Anti-aging EGCG (epigallocatechin gallate) nano composition as well as preparation method and application thereof

Abstract

The invention relates to an anti-aging EGCG (epigallocatechin gallate) nano composition as well as a preparation method and application thereof, and belongs to the technical field of nano carriers. The anti-aging EGCG nano composition disclosed by the invention comprises 0.5 to 5 percent of a carrier block polymer and 0.5 to 5 percent of an active ingredient EGCG, the general formula of the block polymer is Yn-Xm-Xm-Yn, Xm is a hydrophobic block, and Yn is a protonizable block; the polymerization degree m is 10-50, and the polymerization degree n is 20-100; yn is selected from the group consisting of PDMAEMA, PDEAEMA and PTBAEMA, and Xm is selected from the group consisting of PCL, PLA and PGA; the pH value of the nano composition is 3 to 7. The nano composition provided by the invention can be applied to cosmetics or skin medicines for external use, so that EGCG is easier to be ingested by cells and efficiently delivered to mitochondrial target spot parts, the skin still keeps elastic, compact and wrinkle-removing effects after products are not used, and the nano composition has a lasting and long-acting anti-aging effect and a very high application value.

Description

Technical Field

[0001] The present invention relates to the technical field of anti-aging, and particularly relates to an anti-aging EGCG nano-composition, a preparation method thereof, and uses thereof. Background Art

[0002] When the skin is chronically subjected to harmful stimuli such as air pollution, oxidation, ultraviolet irradiation, etc., skin aging is likely to occur. Skin aging is mainly manifested in appearance as skin dryness, relaxation, wrinkles, pigment deposition, etc. Therefore, "anti-aging" has always been a hot topic of concern.

[0003] The decline of mitochondrial function is considered to be an important link in the aging mechanism. With the increase of age and oxidative stress, the function of mitochondria gradually decreases, leading to the decline of cell function, and then causing the decline of tissue and organ functions, and finally manifested as aging. The skin is the largest organ on the surface of the human body. Therefore, by activating the mitochondrial function in skin cells and providing energy for skin cells, skin anti-aging can be effectively achieved.

[0004] Epigallocatechin gallate (EGCG) is a catechin compound and is the component with the highest content in catechins, accounting for 50-60%. EGCG has a special stereochemical structure and has very strong antioxidant activity. It can protect cells and mitochondrial DNA from oxidative stress, activate the mitochondrial function in skin cells, and provide energy for the skin, thereby delaying skin aging. However, in practical applications, EGCG has problems such as poor stability and low transdermal absorption and utilization. In addition, due to the obstruction of the cell membrane, as a small molecule active ingredient, EGCG often can only enter the cell to reach the mitochondrial target by diffusion, and the diffusion efficiency is low. Therefore, its cell uptake efficiency is low, resulting in low bioavailability. In the prior art, dosage forms such as liposomes, nanoemulsions, and ethosomes are used to encapsulate EGCG, which can provide the stability and transdermal permeability of EGCG. However, there are no relevant reports on how to improve the cell uptake efficiency of EGCG and its bioavailability.

[0005] Therefore, it is of great significance to develop a carrier strategy that can improve the cell uptake efficiency of EGCG, enhance the bioavailability of active ingredients, and thus achieve a better and longer-lasting anti-aging effect, so that EGCG can better play its role in the fields of cosmetics, skin care and repair. Summary of the Invention

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art and provide an anti-aging EGCG nano-composition, a preparation method thereof, and uses thereof. The anti-aging EGCG nano-composition of the present invention has a high EGCG encapsulation rate, high transdermal penetration performance, high cell uptake rate, good protection effect on mitochondria, and long-lasting anti-aging performance.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides an anti-aging EGCG nano-composition, which includes a carrier, an active ingredient and a stabilizer. In terms of mass percentage, the content of the carrier is 0.5 - 5%, and the content of the active ingredient is 0.5 - 5%; the carrier is a block polymer, and the active ingredient is EGCG; The general formula of the block polymer is Y n -X m -X m -Y n , where the X m is a hydrophobic block, and the Y n is a protonatable block; the degree of polymerization m of the hydrophobic block is 10 - 50, and the degree of polymerization n of the protonatable block is 20 - 100; The protonatable block is at least one of poly(dimethylaminoethyl methacrylate), poly(diethylaminoethyl methacrylate), and poly(2-tert-butylaminoethyl methacrylate); the hydrophobic block is at least one of polycaprolactone, polylactic acid, and polyglycolide; The pH of the anti-aging EGCG nano-composition is 3 - 7.

[0008] The anti-aging EGCG nano-composition provided by the present invention mainly includes a block polymer carrier, an active ingredient EGCG and a stabilizer. Among them, a protonatable block with a certain degree of polymerization is used to link two hydrophobic blocks with specific degrees of polymerization to obtain a block polymer, which serves as the carrier of the anti-aging EGCG nano-composition of the present invention: under the condition of weakly acidic pH, the block compound of the present invention can encapsulate EGCG through self-assembly to obtain a nano-composition loaded with EGCG, which has the advantages of small particle size and high encapsulation efficiency.

[0009] When the pH value is too high, the block compound cannot be protonated and is hydrophobic, and cannot encapsulate EGCG through self-assembly, and the encapsulation efficiency is very low, and the comprehensive effect is poor; when the pH is too low, the block compound cannot self-assemble well, and the encapsulation efficiency of EGCG decreases significantly instead. The protonatable block in the block polymer is the structural basis for realizing the self-assembly effect and the EGCG encapsulation effect. The block that cannot be protonated cannot change its charge state by accepting protons (H), and thus does not have self-assembly behavior or responsiveness under specific conditions. Adding a stabilizer helps to improve the self-assembly stability of the block compound and enhance the encapsulation efficiency of EGCG. Controlling the degrees of polymerization of the hydrophobic block and the protonatable block in the block polymer, as well as the contents of the block polymer and EGCG, also significantly affects the anti-aging effect of the nano-composition of the present invention.

[0010] In the presence of a stabilizer and under a specific pH environment, by using the block polymer with a specific degree of polymerization and dosage defined in the present invention, the protonatable group - amino group - in it can be successfully protonated under weakly acidic conditions, obtaining a stable anti-aging EGCG nano-composition, and making the prepared nano-composition encapsulating EGCG carry a positive charge, thus being more easily taken up by cells and having a higher cell uptake amount. On the one hand, the anti-aging EGCG nano-composition provided by the present invention has a better protective effect on mitochondria and can efficiently deliver the active substance EGCG to the mitochondrial target site. On the other hand, more nano-compositions encapsulating EGCG are taken up into cells and mitochondria, improving the bioavailability of the active ingredient EGCG and significantly enhancing its anti-aging effect.

[0011] Compared with free EGCG, the anti-aging EGCG nano-composition encapsulating EGCG provided by the present invention has better skin permeability and higher cell uptake amount, has a better protective effect on mitochondria, and has excellent long-lasting anti-aging efficacy, providing a new strategy for nano-encapsulation technology and having high industrial value in anti-aging cosmetics or topical skin medications.

[0012] Preferably, the stabilizer is at least one of phenethyl resorcinol, 4-butyl resorcinol, isobutylamidothiazole resorcinol, 4-cyclohexyl resorcinol, 4-hexyl resorcinol, dimethoxytolyl-4-propyl resorcinol.

[0013] Preferably, in terms of mass percentage, the content of the carrier is one value or the range value of any two of 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%; the content of the active ingredient is one value or the range value of any two of 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%.

[0014] Preferably, the degree of polymerization m of the hydrophobic block is one value or the range value of any two of 10, 20, 30, 40, 50; the degree of polymerization n of the protonatable block is one value or the range value of any two of 20, 30, 40, 50, 60, 70, 80, 90, 100.

[0015] Preferably, the pH of the anti-aging EGCG nano-composition is one value or the range value of any two of 3, 4, 4.1, 4.5, 4.8, 4.9, 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.9, 6.3, 6.5, 6.9, 7.

[0016] Preferably, the preparation method of the block polymer comprises the following steps: (1) Mix the diol, polyester monomer, and ROP reaction catalyst evenly, and react at 80 - 150 °C for 6 - 18 h under an inert atmosphere to obtain an intermediate block; (2) Mix the intermediate block and bromo initiator evenly in an organic solvent, and react at 0 - 25 °C for 8 - 72 h under an inert atmosphere to obtain a bromo - treated intermediate block; (3) Mix the methacrylic monomer, the bromo - treated intermediate block, ATRP reaction catalyst, and catalyst ligand evenly in an organic solvent, and react at 60 - 100 °C for 12 - 48 h under an inert atmosphere to obtain the block polymer.

[0017] Preferably, the polyester monomer is at least one of ξ - caprolactone, D,L - lactide, and glycolide; Preferably, the methacrylic monomer is at least one of dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and 2 - tert - butylaminoethyl methacrylate; Preferably, the diol is at least one of 1,6 - hexanediol, 1,7 - heptanediol, 1,8 - octanediol, 1,9 - nonanediol, 1,10 - decanediol, 1,12 - dodecanediol, 1,14 - dodecanediol, 1,16 - hexadecanediol, 1,18 - octadecanediol, and 1,20 - eicosanediol; Preferably, the ROP reaction catalyst is at least one of stannous octanoate, stannous isooctanoate, stannous tartrate, and stannous stearate; Preferably, the bromo initiator is at least one of 2 - bromoisobutyryl bromide, bis[2 - (2’ - bromoisobutyryloxy)ethyl] disulfide, tert - butyl 2 - bromoisobutyrate, and ethyl 2 - bromoisovalerate; Preferably, the ATRP reaction catalyst is at least one of CuBr, CuCl, and CuI; Preferably, the catalyst ligand is at least one of N,N - diisopropylethylamine, ethanolamine, N,N,N’,N’,N” - pentamethyldiethylenetriamine, and tetrabutylammonium bromide.

