A poly-(2-oxazoline) epoxy derivative and its application

Abstract

The present invention relates to a poly-(2-oxazoline) epoxy derivative and its application, belonging to the field of cross-linking technology. The present invention provides a poly-(2-oxazoline) epoxy derivative. This poly-(2-oxazoline) epoxy derivative is structurally completely different from existing cross-linking agents such as 1,4-butanediol diglycidyl ether (BDDE), divinyl sulfone, and glycidyl methacrylate. It can be used as a cross-linking agent for the cross-linking of 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 existing cross-linking agents, this poly-(2-oxazoline) epoxy derivative has the advantages of easily undergoing cross-linking reactions with polymers such as hyaluronic acid, making the resulting cross-linked products such as sodium hyaluronate gel more stable and uniform, and making the properties of the resulting cross-linked products easier to control, thus having great application prospects.

Description

Technical Field

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

[0002] Hyaluronic acid, also known as hyaluronic acid, is a high-molecular-weight polyanionic polymer and an unbranched glycosaminoglycan. Its repeating disaccharide units consist of D-glucuronic acid and DN-acetylglucosamine linked alternately by β-1-4 and β-1-3 glycosidic bonds. With its unique molecular structure and physicochemical properties, hyaluronic acid exhibits numerous important physiological functions in the body, such as lubricating joints, regulating blood vessel permeability, and promoting wound healing. Most importantly, hyaluronic acid possesses exceptional water-retention properties, making it the most potent naturally occurring moisturizing substance and considered an ideal natural moisturizing factor. Furthermore, while moisturizing, hyaluronic acid also acts as a potent transdermal absorption enhancer. Research has shown that skin tissue also contains significant amounts of hyaluronic acid, and that the maturation and aging processes of human skin are influenced by its hyaluronic acid content and metabolism. Transdermal absorption or injection of hyaluronic acid can improve the skin's nutritional metabolism, making it softer, smoother, and more supple. It also reduces wrinkles, increases elasticity, and prevents aging.

[0003] However, non-cross-linked hyaluronic acid (i.e., hyaluronic acid solution that has not undergone any modification or alteration) undergoes rapid degradation after injection into the skin due to the combined effects of hyaluronidase and reactive oxygen species (ROS) present in the skin, typically completely degrading within a week. This results in a half-life of less than two days in the skin. Therefore, non-cross-linked hyaluronic acid cannot achieve the desired therapeutic effect as a dermal filler. Cross-linked hyaluronic acid gel, when injected subcutaneously, not only provides instant deep moisturization, increases skin elasticity and tonicity, helps restore the skin's normal oil-water balance, improves dry and sagging skin, but also provides soft tissue augmentation for a clinical duration of one year or more. Therefore, cross-linked hyaluronic acid gel is currently the primary choice for clinical use as a dermal filler.

[0004] Hyaluronic acid crosslinking involves intermolecular crosslinking between hyaluronic acid and a crosslinking agent bearing relevant functional groups, or intramolecular crosslinking with the crosslinking agent as a catalyst, resulting in a molecular network structure with varying degrees of crosslinking. This results in longer hyaluronic acid chains, increased average molecular weight, enhanced viscoelasticity, relatively reduced water solubility, and improved mechanical strength. Currently, 1,4-butanediol diglycidyl ether (BDDE) is the most commonly used crosslinker in hyaluronic acid fillers due to its superior stability and biodegradability compared to other crosslinkers such as divinyl sulfone and 2,7,8-diepoxyoctane. However, 1,4-butanediol diglycidyl ether has been found to be mutagenic in the Drosophila model organism, seriously compromising its biosafety. There is an urgent need to identify hyaluronic acid crosslinkers that are both stable and biodegradable, while also offering enhanced biosafety. Summary of the Invention

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

[0006]

[0007] Formula (1);

[0008] wherein a is selected from an integer of 1 to 200, and c is selected from an integer of 0 to 20;

[0009] R1 is selected from —CH2—, —(CH2) m COOCH2—、—(CH2) m NH—, —NHCO(CH2) m —, —CO(CH2) m —or—(CH2) m CONH—;

[0010] R1 is an integer selected from 1 to 10;

[0011] R2 is selected from NH, O or CH2;

[0012] R3 is selected from 、 、 or ;

[0013] In R3, e and f are selected from integers of 1 to 100.

