyl alcohol. Compared with the existing crosslinking agents, the advantages of this poly-(2-oxazoline) epoxy derivative are as follows: First, due to the presence of multiple ether bonds in the molecule, the water solubility of this poly-(2-oxazoline) epoxy derivative is better than that of the traditional crosslinking agent BDDE. Under the same number of moles and the same reaction conditions, this poly-(2-oxazoline) epoxy derivative is more likely to crosslink with high-molecular polymers such as hyaluronic acid to form crosslinked products such as sodium hyaluronate gel; Second, since this poly-(2-oxazoline) epoxy derivative crosslinking agent has more epoxy crosslinking groups than traditional crosslinking agents such as BDDE, the crosslinked products such as sodium hyaluronate gel prepared by using this poly-(2-oxazoline) epoxy derivative are more stable and uniform; Third, since the number of repeating units of this poly-(2-oxazoline) is relatively easy to adjust and the length is relatively easy to control, the properties of the crosslinked products prepared by using it as a crosslinking agent are relatively easy to regulate; Fourth, since the toxicity of this poly-(2-oxazoline) epoxy derivative is significantly reduced compared with BDDE, the crosslinked products such as sodium hyaluronate gel prepared by using it as a crosslinking agent have enhanced safety as human soft tissue fillers, avoiding the adverse reactions that may be caused by the toxicity of the existing crosslinking agent BDDE.

[0036] In summary, in addition to having advantages such as high efficiency (high reaction activity), stronger product uniformity, higher stability, and lower toxicity, this poly-(2-oxazoline) epoxy derivative can also provide more crosslinking sites for the crosslinking of high-molecular polymers such as hyaluronic acid, achieving the purpose of better crosslinking effects with less dosage, and has great application prospects in the preparation of crosslinked products.

[0037] 2. The present invention provides a crosslinked product, which is obtained by crosslinking a high-molecular polymer under the action of a poly-(2-oxazoline) epoxy derivative. Research shows that the crosslinked product prepared by using this poly-(2-oxazoline) epoxy derivative as a crosslinking agent has good enzymatic stability and good uniformity, and has great application prospects in the preparation of skin fillers. Description of the Drawings

[0038] Figure 1 : Synthesis route of poly-(2-oxazoline) epoxy derivative I.

[0039] Figure 2 : 1H NMR results of methyl 4-(2-chloroethylamino)-4-oxobutyrate.

[0040] Figure 3 : 1H NMR results of methyl 3-(4,5-dihydrooxazol-2-yl)propionate (Compound 1).

[0041] Figure 4 : 1H NMR results of Compound 1.

[0042] Figure 5: Synthetic route of poly-(2-oxazoline) epoxy derivative Ⅱ.

[0043] Figure 6 : Synthetic route of poly-(2-oxazoline) epoxy derivative Ⅲ.

[0044] Figure 7 : Synthetic route of poly-(2-oxazoline) epoxy derivative Ⅳ.

[0045] Figure 8 : Observation results of the swollen gel obtained in Example 2-1.

[0046] Figure 9 : Observation results of the swollen gel obtained in Example 2-2.

[0047] Figure 10 : Observation results of the swollen gel obtained in Example 2-3.

[0048] Figure 11 : Observation results of the swollen gel obtained in Example 2-4.

[0049] Figure 12 : Experimental data of extrusion force of sodium hyaluronate gel crosslinked with different crosslinking agents. Detailed implementation manners

[0050] The following examples are provided to better further understand the present invention, which is not limited to the described optimal implementation manner, and does not limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior art features falls within the protection scope of the present invention.

[0051] For those not specifying specific experimental steps or conditions in the following examples, the operations or conditions of the conventional experimental steps described in the literature in this field can be followed. For reagents or instruments not indicating the manufacturer, they are all conventional reagent products that can be obtained through commercial purchase.

[0052] Example 1-1: A poly-(2-oxazoline) epoxy derivative This example provides a poly-(2-oxazoline) epoxy derivative Ⅰ, and the poly-(2-oxazoline) epoxy derivative Ⅰ has the following structure (n is a natural number with a value greater than or equal to 10 and less than or equal to 50):

[0053] Formula (2).

