Anti-aging egcg nano-composition and its preparation method and use

Abstract

The present application relates to an anti-aging EGCG nano composition and its preparation method and use, and belongs to the technical field of nano carriers. The anti-aging EGCG nano composition comprises 0.5-5% carrier block polymer, 0.5-5% active ingredient EGCG; the general formula of the block polymer is Y n -X m -X m -Y n , X m is a hydrophobic block, Y n is a protonatable block; the polymerization degree m is 10-50, and n is 20-100; Y n is selected from PDMAEMA, PDEAEMA and PTBAEMA, X m is selected from PCL, PLA and PGA; the pH of the nano composition is 3-7. The nano composition provided by the present application can be applied to cosmetics or skin external drugs, so that EGCG is more easily taken into cells, efficiently delivered to the mitochondrial target site, the skin still maintains elasticity, tightness and wrinkle-removing effect after the product is stopped, has the function of long-acting anti-aging, and has high application value.

Description

Technical Field

[0001] This invention relates to the field of anti-aging technology, and in particular to an anti-aging EGCG nanocomposition, its preparation method, and its uses. Background Technology

[0002] When skin is subjected to harmful stimuli such as air pollution, oxidation, and ultraviolet radiation for a long time, it is prone to aging. Skin aging is mainly manifested in appearance as dry skin, sagging, wrinkles, and pigmentation. Therefore, "anti-aging" has always been a hot topic of concern.

[0003] The decline in mitochondrial function is considered a crucial aspect of the aging mechanism. With age and increased oxidative stress, mitochondrial function gradually declines, leading to decreased cellular function and subsequently, the functional decline of tissues and organs, ultimately manifesting as aging. The skin is the largest organ on the human body's surface; therefore, activating mitochondrial function in skin cells and providing them with energy can effectively combat skin aging.

[0004] Epigallocatechin gallate (EGCG) is a catechin compound and the most abundant component of catechins, accounting for 50-60%. EGCG possesses a unique stereochemical structure and exhibits very strong antioxidant activity. It can protect cellular and mitochondrial DNA from oxidative stress, activate mitochondrial function in skin cells, and provide energy to the skin, thereby delaying skin aging. However, in practical applications, EGCG suffers from poor stability and low transdermal absorption and utilization. Furthermore, due to the barrier of the cell membrane, as a small molecule active ingredient, EGCG often can only enter cells and reach its mitochondrial target through diffusion, and the diffusion efficiency is low, resulting in low cellular uptake efficiency and thus low bioavailability. Existing technologies utilize liposomes, nanoemulsions, and liposomes to encapsulate EGCG, which can improve its stability and transdermal permeability. However, there are no reports on how to improve the cellular uptake efficiency and bioavailability of EGCG.

[0005] Therefore, developing a carrier strategy that can improve the cellular uptake efficiency of EGCG and enhance the bioavailability of active ingredients, thereby achieving a better and longer-lasting anti-aging effect, is of great significance for EGCG to better play its role in cosmetics, skin care, and repair. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an anti-aging EGCG nanocomposition, its preparation method, and its uses. The anti-aging EGCG nanocomposition of this invention has high EGCG encapsulation efficiency, high transdermal permeability, high cellular uptake rate, good protective effect on mitochondria, and long-lasting anti-aging properties.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] In a first aspect, the present invention provides an anti-aging EGCG nanocomposition, comprising a carrier, an active ingredient, and a stabilizer, wherein the carrier comprises 0.5-5% by mass percentage, and the active ingredient comprises 0.5-5% by mass percentage; the carrier is a block polymer, and the active ingredient is EGCG;

[0009] The block polymer has the general formula Y n -X m -X m -Y n The X m As a hydrophobic block, the Y n The hydrophobic block has a degree of polymerization m = 10-50, and the protonable block has a degree of polymerization n = 20-100.

[0010] The protonable 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 polyglycolic acid.

