CN-121971376-A - Nanogel for astaxanthin delivery and preparation method thereof

Abstract

The invention discloses a nanogel for astaxanthin delivery and a preparation method thereof, belonging to the technical field of bioactive substance delivery. The nanogel is composed of lysozyme-carboxymethyl chitosan complex and loaded with astaxanthin, has pH responsiveness, and undergoes structural swelling or dissociation within the pH range of 5.0-7.4. The preparation method comprises the steps of dissolving and mixing lysozyme and carboxymethyl chitosan, adjusting pH to form a compound, adding astaxanthin dissolved in ethanol for reaction, homogenizing the system, and freeze-drying to obtain astaxanthin nanogel. According to the invention, the nano gel system is constructed by the composite carrier, so that the stability of astaxanthin is improved, the release of astaxanthin in an intestinal environment is realized by utilizing the pH response characteristic, and meanwhile, the system has good biocompatibility and oxidation resistance. The preparation method is simple to operate, mild in condition, suitable for large-scale production and has application prospects in the fields of drug, nutrient components and cosmetic active substance delivery.

Inventors

• WANG DANGFENG
• CUI FANGCHAO
• REN LIKUN
• YAN ZIHAO
• LI JIANRONG
• LIU YUFENG
• LI XUEPENG
• LI TINGTING
• XU RONGNIAN

Assignees

• 渤海大学

Dates

Publication Date

20260505

Application Date

20260311

Claims (9)

1. 1. A nanogel for astaxanthin delivery, characterized in that the nanogel is composed of lysozyme-carboxymethyl chitosan complex and loaded with astaxanthin, has pH responsiveness, and undergoes structural swelling or dissociation in the pH range of 5.0 to 7.4.
2. 2. The nanogel of claim 1 wherein the lysozyme has an enzyme activity of at least 2000U/mg and the concentration of lysozyme solution is 1mg/mL.
3. 3. The nanogel of claim 2 wherein the degree of substitution of carboxymethyl chitosan is greater than or equal to 80% and the concentration of carboxymethyl chitosan solution is 1mg/mL.
4. 4. The nanogel of claim 3 wherein the astaxanthin has a purity of 96% and the astaxanthin solution has a concentration of 5.0 mg/mL.
5. 5. A method of preparing a nanogel for astaxanthin delivery, comprising the steps of: (1) Respectively dissolving lysozyme and carboxymethyl chitosan in ultrapure water to prepare two solutions, and dissolving astaxanthin in ethanol to prepare astaxanthin solution; (2) Adding the lysozyme solution into the carboxymethyl chitosan solution, mixing, and adjusting the pH of the mixed solution by using sodium hydroxide standard solution to form a lysozyme-carboxymethyl chitosan compound; (3) Adding astaxanthin solution into the compound, mixing, and heating to obtain a reaction mixture; (4) Homogenizing the reaction mixture, cooling and freeze-drying to obtain astaxanthin nano gel freeze-dried product.
6. 6. The nanogel of claim 5 wherein the volume ratio of lysozyme solution to carboxymethyl chitosan solution in step (1) is 5:2.
7. 7. The nanogel of claim 6 wherein the pH of the mixed solution is 8.0 using a standard solution of sodium hydroxide in step (2).
8. 8. The nanogel of claim 7 wherein the volume ratio of astaxanthin solution to complex in step (3) is 1:25, the heating temperature is 80 ℃ and the heating time is 40 min.
9. 9. The nanogel of claim 8 wherein the homogenization speed in step (4) is 12000 r/min and the homogenization time is 5 min.

Description

Nanogel for astaxanthin delivery and preparation method thereof Technical Field The invention relates to a biomedical related nano drug delivery system, in particular to a nano gel for astaxanthin delivery and a preparation method thereof. Background Astaxanthin (Astaxanthin) is a natural carotenoid which is widely used in certain algae, shrimp and crab species and fish species due to its excellent antioxidant properties. Researches show that the astaxanthin has 6000 times of antioxidant activity as compared with vitamin C and 110 times of vitamin E, can effectively remove free radicals in vivo, slows down the aging process, and has the effects of resisting cancer, protecting nerves and the like. However, astaxanthin is susceptible to degradation by light, heat and oxygen due to the fact that the astaxanthin contains a plurality of conjugated double bonds in its molecular structure, resulting in a decrease in its biological activity. In addition, astaxanthin is used as a hydrophobic molecule, has low absorption efficiency in vivo, is easily affected by gastrointestinal tract environment when orally administered, and has low bioavailability. Currently, a variety of astaxanthin delivery systems have been studied, mainly including liposomes, microcapsules, nanoparticles, etc. However, although these carrier systems play a role in enhancing the stability and bioavailability of astaxanthin, their targeting properties are still insufficient and it is difficult to fully exert the antioxidant effect of astaxanthin. In particular, when ingested orally, the existing systems are poorly stable in the gastrointestinal environment, resulting in inefficient release and absorption. Therefore, there is a need for a new delivery system that is effective in protecting astaxanthin, and achieving targeted release in the gastrointestinal tract, improving its bioavailability. Disclosure of Invention Aiming at the defects in the prior art, the invention provides a nanogel for astaxanthin delivery and a preparation method thereof. The nanogel is formed by compounding lysozyme and carboxymethyl chitosan, and has good stability and release characteristics in the gastrointestinal tract environment by utilizing the unique pH response performance of the nanogel. The preparation method of the invention not only can effectively improve the stability of the astaxanthin, but also can realize the targeted release of the astaxanthin in the gastrointestinal tract, thereby improving the bioavailability and the antioxidation effect of the astaxanthin. The technical scheme for solving the technical problems is as follows: the invention provides a nanogel for astaxanthin delivery and a preparation method thereof, comprising the following contents: (1) A nanogel for astaxanthin delivery, the nanogel being composed of a lysozyme-carboxymethyl chitosan complex and loaded with astaxanthin, having pH responsiveness, and undergoing structural swelling or dissociation in the pH range of 5.0 to 7.4; (2) A method for preparing the nanogel for delivering astaxanthin comprises the following steps of respectively dissolving lysozyme and carboxymethyl chitosan in ultrapure water to obtain two solutions, dissolving astaxanthin in ethanol to obtain astaxanthin solution, adding the lysozyme solution into the carboxymethyl chitosan solution, mixing, adjusting the pH of the mixed solution by using sodium hydroxide standard solution to form a lysozyme-carboxymethyl chitosan compound, adding the astaxanthin solution into the compound, mixing, heating to obtain a reaction mixture, homogenizing the reaction mixture, cooling and freeze-drying to obtain the astaxanthin nanogel freeze-dried product. Based on the technical scheme, the lysozyme-carboxymethyl chitosan composite nanogel system constructed by the invention has remarkable advantages and wide application prospect. The system effectively isolates external factors such as light, heat, oxygen and the like through embedding and a composite network, remarkably improves and prolongs the stability and the storage life of astaxanthin, simultaneously presents definite pH responsiveness, keeps stable structure in a gastric environment (pH approximately equal to 2), swells in an intestinal environment (pH approximately equal to 7.4) and realizes drug delivery release, and meets the targeted release requirement of oral administration. The synergistic effect of lysozyme and carboxymethyl chitosan not only improves the biocompatibility of the carrier, but also enhances the antioxidant activity of the system, thereby more effectively scavenging active oxygen and protecting cells from oxidative damage. On the other hand, the preparation process of the invention is simple and convenient, green and easy to be amplified industrially, the obtained nanogel has good dispersibility and complete structure, and is suitable for delivering and stably storing other hydrophobic drugs, nutritional ingredients or cosmetic active substances fo