Preparation method of N-acetyl-D-galactosaminated astaxanthin / chitosan microspheres, product and application of N-acetyl-D-galactosaminated astaxanthin / chitosan microspheres

Abstract

The invention relates to the technical field of anti-oxidation free radical eliminating drugs and anti-inflammatory activity, in particular to a preparation method of N-acetyl-D-galactosaminated astaxanthin / chitosan microspheres, a product and application of the N-acetyl-D-galactosaminated astaxanthin / chitosan microspheres. According to the preparation method, N-acetyl-D-galactosamine is taken as a ligand molecule, chitosan is taken as a microsphere carrier, chitosan coats astaxanthin to form chitosan microspheres, N-acetyl-D-galactosamine is used for modifying the chitosan microspheres on the outer layer, and finally the N-acetyl-D-galactosamine aminated astaxanthin / chitosan microspheres are formed. According to the invention, the biological limitation of the astaxanthin is improved, the water solubility of the astaxanthin is improved, and the bioavailability of the astaxanthin is improved. And the N-acetyl-D-galactosamine and the chitosan are natural materials which are non-toxic, degradable and easy to absorb by a human body, so that the safety is high.

Description

Technical Field

[0001] The invention relates to the technical field of antioxidant free radical scavenging drugs and anti-inflammatory activity, and in particular to a preparation method of N-acetyl-D-galactosamined astaxanthin / chitosan microspheres, products and applications thereof. Background Art

[0002] Astaxanthin, chemical formula is C 40 H 52 O4 is a carotenoid and a keto-oxygen derivative. It has 11 conjugated double bonds and two ionone rings. These unsaturated bonds exist in its structure. Its structural formula is Astaxanthin is abundant and widely found in marine organisms such as shrimp, crab, fish, and algae. It can be obtained through natural products, fermentation, and artificial synthesis.

[0003] Astaxanthin, as a pigment, is a fat-soluble pigment widely found in marine crustaceans. Its structure enables it to remove excess free radicals in the body, inhibit cell apoptosis to fight tumor cells, and prevent cardiovascular and cerebrovascular diseases by reducing oxidative stress. At the same time, studies have also shown that astaxanthin has pharmacological activities in lowering blood pressure, preventing and treating atherosclerosis, protecting the nervous system, relieving inflammation, treating liver damage, reducing obesity, preventing and treating diabetes, protecting the skin, protecting vision, reducing sports injuries, and enhancing immunity. In addition, astaxanthin has strong coloring, disease resistance, and improved reproductive capacity, it has been well used in aquaculture. In addition, the fact that the world has known its significant efficacy and health functions has caused a wave of research and development of health products with astaxanthin as the main body in the medical field, giving astaxanthin a very broad prospect for development and utilization.

[0004] Although the unsaturated bonds of astaxanthin bring strong antioxidant properties, they also make astaxanthin very unstable. Astaxanthin will change its structure due to high temperature, sunlight exposure, and high oxygen content in the environment, which will eventually lead to a significant reduction or disappearance of its physiological activity. In addition, astaxanthin powder is highly fat-soluble and poorly water-soluble, which greatly limits its bioavailability. Summary of the invention

[0005] In order to solve the problem of poor water solubility of astaxanthin in the current prior art, the present invention provides a preparation method of N-acetyl-D-galactosamined astaxanthin / chitosan microspheres, a product and application thereof.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] One of the technical solutions of the present invention is a method for preparing N-acetyl-D-galactosamined astaxanthin / chitosan microspheres, comprising the following steps:

[0008] dissolving chitosan in acetic acid solution to obtain chitosan acetic acid solution;

[0009] Dispersing astaxanthin in anhydrous ethanol to obtain an astaxanthin-ethanol solution; (the present invention does not impose any particular limitation on the amount of anhydrous ethanol used, as long as the astaxanthin can be fully dissolved)