[0011] The pH of the anti-aging EGCG nanocomposition is 3-7.

[0012] The anti-aging EGCG nanocomposition provided by this invention mainly comprises a block polymer carrier, the active ingredient EGCG, and a stabilizer. Specifically, a block polymer is obtained by linking two hydrophobic blocks with a specific degree of polymerization using protonable blocks of a certain degree of polymerization. This block polymer serves as the carrier for the anti-aging EGCG nanocomposition of this invention. Under weakly acidic pH conditions, the block compounds of this invention can self-assemble to encapsulate EGCG, resulting in an EGCG-loaded nanocomposition with advantages such as small particle size and high encapsulation efficiency.

[0013] When the pH value is too high, the block compounds cannot be protonated and become hydrophobic, failing to encapsulate EGCG through self-assembly, resulting in a very low encapsulation efficiency and poor overall performance. When the pH value is too low, the block compounds also cannot self-assemble well, and the encapsulation efficiency of EGCG decreases significantly. The selection of protonable blocks in the block polymer is the structural basis for achieving self-assembly and EGCG encapsulation. Blocks that cannot be protonated cannot change their charge state by accepting protons (H), and therefore lack self-assembly behavior or responsiveness under specific conditions. Adding stabilizers helps improve the self-assembly stability of the block compounds and enhances the encapsulation efficiency of EGCG. Similarly, controlling the degree of polymerization of hydrophobic and protonable blocks in the block polymer, as well as the content of the block polymer and EGCG, significantly affects the anti-aging effect of the nanocomposition of this invention.

[0014] By adding stabilizers and using block polymers with specific polymerization degrees and amounts as defined in this invention under a specific pH environment, the protonable groups—amino groups—can be successfully protonated under weakly acidic conditions, resulting in a stable anti-aging EGCG nanocomposition. This also makes the prepared EGCG-encapsulated nanocomposition positively charged, thus facilitating cellular uptake and achieving higher cellular uptake rates. On one hand, the anti-aging EGCG nanocomposition provided by this invention has a better protective effect on mitochondria and can efficiently deliver the active ingredient EGCG to the mitochondrial target site. On the other hand, more EGCG-encapsulated nanocompositions are taken up into cells and mitochondria, improving the bioavailability of the active ingredient EGCG and significantly enhancing its anti-aging effect.

[0015] Compared with free EGCG, the anti-aging EGCG nanocomposition with EGCG encapsulated provided by this invention has better skin permeability and higher cellular uptake, better protection of mitochondria, and excellent long-lasting anti-aging efficacy. It provides a new strategy for nano-encapsulation technology and has high industrial value for use in anti-aging cosmetics or topical skin medications.

[0016] Preferably, the stabilizer is at least one selected from phenylethyl resorcinol, 4-butylresorcinol, isobutylamidothiazole resorcinol, 4-cyclohexylresorcinol, 4-hexylresorcinol, and dimethoxytolyl-4-propylresorcinol.

[0017] Preferably, the content of the carrier, by mass percentage, is one or any two of the following: 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, and 5%; and the content of the active ingredient is one or any two of the following: 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, and 5%.

[0018] Preferably, the degree of polymerization m of the hydrophobic block is a value in the range of one or any two of 10, 20, 30, 40, and 50; and the degree of polymerization n of the protonable block is a value in the range of one or any two of 20, 30, 40, 50, 60, 70, 80, 90, and 100.

[0019] Preferably, the pH of the anti-aging EGCG nanocomposition is a range of one or any two of the following: 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, and 7.

[0020] Preferably, the method for preparing the block polymer includes the following steps:

[0021] (1) Mix the diol, polyester monomer and ROP reaction catalyst and react them at 80-150℃ for 6-18h under an inert atmosphere to obtain the intermediate block.

[0022] (2) The intermediate block and the brominated initiator are mixed in an organic solvent and reacted at 0-25°C for 8-72 hours under an inert atmosphere to obtain the brominated intermediate block.