[0014] In one embodiment of the present invention, the poly-(2-oxazoline) epoxy derivative has a structure as shown in formula (2):

[0015]

[0016] Formula (2);

[0017] Alternatively, the poly-(2-oxazoline) epoxy derivative has a structure as shown in formula (3):

[0018]

[0019] Formula (3);

[0020] Alternatively, the poly-(2-oxazoline) epoxy derivative has a structure as shown in formula (4):

[0021]

[0022] Formula (4);

[0023] Alternatively, the poly-(2-oxazoline) epoxy derivative has a structure as shown in formula (5):

[0024]

[0025] Formula (5);

[0026] Wherein, n is selected from an integer of 1 to 200.

[0027] The present invention also provides a method for preparing the above-mentioned poly-(2-oxazoline) epoxy derivative, which comprises: 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 represented by formula (2);

[0028] Alternatively, the method comprises: 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 a poly-(2-oxazoline) epoxy derivative represented by formula (3);

[0029] Alternatively, the method comprises: 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 a poly-(2-oxazoline) epoxy derivative represented by formula (4);

[0030] Alternatively, the method comprises: 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 diethylene glycol (compound 6), 4-dimethylaminopyridine, triethylamine and tert-butyldimethylsilyl chloride in a solvent to obtain compound 7; reacting compound 7, triethylamine and methylsulfonyl 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 a poly-(2-oxazoline) epoxy derivative represented by formula (4);

[0031] The methyl 3-(4,5-dihydrooxazol-2-yl)propionate has a structure as shown in formula (6):

[0032]

[0033] Formula (6);

[0034] The compound 2 has a structure as shown in formula (7):

[0035]

[0036] Formula (7);

[0037] The compound 3 has a structure as shown in formula (8):

[0038]

[0039] Formula (8);

[0040] The compound 4 has a structure as shown in formula (9):

[0041]

[0042] Formula (9);

[0043] The compound 5 has a structure as shown in formula (10):

[0044]

[0045] Formula (10);

[0046] The compound 7 has a structure as shown in formula (11):

[0047]

[0048] Formula (11);

[0049] The compound 8 has a structure as shown in formula (12):

[0050]

[0051] Formula (12);

[0052] The compound 9 has a structure as shown in formula (13):

[0053]

[0054] Formula (13);

[0055] The compound 10 has a structure as shown in formula (14):

[0056]

[0057] Formula (14).

[0058] The present invention also provides the use of the poly-(2-oxazoline) epoxy derivative in the preparation of a cross-linking agent, a cross-linked product or a skin filler.

[0059] The present invention also provides a cross-linking agent, wherein the cross-linking agent comprises the above-mentioned poly-(2-oxazoline) epoxy derivative.

[0060] The present invention also provides a cross-linked product, which is obtained by cross-linking a high molecular polymer under the action of the poly-(2-oxazoline) epoxy derivative.

[0061] In one embodiment of the present invention, the high molecular weight polymer is selected from one or more of natural high molecular weight polymers and synthetic high molecular weight polymers.

[0062] 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, 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 oligosaccharides and derivatives, inulin and its derivatives, glucosidose and its derivatives, mannooligosaccharides and 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, and agar and its derivatives.

[0063] 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.

[0064] 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 million Daltons (specifically, 50,000, 100,000, 500,000, 1 million, 1.5 million, 2 million, 2.5 million or 3 million Daltons).

[0065] In one embodiment of the present invention, the molecular weight of the sodium hyaluronate is 300,000 to 1.5 million Daltons.

[0066] In one embodiment of the present invention, the synthetic high molecular polymer is selected from one or more of polyvinyl pyrrolidone 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, polyoxyheterocyclobutane and its derivatives, polymaleic anhydride and its derivatives, polyhydroxyethyl methyl acrylate and its derivatives, polypropylene glycol and its derivatives, and polycaprolactone and its derivatives.

[0067] In one embodiment of the present invention, the cross-linked product is sodium hyaluronate cross-linked with the above-mentioned poly-(2-oxazoline) epoxy derivative.

[0068] In one embodiment of the present invention, the method for preparing the cross-linked product comprises: dissolving hyaluronic acid and the poly-(2-oxazoline) epoxy derivative in a solvent and then performing a cross-linking reaction to obtain a hyaluronic acid gel.

[0069] In one embodiment of the present invention, in the cross-linked product, the molar ratio of hyaluronic acid to the poly-(2-oxazoline) epoxy derivative is 0.01 to 1:1 (specifically 0.01:1, 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1 or 1.0:1).

[0070] The present invention also provides a dermal filler, wherein the dermal filler comprises the cross-linked material.