[0018] If the hydrophobic block of the block polymer is polycaprolactone (PCL), then the polyester monomer is ξ - caprolactone, and PCL is obtained through ring - opening polymerization (ROP) reaction; if the hydrophobic block is polylactic acid (PLA), then the polyester monomer is D,L - lactide, and PLA is obtained through ROP reaction; if the hydrophobic block is polyglycolide (PGA), then the polyester monomer is glycolide, and PGA is obtained through ROP reaction.

[0019] The protonatable block of the block polymer is poly(dimethylaminoethyl methacrylate) (PDMAEMA), and the methacrylic monomer is dimethylaminoethyl methacrylate (DMAEMA); the protonatable block is poly(diethylaminoethyl methacrylate) (PDEAEMA), and the methacrylic monomer is diethylaminoethyl methacrylate (DEAEMA); the protonatable block is poly(2-tert-butylaminoethyl methacrylate) (PTBAEMA), and the methacrylic monomer is 2-tert-butylaminoethyl methacrylate (DTBAEMA).

[0020] In step (1), the number of carbon atoms of the diol is ≥6, and both ends of its molecular structure are capped with hydroxyl groups to reduce the steric hindrance during the ROP reaction and allow the polyester monomer to fully react at both ends of the diol. If the number of carbon atoms of the diol is <6 or the two hydroxyl reaction sites are adjacent, the steric hindrance during the ROP reaction is too large, which is not conducive to the progress of the reaction.

[0021] Preferably, in step (1), the molar ratio of the diol, the polyester monomer, and the ROP reaction catalyst is diol: polyester monomer: ROP reaction catalyst = 1: (20 - 100): (2 - 10); Preferably, in step (2), the molar ratio of the middle block to the bromo initiator is 1: (2 - 8); Preferably, in step (3), the molar ratio of the methacrylic monomer, the bromo-treated middle block, the ATRP reaction catalyst, and the catalyst ligand is methacrylic monomer: bromo-treated middle block: ATRP reaction catalyst: catalyst ligand = 1: (40 - 200): (0.4 - 2): (4 - 20).

[0022] As a preferred embodiment of the present invention, after the reaction in step (2), the following purification steps are further included: The reaction mixture is washed 3 - 5 times with hydrochloric acid solution (0.5 - 3 mol / L, 100 - 500 mL), saturated NaHCO3 (100 - 500 mL) solution, and deionized water (100 - 500 mL) respectively. The organic phase is dried with anhydrous MgSO4 overnight. The upper clear liquid is taken and concentrated by rotary evaporation. The product is precipitated with an excessive precipitant, and the solid product is dried at 40 - 60 °C for 12 - 48 h to obtain the refined bromo-treated middle block. The precipitant includes at least one of methanol, ethanol, n-hexane, and petroleum ether; the temperature of the precipitation purification treatment is 0 - 10 °C.

[0023] As a preferred embodiment of the present invention, after the reaction in step (3), a purification process is further included, specifically as follows: The reaction mixture is slowly added to the precipitant, and after precipitation and purification treatment, the solid is collected and dried at 40-60 °C for 12-48 h to obtain the refined block polymer; the precipitant includes at least one of methanol, ethanol, n-hexane, and petroleum ether; the temperature of the precipitation and purification treatment is 0-10 °C.

[0024] Preferably, the organic solvents in the steps (2) and (3) are at least one of N,N-dimethylformamide, triethylamine, N,N-dimethylacetamide, dimethyl sulfoxide, dichloromethane, tetrahydrofuran, acetone, chloroform, acetonitrile, and ethyl acetate.

[0025] Preferably, the inert atmosphere is at least one of nitrogen, argon, and helium; preferably argon.

[0026] Preferably, the anti-aging EGCG nano-composition further includes polyols, water, and a pH regulator.

[0027] More preferably, the polyols are at least one of 1,3-butanediol, 1,4-butanediol, 1,2-propanediol, 1,3-propanediol, glycerol, 1,2-hexanediol, ethoxydiglycol, and octyldodecanol; Preferably, the pH regulator is at least one of glutamic acid, aspartic acid, asparagine, glutamine, hydrochloric acid, citric acid, lactic acid, sulfuric acid, and oxalic acid.

[0028] The solvent and the pH regulator are characterized by being green, safe, non-toxic, and having low skin irritation, avoiding causing skin sensitive stress reactions.

[0029] More preferably, by mass percentage, the composition of the anti-aging EGCG nano-composition is as follows: 0.5-5% carrier, 0.5-2% stabilizer, 0.5-5% active ingredient, 10-30% polyols, 0.02-0.2% pH regulator, and the balance is water.

[0030] In a second aspect, the present invention provides a method for preparing the above anti-aging EGCG nano-composition, including the following steps: S1. Add the carrier, stabilizer, and active ingredient to the polyols and mix well to obtain a phase A solution; add the pH regulator to water and mix well to obtain a phase B solution; the pH of the phase B solution is 3-7; S2. Drop the phase A solution into the phase B solution and perform high-shear treatment simultaneously to obtain a mixed solution; S3. Subject the mixed solution to microfluidic homogenization treatment to obtain the anti-aging EGCG nano-composition.

[0031] If the pH value in the B-phase solution is greater than 7 and is alkaline, the protonatable groups in the block polymer cannot be protonated. At this time, the block polymer exhibits complete hydrophobicity and precipitates out in the B-phase solution, and cannot effectively encapsulate EGCG.

[0032] Preferably, in S2, the dropping speed is 1-10 mL / min; the rotation speed of the high-shear treatment is 6000-12000 rpm, and the treatment time is until the dropping is completed; after the dropping is completed, stir at 200-500 rpm for 1-6 h.

[0033] Preferably, in S3, the microfluidic homogenization treatment is to perform high-pressure homogenization operation on the mixed solution using a microfluidic homogenizer, the pressure of the homogenization is 50-120 MPa, and the number of cycles is 2-8 times.

[0034] Preferably, the mixing method in S1 is magnetic stirring or mechanical stirring.

[0035] In a third aspect, the present invention provides the use of the above anti-aging EGCG nano-composition in anti-aging cosmetics and topical skin medications.

[0036] Preferably, the use is to add the anti-aging EGCG nano-composition to anti-aging cosmetics or topical skin medications for use; calculated by mass percentage, the addition amount of the anti-aging EGCG nano-composition is 0.1-10%.

[0037] When the nano-composition of the present invention is used in anti-aging cosmetics or topical skin medications, after using the product for 4 weeks and stopping using the product for 1 week, the skin can still maintain good skin elasticity, firming effect and wrinkle-removing effect.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention selects protonatable blocks with specific degrees of polymerization, links two hydrophobic blocks with specific degrees of polymerization to obtain a block polymer, enables it to self-assemble and encapsulate EGCG under specific conditions to form a stable nano-composition, with a small particle size and a high encapsulation rate; the formed anti-aging EGCG nano-composition is more easily taken up by cells and has a higher cell uptake amount, thus having a better protective effect on mitochondria, can efficiently deliver the active substance EGCG to the mitochondrial target site, and solves the problem of low bioavailability of EGCG. Adding and applying the anti-aging EGCG nano-composition of the present invention to cosmetics or topical skin medications, the skin can still maintain good skin elasticity, firming effect and wrinkle-removing effect after stopping using the product. Compared with using free EGCG alone or other strategies of the prior art, the anti-aging EGCG nano-composition of the present invention has better skin permeability, a higher cell uptake amount, a better protective effect on mitochondria, can achieve a more lasting anti-aging effect, and has a high application prospect. Brief Description of the Drawings

[0039] Figure 1 It is the synthetic route diagram of the block polymers in Example 1 and Examples 6 - 11; Figure 2 It is the synthetic route diagram of the block polymer in Example 2; Figure 3 It is the synthetic route diagram of the block polymer in Example 3; Figure 4 It is the synthetic route diagram of the block polymer in Example 4; Figure 5 It is the synthetic route diagram of the block polymer in Example 5; Figure 6 It is the GPC curve diagram of the block polymers in Examples 1 - 11; Figure 7 It is the particle size and particle size distribution diagram of the nano - composition in Example 1 of the present invention; Figure 8 It is the eye wrinkle distribution diagram of volunteers after using the anti - aging cream in Example 1 or Comparative Example 1 for 2 weeks, 4 weeks, and 1 week after discontinuation; Detailed Description of the Invention

[0040] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific examples. The test methods used in the following examples are all conventional methods unless otherwise specified; the materials, reagents, etc. used are all reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0041] In the following examples and comparative examples, ξ - caprolactone, D,L - lactide, glycolide, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, 2 - tert - butylaminoethyl methacrylate, 1,6 - hexanediol, stannous octoate, 2 - bromoisobutyryl bromide, CuBr, N,N,N’,N’,N”-pentamethyldiethylenetriamine, and glutamic acid can be directly purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0042] In the following examples and comparative examples, EGCG, phenethyl resorcinol, 4 - butylresorcinol, isobutylamidothiazol resorcinol, and 4 - cyclohexylresorcinol can be directly purchased from Guangzhou Xiyuan Biotechnology Co., Ltd.

[0043] The synthetic route diagrams of the block polymers in the following Example 1 and Examples 6 - 11 are as shown in Figure 1 ; The synthetic route diagrams of the block polymers in the following Examples 2 - 5 are respectively as shown in Figures 2 - 5 ; The test method for the molecular weight of the block polymer in the following examples is as follows: It is measured using a gel permeation chromatograph (GPC, manufacturer: Waters Corporation, USA; model: Waters 1525 / 2414). A chromatographically pure grade THF solution is selected as the mobile phase with a flow rate of 1.0 mL / min. The chromatographic column is calibrated with a monodisperse polystyrene standard sample, and the test temperature is 30 °C.