[0023] (3) Mix the methacrylic acid monomer, the brominated intermediate block, the ATRP reaction catalyst and the catalyst ligand in an organic solvent, and react them at 60-100°C for 12-48 h under an inert atmosphere to obtain the block polymer.

[0024] Preferably, the polyester monomer is at least one selected from ξ-caprolactone, D,L-lactide, and glycolide;

[0025] Preferably, the methacrylic monomer is at least one selected from dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and 2-tert-butylaminoethyl methacrylate.

[0026] Preferably, the diol is at least one selected from 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-eicosenediol.

[0027] Preferably, the ROP reaction catalyst is at least one of stannous octoate, stannous isooctanoate, stannous tartrate, and stannous stearate;

[0028] Preferably, the bromination initiator is at least one selected from 2-bromoisobutyryl bromide, bis[2-(2'-bromoisobutyryloxy)ethyl] disulfide, tert-butyl 2-bromoisobutyrate, and ethyl 2-bromoisovalerate.

[0029] Preferably, the ATRP reaction catalyst is at least one selected from CuBr, CuCl, and CuI;

[0030] Preferably, the catalyst ligand is at least one selected from N,N-diisopropylethylamine, ethanolamine, N,N,N',N',N”-pentamethyldiethylenetriamine, and tetrabutylammonium bromide.

[0031] 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). If the hydrophobic block is polylactic acid (PLA), then the polyester monomer is D,L-lactide, and PLA is obtained through ROP. If the hydrophobic block is polyglycolic acid (PGA), then the polyester monomer is glycolide, and PGA is obtained through ROP.

[0032] The protonable block of the block polymer is poly(dimethylaminoethyl methacrylate) (PDMAEMA), and the methacrylate monomer is dimethylaminoethyl methacrylate (DMAEMA); the protonable block is poly(diethylaminoethyl methacrylate) (PDEAEMA), and the methacrylate monomer is diethylaminoethyl methacrylate (DEAEMA); the protonable block is poly(2-tert-butylaminoethyl methacrylate) (PTBAEMA), and the methacrylate monomer is 2-tert-butylaminoethyl methacrylate (DTBAEMA).

[0033] The diol used in step (1) has ≥6 carbon atoms and its molecular structure is capped with hydroxyl groups at both ends to reduce steric hindrance during the ROP reaction, allowing the polyester monomer to react fully at both ends of the diol. If the diol has <6 carbon atoms or the two hydroxyl reaction sites are adjacent, the steric hindrance during the ROP reaction will be too large, which is not conducive to the reaction.

[0034] Preferably, in step (1), the molar ratio of diol, polyester monomer, and ROP reaction catalyst is diol: polyester monomer: ROP reaction catalyst = 1:(20-100):(2-10);

[0035] Preferably, in step (2), the molar ratio of the intermediate block to the brominated initiator is 1:(2-8);

[0036] Preferably, in step (3), the molar ratio of methacrylic acid monomer, brominated intermediate block, ATRP reaction catalyst, and catalyst ligand is methacrylic acid monomer: brominated intermediate block: ATRP reaction catalyst: catalyst ligand = 1:(40-200):(0.4-2):(4-20).

[0037] As a preferred embodiment of the present invention, after the reaction in step (2) is completed, the following purification step is further included:

[0038] The reaction mixture was washed 3-5 times with hydrochloric acid solution (0.5-3 mol / L, 100-500 mL), saturated NaHCO3 solution (100-500 mL), and deionized water (100-500 mL), respectively. The organic phase was dried overnight with anhydrous MgSO4. The supernatant was collected and concentrated by rotary evaporation. The product was precipitated with an excess of precipitant, and the solid product was dried at 40-60℃ for 12-48 h to obtain the purified brominated intermediate block. The precipitant included at least one of methanol, ethanol, n-hexane, and petroleum ether; the precipitation purification treatment was carried out at 0-10℃.