[0010] Adding the astaxanthin-ethanol solution to the chitosan acetic acid solution, removing anhydrous ethanol, and obtaining an astaxanthin-chitosan acetic acid solution;

[0011] Mixing liquid paraffin and surfactant evenly to obtain an oil phase;

[0012] Dissolving N-acetyl-D-galactosamine in PBS buffer, then adding it to the oil phase, stirring it into an emulsified state, and obtaining colostrum;

[0013] adding the astaxanthin-chitosan acetate solution into the colostrum and stirring to obtain a W / O emulsion;

[0014] Glutaraldehyde solution is added to the W / O emulsion for cross-linking and solidification, and then the supernatant is removed by centrifugation. The obtained product is washed, mixed with a mannitol aqueous solution and freeze-dried to obtain the N-acetyl-D-galactosamined astaxanthin / chitosan microspheres.

[0015] In a preferred embodiment of the present invention, the mass concentration of the acetic acid solution is 1-2%; the mass concentration of chitosan in the chitosan acetic acid solution is 1-3%.

[0016] In a preferred embodiment of the present invention, the mass ratio of the astaxanthin to the chitosan is (0.04-0.05):0.5.

[0017] In some specific embodiments of the present invention, anhydrous ethanol in the astaxanthin-chitosan acetic acid solution is removed by ultrasonic oscillation.

[0018] In a preferred embodiment of the present invention, the surfactant is Span-80; the volume ratio of the liquid paraffin to the surfactant is 49:(1-5).

[0019] In a preferred embodiment of the present invention, the pH of the PBS buffer solution is 6.8-7.3; the mass volume ratio of the N-acetyl-D-galactosamine to the PBS buffer solution is (0.01-0.1) g:1 mL.

[0020] In a preferred embodiment of the present invention, the mass volume ratio of the N-acetyl-D-galactosamine to the oil phase is (0.01-0.1) g:50 mL; the mass volume ratio of the N-acetyl-D-galactosamine to the astaxanthin-chitosan acetic acid solution is (0.01-0.1) g:9 mL.

[0021] When preparing the colostrum and the W / O emulsion, the stirring is performed at 40° C. and 180-250 r / min for 40 min.

[0022] In a preferred embodiment of the present invention, the mass concentration of the glutaraldehyde solution is 0.1%-3%; the volume ratio of the glutaraldehyde solution to the astaxanthin-chitosan acetate solution is (1-5):9.

[0023] In a preferred embodiment of the present invention, the cross-linking and curing is specifically cross-linking and curing at 40-70° C. and 180-250 r / min for 1-3 hours.

[0024] The present invention uses N-acetyl-D-galactosamine as a ligand molecule and chitosan as a microsphere carrier. Chitosan coats astaxanthin to form chitosan microspheres (such as Figure 1 As shown in the figure, N-acetyl-D-galactosamine is used to modify the outer layer of chitosan microspheres, and finally N-acetyl-D-galactosamine-modified astaxanthin / chitosan microspheres are formed; N-acetyl-D-galactosamine can be specifically recognized and bound to asialoglycoprotein receptor (ASGPR), and the modification of N-acetyl-D-galactosamine plays a role in enhancing the targeting of the drug for drug-loaded microspheres.

[0025] The second technical solution of the present invention is N-acetyl-D-galactosamined astaxanthin / chitosan microspheres prepared by the above-mentioned preparation method.

[0026] The third technical solution of the present invention is the use of the above-mentioned N-acetyl-D-galactosamined astaxanthin / chitosan microspheres in the preparation of antioxidant, anti-aging, antihypertensive, anti-inflammatory or anti-tumor drugs.

[0027] The present invention discloses the following technical effects:

[0028] The present invention adopts the method of preparing drug-loaded microspheres by encapsulating astaxanthin with chitosan through emulsification cross-linking technology to improve the biological limitations of astaxanthin itself, improve the water solubility of astaxanthin, and increase its bioavailability. In addition, N-acetyl-D-galactosamine and chitosan are non-toxic, degradable, and natural materials that are easily absorbed by the human body, and have high safety.