[0054] Example 1-2: Preparation method of a poly-(2-oxazoline) epoxy derivative This example provides a preparation method of the poly-(2-oxazoline) epoxy derivative Ⅰ described in Example 1-1 (the synthetic route is shown in Figure 1 ), and the specific steps are as follows: 1. Preparation of the intermediate Step 1: Under an ice bath, add 4-methoxy-4-oxobutyric acid (200 g, 1.52 moL, CAS: 3878-55-5) to a 2 L three-necked flask containing dichloromethane (1 L, from Sinopharm Chemical Reagent Co., Ltd.) and N,N-dimethylformamide (10 mL, from Sinopharm Chemical Reagent Co., Ltd.) to obtain a solution; when the temperature of the solution drops to 0 °C, slowly add oxalyl chloride (326 mL, 3.8 moL, from Sinopharm Chemical Reagent Co., Ltd.) to the solution to obtain a reaction system; react the reaction system at 0 °C for 0.5 h first, then restore it to room temperature (25 °C) and continue to react at room temperature for 1.5 h (stir and react at 160 rpm) to obtain a reaction product; concentrate the reaction product under reduced pressure to obtain crude methyl 4-chloro-4-oxobutyrate (200 g), and the crude product can be directly used in the next step without purification; Step 2: Under an ice bath, add methyl 4-chloro-4-oxobutyrate (200 g, 1.34 moL) and 2-chloroethylamine hydrochloride (172 g, 1.48 moL, CAS: 870-24-6) to a four-necked flask containing dichloromethane (2 L, from Sinopharm Chemical Reagent Co., Ltd.) to obtain a solution; when the temperature of the solution drops to 0 °C, slowly add triethylamine (410 mL, 2.95 moL, from Sinopharm Chemical Reagent Co., Ltd.) to the solution to obtain a reaction system; react the reaction system at 0 °C for 0.5 h first, then restore it to room temperature (25 °C) and continue to react at room temperature for 0.5 h (stir and react at 160 rpm) to obtain a reaction product; filter the reaction product, take the filtrate, and wash the four-necked flask with dichloromethane (200 mL×2) to obtain a washing solution; combine the filtrate and the washing solution to obtain a mixed solution; after washing and extracting with saturated brine (1 L) in the mixed solution, combine the organic phases; concentrate the organic phases under reduced pressure to obtain methyl 4-(2-chloroethylamino)-4-oxobutyrate (180 g); Step 3: At room temperature, add methanol (250 mL, from Sinopharm Chemical Reagent Co., Ltd.) and triethylamine (79.0 g, 0.78 moL, from Sinopharm Chemical Reagent Co., Ltd.) to a 1 L single-necked flask containing methyl 4-(2-chloroethylamino)-4-oxobutyrate (50 g, 0.260 moL) to obtain a solution; replace the solution with nitrogen three times, and then react at 90 °C for 16 h (stir and react at 160 rpm) to obtain a reaction product; first concentrate the reaction product under reduced pressure, and then perform vacuum distillation at 120 °C to obtain the intermediate methyl 3-(4,5-dihydrooxazol-2-yl)propionate (Compound 1, 35 g).