[0071] The technical solution of the present invention has the following advantages:

[0072] 1. The present invention provides a poly-(2-oxazoline) epoxy derivative. This poly-(2-oxazoline) epoxy derivative is structurally distinct from existing crosslinkers such as 1,4-butanediol diglycidyl ether (BDDE), divinyl sulfone, and glycidyl methacrylate. It can be used as a crosslinker to crosslink natural polymers such as polysaccharides (e.g., hyaluronic acid) and proteins, as well as synthetic polymers such as polyethylene glycol and polyvinyl alcohol. Compared to existing crosslinkers, this poly-(2-oxazoline) epoxy derivative has the following advantages:

[0073] First, due to the presence of multiple ether bonds in the molecule, this poly-(2-oxazoline) epoxy derivative is more water-soluble than the traditional crosslinker BDDE. Under the same molar number and reaction conditions, this poly-(2-oxazoline) epoxy derivative is more likely to cross-link with high-molecular-weight polymers such as hyaluronic acid than BDDE to form crosslinked products such as sodium hyaluronate gel.

[0074] Second, because this poly-(2-oxazoline) epoxy derivative crosslinker has more epoxy crosslinking groups than traditional crosslinkers such as BDDE, the crosslinked products such as sodium hyaluronate gel prepared using this poly-(2-oxazoline) epoxy derivative crosslinker are more stable and uniform;

[0075] Third, because the number of repeating units of this poly-(2-oxazoline) is easy to adjust and the length is easy to control, the properties of the cross-linked products prepared using it as a cross-linking agent are easy to control;

[0076] Fourth, because the toxicity of this poly-(2-oxazoline) epoxy derivative is significantly reduced compared to BDDE, the safety of cross-linked products such as sodium hyaluronate gel prepared using it as a cross-linker is enhanced as a human soft tissue filler, avoiding the adverse reactions that may be caused by the toxicity of the existing cross-linker BDDE.

[0077] In summary, in addition to the advantages of high efficiency (high reactivity), enhanced product uniformity, higher stability and lower toxicity, this poly-(2-oxazoline) epoxy derivative can also provide more cross-linking sites for the cross-linking of high-molecular-weight polymers such as hyaluronic acid, achieving better cross-linking effects with less dosage, and has great application prospects in the preparation of cross-linked products.

[0078] 2. The present invention provides a cross-linked product obtained by cross-linking a high molecular weight polymer with a poly(2-oxazoline) epoxy derivative. Studies have shown that this cross-linked product, prepared using a poly(2-oxazoline) epoxy derivative as a cross-linking agent, exhibits excellent enzymatic stability and uniformity, and has great potential for application in the preparation of dermal fillers. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1 :Synthetic route of poly-(2-oxazoline) epoxy derivatives Ⅰ.

[0080] Figure 2 : Hydrogen spectrum results of methyl 4-(2-chloroethylamine)-4-oxobutanoate.

[0081] Figure 3 : Hydrogen spectrum results of methyl 3-(4,5-dihydrooxazol-2-yl)propanoate (Compound 1).

[0082] Figure 4 : Proton spectrum results of compound 1.

[0083] Figure 5 :Synthetic route of poly-(2-oxazoline) epoxy derivatives II.

[0084] Figure 6 :Synthetic route of poly-(2-oxazoline) epoxy derivatives III.

[0085] Figure 7 :Synthetic route of poly-(2-oxazoline) epoxy derivative IV.

[0086] Figure 8 : Observation results of the swollen gel obtained in Example 2-1.

[0087] Figure 9 : Observation results of the swollen gel obtained in Example 2-2.

[0088] Figure 10 : Observation results of the swollen gel obtained in Example 2-3.

[0089] Figure 11 : Observation results of the swollen gel obtained in Examples 2-4.

[0090] Figure 12: Experimental data on the extrusion force of sodium hyaluronate gel obtained by cross-linking with different cross-linking agents. DETAILED DESCRIPTION

[0091] The following examples are provided for a better understanding of the present invention and are not intended to limit the best mode of implementation. They do not limit the content and scope of protection of the present invention. Any product identical or similar to the present invention obtained by anyone under the guidance of the present invention or by combining the features of the present invention with other prior arts shall fall within the scope of protection of the present invention.

[0092] If no specific experimental steps or conditions are specified in the following examples, the experiments were carried out according to the conventional experimental steps or conditions described in the literature in the field. If no manufacturer is specified for the reagents or instruments used, they are all commercially available conventional reagents.