[0029] The N-acetyl-D-galactosaminylated astaxanthin / chitosan microspheres of the present invention can be used to prepare anti-oxidation, anti-aging, blood pressure lowering, anti-inflammatory or anti-tumor drugs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 This is the appearance of the N-acetyl-D-galactosamined astaxanthin / chitosan microspheres prepared in Example 1.

[0032] Figure 2 This is the release curve of N-acetyl-D-galactosylamino astaxanthin / chitosan microspheres prepared in Example 1 under different pH environments. DETAILED DESCRIPTION

[0033] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0034] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0035] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0036] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0037] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0038] The "%" described in the present invention, unless otherwise specified, refers to mass percentage.

[0039] The purpose of the present invention is to solve the instability of the application of the above-mentioned astaxanthin, and to provide a safe, reliable, low-cost and simple technical means. The method is to use astaxanthin-loaded chitosan microspheres with N-acetylgalactosamine as a ligand, wherein the chitosan material of the microsphere carrier is safe and cheap, has excellent stability, high sugar content, and excellent biofunctionality and microbial degradability, thereby improving the stability of the drug. The present invention effectively solves the problems of poor stability, low water solubility and poor bioavailability of astaxanthin, and at the same time improves the controlled release of drug-loaded chitosan microspheres. Astaxanthin-loaded chitosan microspheres modified with N-acetylgalactosamine as a ligand have certain antioxidant and anti-inflammatory activities, and broaden the application of conventional astaxanthin preparations.

[0040] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0041] The phosphate buffer solution (PBS) used in the embodiment of the present invention has a pH of 7.3 and is prepared by the following steps: accurately weigh 0.1973 g of disodium hydrogen phosphate and 0.0224 g of potassium dihydrogen phosphate, dissolve them in a small amount of pure water and transfer them to a 100 mL volumetric flask, dilute to the mark with pure water, sonicate until the solution is clear and transparent, and then place it aside for use.

[0042] The acetic acid solution (2 wt %) used in the embodiment of the present invention is prepared by the following steps: 1 mL of glacial acetic acid is added to a 50 mL volumetric flask, the volume is fixed with purified water, and the mixture is shaken for later use.

[0043] The glutaraldehyde solution used in the embodiment of the present invention is prepared by diluting a glutaraldehyde solution with a mass concentration of 25% with a PBS buffer solution to a mass concentration of 0.1%-3%.

[0044] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0045] Example 1

[0046] A method for preparing N-acetyl-D-galactosamined astaxanthin / chitosan microspheres, the specific steps are as follows:

[0047] (1) Weigh 0.5 g of chitosan into a 500 mL round-bottom flask, pour in 50 mL of acetic acid solution to dissolve, place on a magnetic stirrer at 40°C and stir to dissolve, let stand until all bubbles are removed, and obtain chitosan acetic acid solution for standby use;

[0048] (2) accurately weighing 0.0404 g of astaxanthin and dispersing it in anhydrous ethanol (the amount of anhydrous ethanol used is sufficient to dissolve astaxanthin), transferring the astaxanthin-ethanol solution to the prepared chitosan acetic acid solution after it is completely dissolved, and ultrasonically oscillating until the anhydrous ethanol is completely volatilized to obtain an astaxanthin-chitosan acetic acid solution, which is then sealed for later use;

[0049] (3) Add 49 mL of liquid paraffin measured with a measuring cylinder and 1 mL of Span-80 taken with a pipette into a 250 mL round-bottom flask, place on a magnetic stirrer and stir evenly at 30 °C to obtain an oil phase for later use;

[0050] (4) Accurately weigh 0.0101 g of N-acetyl-D-galactosamine and add it to 1 mL of PBS buffer solution, dissolve it by ultrasonication, and then slowly add it to the round-bottom flask containing the oil phase with a syringe, place it in an air bath constant temperature oscillator, and stir it at 40°C, 200 r / min, and 40 min until it becomes an emulsified state to obtain colostrum;