[0055] The hydrogen spectrum results of methyl 4-(2-chloroethylamino)-4-oxobutyrate are shown in Figure 21H NMR data of methyl 4-(2-chloroethylamino)-4-oxobutanoate: 1H NMR (400 MHz, Chloroform-d) δ 6.27 (s, 1H), 3.70 (s, 3H), 3.63 – 3.59 (m, 4H), 2.69 (t, J = 6.7 Hz, 2H), 2.54 (d, J = 6.8 Hz, 2H). The 1H NMR results of methyl 3-(4,5-dihydrooxazol-2-yl)propanoate are shown in Figure 3 1H NMR data of methyl 3-(4,5-dihydrooxazol-2-yl)propanoate: 1H NMR (400 MHz, Chloroform-d) δ 4.24 (t, J = 9.5 Hz, 2H), 3.85 – 3.79 (m, 2H), 3.70 (s, 3H), 2.70 – 2.64 (m, 2H), 2.62 – 2.56 (m, 2H). 2. Preparation of poly-(2-oxazoline) epoxy derivatives Step 1: Under an ice bath, methyl 3-(4,5-dihydrooxazol-2-yl)propanoate (Compound 1, 5 g, 31.85 mmol) was added to a 100 mL three-necked flask containing acetonitrile (5 mL, Sinopharm) to obtain a solution; after the solution was purged with nitrogen three times, methyl trifluoromethanesulfonate (522.0 mg, 3.19 mmol, Sinopharm, CAS: 333-27-7) was slowly added dropwise to the solution at 0 °C to obtain a reaction system; the reaction system was first reacted at 0 °C for 0.5 h, then heated to 90 °C and reacted at 90 °C for 16 h (stirred at 160 rpm), and a reaction product was obtained; after the reaction product was cooled to room temperature, piperidine (2.7 g, 31.85 mmol) was added dropwise to the reaction product to obtain a mixture; the mixture was concentrated under reduced pressure to obtain a white solid compound 2 (4.2 g); Step 2: Compound 2 (2.0 g) was added to a 5% (w / v, g / 100 mL) aqueous potassium hydroxide solution (20 mL) to obtain a reaction system; the reaction system was reacted at room temperature for 6 h (stirred at 160 rpm), and a reaction product was obtained; first, the pH value of the reaction product was adjusted to 7.0 by adding a 1 M aqueous hydrochloric acid solution to the reaction product, and then the reaction product was concentrated under reduced pressure to obtain a crude compound 3 (1.8 g), and the crude product was used directly in the next step without purification; Step 3: At room temperature, add glycidol (15.0 mg, CAS: 556-52-5), 4-dimethylaminopyridine (5 mg, CAS: 1122-58-3) and N,N'-dicyclohexylcarbodiimide (160 mg) to a 50 mL single-necked flask containing compound 3 (90.0 mg) and dichloromethane (5 mL, Sinopharm) to obtain a solution; after replacing the solution with nitrogen three times, react at room temperature for 6 hours (stir the reaction at 180 rpm) to obtain a reaction product; add water (20 mL) to the reaction product, extract with dichloromethane (20 mL×3) (add dichloromethane to the aqueous phase in three portions for liquid separation in sequence), and combine the organic phases; first dry the organic phases with anhydrous sodium sulfate, and then concentrate under reduced pressure to obtain poly-(2-oxazoline) epoxy derivative I (120 mg).

[0056] The hydrogen spectrum results of compound 1 are shown in Figure 4 . The hydrogen spectrum data of compound 1 are as follows: 1 H NMR (400 MHz, DeuteriumOxide) δ 3.82 (t, J = 5.8 Hz, 2H), 3.71 (t, J = 5.8 Hz, 2H), 3.68 – 3.64 (m,5H), 3.55 – 3.45 (m, 2H). The hydrogen spectrum data of poly-(2-oxazoline) epoxy derivative I are as follows: 1 H NMR (400 MHz, DeuteriumOxide) δ 3.63 (m,2H), 3.54 (m,3H), 3.47 (m,2H), 2.58 (m,3H), 2.40 m,3H). Example 1-3: A poly-(2-oxazoline) epoxy derivative This example provides a poly-(2-oxazoline) epoxy derivative II, and the poly-(2-oxazoline) epoxy derivative II has the following structure (n is a natural number greater than or equal to 10 and less than or equal to 50):

[0057] Formula (3).

[0058] Example 1-4: A preparation method of a poly-(2-oxazoline) epoxy derivative This example provides a preparation method of the poly-(2-oxazoline) epoxy derivative II described in Example 1-3 (the synthesis route is shown in Figure 5 ), and the specific steps are as follows: Step 1: At room temperature, add ethanolamine (25.0 mg, CAS: 141-43-5), 4-dimethylaminopyridine (10 mg, CAS: 1122-58-3), and N,N'-dicyclohexylcarbodiimide (180 mg) to a 50 mL single-necked flask containing compound 3 (100.0 mg) and dichloromethane (5 mL, from Sinopharm Chemical Reagent Co., Ltd.) to obtain a solution; after displacing the solution with nitrogen three times, react at room temperature for 6 hours (stirring the reaction at 180 rpm) to obtain a reaction product; after adding water (20 mL) to the reaction product, extract with dichloromethane (20 mL × 3) (add dichloromethane to the aqueous phase in three portions for liquid separation in sequence), and combine the organic phases; first dry the organic phases with anhydrous sodium sulfate, and then concentrate under reduced pressure to obtain compound 4 (120 mg); Step 2: At room temperature, add epichlorohydrin (100.0 mg, CAS: 106-89-8) to a 50 mL single-necked flask containing compound 4 (100.0 mg), potassium hydroxide (150 mg, CAS: 1310-58-3), and dimethyl sulfoxide (5 mL, from Sinopharm Chemical Reagent Co., Ltd.) to obtain a solution; after displacing the solution with nitrogen three times, react at 70 °C for 6 hours (stirring the reaction at 180 rpm) to obtain a reaction product; after adding water (20 mL) to the reaction product, extract with dichloromethane (20 mL × 3) (add dichloromethane to the aqueous phase in three portions for liquid separation in sequence), and combine the organic phases; first dry the organic phases with anhydrous sodium sulfate, and then concentrate under reduced pressure to obtain poly-(2-oxazoline) epoxy derivative II (105 mg).