[0039] As a preferred embodiment of the present invention, after the reaction in step (3) is completed, a purification process is also included, as follows:

[0040] The reaction mixture is slowly added to a precipitant, and after precipitation purification, the solid is collected and dried at 40-60°C for 12-48 hours to obtain the purified block polymer; the precipitant includes at least one of methanol, ethanol, n-hexane, and petroleum ether; the precipitation purification temperature is 0-10°C.

[0041] Preferably, the organic solvent in steps (2) and (3) is at least one of N,N-dimethylformamide, triethylamine, N,N-dimethylacetamide, dimethyl sulfoxide, dichloromethane, tetrahydrofuran, acetone, chloroform, acetonitrile, and ethyl acetate.

[0042] Preferably, the inert atmosphere is at least one of nitrogen, argon, and helium; argon is preferred.

[0043] Preferably, the anti-aging EGCG nanocomposition further includes polyols, water, and pH adjusters.

[0044] More preferably, the polyol is at least one selected from 1,3-butanediol, 1,4-butanediol, 1,2-propanediol, 1,3-propanediol, glycerol, 1,2-hexanediol, ethoxydiethylene glycol, and octyldodecyl alcohol.

[0045] Preferably, the pH adjuster is at least one selected from glutamic acid, aspartic acid, asparagine, glutamine, hydrochloric acid, citric acid, lactic acid, sulfuric acid, and oxalic acid.

[0046] The solvent and pH adjuster are green, safe, non-toxic, and have low skin irritation, thus avoiding skin sensitivity and stress reactions.

[0047] More preferably, the anti-aging EGCG nanocomposition comprises, by weight percentage: 0.5-5% carrier, 0.5-2% stabilizer, 0.5-5% active ingredient, 10-30% polyol, 0.02-0.2% pH adjuster, and the balance being water.

[0048] Secondly, the present invention provides a method for preparing the above-mentioned anti-aging EGCG nanocomposition, comprising the following steps: S1, adding a carrier, a stabilizer and an active ingredient to a polyol and mixing to obtain a phase A solution; adding a pH adjuster to water and mixing to obtain a phase B solution; wherein the pH of the phase B solution is 3-7;

[0049] S2. The A-phase solution is added dropwise to the B-phase solution, and high-shear treatment is performed simultaneously to obtain a mixed solution;

[0050] S3. The mixed solution is homogenized by microfluidic jet to obtain the anti-aging EGCG nanocomposition.

[0051] If the pH value of the B-phase solution is greater than 7 and is alkaline, the protonable groups in the block polymer cannot be protonated. In this case, the block polymer is completely hydrophobic and precipitates out in the B-phase solution, failing to effectively encapsulate EGCG.

[0052] Preferably, in step S2, the dropping rate is 1-10 mL / min; the high shear treatment speed is 6000-12000 rpm, and the treatment time is until the dropping is completed; after the dropping is completed, the mixture is stirred at 200-500 rpm for 1-6 hours.

[0053] Preferably, the microfluidic homogenization process in S3 involves using a microfluidic homogenizer to perform high-pressure homogenization on the mixed solution, wherein the homogenization pressure is 50-120 MPa and the number of cycles is 2-8.

[0054] Preferably, the mixing method in S1 is magnetic stirring or mechanical stirring.

[0055] Thirdly, the present invention provides the use of the above-mentioned anti-aging EGCG nanocomposition in anti-aging cosmetics and topical skin medications.

[0056] Preferably, the use is to add the anti-aging EGCG nanocomposition to anti-aging cosmetics or topical skin medications; the amount of the anti-aging EGCG nanocomposition added is 0.1-10% by weight.

[0057] When the nanocomposition of the present invention is used in anti-aging cosmetics or topical skin medications, the skin can still maintain good skin elasticity, firmness and wrinkle reduction after 4 weeks of use and 1 week of discontinuation.