[0051] (5) Using a pipette, take 9 mL of the prepared astaxanthin-chitosan acetate solution, slowly add it dropwise to the colostrum, and continue stirring for 40 min under the above conditions (40° C., 200 r / min) to obtain a W / O emulsion;

[0052] (6) Pipette 2.3 mL of 2% glutaraldehyde solution and slowly add it dropwise into the W / O emulsion. Continue with the above conditions (40°C, 200 r / min) and crosslink and cure for 2 h to obtain microspheres.

[0053] (7) Centrifuge at 4500 r / min for 8 min in a centrifuge, remove the supernatant, wash the lower layer product twice with petroleum ether and once with anhydrous ethanol (centrifuge at 4500 r / min for 8 min after each wash), add the same volume of 8% mannitol aqueous solution to the lower layer product after centrifugation, and freeze-dry to obtain N-acetyl-D-galactosamined astaxanthin / chitosan microsphere powder (abbreviated as: drug-loaded microspheres).

[0054] The appearance of the N-acetyl-D-galactosamine astaxanthin / chitosan microspheres prepared in this example is as follows: Figure 1 As shown by Figure 1 It can be seen that the drug-loaded microspheres can be clearly observed to be spherical under the scale of 500nm, with a relatively round appearance and no adhesion.

[0055] Effect Example 1

[0056] In vitro release performance test of N-acetyl-D-galactosamined astaxanthin / chitosan microspheres:

[0057] Standard curve of astaxanthin in simulated artificial gastric fluid: Take 1 mol / mL dilute hydrochloric acid, dilute with water, adjust the pH to 1.5, add 1g pepsin to every 100mL liquid, and mix well. Transfer 1.0mL, 0.8mL, 0.6mL, 0.4mL, and 0.2mL of 60g / mL astaxanthin ethanol solution to 5 10mL volumetric flasks, respectively, add anhydrous ethanol to 1mL, and then dilute with hydrochloric acid solution with pH=1.5, and configure the reference with anhydrous ethanol: hydrochloric acid solution=1:9, measure the absorbance at 478nm, and draw the curve.

[0058] Standard curve of astaxanthin in simulated artificial intestinal fluid: Take 6.8g of potassium dihydrogen phosphate, add 500mL of water to dissolve, adjust the pH value to 6.8 with 0.1mol / L sodium hydroxide solution, take 10g of pancreatic enzyme, add appropriate amount of water to dissolve, mix the two liquids, and dilute to 1000mL with water. Transfer 0.2mL, 0.4mL, 0.6mL, 0.8mL, and 1.0mL of 60g / mL astaxanthin ethanol solution to 5 10mL volumetric flasks, respectively, add 0.8mL, 0.6mL, 0.4mL, 0.2mL, and 0mL of anhydrous ethanol, respectively, and use the above buffer solution with pH=6.8 to make up the volume, and configure the reference with anhydrous ethanol: buffer solution=1:9, measure the absorbance at 478nm, and draw the curve.

[0059] Accurately weigh 10 mg of drug-loaded microspheres into a 250 mL round-bottom flask, add 100 mL (containing 10 mL of anhydrous ethanol) simulated artificial gastric juice and 200 mL (containing 10 mL of anhydrous ethanol) simulated artificial intestinal juice, respectively, and perform release experiments on a constant temperature oscillator at 37 ° C and 100 r / min. After every 2 hours, remove 5 mL of supernatant and add 5 mL of dissolution medium (simulated artificial gastric juice and simulated artificial intestinal juice). Measure the absorbance and calculate the concentration to obtain the release rate. Continue sampling for 24 hours and repeat the measurement to take the average value.