[0059] The hydrogen spectrum data of poly-(2-oxazoline) epoxy derivative I are as follows: 1 H NMR (400 MHz, DeuteriumOxide) δ 3.78 – 3.65 (m, 4H), 3.59 – 3.46 (m, 2H), 3.34 (m, 1H), 2.97 (m,2H), 2.56 (m, 2H), 2.38 (m, 2H), 1.18 (m, 4H). Examples 1-5: A poly-(2-oxazoline) epoxy derivative This example provides a poly-(2-oxazoline) epoxy derivative III, and the poly-(2-oxazoline) epoxy derivative III has the following structure (n is a natural number with a value greater than or equal to 10 and less than or equal to 50):

[0060] Formula (4).

[0061] Examples 1-6: A preparation method of a poly-(2-oxazoline) epoxy derivative This example provides a preparation method of the poly-(2-oxazoline) epoxy derivative Ⅲ described in Examples 1-5 (the synthetic route is shown in Figure 6 ), and the specific steps are as follows: Step 1: At room temperature, anhydrous ethylenediamine (25.0 mg, CAS: 107-15-3), 4-dimethylaminopyridine (15 mg, CAS: 1122-58-3) and N,N'-dicyclohexylcarbodiimide (165 mg) were added to a 50 mL single-necked flask containing compound 3 (100.0 mg) and dichloromethane (5 mL, from Sinopharm Chemical Reagent Co., Ltd.) to obtain a solution; after the solution was purged with nitrogen three times, it was reacted at room temperature for 6 hours (stirred at 180 rpm), and a reaction product was obtained; after adding water (20 mL) to the reaction product, it was extracted with dichloromethane (20 mL × 3) (dichloromethane was added to the aqueous phase in three portions for liquid separation), and the organic phases were combined; the combined organic phases were first dried over anhydrous sodium sulfate and then concentrated under reduced pressure to obtain compound 5 (120 mg); Step 2: At room temperature, epichlorohydrin (120.0 mg, CAS: 106-89-8) was added to a 50 mL single-necked flask containing compound 5 (100.0 mg), potassium carbonate (150 mg, CAS: 584-08-7), tetrabutylammonium chloride (10 mg, CAS: 1112-67-0) and dimethyl sulfoxide (5 mL, from Sinopharm Chemical Reagent Co., Ltd.) to obtain a solution; after the solution was purged with nitrogen three times, it was reacted at 70 °C for 6 hours (stirred at 180 rpm), and a reaction product was obtained; after adding water (20 mL) to the reaction product, it was extracted with dichloromethane (20 mL × 3) (dichloromethane was added to the aqueous phase in three portions for liquid separation), and the organic phases were combined; the combined organic phases were first dried over anhydrous sodium sulfate and then concentrated under reduced pressure to obtain poly-(2-oxazoline) epoxy derivative Ⅲ (105 mg).

[0062] The 1H NMR data of poly-(2-oxazoline) epoxy derivative Ⅲ are as follows: 1 H NMR (400 MHz, DeuteriumOxide) δ 5.53(m, 1H) δ 3.72 – 3.70 (m, 4H), 3.44 – 3.40 (m, 2H), 3.35 (m,1H), 2.90 (m, 2H), 2.51 (m, 2H), 2.33 (m, 2H), 1.12 (m, 4H). Examples 1-7: A poly-(2-oxazoline) epoxy derivative This example provides a poly-(2-oxazoline) epoxy derivative Ⅳ, and the poly-(2-oxazoline) epoxy derivative Ⅳ has the following structure (n is a natural number with a value greater than or equal to 10 and less than or equal to 50):

[0063] Formula (5).

