Hyaluronic acid butyrate compound as well as preparation method and application thereof

Abstract

The invention discloses a hyaluronic acid butyrate compound as well as a preparation method and application thereof. According to the compound, active hydroxyl on the sixth site of a sodium hyaluronate structure and carboxyl of butyric anhydride are combined through a covalent bond, and hyaluronic acid butyrate is synthesized. The hyaluronic acid butyrate provided by the invention can repair the function of injured skin keratinocyte and promote the expression of proteins related to the tight junction function of the skin so as to improve the tight junction function of the injured skin, and meanwhile, the hyaluronic acid butyrate can inhibit the specific dermatitis inflammatory response, enhance the antibacterial, anti-inflammatory and antioxidant capacities of the skin and improve the immunocompetence of the skin.

Description

Technical Field

[0001] The present invention belongs to the field of biomedicine, and specifically relates to a hyaluronic acid butyrate complex and its preparation method and application Background Art

[0002] Skin is the largest human organ, covering the surface of the human body and in direct contact with the external environment. It plays an important role in barrier protection. The stratum corneum is located in the outermost layer of the skin, mainly including ceramide, cholesterol, free fatty acids, cholesterol sulfate and a small amount of phosphoric acid. Skin allergies, atopic dermatitis, cosmetics, etc. can cause stratum corneum dysfunction, while dryness, roughness and other skin problems are the external manifestations of stratum corneum dysfunction.

[0003] Atopic dermatitis (AD) is a chronic, recurrent, inflammatory skin disease associated with symptoms such as severe itching, epidermal hyperplasia, and erythematous plaques. The pathogenesis of AD involves genetic and environmental factors, mainly including impaired epidermal skin barrier and immune dysregulation of the T helper 2 cell (Th2) cytokine inflammatory pathway, which interact with each other to create a feedback loop of chronic inflammation and epidermal damage. Therefore, inhibiting inflammatory immune responses and restoring skin barrier function are key goals of AD treatment. Currently, the first-line topical treatment for AD is topical preparations of steroid hormones and calcineurin inhibitors combined with emollients, but long-term use of drugs such as steroid hormones and immunosuppressants can produce side effects, causing extreme skin atrophy and sensitivity to infection, and even affecting children's metabolism and bone development.

[0004] Skin allergy is a very common form of allergy, and 20% of people have skin allergies. Skin allergy is also called allergic skin. A major feature of allergic skin is itching. From a medical point of view, skin allergy mainly refers to skin allergy symptoms such as redness, itching, peeling and allergic dermatitis when the skin is stimulated by various stimuli such as adverse reactions to cosmetics, chemicals, pollen, certain foods, polluted air, etc. According to the characteristics of different rashes, antihistamines (anti-allergic drugs), glucocorticoids, immunosuppressants, etc. can be selected.

[0005] Clinical results have shown that both AD and skin allergies have the limitation of large side effects. Therefore, it is necessary to develop therapeutic drugs with good therapeutic effects, small side effects and good biocompatibility. Summary of the invention

[0006] Purpose of the Invention

[0007] In view of the existing problems, the purpose of the present invention is to provide a hyaluronic acid butyrate complex. The hyaluronic acid butyrate in the present invention can play a synergistic role in anti-inflammatory and skin barrier repair.

[0008] Technical Solution

[0009] The technical solution adopted by the present invention to achieve the above-mentioned purpose is:

[0010] A hyaluronic acid butyrate complex, characterized in that the complex is formed by the reaction of sodium hyaluronate and butyric anhydride, wherein the weight average molecular weight of sodium hyaluronate is 5K-220W, and its structural formula is as follows:

[0011]

[0012] As a preferred embodiment, the weight average molecular weight of sodium hyaluronate is 5K.

[0013] The complex is formed by a series of reactions between hyaluronic acid and butyric anhydride.

[0014] The present invention also provides a method for preparing a hyaluronic acid butyrate complex, comprising the following steps:

[0015] (1) Sodium hyaluronate is added to distilled water and allowed to stand until it is completely swollen, then H-type cationic resin is added, stirred at room temperature, filtered, and the filtrate is collected, the pH value is adjusted with a tetrabutylammonium hydroxide solution, and freeze-dried to obtain a hyaluronic acid butyrate tetrabutylammonium hydroxide complex.