[0060] like Figure 2 The figure shows the release curves of drug-loaded microspheres in simulated artificial gastric juice and simulated artificial intestinal juice. Curve A in the figure shows the release in a hydrochloric acid solution with a pH of 1.5, and curve B shows the release in a PBS solution with a pH of 6.8. By comparison, it can be seen that the release of drug-loaded microspheres in a solution with a pH of 6.8 is significantly higher than that in a solution with a pH of 1.5. Therefore, in an acidic environment, the encapsulation of chitosan microspheres can better protect the structure of astaxanthin, have a good sustained-release effect, and can better improve the bioavailability of astaxanthin.

[0061] Effect Example 2

[0062] Study on the antioxidant activity of astaxanthin / chitosan microspheres mediated by ASGPR

[0063] Accurately weigh 0.0059g DPPH free radical, dissolve it with anhydrous ethanol and dilute it to a 25mL volumetric flask. After shaking well, transfer 1mL to a 10mL volumetric flask. At this time, a DPPH solution with a concentration of 0.06mmol / L is prepared and stored at low temperature and away from light (0-4℃). Accurately weigh 10mg of drug-loaded microspheres and 10mg of blank microspheres, dissolve them with anhydrous ethanol, and dilute them to a 10mL volumetric flask. Shake well for later use. Use anhydrous ethanol as a reference, measure the absorbance of the above sample solution at 515nm, record A1; transfer 0.1mL of sample solution and 3.5mL of DPPH solution into a centrifuge tube, mix well, let it stand at room temperature for 30min, and detect the absorbance at a wavelength of 515nm, record A2; as above, transfer an equal amount of blank solution to DPPH, let it stand and measure the absorbance, record A0. Each sample is operated in parallel 3 times, and the average value is taken to calculate the ability to scavenge DPPH free radicals. The calculation formula is as follows:

[0064] Clearance rate (%) = [A0-(A2-A1)] / A0×100;

[0065] Among them, A0——absorbance of DPPH plus blank solution;

[0066] A1——absorbance of the sample itself;

[0067] A2——Absorbance after sample action.

[0068] With anhydrous ethanol as a reference, the measured absorbance and calculated clearance are shown in Table 1. The clearance rate of N-acetyl-D-galactosamined astaxanthin / chitosan microspheres was about 32.12%, indicating that the drug-loaded microspheres have antioxidant properties.

[0069] Table 1 Absorbance and DPPH free radical scavenging rate

[0070]

[0071] Effect Example 3

[0072] Study on the anti-inflammatory properties of ASGPR-mediated N-acetyl-D-galactosaminyl astaxanthin / chitosan microspheres

[0073] Weigh 4.6g of sodium acetate and transfer 0.57mL of glacial acetic acid into a 100mL volumetric flask, dilute to the mark with purified water, shake well to obtain an acetate buffer solution for standby use. Accurately weigh 0.8556g of bovine serum albumin, dissolve it in 42.78g of the above-mentioned acetate solution, stir until completely dissolved, and let stand until all bubbles are removed. Weigh 10mg of drug-loaded microspheres and blank microspheres respectively (the preparation method of the blank microspheres is the same as in Example 1, the only difference is that the addition of astaxanthin is omitted, and the remaining steps and parameters are the same as in Example 1), dissolve it in water and dilute to a 10mL volumetric flask, shake well for standby use. Take three 3mL 2% bovine serum albumin, keep warm at 37℃ for 20min, add 0.5mL 1.0mg / mL sample aqueous solution to one tube, dilute to 10mL with purified water; add 0.5mL blank solution to one tube and dilute to 10mL with purified water; dilute the last tube directly to 10mL with purified water, place in a 70℃ water bath for 10min and then quickly cool to room temperature. Use an ultraviolet spectrophotometer to measure the sample turbidity at 660nm, and calculate the inhibition rate of bovine serum albumin denaturation. The calculation formula is as follows:

[0074] Inhibition rate (%) = [1-A1 / A2] × 100;

[0075] Among them, A1——represents the absorbance of the added sample solution;

[0076] A2——indicates the absorbance of the blank solution added.