[0064] Examples 1-8: A preparation method of a poly-(2-oxazoline) epoxy derivative This example provides a preparation method of the poly-(2-oxazoline) epoxy derivative Ⅳ described in Examples 1-7 (the synthesis route is shown in Figure 7 ), and the specific steps are as follows: Step 1: Under an ice bath, tert-butyldimethylchlorosilane (1.0 g, CAS: 18162-48-6) was added dropwise to a one-necked 50 mL flask containing diethylene glycol (compound 6, 3.5 g, CAS: 111-46-6, Sinopharm), 4-dimethylaminopyridine (0.16 g, CAS: 1122-58-3), triethylamine (0.67 g, CAS: 121-44-8), and dichloromethane (5 mL, Sinopharm) to obtain a solution; the solution was reacted at room temperature for 6 hours (stirred and reacted at 180 rpm) to obtain a reaction product; after adding saturated ammonium chloride aqueous solution (20 mL) to the reaction product, extraction was carried out with dichloromethane (20 mL×3) (dichloromethane was added to the aqueous phase in three portions in turn for liquid separation), and the organic phases were combined; the organic phases were first dried with anhydrous sodium sulfate and then concentrated under reduced pressure to obtain compound 7 (1.3 g); Step 2: Under an ice bath, methanesulfonyl chloride (0.37 mL, CAS: 124-63-0) was added dropwise to a reaction flask containing compound 7 (800 mg), triethylamine (1.1 mL, CAS: 121-44-8), and dichloromethane (10 mL, Sinopharm) to obtain a reaction system; the reaction system was first reacted at 0°C for 0.5 hour, then restored to room temperature (25°C) and continued to react at room temperature for 2 hours (stirred and reacted at 160 rpm) to obtain a reaction product; after adding 1M hydrochloric acid to adjust the pH value to 7.2 to the reaction product, extraction was carried out with dichloromethane (50 mL×3) (dichloromethane was added to the aqueous phase in three portions in turn for liquid separation), and the organic phases were combined; the organic phases were first dried with anhydrous sodium sulfate and then concentrated under reduced pressure to obtain compound 8 (1 g); Step 3: At room temperature, add tetrabutylammonium chloride (20 mg, CAS: 1112-67-0) to a single-necked flask containing compound 8 (150 mg), compound 5 (100 mg), potassium carbonate (350 mg, CAS: 584-08-7), and N,N-dimethylformamide (5 mL) to obtain a solution; after replacing the solution with nitrogen three times, react at 80 °C for 6 hours (stirring the reaction at 180 rpm) to obtain a reaction product; add a saturated saline solution (20 mL) to the reaction product, extract with ethyl acetate (20 mL × 3) (add ethyl acetate to the aqueous phase in three portions for liquid separation in sequence), and combine the organic phases; first dry the organic phases with anhydrous sodium sulfate, and then concentrate under reduced pressure to obtain compound 9 (130 mg); Step 4: At room temperature, add trifluoroacetic acid (2 mL, CAS: 76-05-1) to a single-necked flask containing compound 9 (130 mg) and dichloromethane (5 mL) to obtain a solution; react the solution at 30 °C for 3 hours (stirring the reaction at 180 rpm) to obtain a reaction product; concentrate the reaction product under reduced pressure to obtain compound 10 (120 mg); Step 5: At room temperature, add epichlorohydrin (120.0 mg, CAS: 106-89-8) to a 50 mL single-necked flask containing compound 10 (100.0 mg), potassium hydroxide (130 mg, CAS: 1310-58-3), and dimethyl sulfoxide (5 mL) to obtain a solution; after replacing the solution with nitrogen three times, react at 70 °C for 6 hours (stirring the reaction at 180 rpm) to obtain a reaction product; add water (20 mL) to the reaction product, extract with dichloromethane (20 mL × 3) (add dichloromethane to the aqueous phase in three portions for liquid separation in sequence), and combine the organic phases; first dry the organic phases with anhydrous sodium sulfate, and then concentrate under reduced pressure to obtain poly-(2-oxazoline) epoxy derivative Ⅳ (110 mg).