[0058] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0059] This invention selects protonable blocks with specific degrees of polymerization and links two hydrophobic blocks with specific degrees of polymerization to obtain a block polymer. This allows the polymer to self-assemble under specific conditions, encapsulating EGCG into a stable nanocomposite with small particle size and high encapsulation efficiency. The resulting anti-aging EGCG nanocomposite is more easily taken up by cells, exhibiting higher cellular uptake and thus providing better protection for mitochondria. It efficiently delivers the active ingredient EGCG to the mitochondrial target site, solving the problem of low EGCG bioavailability. Adding this anti-aging EGCG nanocomposite to cosmetics or topical skin medications allows the skin to maintain good elasticity, firmness, and wrinkle reduction even after product discontinuation. Compared to using free EGCG alone or other existing strategies, this anti-aging EGCG nanocomposite exhibits superior skin permeability, higher cellular uptake, and better mitochondrial protection, achieving a more lasting anti-aging effect and showing great application potential. Attached Figure Description

[0060] Figure 1 The synthetic routes for the block polymers in Examples 1 and 6-11 are shown below.

[0061] Figure 2 This is a synthetic route diagram of the block polymer in Example 2;

[0062] Figure 3 This is a synthetic route diagram of the block polymer in Example 3;

[0063] Figure 4 This is a synthetic route diagram of the block polymer in Example 4;

[0064] Figure 5 This is a synthetic route diagram of the block polymer in Example 5;

[0065] Figure 6 The GPC curves of the block polymers in Examples 1-11 are shown below.

[0066] Figure 7 This is a particle size and particle size distribution diagram of the nanocomposite of Example 1 of the present invention;

[0067] Figure 8 The distribution of eye wrinkles in volunteers after 2 weeks, 4 weeks and 1 week after discontinuation of the anti-aging cream of Example 1 or Comparative Example 1. Detailed Implementation

[0068] 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 embodiments. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available reagents and materials.

[0069] In the following examples and comparative examples, the 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 used can be purchased directly from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0070] In the following examples and comparative examples, the EGCG, phenylethyl resorcinol, 4-butylresorcinol, isobutylamidothiazole resorcinol, and 4-cyclohexylresorcinol used can be purchased directly from Guangzhou Xiyuan Biotechnology Co., Ltd.

[0071] The synthetic routes of the block polymers in Examples 1 and 6-11 below are as follows: Figure 1 ;

[0072] The synthetic routes of the block polymers in Examples 2-5 below are respectively shown in the diagrams below. Figure 2-5 ;

[0073] The molecular weight of the block polymer in the following examples was determined by gel permeation chromatography (GPC, manufacturer: Waters Corporation, USA; model: Waters 1525 / 2414), using chromatographically pure THF solution as the mobile phase, a flow rate of 1.0 mL / min, a column calibrated with monodistributed polystyrene standard, and a test temperature of 30 °C.

[0074] Example 1

[0075] An embodiment of the anti-aging EGCG nanocomposition of the present invention, wherein the anti-aging EGCG nanocomposition material of this embodiment is composed of the following components in mass percentage: 2% carrier, 1% stabilizer, 2% active ingredient, 20% polyol, 0.08% pH adjuster, and the balance being water;

[0076] The carrier block polymer PDEAEMA 60 -PCL 30 -PCL 30 -PDEAEMA 60The stabilizer is isobutylamidothiazol resorcinol, the active ingredient is EGCG, the polyol is 1,3-butanediol, and the pH adjuster is glutamic acid.