[0093] Example 1-1: A poly-(2-oxazoline) epoxy derivative

[0094] This embodiment provides a poly-(2-oxazoline) epoxy derivative I, which has the following structure (n is a natural number greater than or equal to 10 and less than or equal to 50):

[0095]

[0096] Formula (2).

[0097] Example 1-2: Preparation method of poly-(2-oxazoline) epoxy derivative

[0098] This example provides a method for preparing the poly-(2-oxazoline) epoxy derivative I described in Example 1-1 (synthetic route see Figure 1 ), the specific steps are as follows:

[0099] 1. Preparation of intermediates

[0100] Step 1: Under an ice bath, 4-methoxy-4-oxobutanoic acid (200 g, 1.52 mol, CAS: 3878-55-5) was added to a 2 L three-necked flask containing dichloromethane (1 L, Sinopharm) and N,N-dimethylformamide (10 mL, Sinopharm) to obtain a dissolving solution. When the temperature of the dissolving solution dropped to 0°C, oxalyl chloride (326 mL, 3.8 mol, Sinopharm) was slowly added dropwise to the dissolving solution to obtain a reaction system. The reaction system was first reacted at 0°C for 0.5 hour, then returned to room temperature (25°C) and continued to react at room temperature for 1.5 hours (stirring the reaction at 160 rpm) to obtain a reaction product. The reaction product was concentrated under reduced pressure to obtain crude methyl 4-chloro-4-oxobutanoate (200 g), which was used directly in the next step without purification.

[0101] Step 2: Under an ice bath, methyl 4-chloro-4-oxobutanoate (200 g, 1.34 mol) and 2-chloroethylamine hydrochloride (172 g, 1.48 mol, CAS: 870-24-6) were added to a four-necked flask containing dichloromethane (2 L, Sinopharm) to obtain a dissolving solution; when the temperature of the dissolving solution dropped to 0°C, triethylamine (410 mL, 2.95 mol, Sinopharm) was slowly added to the dissolving solution to obtain a reaction system; the reaction system was first reacted at 0°C for 0.5 hour, then returned to room temperature (25°C) and continued to react at room temperature for 0.5 hour (stirring the reaction at 160 rpm) to obtain a reaction product; the reaction product was filtered, the filtrate was taken, and the four-necked flask was rinsed with dichloromethane (200 mL×2) to obtain a rinsing solution; the filtrate and the rinsing solution were combined to obtain a mixed solution; saturated salt water (1 L) After washing, the organic phases were combined and concentrated under reduced pressure to obtain methyl 4-(2-chloroethylamino)-4-oxobutanoate (180 g);

[0102] Step 3: At room temperature, methanol (250 mL, Sinopharm) and triethylamine (79.0 g, 0.78 moL, Sinopharm) were added to a 1 L single-necked bottle containing methyl 4-(2-chloroethylamine)-4-oxobutanoate (50 g, 0.260 mol) to obtain a dissolving solution; the dissolving solution was replaced with nitrogen three times, and then reacted at 90 ° C for 16 hours (stirring the reaction at 160 rpm) to obtain a reaction product; the reaction product was first concentrated under reduced pressure and then distilled under reduced pressure at 120 ° C to obtain the intermediate methyl 3-(4,5-dihydrooxazol-2-yl)propanoate (compound 1, 35 g).

[0103] The hydrogen spectrum results of methyl 4-(2-chloroethylamino)-4-oxobutanoate are shown in Figure 2 Proton spectrum 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).

[0104] The hydrogen spectrum results of methyl 3-(4,5-dihydrooxazol-2-yl)propionate are shown in Figure 3Proton spectrum 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).

[0105] 2. Preparation of poly-(2-oxazoline) epoxy derivatives

[0106] Step 1: Under ice bath, methyl 3-(4,5-dihydrooxazol-2-yl)propionate (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 replaced 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 hour, then heated to 90°C and reacted at 90°C for 16 hours (stirring the reaction at 160 rpm) to obtain a reaction product; after the reaction product returned 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 compound 2 (4.2 g) as a white solid;

[0107] Step 2: Compound 2 (2.0 g) was added to a 5% (w / v, g / 100 mL) potassium hydroxide aqueous solution (20 mL) to obtain a reaction system; the reaction system was reacted at room temperature for 6 hours (stirred at 160 rpm) to obtain a reaction product; a 1 M hydrochloric acid aqueous solution was added to the reaction product to adjust the pH value of the reaction product to 7.0, and the reaction product was then concentrated under reduced pressure to obtain a crude compound 3 (1.8 g). The crude product was used directly in the next step without purification;