[0044] Example 1 An example of the anti-aging EGCG nano-composition of the present invention. The anti-aging EGCG nano-composition material in this example is composed of the following components by mass percentage: 2% carrier, 1% stabilizer, 2% active ingredient, 20% polyol, 0.08% pH regulator, and the balance is water; The carrier is the block polymer PDEAEMA 60 -PCL 30 -PCL 30 -PDEAEMA 60 , the stabilizer is isobutylamido thiazole resorcinol, the active ingredient is EGCG, the polyol is 1,3-butanediol, and the pH regulator is glutamic acid.

[0045] The block polymer PDEAEMA 60 -PCL 30 -PCL 30 -PDEAEMA 60 is prepared as follows (taking the preparation of 1.0 mmol as an example): (1) Mix 1,6-hexanediol (118.17 mg, 1.0 mmol), ξ-caprolactone (6.85 g, 60 mmol), and stannous octanoate (2.43 g, 6.0 mmol) evenly, protect with argon, and react at 130 °C for 12 h to obtain the middle block polycaprolactone PCL 30 -PCL 30 ; (2) Dissolve the middle block PCL 30 -PCL 30 (6.97 g, 1.0 mmol) in a mixed solution of dichloromethane (100 mL) and triethylamine (10 mL), protect with argon, add 2-bromo-2-methylpropionyl bromide (1.38 g, 6.0 mmol), and react at 20 °C for 24 h. The reaction mixture is washed 4 times with hydrochloric acid solution (1.0 mol / L), saturated NaHCO3, and deionized water, 300 mL each time. The organic phase is dried over anhydrous MgSO4 overnight; take the supernatant, rotary evaporate and concentrate; precipitate the product with an excess of n-hexane (5 °C), and dry the solid product at 50 °C for 24 h to obtain brominated polycaprolactone Br-PCL 30 -PCL30 -Br

[0046] (3) Add Br-PCL 30 -PCL 30 -Br (7.21 g, 1.0 mmol), diethylaminoethyl methacrylate (22.23 g, 120 mmol), CuBr (172.14 mg, 1.2 mmol), and N,N,N’,N’,N”-pentamethyldiethylenetriamine (2.08 g, 12 mmol) were added to tetrahydrofuran (100 mL). Under argon protection, the reaction was carried out at 65 °C for 48 h. The reaction mixture was added to an excess of n-hexane (5 °C), and after precipitation purification, the solid product was collected and dried at 50 °C for 24 h to obtain the block polymer PDEAEMA 60 -PCL 30 -PCL 30 -PDEAEMA 60 (The GPC curve is as Figure 6 , and the calculated Mn = 27002).

[0047] The preparation method of the anti-aging EGCG nano-composition described in this example is as follows: S1. According to the mass percentage, the block polymer PDEAEMA 60 -PCL 30 -PCL 30 -PDEAEMA 60 , the stabilizer isobutylamidothiazoleresorcinol, and the active ingredient EGCG were added to 1,3-butanediol and heated to 50 °C, and stirred at a speed of 300 rpm for 4 h to obtain a phase A solution; Glutamic acid was dissolved in deionized water to obtain a phase B solution with a pH of 5.0; S2. The above phase A solution was added dropwise to the phase B solution, and high-speed shearing treatment was started synchronously at a speed of 8000 rpm, and the dropping speed of the phase A solution was 3 mL / min; After the dropping was completed, it was continuously stirred at a speed of 300 rpm for 4 h to obtain a mixed solution; S3. The above mixed solution was processed by high-pressure microfluidic homogenization (pressure of 70 MPa) 5 times to obtain the anti-aging EGCG nano-composition.

[0048] The measured pH value of the anti-aging EGCG nano-composition in Example 1 was 5.2.

[0049] Example 2 An embodiment of the anti-aging EGCG nano-composition of the present invention. The difference between this example and Example 1 is only that the carrier is replaced with the block polymer PDMAEMA 60 -PCL 30 -PCL 30-PDMAEMA 60 (i.e., the protonatable block is different), and its preparation method is as follows: Step (1), (2) Preparation of brominated polycaprolactone Br-PCL 30 -PCL 30 -Br is prepared in the same way as in Example 1; (3) Add Br-PCL 30 -PCL 30 -Br (7.21 g, 1.0 mmol), 2-(dimethylamino)ethyl methacrylate (18.87 g, 120 mmol), CuBr (172.14 mg, 1.2 mmol), and N,N,N’,N’,N”-pentamethyldiethylenetriamine (2.08 g, 12 mmol) into tetrahydrofuran (100 mL), protect with argon, react at 65 °C for 48 h, add the reaction mixture into excessive n-hexane (5 °C), after precipitation and purification, collect the solid product, and dry it at 50 °C for 24 h to obtain the block polymer PDMAEMA 60 -PCL 30 -PCL 30 -PDMAEMA 60 (The GPC curve is as Figure 6 , and calculate Mn = 24155).

[0050] Example 3 An example of the anti-aging EGCG nano-composition of the present invention. The difference between this example and Example 1 is only that the carrier is replaced with the block polymer PTBAEMA 60 -PCL 30 -PCL 30 -PTBAEMA 60 (i.e., the protonatable block is different), and the preparation method of the block polymer PTBAEMA 60 -PCL 30 -PCL 30 -PTBAEMA 60 is as follows: Step (1), (2) Preparation of brominated polycaprolactone Br-PCL 30 -PCL 30 -Br is prepared in the same way as in Example 1; (3) Add Br-PCL 30 -PCL 30-Br (7.21 g, 1.0 mmol), 2-(tert-Butylamino)ethyl methacrylate (22.23 g, 120 mmol), CuBr (172.14 mg, 1.2 mmol), and N,N,N’,N’,N”-pentamethyldiethylenetriamine (2.08 g, 12 mmol) were added to tetrahydrofuran (100 mL). The mixture was protected by argon gas and reacted at 65 °C for 48 h. The reaction mixture was added to an excess of n-hexane (5 °C), and after precipitation purification, the solid product was collected and dried at 50 °C for 24 h to obtain the block polymer PTBAEMA 60 -PCL 30 -PCL 30 -PTBAEMA 60 (The GPC curve is as Figure 6 , and Mn was calculated to be 26763).

[0051] Example 4 An example of the anti-aging EGCG nano-composition of the present invention. The difference between this example and Example 1 is only that the carrier is replaced with the block polymer PDEAEMA 60 -PLA 30 -PLA 30 -PDEAEMA 60 (i.e., the hydrophobic block is different). The preparation method is as follows (taking the preparation of 1.0 mmol as an example): (1) 1,6-Hexanediol (118.17 mg, 1.0 mmol), D,L-lactide (4.32 g, 30 mmol), and stannous octoate (2.43 g, 3.0 mmol) were mixed evenly. The mixture was protected by argon gas and reacted at 130 °C for 12 h to obtain the middle block polycaprolactone PLA 30 -PLA 30 .

[0052] (2) The middle block PLA 30 -PLA 30 (4.44 g, 1.0 mmol) was dissolved in a mixed solution of dichloromethane (100 mL) and triethylamine (10 mL). The mixture was protected by argon gas, and 2-bromoisobutyryl bromide (1.38 g, 6.0 mmol) was added. The reaction was carried out at 20 °C for 24 h. The reaction mixture was washed 4 times with hydrochloric acid solution (1.0 mol / L), saturated NaHCO3, and deionized water, 300 mL each time. The organic phase was dried over anhydrous MgSO4 overnight. The supernatant was taken and concentrated by rotary evaporation. The product was precipitated with an excess of n-hexane (5 °C), and the solid product was dried at 50 °C for 24 h to obtain brominated Br-PLA 30 -PLA 30 -Br.

[0053] (3) Add Br-PLA 30 -PLA 30 -Br (4.69 g, 1.0 mmol), diethylaminoethyl methacrylate (22.23 g, 120 mmol), CuBr (172.14 mg, 1.2 mmol), and N,N,N’,N’,N”-pentamethyldiethylenetriamine (2.08 g, 12 mmol) into tetrahydrofuran (100 mL), protect with argon, react at 65 °C for 48 h, add the reaction mixture into excess n-hexane (5 °C), after precipitation and purification, collect the solid product, dry at 50 °C for 24 h to obtain the block polymer PDEAEMA 60 -PLA 30 -PLA 30 -PDEAEMA 60 (The GPC curve is as Figure 6 , calculate Mn = 23986).

[0054] Example 5 An example of the anti-aging EGCG nano-composition of the present invention. The difference between this example and Example 1 is only that the carrier is replaced by the block polymer PDEAEMA 60 -PGA 30 -PGA 30 -PDEAEMA 60 (That is, the hydrophobic block is different), and its preparation method is (taking the preparation of 1.0 mmol as an example): (1) Mix 1,6-hexanediol (118.17 mg, 1.0 mmol), glycolide (3.48 g, 30 mmol), and stannous octanoate (2.43 g, 3.0 mmol) evenly, protect with argon, react at 130 °C for 12 h to obtain the middle block polycaprolactone PGA 30 -PGA 30 .

[0055] (2) Dissolve the middle block PGA 30 -PGA 30 (3.60 g, 1.0 mmol) in a mixed solution of dichloromethane (100 mL) and triethylamine (10 mL), protect with argon, add 2-bromoisobutyryl bromide (1.38 g, 6.0 mmol), react at 20 °C for 24 h, wash the reaction mixture 4 times with hydrochloric acid solution (1.0 mol / L), saturated NaHCO3 and deionized water, 300 mL each time, dry the organic phase with anhydrous MgSO4 overnight; take the supernatant, rotary evaporate and concentrate; precipitate the product with excess n-hexane (5 °C), dry the solid product at 50 °C for 24 h to obtain brominated Br-PGA 30 -PGA 30-Br.