[0077] The block polymer PDEAEMA 60 -PCL 30 -PCL 30 -PDEAEMA 60 The preparation method is as follows (taking the preparation of 1.0 mmol as an example):

[0078] (1) 1,6-hexanediol (118.17 mg, 1.0 mmol), ξ-caprolactone (6.85 g, 60 mmol), and stannous octoate (2.43 g, 6.0 mmol) were mixed thoroughly, and the mixture was reacted at 130 °C for 12 h under argon protection to obtain mesoblock polycaprolactone PCL. 30 -PCL 30 ;

[0079] (2) The intermediate block PCL 30 -PCL 30 (6.97 g, 1.0 mmol) was dissolved in a mixed solution of dichloromethane (100 mL) and triethylamine (10 mL) under argon protection. 2-Bromoisobutyryl bromide (1.38 g, 6.0 mmol) was added, and the reaction was carried out at 20 °C for 24 h. The reaction mixture was washed four times with 300 mL each time with hydrochloric acid solution (1.0 mol / L), saturated NaHCO3, and deionized water. The organic phase was dried overnight with anhydrous MgSO4. The supernatant was collected and concentrated by rotary evaporation. The product was precipitated with excess n-hexane (5 °C), and the solid product was dried at 50 °C for 24 h to obtain brominated polycaprolactone Br-PCL. 30 -PCL 30 -Br.

[0080] (3) 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), and the mixture was reacted under argon protection at 65 °C for 48 h. The reaction mixture was then added to excess 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 -PDEAEMA60 (GPC curve as shown) Figure 6 Calculate Mn = 27002).

[0081] The preparation method of the anti-aging EGCG nanocomposition described in this embodiment is as follows:

[0082] S1. The block polymer PDEAEMA is added according to a mass percentage. 60 -PCL 30 -PCL 30 -PDEAEMA 60 The stabilizer isobutylamidothiazole resorcinol and the active ingredient EGCG were added to 1,3-butanediol, heated to 50°C, and stirred at 300 rpm for 4 hours to obtain phase A solution; glutamic acid was dissolved in deionized water to obtain phase B solution with pH 5.0.

[0083] S2. Add the above phase A solution dropwise to the phase B solution, and simultaneously start high-speed shearing treatment at 8000 rpm. The dropwise addition rate of phase A solution is 3 mL / min. After the addition is complete, continue stirring at 300 rpm for 4 hours to obtain a mixed solution.

[0084] S3. The above mixed solution is subjected to high-pressure microfluidic homogenization (pressure 70MPa) 5 times to obtain the anti-aging EGCG nanocomposition.

[0085] The measured pH value of the anti-aging EGCG nanocomposite in Example 1 was 5.2.

[0086] Example 2

[0087] One embodiment of the anti-aging EGCG nanocomposition of the present invention differs from Example 1 only in that the carrier is replaced with the block polymer PDMAEMA. 60 -PCL 30 -PCL 30 -PDMAEMA 60 (That is, different protonated blocks), its preparation method is as follows:

[0088] Steps (1) and (2) Brominated polycaprolactone Br-PCL 30 -PCL 30 The preparation of -Br is the same as in Example 1;

[0089] (3) Br-PCL 30 -PCL 30Br (7.21 g, 1.0 mmol), dimethylaminoethyl 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) were added to tetrahydrofuran (100 mL), and the mixture was reacted under argon protection at 65 °C for 48 h. The reaction mixture was then added to excess 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 PDMAEMA. 60 -PCL 30 -PCL 30 -PDMAEMA 60 (GPC curve as shown) Figure 6 Calculate Mn = 24155).

[0090] Example 3

[0091] One embodiment of the anti-aging EGCG nanocomposition of the present invention differs from Example 1 only in that the carrier is replaced with the block polymer PTBAEMA. 60 -PCL 30 -PCL 30 -PTBAEMA 60 (i.e., different protonated blocks), block polymer PTBAEMA 60 -PCL 30 -PCL 30 -PTBAEMA 60 The preparation method is as follows:

[0092] Steps (1) and (2) Brominated polycaprolactone Br-PCL 30 -PCL 30 The preparation of -Br is the same as in Example 1;

[0093] (3) Br-PCL 30 -PCL 30 Br (7.21 g, 1.0 mmol), 2-tert-butylaminoethyl 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), and the mixture was reacted under argon protection at 65 °C for 48 h. The reaction mixture was then added to excess 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 -PCL30 -PTBAEMA 60 (GPC curve as shown) Figure 6 Calculate Mn = 26763).