[0108] Step 3: At room temperature, glycidol (15.0 mg, CAS: 556-52-5), 4-dimethylaminopyridine (5 mg, CAS: 1122-58-3) and N,N'-dicyclohexylcarbodiimide (160 mg) were added to a 50 mL single-necked bottle containing compound 3 (90.0 mg) and dichloromethane (5 mL, Sinopharm) to obtain a solution; the solution was replaced with nitrogen three times and reacted at room temperature for 6 hours (stirring the reaction at 180 rpm) to obtain a reaction product; water (20 mL) was added to the reaction product, and then extracted with dichloromethane (20 mL×3) (dichloromethane was added to the aqueous phase three times in sequence to separate the liquid), and the organic phases were combined; the organic phase was first dried over anhydrous sodium sulfate and then concentrated under reduced pressure to obtain poly-(2-oxazoline) epoxy derivative I (120 mg).

[0109] The hydrogen spectrum results of compound 1 are shown in Figure 4 The hydrogen spectrum data of compound 1 is: 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).

[0110] The hydrogen spectrum data of poly-(2-oxazoline) epoxy derivative I are: 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).

[0111] Example 1-3: A poly-(2-oxazoline) epoxy derivative

[0112] This embodiment provides a poly-(2-oxazoline) epoxy derivative II, which has the following structure (n is a natural number greater than or equal to 10 and less than or equal to 50):

[0113]

[0114] Formula (3).

[0115] Example 1-4: Preparation method of poly-(2-oxazoline) epoxy derivative

[0116] This example provides a method for preparing the poly-(2-oxazoline) epoxy derivative II described in Examples 1-3 (synthetic route see Figure 5), the specific steps are as follows:

[0117] Step 1: At room temperature, ethanolamine (25.0 mg, CAS: 141-43-5), 4-dimethylaminopyridine (10 mg, CAS: 1122-58-3) and N,N'-dicyclohexylcarbodiimide (180 mg) were added to a 50 mL single-necked bottle containing compound 3 (100.0 mg) and dichloromethane (5 mL, Sinopharm) to obtain a solution; the solution was replaced with nitrogen three times and reacted at room temperature for 6 hours (stirring the reaction at 180 rpm) to obtain a reaction product; water (20 mL) was added to the reaction product, and then extracted with dichloromethane (20 mL × 3) (dichloromethane was added to the aqueous phase three times in sequence to separate the liquid), and the organic phases were combined; the organic phase was first dried over anhydrous sodium sulfate and then concentrated under reduced pressure to obtain compound 4 (120 mg);

[0118] Step 2: At room temperature, epichlorohydrin (100.0 mg, CAS: 106-89-8) was added to a 50 mL single-necked bottle containing compound 4 (100.0 mg), potassium hydroxide (150 mg, CAS: 1310-58-3) and dimethyl sulfoxide (5 mL, Sinopharm) to obtain a solution; the solution was replaced with nitrogen three times, and then reacted at 70°C for 6 hours (stirring the reaction at 180 rpm) to obtain a reaction product; water (20 mL) was added to the reaction product, and then extracted with dichloromethane (20 mL × 3) (dichloromethane was added to the aqueous phase three times in sequence to separate the liquid), and the organic phases were combined; the organic phase was first dried over anhydrous sodium sulfate and then concentrated under reduced pressure to obtain poly-(2-oxazoline) epoxy derivative II (105 mg).

[0119] The hydrogen spectrum data of poly-(2-oxazoline) epoxy derivative I are: 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).

[0120] Example 1-5: A poly-(2-oxazoline) epoxy derivative

[0121] This embodiment provides a poly-(2-oxazoline) epoxy derivative III, which has the following structure (n is a natural number greater than or equal to 10 and less than or equal to 50):

[0122]

[0123] Formula (4).

[0124] Example 1-6: Preparation method of poly-(2-oxazoline) epoxy derivative

[0125] This example provides a method for preparing the poly-(2-oxazoline) epoxy derivative III described in Examples 1-5 (synthetic route see Figure 6 ), the specific steps are as follows:

[0126] 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 bottle containing compound 3 (100.0 mg) and dichloromethane (5 mL, Sinopharm) to obtain a solution; the solution was replaced with nitrogen three times and reacted at room temperature for 6 hours (stirring at 180 rpm) to obtain a reaction product; water (20 mL) was added to the reaction product, and then extracted with dichloromethane (20 mL × 3) (dichloromethane was added to the aqueous phase three times in sequence to separate the liquid), and the organic phases were combined; the organic phase was first dried over anhydrous sodium sulfate and then concentrated under reduced pressure to obtain compound 5 (120 mg);