[0065] The hydrogen spectrum data of poly-(2-oxazoline) epoxy derivative Ⅳ are as follows: 1H NMR: δ 5.53 (1H), 3.75 (8H), 3.70 (2H), 3.56 (4H), 3.53 (4H), 3.33 (2H), 3.22 (2H), 2.90 (1H), 2.76 (4H), 2.65 (2H), 2.24 (2H), 1.90 (2H), 1.56 (2H), 0.89 (3H). Example 2-1: A modified sodium hyaluronate gel for injection and its preparation method This example provides a modified sodium hyaluronate gel Ⅰ for injection, and the preparation method of the modified sodium hyaluronate gel Ⅰ for injection is as follows: Dissolve poly-(2-oxazoline) epoxy derivative Ⅰ (0.2 mol) prepared in Example 1-2 in a NaOH solution with a concentration of 5% (w / v, g / 100 mL) to obtain a dissolution solution; after adding sodium hyaluronate powder (1 mol) to the dissolution solution, react at 40 °C for 16 h (stir and react at 160 rpm) to form a cross-linked sodium hyaluronate gel; after adding hydrochloric acid to adjust the pH of the cross-linked sodium hyaluronate gel to 7.0, first add 20 mL of PBS buffer solution to the gel, and then let the gel swell at room temperature (25 °C) for 15 min (the obtained swollen gel is shown in Figure 8 ), then sieve the gel through a standard pharmacopoeia sieve, collect the gel particles, and finally dialyze the gel using a dialysis bag with a specification of 500 (cut-off molecular weight 500 Dalton) for three days to obtain the modified sodium hyaluronate gel Ⅰ for injection.

[0066] Examples 2-2 to 2-4: A modified sodium hyaluronate gel for injection and its preparation method This example provides modified sodium hyaluronate gels Ⅱ to Ⅳ for injection. The preparation method of the modified sodium hyaluronate gels Ⅱ to Ⅳ is as follows: On the basis of the modified sodium hyaluronate gel Ⅰ for injection, replace poly-(2-oxazoline) epoxy derivative Ⅰ prepared in Example 1-2 with an equimolar amount of poly-(2-oxazoline) epoxy derivative Ⅱ prepared in Example 1-4, poly-(2-oxazoline) epoxy derivative Ⅲ prepared in Example 1-6, and poly-(2-oxazoline) epoxy derivative Ⅳ prepared in Example 1-8 respectively to obtain the modified sodium hyaluronate gels Ⅱ to Ⅳ for injection (the swollen gels obtained during the preparation process of the modified sodium hyaluronate gels Ⅱ to Ⅳ are shown in Figures 9 to 11 ).

[0067] Comparative Example 2-1: A modified sodium hyaluronate gel for injection and its preparation method This comparative example provides a modified sodium hyaluronate gel BDDE-HA for injection. The preparation method of the modified sodium hyaluronate gel BDDE-HA is as follows: On the basis of the modified sodium hyaluronate gel Ⅰ for injection, replace poly-(2-oxazoline) epoxy derivative Ⅰ prepared in Example 1-2 with an equimolar amount of BDDE (CAS: 2425-79-8).

[0068] Experimental Example 1: Performance verification experiment of the modified sodium hyaluronate gel for injection This experiment provides a performance verification experiment of poly-(2-oxazoline) epoxy derivative. The specific process is as follows: 1. In vitro enzymatic hydrolysis stability experiment Take 0.5 g of modified sodium hyaluronate gel for injection, add 2 mL of hyaluronidase solution (purchased from Sinopharm) at 300 U / mL, incubate at 37 °C for 40 h for degradation to obtain a degradation product; add PBS buffer (purchased from Sinopharm) to the degradation product and dilute it to 5 mL to obtain a diluted degradation product; after adding 4 mL of absolute ethanol to 1 mL of the diluted degradation product, centrifuge at 10000 r / min for 15 min. After centrifugation, take the supernatant; dilute 2 mL of the supernatant to 5 mL with PBS buffer to obtain solution A. Take another 0.5 g of modified sodium hyaluronate gel for injection, add 10 mL of 0.5 mo1 / L sulfuric acid solution, and hydrolyze in a boiling water bath for 15 min to obtain a hydrolysis product; dilute the hydrolysis product with water to 100 mL to obtain solution B. Take 1 mL of solution A and solution B respectively, and measure the glucuronic acid content by the modified carbazole colorimetric method (see the literature "Zhang Suwen, Li Hongmei, Hou Xiuju, et al. Degradation test study of cross-linked sodium hyaluronate gel for injection [J]. Chemical Research, 2023, 34(6): 527-532."). Calculate the in vitro enzymatic hydrolysis stability of the gel according to the glucuronic acid content. The in vitro enzymatic hydrolysis stability of the gel is represented by the coefficient R, and R = 1 - 0.625A / B, where A is the glucuronic acid content of solution A and B is the glucuronic acid content of solution B. The higher the R value, the better the in vitro enzymatic hydrolysis stability of the gel. This result can be used to judge whether the gel cross-linked by the cross-linking agent is stable. The detection results of the in vitro enzymatic hydrolysis stability are shown in Table 1.