[0094] Example 4

[0095] One embodiment of the anti-aging EGCG nanocomposition of the present invention differs from Example 1 only in that the carrier is replaced with the block polymer PDEAEMA. 60 -PLA 30 -PLA 30 -PDEAEMA 60 (i.e., different hydrophobic blocks), its preparation method is as follows (taking the preparation of 1.0 mmol as an example):

[0096] (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, and reacted at 130 °C for 12 h under argon protection to obtain intermediate block polycaprolactone PLA. 30 -PLA 30 .

[0097] (2) The intermediate segment PLA 30 -PLA 30 (4.44 g, 1.0 mmol) was dissolved in a mixed solution of dichloromethane (100 mL) and triethylamine (10 mL) under argon protection. 2-Bromoisobutyryl bromide (1.38 g, 6.0 mmol) was added, and the reaction was carried out at 20 °C for 24 h. The reaction mixture was washed four times with 300 mL each time with hydrochloric acid solution (1.0 mol / L), saturated NaHCO3, and deionized water. The organic phase was dried overnight with anhydrous MgSO4. The supernatant was collected and concentrated by rotary evaporation. The product was precipitated with excess 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.

[0098] (3) Br-PLA 30 -PLA 30Br (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) were added to tetrahydrofuran (100 mL), and the mixture was reacted under argon protection at 65 °C for 48 h. The reaction mixture was then added to excess 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 -PLA 30 -PLA 30 -PDEAEMA 60 (GPC curve as shown) Figure 6 Calculate Mn = 23986).

[0099] Example 5

[0100] One embodiment of the anti-aging EGCG nanocomposition of the present invention differs from Example 1 only in that the carrier is replaced with the block polymer PDEAEMA. 60 -PGA 30 -PGA 30 -PDEAEMA 60 (i.e., different hydrophobic blocks), its preparation method is as follows (taking the preparation of 1.0 mmol as an example):

[0101] (1) 1,6-hexanediol (118.17 mg, 1.0 mmol), glycolide (3.48 g, 30 mmol), and stannous octoate (2.43 g, 3.0 mmol) were mixed evenly, and reacted at 130 °C for 12 h under argon protection to obtain intermediate block polycaprolactone PGA. 30 -PGA 30 .

[0102] (2) The intermediate segment PGA 30 -PGA 30 (3.60 g, 1.0 mmol) was dissolved in a mixed solution of dichloromethane (100 mL) and triethylamine (10 mL) under argon protection. 2-Bromoisobutyryl bromide (1.38 g, 6.0 mmol) was added, and the reaction was carried out at 20 °C for 24 h. The reaction mixture was washed four times with 300 mL each time with hydrochloric acid solution (1.0 mol / L), saturated NaHCO3, and deionized water. The organic phase was dried overnight with anhydrous MgSO4. The supernatant was collected and concentrated by rotary evaporation. The product was precipitated with excess n-hexane (5 °C), and the solid product was dried at 50 °C for 24 h to obtain brominated Br-PGA. 30 -PGA 30 -Br.

[0103] (3) Br-PGA 30 -PGA 30 Br (3.84 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), and the mixture was reacted under argon protection at 65 °C for 48 h. The reaction mixture was then added to excess 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 -PGA 30 -PGA 30 -PDEAEMA 60 (GPC curve as shown) Figure 6 Calculate Mn = 24005).