[0016] (2) Add the hyaluronic acid tetrabutylammonium hydroxide complex to N,N-dimethylformamide, heat until completely dissolved, add anhydrous pyridine and butyric anhydride, and stir to react at room temperature.

[0017] Furthermore, in step (1), the ratio of sodium hyaluronate to distilled water is 1 g:100 ml, the mass ratio of sodium hyaluronate to H-type cationic resin is 1 g:3 g, the room temperature stirring time is 3 h, the concentration of tetrabutylammonium hydroxide solution is 0.25 mg / ml, and the pH value is 7.0.

[0018] Furthermore, the ratio of the hyaluronic acid tetrabutylammonium hydroxide complex to the N,N-dimethylformamide solution is 1g:50ml, the ratio of the hyaluronic acid tetrabutylammonium hydroxide complex to the anhydrous pyridine solution is 4mg:1ml, the ratio of the hyaluronic acid tetrabutylammonium hydroxide complex to the butyric anhydride solution is 4mg:3ml, the heating temperature is 40°C, and the room temperature stirring reaction time is 24h.

[0019] The application of the hyaluronic acid butyrate complex in the preparation of medicines or cosmetics for moisturizing or repairing skin barriers.

[0020] The application of the hyaluronic acid butyrate complex in the preparation of medicines for treating skin diseases.

[0021] The application is characterized in that the skin disease is allergic dermatitis, eczema or atopic dermatitis.

[0022] The molecular formula of butyric anhydride used in the present invention is:

[0023]

[0024] The chemical formula of sodium hyaluronate used in the present invention is:

[0025]

[0026] The effects of HA-But of the present invention are summarized as follows:

[0027] 1. HA and HA-But promote cell expression of genes related to skin barrier function

[0028] HA and HA-But with a molecular weight of 5K acted on HaCaT and had a positive regulatory effect on skin barrier-related proteins: filaggrin (FLG), human aquaporin-3 (AQP-3), involucrin (IVL), and tight junction protein-1 (Cldn-1). In the SDS-induced cell damage model, compared with HA with a molecular weight of 5K, the synthetic product HA-But had a significant positive regulatory effect on FLG, AQP-3, IVL, and Cldn-1, and could even restore them to their original levels.

[0029] 2. Study on the antioxidant and anti-inflammatory activities of HA and HA-But in vitro

[0030] Compared with the positive model group, HA and HA-But both had different degrees of antioxidant effects, and the antioxidant effect of the modified derivative HA-But was better than that of HA at the same concentration. 1μg / mL LPS was used to induce the HaCaT cell inflammation model. The results showed that the inhibitory effect of HA-But on IL-31 and TSLP was better than that of HA at the same concentration, and it was significant.

[0031] 3. HA and HA-But promote animal skin barrier repair and anti-inflammation

[0032] After establishing the mouse AD model with DNFB, the drug was administered, and the pathological differences of skin tissue after administration were observed by HE staining. The results showed that the HA-But group significantly reduced the pathological thickening and acanthosis of the back skin of mice, significantly improved the infiltration of inflammatory cells in the dermis, and the hair follicles in the dermis gradually recovered, which was similar to the level of the blank control group. It was also investigated from the genetic level whether HA and HA-But with a molecular weight of 5K had a positive regulatory effect on skin barrier-related proteins and whether they had a downregulatory effect on inflammatory-related factors in mouse skin. Compared with HA with a molecular weight of 5K, the synthetic product HA-But had a significant positive regulatory effect on mouse skin barrier repair-related proteins: FLG, AQP-3, IVL, and Cldn-1. Compared with the disease group, HA-But had a significant inhibitory effect on the main inflammatory factors related to mouse AD: IL-4, IL-13 and IL-31, and the inhibitory effect was more obvious than HA.