[0127] Step 2: Epichlorohydrin (120.0 mg, CAS: 106-89-8) was added to a 50 mL single-necked bottle 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, Sinopharm) at room temperature to obtain a solution. The solution was replaced with nitrogen three times and reacted at 70°C for 6 hours (stirring at 180 rpm) to obtain a reaction product. Water (20 mL) was added to the reaction product, and the mixture was extracted with dichloromethane (20 mL × 3) (dichloromethane was added to the aqueous phase three times in sequence to separate the liquids), and the organic phases were combined. The organic phase was first dried over anhydrous sodium sulfate and then concentrated under reduced pressure to obtain poly-(2-oxazoline) epoxy derivative III (105 mg).

[0128] The hydrogen spectrum data of poly-(2-oxazoline) epoxy derivative III are: 1H 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).

[0129] Example 1-7: A poly-(2-oxazoline) epoxy derivative

[0130] This embodiment provides a poly-(2-oxazoline) epoxy derivative IV, which has the following structure (n is a natural number greater than or equal to 10 and less than or equal to 50):

[0131]

[0132] Formula (5).

[0133] Example 1-8: Preparation method of poly-(2-oxazoline) epoxy derivative

[0134] This example provides a method for preparing the poly-(2-oxazoline) epoxy derivative IV described in Examples 1-7 (synthetic route see Figure 7 ), the specific steps are as follows:

[0135] Step 1: Under ice bath, tert-butyldimethylsilyl chloride (1.0 g, CAS: 18162-48-6) was added dropwise to a 50 mL single-necked bottle 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 at 180 rpm) to obtain a reaction product; saturated aqueous ammonium chloride solution (20 mL) was added to the reaction product, and then extracted with dichloromethane (20 mL × 3) (dichloromethane was added to the aqueous phase three times in sequence to separate the liquid), and the organic phases were combined; the organic phase was first dried over anhydrous sodium sulfate and then concentrated under reduced pressure to obtain compound 7 (1.3 g);

[0136] Step 2: Under an ice bath, methylsulfonyl 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 returned to room temperature (25°C) and continued to react at room temperature for 2 hours (stirring the reaction at 160 rpm) to obtain a reaction product; 1M hydrochloric acid was added to the reaction product to adjust the pH to 7.2, and then extracted with dichloromethane (50 mL×3) (dichloromethane was added to the aqueous phase three times in sequence to separate the liquid), and the organic phases were combined; the organic phase was first dried over anhydrous sodium sulfate and then concentrated under reduced pressure to obtain compound 8 (1 g);

[0137] Step 3: Tetrabutylammonium chloride (20 mg, CAS: 1112-67-0) was added to a single-necked bottle containing compound 8 (150 mg), compound 5 (100 mg), potassium carbonate (350 mg, CAS: 584-08-7) and N,N-dimethylformamide (5 mL) at room temperature to obtain a solution; the solution was replaced with nitrogen three times and reacted at 80°C for 6 hours (stirring the reaction at 180 rpm) to obtain a reaction product; saturated saline solution (20 mL) was added to the reaction product, and then extracted with ethyl acetate (20 mL × 3) (ethyl acetate was added to the aqueous phase three times in sequence to separate the liquid), and the organic phases were combined; the organic phase was first dried over anhydrous sodium sulfate and then concentrated under reduced pressure to obtain compound 9 (130 mg);

[0138] Step 4: To a single-necked bottle containing compound 9 (130 mg) and dichloromethane (5 mL) was added trifluoroacetic acid (2 mL, CAS: 76-05-1) at room temperature to obtain a solution; the solution was reacted at 30°C for 3 hours (stirred at 180 rpm) to obtain a reaction product; the reaction product was concentrated under reduced pressure to obtain compound 10 (120 mg);

[0139] Step 5: At room temperature, epichlorohydrin (120.0 mg, CAS: 106-89-8) was added to a 50 mL single-necked bottle containing compound 10 (100.0 mg), potassium hydroxide (130 mg, CAS: 1310-58-3) and dimethyl sulfoxide (5 mL) to obtain a solution; the solution was replaced with nitrogen three times, and then reacted at 70°C for 6 hours (stirring the reaction at 180 rpm) to obtain a reaction product; water (20 mL) was added to the reaction product, and then extracted with dichloromethane (20 mL×3) (dichloromethane was added to the aqueous phase three times in sequence to separate the liquid), and the organic phases were combined; the organic phase was first dried over anhydrous sodium sulfate and then concentrated under reduced pressure to obtain poly-(2-oxazoline) epoxy derivative IV (110 mg).