[0056] (3) Add Br-PGA 30 -PGA 30 -Br (3.84 g, 1.0 mmol), 2-(Diethylamino)ethyl methacrylate (22.23 g, 120 mmol), CuBr (172.14 mg, 1.2 mmol), and N,N,N’,N’,N”-pentamethyldiethylenetriamine (2.08 g, 12 mmol) to tetrahydrofuran (100 mL), protect with argon, react at 65 °C for 48 h, add the reaction mixture to excess n-hexane (5 °C), after precipitation purification, collect the solid product, and dry at 50 °C for 24 h to obtain the block polymer PDEAEMA 60 -PGA 30 -PGA 30 -PDEAEMA 60 (The GPC curve is as Figure 6 , and calculate Mn = 24005).

[0057] Example 6 An example of the anti-aging EGCG nano-composition of the present invention. The difference between this example and Example 1 is only that the carrier is replaced with the block polymer PDEAEMA 20 -PCL 30 -PCL 30 -PDEAEMA 20 (The degree of polymerization of the protonatable block is different), and its preparation method is as follows: Steps (1) and (2) Preparation of brominated polycaprolactone Br-PCL 30 -PCL 30 -Br is the same as in Example 1; (3) Add Br-PCL 30 -PCL 30 -Br (7.21 g, 1.0 mmol), 2-(Diethylamino)ethyl methacrylate (7.41 g, 40 mmol), CuBr (57.38 mg, 0.4 mmol), and N,N,N’,N’,N”-pentamethyldiethylenetriamine (0.69 g, 4 mmol) to tetrahydrofuran (100 mL), protect with argon, react at 65 °C for 48 h, add the reaction mixture to excess n-hexane (5 °C), after precipitation purification, collect the solid product, and dry at 50 °C for 24 h to obtain the block polymer PDEAEMA 20 -PCL 30 -PCL 30 -PDEAEMA 20 (The GPC curve is as Figure 6, calculate Mn = 13687).

[0058] Example 7 An example of the anti-aging EGCG nano-composition of the present invention. The difference between this example and Example 1 is only that the carrier is replaced by the block polymer PDEAEMA 40 -PCL 30 -PCL 30 -PDEAEMA 40 (with different degrees of polymerization of protonatable blocks), the preparation method of the block polymer PDEAEMA 40 -PCL 30 -PCL 30 -PDEAEMA 40 is as follows: Step (1), (2) The preparation of brominated polycaprolactone Br-PCL 30 -PCL 30 -Br is the same as that in Example 1; (3) Add Br-PCL 30 -PCL 30 -Br (7.21 g, 1.0 mmol), diethylaminoethyl methacrylate (14.82 g, 80 mmol), CuBr (114.8 mg, 0.8 mmol), N,N,N’,N’,N”-pentamethyldiethylenetriamine (1.39 g, 8 mmol) into tetrahydrofuran (100 mL), protect with argon, react at 65 °C for 48 h, add the reaction mixture to excessive n-hexane (5 °C), after precipitation and purification treatment, collect the solid product, and dry it at 50 °C for 24 h to obtain the block polymer PDEAEMA 40 -PCL 30 -PCL 30 -PDEAEMA 40 (The GPC curve is as Figure 6 , calculate Mn = 19872).

[0059] Example 8 An example of the anti-aging EGCG nano-composition of the present invention. The difference between this example and Example 1 is only that the carrier is replaced by the block polymer PDEAEMA 80 -PCL 30 -PCL 30 -PDEAEMA 80 (with different degrees of polymerization of protonatable blocks), and its preparation method is as follows: Step (1), (2) The preparation of brominated polycaprolactone Br-PCL 30 -PCL 30 -Br is the same as that in Example 1; (3) Add Br-PCL 30 -PCL 30 -Br (7.21 g, 1.0 mmol), diethylaminoethyl methacrylate (29.64 g, 160 mmol), CuBr (229.6 mg, 1.6 mmol), and N,N,N’,N’,N”-pentamethyldiethylenetriamine (2.77 g, 16 mmol) to tetrahydrofuran (100 mL), protect with argon, react at 65 °C for 48 h, add the reaction mixture to excess n-hexane (5 °C), after precipitation purification, collect the solid product, and dry at 50 °C for 24 h to obtain the block polymer PDEAEMA 80 -PCL 30 -PCL 30 -PDEAEMA 80 (The GPC curve is as shown in Figure 6 , and calculate Mn = 35021).

[0060] Example 9 An example of the anti-aging EGCG nano-composition of the present invention. The difference between this example and Example 1 is only that the carrier is replaced with the block polymer PDEAEMA 100 -PCL 30 -PCL 30 -PDEAEMA 100 (The degree of polymerization of the protonatable block is different), and its preparation method is as follows: Steps (1) and (2): The preparation of brominated polycaprolactone Br-PCL 30 -PCL 30 -Br is the same as in Example 1; (3) Add Br-PCL 30 -PCL 30 -Br (7.21 g, 1.0 mmol), diethylaminoethyl methacrylate (37.05 g, 200 mmol), CuBr (287 mg, 2.0 mmol), and N,N,N’,N’,N”-pentamethyldiethylenetriamine (3.46 g, 20 mmol) to tetrahydrofuran (100 mL), protect with argon, react at 65 °C for 48 h, add the reaction mixture to excess n-hexane (5 °C), after precipitation purification, collect the solid product, and dry at 50 °C for 24 h to obtain the block polymer PDEAEMA 100 -PCL 30 -PCL 30 -PDEAEMA 100 (The GPC curve is as shown in Figure 6 , and calculate Mn = 42287).

[0061] Example 10 An example of the anti-aging EGCG nano-composition of the present invention. The difference between this example and Example 1 is only that the carrier is replaced by the block polymer PDEAEMA 60 -PCL 10 -PCL 10 -PDEAEMA 60 (i.e., the degree of polymerization of the hydrophobic block is different), and its preparation method is (taking the preparation of 1.0 mmol as an example): (1) Mix 1,6-hexanediol (118.17 mg, 1.0 mmol), ξ-caprolactone (2.28 g, 20 mmol), and stannous octanoate (0.81 g, 2.0 mmol) evenly, protect with argon, and react at 130 °C for 12 h to obtain the middle block polycaprolactone PCL 10 -PCL 10 .

[0062] (2) Dissolve the middle block polycaprolactone PCL 10 -PCL 10 (2.40 g, 1.0 mmol) in a mixed solution of dichloromethane (100 mL) and triethylamine (10 mL), protect with argon, add 2-bromo-2-methylpropionyl bromide (1.38 g, 6.0 mmol), and react at 20 °C for 24 h. The reaction mixture is washed 4 times with hydrochloric acid solution (1.0 mol / L), saturated NaHCO3, and deionized water, 300 mL each time. The organic phase is dried over anhydrous MgSO4 overnight; take the supernatant, rotary evaporate and concentrate; precipitate the product with excess n-hexane (5 °C), and dry the solid product at 50 °C for 24 h to obtain brominated polycaprolactone Br-PCL 10 -PCL 10 -Br.

[0063] (3) Add Br-PCL 10 -PCL 10 -Br (2.65 g, 1.0 mmol), 2-(diethylamino)ethyl methacrylate (22.23 g, 120 mmol), CuBr (172.14 mg, 1.2 mmol), and N,N,N’,N’,N”-pentamethyldiethylenetriamine (2.08 g, 12 mmol) to tetrahydrofuran (100 mL), protect with argon, and react at 65 °C for 48 h. Add the reaction mixture to excess n-hexane (5 °C), after precipitation and purification, collect the solid product, and dry it at 50 °C for 24 h to obtain the block polymer PDEAEMA 60 -PCL 10 -PCL 10 -PDEAEMA 60 (The GPC curve is asFigure 6 , calculate Mn = 22410).

[0064] Example 11 An example of the anti-aging EGCG nano-composition of the present invention. The difference between this example and Example 1 is only that the carrier is replaced by the block polymer PDEAEMA 60 -PCL 50 -PCL 50 -PDEAEMA 60 (i.e., the degree of polymerization of the hydrophobic block is different), and its preparation method is (taking the preparation of 1.0 mmol as an example): (1) Mix 1,6-hexanediol (118.17 mg, 1.0 mmol), ξ-caprolactone (11.4 g, 100 mmol), and stannous octanoate (0.81 g, 2.0 mmol) evenly, protect with argon, and react at 130 °C for 12 h to obtain the intermediate block polycaprolactone PCL 50 -PCL 50 .

[0065] (2) Dissolve the intermediate block polycaprolactone PCL 50 -PCL 50 (11.53 g, 1.0 mmol) in a mixed solution of dichloromethane (100 mL) and triethylamine (10 mL), protect with argon, add 2-bromo-2-methylpropionyl bromide (1.38 g, 6.0 mmol), and react at 20 °C for 24 h. The reaction mixture is washed 4 times with hydrochloric acid solution (1.0 mol / L), saturated NaHCO3, and deionized water, 300 mL each time. The organic phase is dried over anhydrous MgSO4 overnight; take the supernatant, rotary evaporate and concentrate; precipitate the product with excess n-hexane (5 °C), and dry the solid product at 50 °C for 24 h to obtain brominated polycaprolactone Br-PCL 50 -PCL 50 -Br.