[0033] Beneficial Effects

[0034] (1) Hyaluronic acid (HA) participates in biological processes such as inflammation regulation, cell migration / proliferation, and wound repair. It also has good moisturizing effects, stimulates collagen regeneration, and resists skin aging, making it widely used in drug carriers and cosmetic formulations. However, HA has limited ability to repair damaged skin.

[0035] The short-chain fatty acid butyrate (Butyrate, But) has certain anti-inflammatory and intestinal epithelial cell barrier function-maintaining effects, but there are no reports on its effect on repairing damaged skin. It is impossible to reasonably predict whether the two can be combined to form an independent compound and whether it can greatly enhance the ability to repair damaged skin.

[0036] HA itself is a polysaccharide biomacromolecule. Because it can bind water molecules that are several times larger than its own weight, it has a good moisturizing effect. At the same time, studies have shown that HA also has anti-wrinkle and other effects. In addition, HA also has CD44 receptor targeting, which can enhance its skin positioning ability and retention effect. The present invention creatively synthesizes the two into a new compound hyaluronic acid butyrate complex HA-But, which has both the function of HA to repair damaged skin keratinocytes and enhance its skin positioning ability and retention effect, and the anti-inflammatory effect of But, and at the same time produces a synergistic effect and moisturizing function. Specifically:

[0037] It can repair the function of damaged skin keratinocytes, promote the expression of proteins related to skin tight junction function, thereby improving the tight junction function of damaged skin, and inhibit specific dermatitis-like inflammatory response, which is much better than the effect of HA. In particular, in the in vivo experiment, after 28 days, the evaluation index of mice in the HA-But treatment group was close to that of the blank control group, indicating that it had basically recovered to a normal level after 21 days of administration, while the improvement effect of the HA group was limited, which was significantly different from the HA group. The present invention solves the technical problems that have been difficult to solve in the field.

[0038] (2) The preparation method provided by the present invention is simple and easy to synthesize. The composite prepared by the present invention has a wide source of raw materials, low synthesis cost, and has broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Infrared spectra of HA-But structure; a is 5k-HA, b is 5K-HA-But-3, c is 5K-HA-But-6, and d is 5K-HA-But-9;

[0040] Figure 2 It is the H NMR spectrum of HA-But structure; a is 5K-HA, b is 5K-HA-But-3, c is 5K-HA-But-6, d is 5K-HA-But-9;

[0041] Figure 3 The effect of HA-But on the activity of HaCaT cells; a is 5k-HA-But, b is 1w-HA-But, c is 4w-HA-But, and d is the effect of HA, But mixture and synthetic product on cell activity;

[0042] Figure 4 The effect of HA-But on the expression of genes related to skin barrier function in HaCaT cells; a is FLG, b is APQ3, c is IVL, and d is Cldn-1;

[0043] Figure 5 The effect of HA-But on the resistance of HaCaT cells to reactive oxygen species; a is the MTT method to determine different molecular weight HA and HA-But, b, c is the flow cytometry detection of 5k-HA and 5K-But-9;

[0044] Figure 6 The effect of HA-But on the expression of inflammation-related genes in HaCaT cells; a represents cell activity, b represents IL-31, and c represents TSLP;

[0045] Figure 7 The effect of HA-But on mouse animal model;

[0046] Figure 8 HE staining of mouse animal model skin by HA-But; a is the control group, b is the model group, c is the HA group, and d is the HA-But group;

[0047] Fig. 9 This is the evaluation of the degree of barrier damage and inflammation of the mouse animal model by HA-But; a represents weight change, b represents erythema and swelling, and c represents dryness and peeling;

[0048] Fig.10 This is the effect of HA-But on the expression of skin barrier-related proteins and inflammatory factor-related genes in mouse animal models; a is FLG, b is AQP-3, c is IVL, d is Cldn-1, and e is IL-4, IL-13 and IL-31, respectively. DETAILED DESCRIPTION

[0049] The technical solution of the present invention is further explained and illustrated by means of specific embodiments below.