[0069] 2. Pushing force test Using a Fangneng mechanical tester, through the extrusion force experiment, understand the actual use situation of the cross-linked sodium hyaluronate gel, which is one of the evaluation indicators of product quality. Push the push rod at a constant speed of 20 mm / min, and the sample in the syringe is extruded through a 29G needle to obtain a pushing force curve, so as to see the change of the pushing force during the extrusion process of the sample. If the pushing force is small, the sample is easy to be extruded; if the pushing force is large, the sample is not easy to be extruded; in addition, if the height difference of the pushing force is large, it indicates that the sample has uneven dispersion or aggregation and concentration phenomena, which will also affect the comfort during injection. Table 2 records the change of the pushing force during the gel extrusion process. The pushing force experiment data of the sodium hyaluronate gel cross-linked by epoxy polymer (poly-(2-oxazoline) epoxy derivative) and the pushing force experiment data of the sodium hyaluronate gel cross-linked by ether (BDDE) are shown in Figure 12 . If the pushing force curve fluctuates greatly, the uniformity of the gel is poor.

[0070] From the results of Table 1 - Table 2 and Figure 12 it can be seen that the sodium hyaluronate gel cross-linked by epoxy polymer (i.e., poly-(2-oxazoline) epoxy derivative) is superior to the sodium hyaluronate gel cross-linked by ether (BDDE) in terms of in vitro enzymatic hydrolysis stability and uniformity.

[0071] Table 1 Detection results of in vitro enzymatic hydrolysis stability of sodium hyaluronate gels crosslinked with different crosslinking agents

[0072] Table 2 Detection results of extrusion force of sodium hyaluronate gels crosslinked with different crosslinking agents

[0073] Obviously, the above embodiments are only examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. A poly-(2-oxazoline) epoxy derivative, characterized in that, The poly-(2-oxazoline) epoxy derivative has a structure shown in formula (1): Formula (1); wherein, a is an integer selected from 1 to 200, and c is an integer selected from 0 to 20; R1 is selected from —CH2—, —(CH2) m COOCH2—, —(CH2) m NH—, —NHCO(CH2) m —, —CO(CH2) m — or —(CH2) m CONH—; In R1, is an integer selected from 1 to 10; R2 is selected from NH, O or CH2; R3 is selected from , , or ; In R3, e and f are integers selected from 1 to 100.

2. The poly-(2-oxazoline) epoxy derivative according to claim 1, characterized in that, The poly-(2-oxazoline) epoxy derivative has a structure shown in formula (2): Formula (2); Alternatively, the poly-(2-oxazoline) epoxy derivative has a structure shown in formula (3): Formula (3); Alternatively, the poly-(2-oxazoline) epoxy derivative has a structure shown in formula (4): Formula (4); Alternatively, the poly-(2-oxazoline) epoxy derivative has a structure shown in formula (5): Formula (5); wherein, n is an integer selected from 1 to 200.