[0077] Using the bovine serum albumin solution without drug-loaded microspheres as a reference, the measured absorbance and calculated inhibition rate are shown in Table 2; the denaturation inhibition rate of bovine serum albumin is about 48%, indicating that the drug-loaded microspheres prepared by the present invention have good anti-inflammatory activity.

[0078] Table 2 Absorbance and bovine serum albumin denaturation inhibition rate

[0079]

[0080] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing N-acetyl-D-galactosaminylated astaxanthin / chitosan microspheres, characterized in that: The following steps are involved: dissolving chitosan in acetic acid solution to obtain chitosan acetic acid solution; dispersing astaxanthin in anhydrous ethanol to obtain an astaxanthin-ethanol solution; Adding the astaxanthin-ethanol solution to the chitosan acetic acid solution, removing anhydrous ethanol, and obtaining an astaxanthin-chitosan acetic acid solution; Mixing liquid paraffin and surfactant evenly to obtain an oil phase; Dissolving N-acetyl-D-galactosamine in PBS buffer, then adding it to the oil phase, stirring it into an emulsified state, and obtaining colostrum; adding the astaxanthin-chitosan acetate solution into the colostrum and stirring to obtain a W / O emulsion; Glutaraldehyde solution is added to the W / O emulsion for cross-linking and solidification, and then the supernatant is removed by centrifugation. The obtained product is washed, mixed with a mannitol aqueous solution and freeze-dried to obtain the N-acetyl-D-galactosamined astaxanthin / chitosan microspheres.

2. The method for preparing N-acetyl-D-galactosaminylated astaxanthin / chitosan microspheres according to claim 1, characterized in that: The mass concentration of the acetic acid solution is 1-2%; the mass concentration of chitosan in the chitosan acetic acid solution is 1-3%.

3. The method for preparing N-acetyl-D-galactosaminylated astaxanthin / chitosan microspheres according to claim 1, characterized in that: The mass ratio of the astaxanthin to the chitosan is (0.04-0.05):0.

5.

4. The method for preparing N-acetyl-D-galactosaminylated astaxanthin / chitosan microspheres according to claim 1, characterized in that: The surfactant is Span-80; the volume ratio of the liquid paraffin to the surfactant is 49:(1-5).

5. The method for preparing N-acetyl-D-galactosaminylated astaxanthin / chitosan microspheres according to claim 1, characterized in that: The pH of the PBS buffer solution is 6.8-7.3; the mass volume ratio of the N-acetyl-D-galactosamine to the PBS buffer solution is (0.01-0.1) g:1 mL.

6. The method for preparing N-acetyl-D-galactosaminylated astaxanthin / chitosan microspheres according to claim 1, characterized in that: The mass volume ratio of the N-acetyl-D-galactosamine to the oil phase is (0.01-0.1) g:50 mL; the mass volume ratio of the N-acetyl-D-galactosamine to the astaxanthin-chitosan acetic acid solution is (0.01-0.1) g:9 mL.

7. The method for preparing N-acetyl-D-galactosaminylated astaxanthin / chitosan microspheres according to claim 1, characterized in that: The mass concentration of the glutaraldehyde solution is 0.1%-3%; the volume ratio of the glutaraldehyde solution to the astaxanthin-chitosan acetic acid solution is (1-5):

9.

8. The method for preparing N-acetyl-D-galactosaminylated astaxanthin / chitosan microspheres according to claim 1, characterized in that: The cross-linking and curing is specifically carried out at 40-70° C. and 180-250 r / min for 1-3 hours.

9. N-acetyl-D-galactosaminylated astaxanthin / chitosan microspheres prepared according to the preparation method according to any one of claims 1 to 8.

10. Use of the N-acetyl-D-galactosaminylated astaxanthin / chitosan microspheres according to claim 9 in the preparation of anti-oxidation, anti-aging, blood pressure lowering, anti-inflammatory or anti-tumor drugs.

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