[0140] The proton spectrum data of poly-(2-oxazoline) epoxide 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).

[0141] Example 2-1: A modified sodium hyaluronate gel for injection and its preparation method

[0142] This embodiment provides a modified sodium hyaluronate gel I for injection. The preparation method of the modified sodium hyaluronate gel I for injection is as follows:

[0143] The poly-(2-oxazoline) epoxy derivative I (0.2 mol) prepared in Example 1-2 was dissolved in a 5% (w / v, g / 100 mL) NaOH solution to obtain a solution. Sodium hyaluronate powder (1 mol) was added to the solution, and the mixture was reacted at 40°C for 16 h (with stirring at 160 rpm) to form a cross-linked sodium hyaluronate gel. Hydrochloric acid was added to the cross-linked sodium hyaluronate gel to adjust its pH to 7.0, and 20 mL of PBS buffer was added to the gel, which was then allowed to stand at room temperature (25°C) for 15 min to swell the gel (the resulting swollen gel is shown in FIG. 2 ). Figure 8 ), and then sieve the gel with a standard pharmacopoeia sieve to collect the gel particles. Finally, the gel is dialyzed for three days using a dialysis bag with a specification of 500 (molecular weight cut-off 500 Dalton) to obtain modified sodium hyaluronate gel I for injection.

[0144] Examples 2-2 to 2-4: A modified sodium hyaluronate gel for injection and its preparation method

[0145] This embodiment provides modified sodium hyaluronate gels II to IV for injection. The preparation method of the modified sodium hyaluronate gels II to IV for injection is as follows: on the basis of the modified sodium hyaluronate gel I for injection, the poly-(2-oxazoline) epoxy derivative I prepared in Example 1-2 is replaced by equimolar amounts of the poly-(2-oxazoline) epoxy derivative II prepared in Example 1-4, the poly-(2-oxazoline) epoxy derivative III prepared in Example 1-6, and the poly-(2-oxazoline) epoxy derivative IV prepared in Example 1-8, respectively, to obtain modified sodium hyaluronate gels II to IV for injection (the swollen gels obtained during the preparation of the modified sodium hyaluronate gels II to IV for injection are shown in FIG. Figures 9 to 11 ).

[0146] Comparative Example 2-1: A modified sodium hyaluronate gel for injection and its preparation method

[0147] This comparative example provides a modified sodium hyaluronate gel BDDE-HA for injection. The preparation method of the modified sodium hyaluronate gel BDDE-HA for injection is as follows: on the basis of the modified sodium hyaluronate gel I for injection, the poly-(2-oxazoline) epoxy derivative I prepared in Example 1-2 is replaced with an equal molar amount of BDDE (CAS: 2425-79-8).

[0148] Experimental Example 1: Performance Verification Experiment of Modified Sodium Hyaluronate Gel for Injection

[0149] This experiment provides a performance verification experiment of poly-(2-oxazoline) epoxy derivatives. The specific process is as follows:

[0150] 1. In vitro enzymatic stability test

[0151] To 0.5 g of modified sodium hyaluronate gel for injection, 2 mL of 300 U / mL hyaluronidase solution (purchased from Sinopharm) was added and the mixture was degraded at 37°C for 40 h to obtain a degradation product. PBS buffer (purchased from Sinopharm) was added to the degradation product to dilute it to 5 mL to obtain the diluted degradation product. To 1 mL of the diluted degradation product, 4 mL of anhydrous ethanol was added and the mixture was centrifuged at 10,000 rpm for 15 min. After centrifugation, the supernatant was collected and 2 mL of the supernatant was diluted to 5 mL with PBS buffer to form Solution A. Separately, 0.5 g of modified sodium hyaluronate gel for injection was added to 10 mL of 0.5 mol / L sulfuric acid solution and hydrolyzed in a boiling water bath for 15 min to obtain the hydrolyzate. The hydrolyzate was diluted to 100 mL with water to form Solution B. 1 mL of solution A and solution B were taken respectively, and the glucuronic acid content was measured using the modified carbazole colorimetric method (see the reference "Zhang Suwen, Li Hongmei, Xiao Xiuju, et al. Degradation study of cross-linked sodium hyaluronate gel for injection [J]. Chemical Research, 2023, 34(6): 527-532."). The in vitro enzymatic stability of the gel was calculated based on the glucuronic acid content. The in vitro enzymatic stability of the gel was expressed by the coefficient R, 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 stability of the gel. This result can be used to determine whether the gel cross-linked by the cross-linking agent is stable. The test results of in vitro enzymatic stability are shown in Table 1.