[0066] (3) Add Br-PCL 50 -PCL 50 -Br (11.78 g, 1.0 mmol), 2-(diethylamino)ethyl methacrylate (22.23 g, 120 mmol), CuBr (172.14 mg, 1.2 mmol), and N,N,N’,N’,N”-pentamethyldiethylenetriamine (2.08 g, 12 mmol) to tetrahydrofuran (100 mL), protect with argon, and react at 65 °C for 48 h. Add the reaction mixture to excess n-hexane (5 °C), after precipitation and purification, collect the solid product, and dry it at 50 °C for 24 h to obtain the block polymer PDEAEMA 60 -PCL50 -PCL 50 -PDEAEMA 60 (The GPC curve is as Figure 6 , and Mn = 31540 is calculated).

[0067] Examples 12 - 15 Examples 12 - 15 are examples of the anti - aging EGCG nano - composition of the present invention. The differences from Example 1 are only that the added pH regulator and the pH value of the nano - composition are adjusted as follows: In Example 12, 0.08% glutamic acid is replaced with 0.2% glutamic acid by mass percentage, and the composition of the remaining components is adjusted with the balance of water unchanged. The pH of the B - phase solution is 3, and the measured pH value of the anti - aging EGCG nano - composition is 3.

[0068] In Example 13, 0.08% glutamic acid is replaced with 0.14% glutamic acid by mass percentage, and the composition of the remaining components is adjusted with the balance of water unchanged. The pH of the B - phase solution is 4, and the measured pH value of the anti - aging EGCG nano - composition is 4.1.

[0069] In Example 14, 0.08% glutamic acid is replaced with 0.04% glutamic acid by mass percentage, and the composition of the remaining components is adjusted with the balance of water unchanged. The pH of the B - phase solution is 6, and the measured pH value of the anti - aging EGCG nano - composition is 6.3.

[0070] In Example 15, 0.08% glutamic acid is replaced with 0.08% deionized water by mass percentage, and the remaining components remain unchanged. The pH of the B - phase solution is 7, and the measured pH value of the anti - aging EGCG nano - composition is 6.9.

[0071] Examples 16 - 18 Examples 16 - 18 are examples of the anti - aging EGCG nano - composition of the present invention. The differences from Example 1 are only that the types of stabilizers used are changed.

[0072] In Example 16, the stabilizer isobutylamido thiazole resorcinol is replaced with phenethyl resorcinol, and the mass percentage remains unchanged.

[0073] In Example 17, the stabilizer isobutylamido thiazole resorcinol is replaced with 4 - butyl resorcinol, and the mass percentage remains unchanged.

[0074] In Example 18, the stabilizer isobutylamido thiazole resorcinol is replaced with 4 - cyclohexyl resorcinol, and the mass percentage remains unchanged.

[0075] Examples 19 - 22 Examples 19 - 22 are examples of the anti - aging EGCG nano - composition of the present invention. The difference from Example 1 is only that the dosage of the carrier or the active ingredient is changed.

[0076] In Example 19, the mass percentage of the block polymer PDEAEMA 60 -PCL 30 -PCL 30 -PDEAEMA 60 is reduced to 0.5%.

[0077] In Example 20, the mass percentage of the block polymer PDEAEMA 60 -PCL 30 -PCL 30 -PDEAEMA 60 is increased to 5%.

[0078] In Example 21, the mass percentage of the active ingredient EGCG is reduced to 0.5%.

[0079] In Example 22, the mass percentage of the active ingredient EGCG is increased to 5%.

[0080] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is only that the carrier is replaced by the block polymer PPEGMA 60 -PCL 30 -PCL 30 -PPEGMA 60 , and the preparation method of the block polymer PPEGMA 60 -PCL 30 -PCL 30 -PPEGMA 60 is as follows: Step (1), (2) The preparation of brominated polycaprolactone Br - PCL 30 -PCL 30 -Br is the same as in Example 1; (3) Add Br - PCL 30 -PCL 30 -Br (7.21 g, 1.0 mmol), polyethylene glycol methacrylate (Mn = 500, 60 g, 120 mmol), CuBr (172.14 mg, 1.2 mmol), N,N,N’,N’,N”-pentamethyldiethylenetriamine (2.08 g, 12 mmol) into tetrahydrofuran (100 mL), protect with argon, react at 65 °C for 48 h, add the reaction mixture to excess n - hexane (5 °C), after precipitation and purification, collect the solid product, and dry at 50 °C for 24 h to obtain the block polymer PPEGMA 60 -PCL30 -PCL 30 -PPEGMA 60 (Mn = 66850).

[0081] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is only that the carrier is replaced by the block polymer PDEAEMA 10 -PCL 30 -PCL 30 -PDEAEMA 10 (i.e., further reducing the degree of polymerization of the protonatable block), the block polymer PDEAEMA 10 -PCL 30 -PCL 30 -PDEAEMA 10 is prepared as follows: Step (1), (2) Brominated polycaprolactone Br-PCL 30 -PCL 30 -Br is prepared in the same manner as in Example 1; (3) Add Br-PCL 30 -PCL 30 -Br (7.21 g, 1.0 mmol), diethylaminoethyl methacrylate (3.71 g, 20 mmol), CuBr (28.69 mg, 0.2 mmol), N,N,N’,N’,N”-pentamethyldiethylenetriamine (0.35 g, 2 mmol) into tetrahydrofuran (100 mL), protect with argon, react at 65 °C for 48 h, add the reaction mixture to excess n-hexane (5 °C), after precipitation and purification, collect the solid product, and dry at 50 °C for 24 h to obtain the block polymer PDEAEMA 10 -PCL 30 -PCL 30 -PDEAEMA 10 (Mn = 10555).

[0082] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is only that the carrier is replaced by the block polymer PDEAEMA 60 -PCL 60 -PCL 60 -PDEAEMA 60 (i.e., further increasing the degree of polymerization of the hydrophobic block), the block polymer PDEAEMA 60 -PCL 60 -PCL 60 -PDEAEMA 60 is prepared as follows: (1) Mix 1,6 - hexanediol (118.17 mg, 1.0 mmol), ε - caprolactone (13.68 g, 120 mmol), and stannous octoate (4.86 g, 12.0 mmol) evenly, protect with argon gas, and react at 130 °C for 12 h to obtain the middle - block polycaprolactone PCL 60 -PCL 60 .

[0083] (2) Dissolve the middle - block PCL 60 -PCL 60 (13.82 g, 1.0 mmol) in a mixed solution of dichloromethane (100 mL) and triethylamine (10 mL), protect with argon gas, add 2 - bromoisobutyryl bromide (1.38 g, 6.0 mmol), and react at 20 °C for 24 h. The reaction mixture is washed 4 times with hydrochloric acid solution (1.0 mol / L), saturated NaHCO3, and deionized water, 300 mL each time. The organic phase is dried over anhydrous MgSO4 overnight; take the supernatant, rotary evaporate and concentrate; precipitate the product with excess n - hexane (5 °C), and dry the solid product at 50 °C for 24 h to obtain brominated polycaprolactone Br - PCL 60 -PCL 60 -Br.

[0084] (3) Add Br - PCL 60 -PCL 60 -Br (14.06 g, 1.0 mmol), diethylaminoethyl methacrylate (22.23 g, 120 mmol), CuBr (172.14 mg, 1.2 mmol), and N,N,N’,N’,N”-pentamethyldiethylenetriamine (2.08 g, 12 mmol) into tetrahydrofuran (100 mL), protect with argon gas, and react at 65 °C for 48 h. Add the reaction mixture into excess n - hexane (5 °C), after precipitation and purification, collect the solid product, and dry it at 50 °C for 24 h to obtain the block polymer PDEAEMA 60 -PCL 60 -PCL 60 -PDEAEMA 60 (Mn = 35930).

[0085] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is only that the stabilizer with a mass percentage of 1% is replaced by 1% of deionized water.

[0086] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is only that 0.04% of glutamic acid is replaced with 0.1% of concentrated hydrochloric acid by mass percentage, and the composition of the remaining components is adjusted with the balance of water unchanged. The pH of the B-phase solution is 2, and the measured pH of the nano-composition is 2.

[0087] Comparative Example 6 The difference between Comparative Example 6 and Example 1 is only that 0.08% of glutamic acid is replaced with 0.08% of sodium glutamate by mass percentage, and the composition of the remaining components is adjusted with the balance of water unchanged. The pH of the B-phase solution is 8, and the measured pH of the nano-composition is 7.8.

[0088] Comparative Example 7 The difference between Comparative Example 7 and Example 1 is only that the mass percentage of the block copolymer PDEAEMA 60 -PCL 30 -PCL 30 -PDEAEMA 60 is reduced to 0.1%.

[0089] Comparative Example 8 The difference between Comparative Example 8 and Example 1 is only that the mass percentage of the active ingredient EGCG is increased to 6%.

[0090] Comparative Example 9 The nano-composition in Comparative Example 9 is composed of the following components by mass percentage: 2% active ingredient, 0.08% pH regulator, and the balance is water. The active ingredient is EGCG, and the pH regulator is glutamic acid. Its preparation method is as follows: Add EGCG and glutamic acid to deionized water according to the mass percentage, stir at 300 rpm for 15 min, and wait until EGCG is completely dissolved to obtain an EGCG aqueous solution with a pH value of 5.

[0091] Effect Example 1 To explore the encapsulation effect of the anti-aging EGCG nano-composition provided by the present invention, the particle size and encapsulation efficiency in the above Examples and Comparative Examples 1-8 were detected, as follows: Determination of particle size: The particle size of the samples in the above Examples and Comparative Examples 1-8 was characterized by a Malvern Nano-ZS90 dynamic light scattering particle size analyzer. The measurement angle was 90°, the measurement temperature was 25 °C, and each group of experiments was carried out in three parallel experiments. The experimental results were taken as their arithmetic mean.