[0050] Abbreviations: HA: hyaluronic acid; But: butyric anhydride; HA-But: hyaluronic acid butyrate complex

[0051] Example 1 Preparation of hyaluronic acid butyrate complex HA-But

[0052] 1.5 g (0.3 mM) sodium hyaluronate was added to 150 ml distilled water and allowed to stand until completely swollen, then 4.5 g H-type cationic resin was added and stirred at room temperature for 3 h. The filtrate was filtered and the pH value was adjusted to 7.0 with 25% tetrabutylammonium hydroxide solution, and lyophilized to obtain a hyaluronic acid butyrate tetrabutylammonium hydroxide complex.

[0053] 0.4 g of hyaluronic acid tetrabutylammonium hydroxide complex was added to 20 ml of N,N-dimethylformamide, heated at 40°C until completely dissolved, 0.1 ml of anhydrous pyridine and 0.3 ml of butyric anhydride (2.7 mM) were added, and stirred at room temperature for 24 hours to prepare HA-But-9 (sodium hyaluronate:butyric anhydride=1:9 molar ratio), wherein: the molecular weight of hyaluronic acid is 5K;

[0054] The ratio of hyaluronic acid tetrabutylammonium hydroxide complex and butyric anhydride was adjusted to obtain:

[0055] HA-But-3 (sodium hyaluronate: butyric anhydride = 1:3 molar ratio), other ingredients are the same as above

[0056] HA-But-6 (sodium hyaluronate:butyric anhydride=1:6 molar ratio), the rest is the same as above.

[0057] Example 2 Validation of the efficacy of hyaluronic acid butyrate complex HA-But

[0058] 1.1 HaCaT cytotoxicity assay and cell experiment grouping

[0059] HaCaT cells were inoculated in a culture plate and treated with DMEM medium containing 10% serum and 1% double antibody for 24 h. The cell experimental groups were as follows:

[0060] (1) Control group: HaCaT cells were treated with 10, 50, 100, 200, 300, 400, 600, and 800 μg / ml HA for 24 h;

[0061] (2) HA-But-3 group: HaCaT cells were treated with 10, 50, 100, 200, 300, 400, 600, and 800 μg / ml HA-But-3 for 24 h;

[0062] (3) HA-But-6 group: HaCaT cells were treated with 10, 50, 100, 200, 300, 400, 600, and 800 μg / ml HA-But-6 for 24 h;

[0063] (4) HA-But-9 group: HaCaT cells were treated with 10, 50, 100, 200, 300, 400, 600, and 800 ug / ml HA-But-9 for 24 h.

[0064] 1.2 HA-But promotes HaCaT cell proliferation experiment and cell grouping HaCaT cells were inoculated in a culture plate and treated with DMEM medium containing 10% serum and 1% double antibody for 24 hours. The cell experiment grouping is as follows:

[0065] (1) Control group: HaCaT cells were treated with 200ug / ml HA for 24h;

[0066] (2) HA-But-3 group: HaCaT cells were treated with 200ug / ml HA-But-3 for 24h;

[0067] (3) HA-But-6 group: HaCaT cells were treated with 200ug / ml HA-But-6 for 24h;

[0068] (4) HA-But-9 group: HaCaT cells were treated with 200ug / ml HA-But-9 for 24h.

[0069] 1.3 Cell viability assay

[0070] After the cells were treated, the absorbance at 490 nm was measured using an enzyme-linked immunosorbent assay (ELISA) to reflect cell activity.

[0071] 1.4 Establishment of HaCaT cell model and cell experiment grouping

[0072] HaCaT cells were inoculated in a culture plate and treated with DMEM medium containing 10% serum and 1% double antibody for 24 h. The cell experimental groups were as follows:

[0073] (1) Control group: HaCaT cells were treated with complete culture medium for 24 h;

[0074] (2) SDS group: HaCaT cells were treated with complete medium containing 12 μg / ml SDS for 24 h;

[0075] (3) 5K HA group: HaCaT cells were treated with 200ug / ml HA (HA molecular weight 5K) for 24h;

[0076] (4) 5K-HA-But-9 group: HaCaT cells were treated with 200ug / ml HA-But-9 (HA molecular weight is 5K) for 24h.