[0152] 2. Pushing force test

[0153] Using a square energy mechanical tester, through the extrusion force experiment, we can understand the actual use status of the cross-linked sodium hyaluronate gel, which is used as one of the evaluation indicators of product quality. The push rod is pushed at a constant speed of 20 mm / min, and the sample in the syringe is squeezed out through a 29G needle to obtain a pushing force curve, so that the change of pushing force during the sample extrusion process can be seen. When the pushing force is small, the sample is easily squeezed out, and when the pushing force is large, the sample is not easily squeezed out; in addition, the large difference in pushing force indicates that the sample is unevenly dispersed or aggregated and concentrated, which will also affect the hand suitability during injection. Table 2 records the changes in the pushing force during the gel squeezing process. The pushing force experimental data of the sodium hyaluronate gel obtained by cross-linking epoxy polymer (poly-(2-oxazoline) epoxy derivative) and the pushing force experimental data of the sodium hyaluronate gel obtained by cross-linking ether (BDDE) are shown in Table 2. Figure 12 The greater the fluctuation of the extrusion force curve, the poorer the uniformity of the gel.

[0154] From Table 1 to Table 2 and Figure 12According to the results, the sodium hyaluronate gel obtained by cross-linking epoxy polymers (i.e., poly-(2-oxazoline) epoxy derivatives) has better enzymatic stability and uniformity in vitro than the sodium hyaluronate gel obtained by cross-linking ether (BDDE).

[0155] Table 1 In vitro enzymatic stability test results of sodium hyaluronate gels obtained by cross-linking with different cross-linking agents

[0156]

[0157] Table 2 Extrusion force test results of sodium hyaluronate gel obtained by cross-linking with different cross-linking agents

[0158]

[0159] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A poly-(2-oxazoline) epoxy derivative, characterized in that The poly-(2-oxazoline) epoxy derivative has a structure as shown in formula (1): Formula (1); wherein a is selected from an integer of 1 to 200, and c is selected from an integer of 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, m 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 selected from integers of 1 to 100.

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

3. A method for preparing the poly-(2-oxazoline) epoxy derivative according to claim 2, characterized in that: The method comprises: 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 a poly-(2-oxazoline) epoxy derivative represented by formula (2); Alternatively, the method comprises: 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 a poly-(2-oxazoline) epoxy derivative represented by formula (3); Alternatively, the method comprises: 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 a poly-(2-oxazoline) epoxy derivative represented by formula (4); Alternatively, the method comprises: 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 diethylene glycol, 4-dimethylaminopyridine, triethylamine and tert-butyldimethylsilyl chloride in a solvent to obtain compound 7; reacting compound 7, triethylamine and methylsulfonyl 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 a poly-(2-oxazoline) epoxy derivative represented by formula (4); The methyl 3-(4,5-dihydrooxazol-2-yl)propionate has a structure as shown in formula (6): Formula (6); The compound 2 has a structure as shown in formula (7): Formula (7); The compound 3 has a structure as shown in formula (8): Formula (8); The compound 4 has a structure as shown in formula (9): Formula (9); The compound 5 has a structure as shown in formula (10): Formula (10); The compound 7 has a structure as shown in formula (11): Formula (11); The compound 8 has a structure as shown in formula (12): Formula (12); The compound 9 has a structure as shown in formula (13): Formula (13); The compound 10 has a structure as 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 cross-linking agent, a cross-linked product or a skin filler.

5. A cross-linking agent, characterized in that The cross-linking agent comprises the poly-(2-oxazoline) epoxy derivative according to claim 1 or 2.

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

7. The cross-linked product according to claim 6, wherein The high molecular polymer is selected from one or more of natural high molecular polymers and synthetic high molecular polymers.

8. The cross-linked product according to claim 7, wherein 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, gum arabic and its derivatives, casein 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 oligosaccharides and their derivatives, inulin and its derivatives, glucosidose and its derivatives, mannooligosaccharides and their 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, and agar and its derivatives.

9. The cross-linked product according to claim 7, wherein The synthetic high molecular polymer is selected from one or more of polyvinyl pyrrolidone 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, polyoxyheterocyclobutane and its derivatives, polymaleic anhydride and its derivatives, polyhydroxyethyl methyl acrylate and its derivatives, polypropylene glycol and its derivatives, and polycaprolactone and its derivatives.

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

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