3. A method for preparing the poly-(2-oxazoline) epoxy derivative according to claim 2, characterized in that, The method includes: reacting methyl 3-(4,5-dihydrooxazol-2-yl)propionate and methyl trifluoromethanesulfonate in a solvent to obtain compound 2; reacting compound 2 and potassium hydroxide in a solvent to obtain compound 3; reacting compound 3, glycidol, 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide in a solvent to obtain the poly-(2-oxazoline) epoxy derivative shown in formula (2); Alternatively, the method includes: reacting methyl 3-(4,5-dihydrooxazol-2-yl)propionate and methyl trifluoromethanesulfonate in a solvent to obtain compound 2; reacting compound 2 and potassium hydroxide in a solvent to obtain compound 3; reacting compound 3, ethanolamine, 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide in a solvent to obtain compound 4; reacting compound 4, potassium hydroxide and epichlorohydrin in a solvent to obtain the poly-(2-oxazoline) epoxy derivative shown in formula (3); Alternatively, the method includes: reacting methyl 3-(4,5-dihydrooxazol-2-yl)propionate and methyl trifluoromethanesulfonate in a solvent to obtain compound 2; reacting compound 2 and potassium hydroxide in a solvent to obtain compound 3; reacting compound 3, ethylenediamine, 4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide in a solvent to obtain compound 5; reacting compound 5, potassium carbonate, tetrabutylammonium chloride and epichlorohydrin in a solvent to obtain the poly-(2-oxazoline) epoxy derivative shown in formula (4); Alternatively, the method includes: methyl 3-(4,5-dihydrooxazol-2-yl)propionate and methyl trifluoromethanesulfonate react in a solvent to obtain Compound 2; Compound 2 and potassium hydroxide react in a solvent to obtain Compound 3; Compound 3, ethylenediamine, 4-dimethylaminopyridine, and N,N'-dicyclohexylcarbodiimide react in a solvent to obtain Compound 5; diethylene glycol, 4-dimethylaminopyridine, triethylamine, and tert-butyldimethylchlorosilane react in a solvent to obtain Compound 7; Compound 7, triethylamine, and methanesulfonyl chloride react in a solvent to obtain Compound 8; Compound 8, Compound 5, potassium carbonate, and tetrabutylammonium chloride react in a solvent to obtain Compound 9; Compound 9 and trifluoroacetic acid react in a solvent to obtain Compound 10; Compound 10, potassium hydroxide, and epichlorohydrin react in a solvent to obtain the poly-(2-oxazoline) epoxy derivative shown in Formula (4); The methyl 3-(4,5-dihydrooxazol-2-yl)propionate has the structure shown in Formula (6): Formula (6); The Compound 2 has the structure shown in Formula (7): Formula (7); The Compound 3 has the structure shown in Formula (8): Formula (8); The Compound 4 has the structure shown in Formula (9): Formula (9); The Compound 5 has the structure shown in Formula (10): Formula (10); The Compound 7 has the structure shown in Formula (11): Formula (11); The Compound 8 has the structure shown in Formula (12): Formula (12); The Compound 9 has the structure shown in Formula (13): Formula (13); The Compound 10 has the structure shown in Formula (14): Formula (14).

4. Use of the poly-(2-oxazoline) epoxy derivative according to Claim 1 or 2 in the preparation of a crosslinking agent, a crosslinked product, or a skin filler.

5. A crosslinking agent, characterized in that, The composition of the crosslinking agent contains the poly-(2-oxazoline) epoxy derivative according to Claim 1 or 2.

6. A crosslinked product, characterized in that, The crosslinked product is obtained by crosslinking a high molecular polymer under the action of the poly-(2-oxazoline) epoxy derivative according to Claim 1 or 2.

7. The crosslinked product according to claim 6, characterized in that, The high molecular polymer is selected from one or more of natural high molecular polymers and synthetic high molecular polymers.

8. The crosslinked product according to claim 7, wherein The natural polymer is selected from one or more of starch and its derivatives, chitosan and its derivatives, chitin and its derivatives, cellulose and its derivatives, pectin and its derivatives, gelatin and its derivatives, gum arabic and its derivatives, casein and its derivatives, chitin and its derivatives, fibroin and its derivatives, albumin and its derivatives, casein and its derivatives, hyaluronic acid and its derivatives, glycogen and its derivatives, sericin and its derivatives, gellan gum and its derivatives, xanthan gum and its derivatives, guar gum and its derivatives, dextran and its derivatives, chitosan oligosaccharide and its derivatives, inulin and its derivatives, glucan and its derivatives, mannan oligosaccharide and its derivatives, mannan and its derivatives, galactan and its derivatives, chondroitin sulfate and its derivatives, dermatan sulfate and its derivatives, heparin and its derivatives, heparan sulfate and its derivatives, agar and its derivatives.

9. The crosslinked product according to claim 7, wherein, The synthetic polymer is selected from one or more of polyvinylpyrrolidone and its derivatives, polyethylene glycol and its derivatives, polyethylene oxide and its derivatives, polyvinyl alcohol and its derivatives, polyvinyl acetate and its derivatives, polylactic acid and its derivatives, polyglycolic acid and its derivatives, polyacrylic acid and its derivatives, polyacrylamide and its derivatives, polytetrahydrofuran and its derivatives, polybutylene oxide and its derivatives, polyoxetane and its derivatives, poly maleic anhydride and its derivatives, poly (methyl methacrylate hydroxyethyl acrylate) and its derivatives, polypropylene glycol and its derivatives, polycaprolactone and its derivatives.

10. A skin filler, characterized in that, The composition of the dermal filler comprises the crosslinking product according to any one of claims 6-9.

Images