[0077] 1.5 Real-time fluorescence quantitative PCR experiment

[0078] RT-PCR experiments were used to detect the expression of protein expression genes related to skin barrier function, such as FLG, AQP3, IVL, Cldn-1, and protein expression genes related to inflammation, such as IL-31 and TSLP in HaCaT cells.

[0079] 1.6 Antioxidant capacity test

[0080] The cells were treated according to the experimental protocol, and the DCFH-FA probe was used to detect the intracellular mean fluorescence intensity by flow cytometry to reflect the cellular antioxidant capacity.

[0081] 1.7 Establishment of mouse animal model and animal grouping

[0082] The 2,4-dinitrofluorobenzene (DNFB)-induced allergic contact dermatitis (ACD) model is one of the most commonly used animal models in the study of inflammation or chronic pruritus.

[0083] On the first day of the experiment, the backs of mice were depilated, acetone and olive oil were prepared into a base solution in a ratio of 3:1, and then DNFB (2,4-dinitrofluorobenzene) solutions with concentrations of 0.5% and 0.1% were prepared using DNFB and the base solution.

[0084] (1) Control group: applied with the base solution for 7 days, followed by blank Carbopol 940 gel for 21 days;

[0085] (2) Model group: 0.5% DNFB was applied for 2 days, followed by 0.1% DNFB for 4 consecutive days, and then blank Carbomer 940 gel was applied for 21 days;

[0086] (3) HA group: 0.5% DNFB was applied for 2 days, followed by 0.1% DNFB for 4 consecutive days, and 0.5% HA carbomer gel was applied for 21 days;

[0087] (4) HA-But group: 0.5% DNFB was applied for 2 days, followed by 0.1% DNFB for 4 consecutive days, and then 0.5% HA-But carbomer gel was applied for 21 days.

[0088] 1.8 Evaluation of skin barrier damage and inflammation in mice

[0089] The objective scoring system was used to score the severity of redness, swelling, erythema and dryness and peeling of the mouse back skin. After the animal model was established, observations were made and recorded on the 3rd, 5th, 7th, 10th, 14th, 17th, 21st, 24th and 28th days of the experimental cycle: the severity was divided into 0-4 levels, where 0-none; 1-mild; 2-moderate; 3-severe; 4-very severe.

[0090] Table 1 Scoring criteria for skin inflammation

[0091]

[0092] 1.9 HE staining of mouse skin

[0093] The back skin tissue of the mice was fixed with 4% paraformaldehyde and then stained with HE, and the sections were placed under an inverted microscope to observe the histopathological differences.

[0094] 1.10 Real-time fluorescence quantitative PCR reaction of mouse skin tissue

[0095] The mouse skin tissue was ground with liquid nitrogen and RNA was extracted. RT-PCR experiments were used to detect the expression of protein expression genes related to skin barrier function, such as FLG, AQP3, IVL, Cldn-1, and protein expression genes related to inflammation, such as IL-4, IL-13, and IL-31.

[0096] result:

[0097] 2.1 FT-IR structure confirmation

[0098] like Figure 1 As shown in ad, the infrared spectra of HA and each synthetic product HA-But are summarized, and the hydroxyl absorption peak is at 3420-3380cm -1, the peak is relatively broad, indicating that the -OH on the HA molecule forms intermolecular or intramolecular hydrogen bonds; 1650-1610cm -1 、1380cm -1 The absorption peak at 1153 cm is caused by the residues on the HA molecule. Compared with the HA raw material, HA-But still maintains the absorption peak at 1153 cm -1 、1079cm -1 、1045cm -1 and 946cm -1 The characteristic absorption peak of sugars near the wavelength. From this analysis, the product HA-But basically maintains the original basic structure of HA, and the vibration absorption of the ester bond appears at 1735cm-1, which indicates that the butyric acid group is successfully connected to the 6-hydroxyl group of HA.