[0092] Determination of encapsulation efficiency: Take 200 μL of the samples of the examples and Comparative Examples 1-8, subject them to ultrafiltration centrifugation (9000 rpm, 30 min), take 5 μL of the filtrate, and determine the content of EGCG in the filtrate by a high-performance liquid chromatograph (HPLC, Shimadzu, Japan), which is the content of unencapsulated EGCG in the nano-composition. The analytical column used in the HPLC system is a non-polar C 18 column, the mobile phase is acetonitrile, the flow rate is 1.0 ml / min, the column temperature of the chromatographic column is 30 °C. Each group of experiments is carried out in three parallel experiments, and the arithmetic mean of the experimental results is taken.

[0093] Take another nano-composition in the examples and comparative examples, add a mixed solution of methanol and water, and perform ultrasonic demulsification for 30 min according to sample: methanol: water = 1:4:5 (v / v). After filtering through a 0.45 μm organic filter membrane, take 5 μL of the sample solution and determine the content of EGCG by a high-performance liquid chromatograph (HPLC, Shimadzu, Japan), which is the content of EGCG in the nano-composition. Calculate the encapsulation efficiency (EE) of EGCG in the nano-composition according to the following formula: where C1 represents the concentration of unencapsulated EGCG in the sample; C0 represents the concentration of EGCG in the sample after ultrasonic demulsification with a mixed solution of methanol and deionized water.

[0094] The detection results of the particle size and encapsulation efficiency in the above examples and Comparative Examples 1-8 are shown in Table 1 below; among them, the particle size and particle size distribution of the nano-composition in Example 1 are as Figure 7 .

[0095] Table 1 Test results of particle size and EGCG encapsulation efficiency of nano-composition Sample Particle Size (nm) EGCG Encapsulation Efficiency (%) Example 1 76.4 87.2 Example 2 85.2 82.6 Example 3 88.7 80.5 Example 4 91.5 80.0 Example 5 89.1 81.5 Example 6 158.6 68.5 Example 7 122.3 76.3 Example 8 84.2 83.5 Example 9 101.2 78.9 Example 10 97.4 80.5 Example 11 164.3 65.2 Example 12 91.5 78.6 Example 13 80.6 81.5 Example 14 123.5 74.2 Example 15 189.5 58.4 Example 16 102.8 72.2 Example 17 95.4 75.4 Example 18 113.6 68.7 Example 19 136.5 62.1 Example 20 101.7 77.3 Example 21 98.4 71.5 Example 22 154.3 54.3 Comparative Example 1 165.4 48.3 Comparative Example 2 315.4 32.6 Comparative Example 3 287.6 35.7 Comparative Example 4 212.1 51.2 Comparative Example 5 187.5 44.5 Comparative Example 6 673.2 21.5 Comparative Example 7 225.6 33.6 Comparative Example 8 204.9 52.8 It can be seen from the results in Table 1 that: Comparing Examples 1-5, it can be seen that different types of protonatable blocks and hydrophobic blocks in the block copolymer will affect the particle size and encapsulation efficiency of the product. The protonatable blocks in the block copolymer in Examples 1-3 are PDEAEMA, PDMAEMA, and PTBAEMA respectively. When the protonatable block is selected as PDEAEMA (Example 1), the final product has the smallest particle size, the highest encapsulation efficiency, and the best encapsulation effect on EGCG; the hydrophobic blocks of the block copolymer in Examples 1, 4, and 5 are PCL, PLA, and PGA respectively. When the hydrophobic block is selected as PCL (Example 1), the particle size of the nano-composition product is the smallest, the encapsulation efficiency is the highest, and the encapsulation effect on EGCG is better.

[0096] Comparing Comparative Example 1, Examples 6-11 and Comparative Examples 2 and 3, the degrees of polymerization of the protonatable block and the hydrophobic block in the block polymer are different, which all affect the particle size and encapsulation efficiency of the product. In Comparative Example 1, Examples 6-9, and Comparative Example 2, the degrees of polymerization of the protonatable block are 60, 20, 40, 80, 100, and 10 respectively. When the degree of polymerization of the protonatable block in the block polymer gradually increases, the particle size of the product first decreases and then increases, while the encapsulation efficiency first increases and then decreases. When the degree of polymerization of the protonatable block in Example 1 is selected as 60, the particle size of the final product is the smallest, the encapsulation efficiency is the highest, and the loading effect on EGCG is the best. In Comparative Example 1, Examples 10-11, and Comparative Example 3, the degrees of polymerization of the hydrophobic block are 30, 10, 50, and 60 respectively. When the degree of polymerization of the hydrophobic block in the block polymer gradually increases, the particle size of the product first decreases and then increases, while the encapsulation efficiency first increases and then decreases. When the degree of polymerization of the hydrophobic block is selected as 30 (Example 1), the particle size of the product is the smallest, the encapsulation efficiency is the highest, and the loading effect on EGCG is the best.

[0097] Comparing Comparative Example 1, Examples 12-15 and Comparative Examples 5-6, the pH value in the nano-composition significantly affects the particle size and encapsulation efficiency of the product. The pH values of the nano-compositions in Comparative Example 1, Examples 12-15 and Comparative Examples 5-6 are 5.2, 3.0, 4.1, 6.3, 6.9, 2.0, and 7.8 respectively. When the pH value of the nano-composition gradually increases, the particle size first decreases and then increases, while the encapsulation efficiency first increases and then decreases. When the pH is 5.2 (Example 1), the particle size of the product is the smallest, the encapsulation efficiency is the highest, and the comprehensive effect is the best.

[0098] Among Comparative Example 1, Examples 16-18 and Comparative Example 4 in the nano-composition, the stabilizers are isobutylamidothiazol resorcinol, phenethyl resorcinol, 4-butyl resorcinol, 4-cyclohexyl resorcinol, and no stabilizer is added. The results show that when the stabilizer is selected as isobutylamidothiazol resorcinol (Example 1), the particle size of the final product is smaller, the encapsulation efficiency is higher, and its loading effect on EGCG is better.

[0099] In Comparative Example 1, 19 - 20, and Comparative Example 7, the addition amounts of the block polymer were 2%, 0.5%, 5%, and 0.1% respectively: when the addition amount of the block polymer in the nano - composition gradually increased, its particle size first decreased and then increased, and the encapsulation efficiency first increased and then decreased. When the addition amount of the block polymer was 2% (Example 1), the particle size of the product was the smallest and the encapsulation efficiency was the highest. In Comparative Example 1, 21 - 22, and Comparative Example 8, the addition amounts of EGCG in the nano - composition were 2%, 0.5%, 5%, and 6% respectively. When the addition amount of EGCG gradually increased, its particle size first decreased and then increased, and the encapsulation efficiency first increased and then decreased. When the addition amount of EGCG was 2% (Example 1), it was the most suitable. At this time, the particle size of the product was the smallest and the encapsulation efficiency was the highest. Considering comprehensively, the mass percentage of EGCG was selected as 2%, and the situations of too much or too little active ingredient were no longer explored.

[0100] Comparing Comparative Example 1 and Comparative Example 1, compared with PPEGMA (non - protonated block), the block polymer prepared by using protonatable block PDEAEMA and linking hydrophobic block PCL to encapsulate EGCG had a smaller particle size, a higher encapsulation efficiency, and a better encapsulation ability for EGCG.

[0101] Effect Example 2 To explore the transdermal absorption effect of the anti - aging EGCG nano - composition provided by the present invention, a transdermal absorption (permeation - enhancing) experiment was used to evaluate the transdermal absorption ability of the nano - composition. The specific method was as follows: For the in vitro transdermal experiment, a vertical diffusion cell was selected, and the skin of nude mice (abdominal skin, removing the subcutaneous fat layer and blood vessels) was used as the model. The receiving solution was PBS solution. The skin piece was fixed between the supply pool and the receiving pool, with the skin layer facing up, and equilibrated for 20 min. The nano - composition samples in each example and comparative example were prepared into a sample solution with a mass percentage of 10%, and the solution was taken and added to the supply pool. The receiving solution was taken at 1 h, 4 h, 8 h, and 24 h. The receiving solution was ultrasonically demulsified with a mixed solution of methanol and deionized water, ultrasonically treated for 30 min according to receiving solution: methanol: water = 1:4:5 (V / V), filtered through a 0.45 μm organic filter membrane, and the content of EGCG was determined by high - performance liquid chromatography (HPLC, Shimadzu, Japan), and the cumulative permeation amount per unit area was calculated therefrom. Each group of experiments was carried out in three parallel experiments, and the arithmetic mean of the experimental results was taken. The calculation formula for the cumulative permeation amount per unit area on the skin piece was as follows: Among them, Q n is the cumulative permeation rate per unit area of the sample at time t (μg / cm 2 ), A is the permeation area, C n is the measured value of the concentration of the active substance at time t, C iThe measured value of the active substance concentration sampled at time point t, V is the total volume of the receiving solution, and V0 is the sampling volume at each time point. The results are shown in Table 2 below.

[0102] Table 2 In vitro transdermal test results of the nano-composition It can be seen from the results in Table 2 that: Comparing Examples 1-5, the types of protonatable block and hydrophobic block in the block polymer affect the transdermal penetration performance of the product. When the protonatable block is selected as PDEAEMA (Example 1), the cumulative permeation amounts per unit area of the final prepared EGCG nano-composition (Example 1) at 1 h, 4 h, 8 h and 24 h are 2.91 μg / cm 2 、15.45 μg / cm 2 、36.52 μg / cm 2 、88.72 μg / cm 2 , all higher than the samples of Examples 2-3. The carrier selected in Example 1 has the best transdermal penetration performance. When the hydrophobic block is selected as PCL (Example 1), the cumulative permeation amount per unit area of the final product is higher, indicating that its transdermal penetration performance is better.