[0099] 2.2 1H-NMR structure confirmation

[0100] like Figure 2 As shown in Figures ad, the chemical shift of HA-But is mostly consistent with that of the raw material HA, among which the characteristic peak of the amidomethyl group on the N-acetylglucosamine in the HA sugar unit (δ = 1.99 ppm) is strong and is not affected in the reaction, and can be used as a characteristic group of HA. HA-But has a characteristic peak near 1.69 ppm, which is caused by the peak of the methylene group in the butyric acid group due to the electron-withdrawing effect, indicating that the butyric acid group is successfully connected to HA.

[0101] Table 2 Chemical shifts of groups in HA-But

[0102]

[0103] 2.3 MTT cytotoxicity test results

[0104] like Figure 3 As shown, different concentrations of HA and HA-But have obvious proliferation effects, and the modified HA-But has a higher proliferation effect on HaCaT than HA. Taking HA and HA-But with a molecular weight of 5K as an example, the synthetic product HA-But has a greater proliferation effect on HaCaT cells than the original mixture of HA and butyrate (Mix), among which 5K-HA-But-9 has the most obvious proliferation effect. The introduction of butyric acid groups improves the survival rate of HaCaT cells to varying degrees, proving that HA-But is safer.

[0105] 2.4 Expression of genes related to cell models

[0106] 2.4.1 Gene expression of proteins related to skin barrier function in cell models

[0107] like Figure 4As shown in ad, in the SDS-induced skin barrier damage model, compared with HA, 5K-HA-But-9 has a significant positive regulatory effect on skin barrier repair-related proteins: FLG, AQP-3, IVL, and Cldn-1, and can even restore them to their original levels. The results of RT-PCR overall show that 5K-HA-But-9 can promote the expression of FLG, AQP-3, IVL, and Cldn-1, which indicates that the introduction of butyric acid groups is beneficial to improving the tight junctions of HaCaT cells.

[0108] 2.4.2 Gene expression of skin inflammation-related proteins in cell models

[0109] like Figure 6 As shown in Figures ac, the inhibitory effect of 5K-HA-But-9 on the inflammatory factor IL-31 and the upstream inflammatory factor TSLP is better than that of 5K-HA at the same concentration, and the difference is significant, indicating that the butyric acid group carried by the modified HA-But also has an inhibitory effect on the AD-like inflammation-related cytokine TSLP and the inflammatory factor IL-31.

[0110] 2.5 Cellular antioxidant capacity test results

[0111] like Figure 5 As shown in Figures ac, both HA and HA-But have different degrees of antioxidant effects. Compared with HA, the antioxidant effect of the modified complex HA-But is better than that of HA at the same concentration. The antioxidant effect of HA-But at a concentration of 200ug / mL is better than that of HA, and the difference is significant.

[0112] 2.6 Appearance results of mouse animal model experiment

[0113] like Figure 7 As shown, by the end of the experiment (28th day), the skin inflammation and barrier damage on the mouse skin surface had been alleviated, and the skin conditions of the mice in the HA and HA-But groups were improved compared with the model group, among which the recovery effect of the HA-But group was the most significant. The naked eye observation showed that there was no redness, swelling, scabs, peeling and dryness on the back skin of the mice, and the mice had no scratching behavior and had grown hair. The HA treatment group also improved the dermatitis and barrier damage on the skin surface of AD-like mice, but the improvement effect was not as good as that of the HA-But group.

[0114] 2.7 HE staining results of mouse skin

[0115] like Figure 8As shown in ad, the back skin of mice in the HA and HA-But administration groups showed a certain improvement effect, improved the pathological symptoms of skin tissue, and had a certain effect of inhibiting skin inflammation. The HA-But group significantly reduced the pathological thickening and acanthosis of the back skin of mice, significantly improved the infiltration of inflammatory cells in the dermis, and the hair follicles in the dermis gradually recovered.

[0116] 2.8 Results of evaluation of barrier damage and inflammation in mouse models

[0117] like Fig. 9 As shown in Figures ac, the evaluation values ​​of erythema, swelling, dryness and peeling of mice in the HA and HA-But groups decreased significantly on days 8-21, indicating that the AD-like inflammation and barrier damage of mice improved during this period and were gradually recovering, and the improvement effect of mice in the HA-But group was significantly better than that of the HA group. After 28 days, the skin of mice in the model group also recovered slightly, but the evaluation values ​​of erythema, swelling, dryness and peeling of mice in the HA and HA-But treatment groups dropped to 0-1 on days 21-28, and even the evaluation index of mice in the HA-But treatment group was close to that of the blank control group, indicating that mice in the HA-But group had basically recovered to normal levels after 21 days of administration.