[0103] Comparing Example 1, Examples 6-11, Comparative Examples 2 and 3, the degree of polymerization of the protonatable block and hydrophobic block in the block polymer affects the transdermal penetration performance of the product. When the degree of polymerization of the protonatable block is selected as 60 (Example 1), the cumulative permeation amount per unit area of the product is higher, indicating that its transdermal penetration performance is better. When the degree of polymerization of the hydrophobic block is selected as 30 (Example 1), the cumulative permeation amount per unit area of the product is higher and the transdermal penetration performance is better.

[0104] Comparing Example 1, Examples 12-15, Comparative Examples 5-6, the pH value of the nano-composition significantly affects the transdermal penetration performance of the product: when the pH of the nano-composition in Example 1 is 5.2, the cumulative permeation amount per unit area of the product is higher and its transdermal penetration performance is better. Comparing Example 1, Examples 16-18, Comparative Example 4, the influence of the type of stabilizer in the nano-composition on the transdermal penetration performance: when the stabilizer is selected as isobutylamido thiazole resorcinol (Example 1), the cumulative permeation amount per unit area of the product is higher and the transdermal penetration performance is better. Comparing Example 1, Examples 19-20, Comparative Example 7, the influence of the addition amount of the block polymer: when the addition amount of the block polymer is 2% (Example 1), the cumulative permeation amount per unit area is higher and the transdermal penetration performance is better.

[0105] Comparing Example 1 and Comparative Example 1, it can be seen that compared with PPEGMA (non-protonated block), the block polymer prepared by the present invention using the protonatable block PDEAEMA to link the hydrophobic block PCL and encapsulating EGCG has a higher cumulative permeation amount per unit area and better percutaneous penetration performance. Comparing Example 1 and Comparative Example 9 (EGCG aqueous solution), it can be seen that compared with free EGCG without encapsulation treatment, the encapsulation strategy for EGCG adopted in this application can significantly improve the percutaneous penetration performance of EGCG.

[0106] Effect Example 3 To explore the effect of the anti-aging EGCG nano-composition provided by the present invention on cells damaged by ultraviolet rays, the amount of ATP generated in the cells was detected to evaluate the function and activity of mitochondria in the cells, as follows: The detection of ATP content was carried out using an ATP detection kit, which can be purchased from Shanghai Beyotime Biotechnology Co., Ltd. The specific experimental method is as follows: a. Preparation of ATP standard solution: Thaw the reagent to be used on ice bath, and dilute the ATP standard solution with ATP detection lysis solution into a certain concentration gradient (0.1 nM, 0.3 nM, 1 nM, 3 nM, 10 nM, 30 nM, 100 nM).

[0107] b. Preparation for sample determination: Digest human skin keratinocytes (HaCaT cells), make them into a cell suspension, and inoculate them into a 6-well plate, with 5 - 10.0×10 5 cells per well. Culture them using DMEM medium. After 24 h of culture, then irradiate the blank control group and the experimental group with UVA light (light dose is 6 - 10 J / cm 2 ). After the irradiation, change the medium, and add 50 μL of the nano-composition samples in the examples and comparative examples (experimental group) or PBS solution (blank group and control group) respectively, and continue to culture for 24 h. Remove the cell culture medium, wash 3 times with PBS. Centrifuge to collect the cells, and wash once with PBS. After sucking out the PBS, gently disperse the cells appropriately. Add 200 μL of lysis solution according to the cell amount per well to lyse the cells. After lysis, centrifuge at 4 °C for 5 min (rotation speed 12000 rpm), take the supernatant for testing.

[0108] c. Determination of ATP concentration: Add 100 μL of the ATP detection working solution into the detection tube, and place it at room temperature for 3 - 5 min to consume all the background ATP, thereby reducing the background. Add 20 μL of the sample to be tested or the ATP standard solution into the detection tube, mix well with a micropipette, and measure the RLU value with a chemiluminescence analyzer. Plot the ATP standard curve with the ATP content of the ATP standard solution as the abscissa and the RLU value as the ordinate. The ATP content of the sample to be tested can be calculated according to the ATP standard curve. The results are shown in Table 3 below. Table 3 Test results of the ATP content of ultraviolet-damaged cells treated with the nano-composition As can be seen from the results in Table 3: Comparing Examples 1 - 5, different types of protonatable blocks and hydrophobic blocks in the block polymer affect the protective effect of the product on mitochondria. After the ultraviolet-damaged cells were co-incubated with the sample of Example 1, the ATP content in mitochondria was the highest, which was 0.357 nM, and the cells could be restored to 92.97% of the normal healthy cells. Example 1 selected the protonatable block PDEAEMA to have the best protective effect on mitochondria. When the hydrophobic block was selected as PCL (Example 1), after the prepared nano-composition was co-incubated with the ultraviolet-damaged cells, the ATP content in mitochondria was the highest, and the protective effect on mitochondria was the best.

[0109] Comparing Example 1, Examples 6 - 11, Comparative Examples 2 and 3, the degree of polymerization of the protonatable block and the hydrophobic block in the block polymer affects the protective effect of the product on mitochondria. When the degree of polymerization of the protonatable block was selected as 60 (Example 1), after the prepared nano-composition was co-incubated with the ultraviolet-damaged cells, the ATP content in mitochondria was the highest, and its protective effect on mitochondria was the best. When the degree of polymerization of the hydrophobic block was selected as 30 (Example 1), after the nano-composition was co-incubated with the ultraviolet-damaged cells, the ATP content in mitochondria was the highest, and the protective effect on mitochondria was the best.

[0110] Comparative Example 1, Examples 12 - 15, and Comparative Examples 5 - 6 investigated the effect of the pH of the nano - composition on the protective effect of the product on mitochondria. When the pH of the nano - composition was 5.2 (Example 1) and it was co - incubated with ultraviolet - damaged cells, the ATP content in mitochondria was the highest, and its protective effect on mitochondria was the best. Comparing Comparative Example 1, Examples 16 - 18, and Comparative Example 4, it can be seen that the addition of stabilizers and their types have a great influence. When the stabilizer was selected as isobutylamido thiazole resorcinol (Example 1) and the nano - composition was co - incubated with ultraviolet - damaged cells, the ATP content in mitochondria was the highest and the protective effect on mitochondria was the best. Comparing Comparative Example 1, Examples 19 - 20, and Comparative Example 7, different addition amounts of block polymers in the nano - composition significantly affected the protective effect of the product on mitochondria; when the addition amount of the block polymer was 2% (Example 1), the nano - composition had the best protective effect on mitochondria.

[0111] Comparing Comparative Example 1 and Comparative Example 1, compared with PPEGMA (non - protonated block), the block polymer prepared by using the protonatable block PDEAEMA to link the hydrophobic block PCL in the present invention to encapsulate EGCG, after co - incubation with ultraviolet - damaged cells, the ATP content in mitochondria was higher and the protective effect on mitochondria was better. Comparing Comparative Example 1 and Comparative Example 9 (EGCG aqueous solution), compared with free EGCG without encapsulation treatment, the nano - composition prepared by using the encapsulation strategy of the present invention had a higher ATP content in mitochondria after co - incubation with ultraviolet - damaged cells, and its protective effect on mitochondria was better.

[0112] Effect Example 4 To further explore the uptake of the anti - aging EGCG nano - composition provided by the present invention by cells and its bioavailability, the specific content is as follows: Exponentially growing HACAT cells (density 5×10 4Inoculate (in the wells) in a six-well plate pre-laid with cover glasses, with the culture medium being DMEM solution (2 mL), and incubate in an incubator at 37 °C, saturated humidity and containing 5% CO2 for 24 h. Aspirate the culture medium, and add 2 mL of sample solution to each well (aqueous solutions with a mass percentage of 1% of the nano-compositions of Example 1, Examples 12 - 15 and Comparative Example 1, Comparative Examples 4 - 6, 9 prepared separately), and incubate in an incubator at 37 °C, saturated humidity and containing 5% CO2 for 30 min, 1 h, 2 h and 4 h respectively. Aspirate the culture medium, rinse the cells twice with PBS solution, and fix with 4% paraformaldehyde for 0.5 h. Remove the paraformaldehyde solution, and rinse the cells twice with PBS solution. Incubate with DAPI (4',6-diamidino-2-phenylindole) for 30 min, rinse the cells three times with PBS solution, and mount the cover glass after placing it. Place the cover glass under a laser confocal microscope (CLSM, Leica SP8, Leica Microsystems, USA) to test the fluorescence intensity, with an excitation wavelength of 488 nm and an emission wavelength of 525 nm. The results are shown in Table 4.

[0113] Table 4 Results of cell endocytosis test of nano-compositions From the results in Table 4, it can be seen that: with the increase of the action time, the fluorescence intensity in the experimental groups of Example 1, Examples 12 - 15, Comparative Example 1, Comparative Examples 4 - 6, and Comparative Example 9 gradually increases, indicating that more samples enter the cells and cell nuclei in the form of endocytosis. Compared with Example 12 (pH value 3.0), Example 13 (pH value 4.1), Example 14 (pH value 6.3), Example 15 (pH value 6.9), Comparative Example 5 (pH value 2.0) and Comparative Example 6 (pH value 7.8), during the co-incubation time of 30 min, 1 h, 2 h and 4 h between the sample of Example 1 (pH value 5.2) and HACAT cells, the fluorescence intensity in the cells is the largest, indicating that the number of EGCG nano-compositions in Example 1 entering the cells and reaching the cell nuclei is the largest, and the amount of it taken up by the cells is the largest. Compared with Comparative Example 1 and Comparative Example 4, the block polymer of the present invention selects the protonatable block PDEAEMA, links the hydrophobic block PCL to encapsulate EGCG, and selects isobutylamido thiazolyl resorcinol as the stabilizer. During the co-incubation time of 30 min, 1 h, 2 h and 4 h between the prepared nano-composition and HACAT cells, the fluorescence intensity in the cells is the largest, indicating that the number of the nano-composition in Example 1 entering the cells and reaching the cell nuclei is more, and the amount of it taken up by the cells is more. At the same time, compared with the EGCG aqueous solution of Comparative Example 9, the present application uses a specific block polymer to encapsulate EGCG to prepare the anti-aging EGCG nano-composition, and the number of EGCG entering the cells and reaching the cell nuclei increases significantly, and the amount taken up by the cells is significantly more and the effect is significantly better.

[0114] Effect Example 5 To further explore the anti-aging application effect of the anti-aging EGCG nano-composition of the present invention, anti-aging creams were prepared using the nano-compositions of Example 1, Comparative Example 1, Comparative Example 4, and Comparative Example 9 respectively according to the formula in Table 5 below. The preparation method is as follows: According to the formula in Table 5, triglyceride caprylate / caprate, cetearyl alcohol, and cetyl palmitate were added to 1,3-butanediol, heated to 80 °C, stirred at 300 rpm for 30 min, then deionized water was added, and high-speed homogenization was carried out at 11000 rpm for 10 min, and then cooled to 45 °C; finally, the nano-compositions of Example 1, Comparative Example 1, Comparative Example 4, and Comparative Example 9 were added respectively, and stirring was continued at 300 rpm for 20 min to obtain the corresponding anti-aging creams. The nano-composition was replaced with an equal amount of deionized water, and the rest remained unchanged to prepare a cream matrix.

[0115] Table 5 Anti-aging cream formula table The test method is as follows: People (30 - 45 years old) with facial wrinkles were selected as anti-aging efficacy test volunteers, a total of 120 people, randomly divided into 4 groups, with 30 people in each group. The anti-aging creams of Example 1, Comparative Example 1, Comparative Example 4, and Comparative Example 9 were randomly applied to both sides of the faces of the 4 groups of volunteers. The test was carried out for a total of five weeks, and tests were carried out at the initial stage (week 0), after 2 weeks of use, after 4 weeks of use, and 1 week after discontinuation of use to measure the skin firmness (facial), skin elasticity (facial), and wrinkle area (ocular) indicators. The results are shown in Table 6 below; among them, the distribution of ocular wrinkles in the volunteers of Example 1 and Comparative Example 1 after 2 weeks, 4 weeks of use of the anti-aging cream and 1 week after discontinuation of use is as Figure 8 .

[0116] Table 6 Test results of skin firmness, skin elasticity, and wrinkle area indicators of anti-aging creams From the results in Table 6, it can be seen that the anti-aging effect of the anti-aging cream of Example 1 is better than that of Comparative Example 1, further verifying that the block polymer encapsulation strategy with a specific protonatable block composition adopted in this application has a better anti-aging effect. The comparison between the anti-aging creams of Example 1 and Comparative Example 4 verified that the specific isobutylamido thiazole resorcinol stabilizer of the present invention has a greater impact on the anti-aging effect of the prepared cream. The comparison between the anti-aging creams of Example 1 and Comparative Example 9 shows that the overall strategy of using block polymer encapsulation in the present invention can effectively improve the bioavailability of EGCG and better exert its efficacy. In addition, 1 week after the volunteers discontinued using the product, only the skin condition of the group of Example 1 could still significantly maintain good elasticity, firming effect, and anti-wrinkle effect. It can be seen that the application of the anti-aging EGCG nano-composition of the present invention in cosmetics has a significant and lasting anti-aging effect.

[0117] In summary, the present invention selects protonatable block chains with a certain degree of polymerization and hydrophobic block chains to prepare block polymers with a specific structure, and selects a suitable stabilizer, adjusts to a certain pH value, and forms an anti-aging EGCG nano-composition by self-assembling and encapsulating the active ingredient EGCG, which can achieve a high encapsulation rate and at the same time has high percutaneous penetration performance. It has a high cell uptake rate and has a good mitochondrial protection effect on ultraviolet-damaged cells; moreover, the nano-composition provided by the present invention has long-term anti-aging performance. After using the nano-composition to prepare cosmetics or topical medications and stopping using them for one week, the skin can still maintain good elasticity, firming effect and wrinkle-removing effect, and has high application value.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An anti-aging EGCG nano-composition, characterized in that, It includes a carrier, an active ingredient, and a stabilizer. By mass percentage, the content of the carrier is 0.5 - 5%, and the content of the active ingredient is 0.5 - 5%; the carrier is a block polymer, and the active ingredient is EGCG; The general formula of the block polymer is Y n -X m -X m -Y n , where X m is a hydrophobic block, and Y n is a protonatable block; m is the degree of polymerization of the hydrophobic block, m = 10 - 50; n is the degree of polymerization of the protonatable block, n = 20 - 100; The protonatable block is at least one of poly(dimethylaminoethyl methacrylate), poly(diethylaminoethyl methacrylate), and poly(2-tert-butylaminoethyl methacrylate); the hydrophobic block is at least one of polycaprolactone, polylactic acid, and polyglycolide; The pH of the anti-aging EGCG nano-composition is 3 - 7.

2. The anti-aging EGCG nano-composition according to claim 1, wherein The stabilizer is at least one of phenethyl resorcinol, 4-butyl resorcinol, isobutylamidothiazole resorcinol, 4-cyclohexyl resorcinol, 4-hexyl resorcinol, and dimethoxytolyl-4-propyl resorcinol.

3. The anti-aging EGCG nano-composition according to claim 1, characterized in that, The preparation method of the block polymer includes the following steps: (1) Mix a diol, a polyester monomer, and a ROP reaction catalyst, and react at 80 - 150 °C for 6 - 18 h under an inert atmosphere to obtain an intermediate block; (2) Mix the intermediate block and a bromo initiator in an organic solvent, and react at 0 - 25 °C for 8 - 72 h under an inert atmosphere to obtain a bromo-treated intermediate block; (3) Mix a methacrylic acid monomer, the bromo-treated intermediate block, an ATRP reaction catalyst, and a catalyst ligand in an organic solvent, and react at 60 - 100 °C for 12 - 48 h under an inert atmosphere to obtain the block polymer.

4. The anti-aging EGCG nano-composition according to claim 3, characterized in that, The polyester monomer is at least one of ξ-caprolactone, D,L-lactide, and glycolide; and / or the methacrylic acid monomer is at least one of dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and 2-tert-butylaminoethyl methacrylate; and / or the diol is at least one of 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,14-dodecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, and 1,20-eicosanediol; and / or the ROP reaction catalyst is at least one of stannous octanoate, stannous isooctanoate, stannous tartrate, and stannous stearate; and / or the bromo initiator is at least one of 2-bromo-2-methylpropionyl bromide, bis[2-(2'-bromo-2-methylpropionyloxy)ethyl] disulfide, tert-butyl 2-bromo-2-methylpropionate, and ethyl 2-bromo-2-methylpropionate; and / or the ATRP reaction catalyst is at least one of CuBr, CuCl, and CuI; and / or the catalyst ligand is at least one of N,N-diisopropylethylamine, ethanolamine, N,N,N',N',N''-pentamethyldiethylenetriamine, and tetrabutylammonium bromide.

5. The anti-aging EGCG nano-composition according to claim 3, wherein In step (1), the molar ratio of the diol, the polyester monomer, and the ROP reaction catalyst is diol: polyester monomer: ROP reaction catalyst = 1:(20 - 100):(2 - 10); and / or in step (2), the molar ratio of the intermediate block to the bromo initiator is 1:(2 - 8); And / or in the step (3), the molar ratio of the methacrylic acid monomer, the brominated intermediate block, the ATRP reaction catalyst, and the catalyst ligand is methacrylic acid monomer: brominated intermediate block: ATRP reaction catalyst: catalyst ligand = 1: (40 - 200): (0.4 - 2): (4 - 20).

6. The anti-aging EGCG nano-composition according to claim 1, wherein It further includes polyhydric alcohol, water, and a pH regulator.

7. The anti-aging EGCG nano-composition according to claim 6, wherein The polyhydric alcohol is at least one of 1,3 - butanediol, 1,4 - butanediol, 1,2 - propanediol, 1,3 - propanediol, glycerol, 1,2 - hexanediol, ethoxydiglycol, and octyldodecanol; And / or the pH regulator is at least one of glutamic acid, aspartic acid, asparagine, glutamine, hydrochloric acid, citric acid, lactic acid, sulfuric acid, and oxalic acid.

8. The anti-aging EGCG nano-composition according to claim 6, characterized in that, By mass percentage, the composition of the anti - aging EGCG nano - composition is as follows: 0.5 - 5% carrier, 0.5 - 2% stabilizer, 0.5 - 5% active ingredient, 10 - 30% polyhydric alcohol, 0.02 - 0.2% pH regulator, and the balance is water.

9. The preparation method of the anti-aging EGCG nano-composition according to any one of claims 6-8, characterized in that, It includes the following steps: S1. Add the carrier, stabilizer, and active ingredient into the polyhydric alcohol and mix evenly to obtain a phase A solution; add the pH regulator into water and mix evenly to obtain a phase B solution; the pH of the phase B solution is 3 - 7; S2. Drop the phase A solution into the phase B solution while performing high - shear treatment to obtain a mixed solution; S3. Subject the mixed solution to micro - fluidic homogenization treatment to obtain the anti - aging EGCG nano - composition.

10. Use of the anti - aging EGCG nano - composition according to any one of claims 1 - 8 in anti - aging cosmetics and skin topical medications.

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