[0118] 2.9 Expression of genes related to mouse animal model

[0119] 2.9.1 Gene expression of proteins related to skin barrier function in mouse animal models

[0120] As shown in 10a-d, compared with HA with a molecular weight of 5K, HA-But has a significant positive regulatory effect on mouse skin barrier repair-related proteins: FLG, AQP-3, IVL and Cldn-1. The overall results of RT-PCR show that HA-But can promote the expression of FLG, AQP-3, IVL, and Cldn-1, which indicates that the introduction of butyric acid groups is beneficial to repairing the damaged skin barrier of mice, which is consistent with the results of cell experiments.

[0121] 2.9.2 Gene expression of inflammation-related proteins in mouse models

[0122] like Fig.10As shown in the figure, HA with a molecular weight of 5K and the synthetic product HA-But have significant inhibitory effects on the main inflammatory factors related to mouse AD: IL-4, IL-13 and IL-31, but the inhibitory effect of HA-But is more obvious than HA. The degree of downregulation of the expression of each gene by HA-But is different. Compared with the model group, the downregulation effect of HA-But on the expression of IL-4 and IL-13 factors is better than IL-31. These results all indicate that HA-But can inhibit the expression of AD inflammatory factors IL-4, IL-13 and IL-31, which shows that the introduction of butyric acid groups is beneficial to improve the skin inflammation of AD-like mice, which is consistent with the cell results.

Claims

1. A hyaluronic acid butyrate complex, It is characterized in that The complex is formed by the reaction of sodium hyaluronate and butyric anhydride, wherein the weight average molecular weight of sodium hyaluronate is 5K-220W, and its structural formula is as follows:

2. The method for preparing the hyaluronic acid butyrate complex according to claim 1, It is characterized in that The following steps are involved: (1) Sodium hyaluronate is added to distilled water and allowed to stand until it is completely swollen, then H-type cationic resin is added, stirred at room temperature, filtered, and the filtrate is collected, the pH value is adjusted with a tetrabutylammonium hydroxide solution, and freeze-dried to obtain a hyaluronic acid butyrate tetrabutylammonium hydroxide complex; (2) Add the hyaluronic acid tetrabutylammonium hydroxide complex to N,N-dimethylformamide, heat until completely dissolved, add anhydrous pyridine and butyric anhydride, stir and react at room temperature to obtain a hyaluronic acid butyrate complex.

3. The method according to claim 2, It is characterized in that In step (1), the ratio of sodium hyaluronate to distilled water is 1 g:100 ml, the mass ratio of sodium hyaluronate to H-type cationic resin is 1 g:3 g, the stirring time at room temperature is 3 h, the concentration of tetrabutylammonium hydroxide solution is 0.25 mg / ml, and the pH value is 7.0; In step (2), the ratio of the hyaluronic acid tetrabutylammonium hydroxide complex to the N,N-dimethylformamide solution is 1g:50ml, the ratio of the hyaluronic acid tetrabutylammonium hydroxide complex to the anhydrous pyridine solution is 4mg:1ml, and the ratio of the hyaluronic acid tetrabutylammonium hydroxide complex to the butyric anhydride solution is 4mg:3ml.

4. According to the preparation method described in claim 2, It is characterized in that The heating temperature in step (2) is 40° C., and the stirring reaction time at room temperature is 24 h.

5. Use of the hyaluronic acid butyrate complex according to claim 1 in the preparation of medicines or cosmetics for moisturizing or repairing skin barrier.

6. Use of the hyaluronic acid butyrate complex according to claim 1 in the preparation of drugs for treating skin diseases.

7. The use according to claim 6, It is characterized in that The skin disease is allergic dermatitis, eczema or atopic dermatitis.

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