[0104] Example 6

[0105] One embodiment of the anti-aging EGCG nanocomposition of the present invention differs from Example 1 only in that the carrier is replaced with the block polymer PDEAEMA. 20 -PCL 30 -PCL 30 -PDEAEMA 20 (Different degrees of protonable block polymerization) are prepared as follows:

[0106] Steps (1) and (2) Brominated polycaprolactone Br-PCL 30 -PCL 30 The preparation of -Br is the same as in Example 1;

[0107] (3) Br-PCL 30 -PCL 30 Br (7.21 g, 1.0 mmol), diethylaminoethyl 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) were added to tetrahydrofuran (100 mL), and the mixture was reacted under argon protection at 65 °C for 48 h. The reaction mixture was then added to excess 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. 20 -PCL 30 -PCL 30 -PDEAEMA20 (GPC curve as shown) Figure 6 Calculate Mn = 13687).

[0108] Example 7

[0109] One embodiment of the anti-aging EGCG nanocomposition of the present invention differs from Example 1 only in that the carrier is replaced with the block polymer PDEAEMA. 40 -PCL 30 -PCL 30 -PDEAEMA 40 (Different degrees of protonatable block polymerization), block polymer PDEAEMA 40 -PCL 30 -PCL 30 -PDEAEMA 40 The preparation method is as follows:

[0110] Steps (1) and (2) Brominated polycaprolactone Br-PCL 30 -PCL 30 The preparation of -Br is the same as in Example 1;

[0111] (3) 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), and N,N,N',N',N”-pentamethyldiethylenetriamine (1.39 g, 8 mmol) were added to tetrahydrofuran (100 mL), and the mixture was reacted under argon protection at 65 °C for 48 h. The reaction mixture was then added to excess 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. 40 -PCL 30 -PCL 30 -PDEAEMA 40 (GPC curve as shown) Figure 6 Calculate Mn = 19872).

[0112] Example 8

[0113] One embodiment of the anti-aging EGCG nanocomposition of the present invention differs from Example 1 only in that the carrier is replaced with the block polymer PDEAEMA. 80 -PCL 30 -PCL 30 -PDEAEMA 80 (Different degrees of protonable block polymerization) are prepared as follows:

[0114] Steps (1) and (2) Brominated polycaprolactone Br-PCL 30 -PCL 30 The preparation of -Br is the same as in Example 1;

[0115] (3) 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) were added to tetrahydrofuran (100 mL), and the mixture was reacted under argon protection at 65 °C for 48 h. The reaction mixture was then added to excess 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. 80 -PCL 30 -PCL 30 -PDEAEMA 80 (GPC curve as shown) Figure 6 Calculate Mn = 35021).

[0116] Example 9

[0117] One embodiment of the anti-aging EGCG nanocomposition of the present invention differs from Example 1 only in that the carrier is replaced with the block polymer PDEAEMA. 100 -PCL 30 -PCL 30 -PDEAEMA 100 (Different degrees of protonable block polymerization) are prepared as follows:

[0118] Steps (1) and (2) Brominated polycaprolactone Br-PCL 30 -PCL 30 The preparation of -Br is the same as in Example 1;

[0119] (3) 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) were added to tetrahydrofuran (100 mL), and the mixture was reacted under argon protection at 65 °C for 48 h. The reaction mixture was then added to excess 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. 100 -PCL 30 -PCL 30 -PDEAEMA 100 (GPC curve as shown) Figure 6 Calculate Mn = 42287).

[0120] Example 10

[0121] One embodiment of the anti-aging EGCG nanocomposition of the present invention differs from Example 1 only in that the carrier is replaced with the block polymer PDEAEMA. 60 -PCL 10 -PCL 10 -PDEAEMA 60 (i.e., the degree of polymerization of the hydrophobic blocks is different), and its preparation method is as follows (taking the preparation of 1.0 mmol as an example):

[0122] (1) 1,6-hexanediol (118.17 mg, 1.0 mmol), ξ-caprolactone (2.28 g, 20 mmol), and stannous octoate (0.81 g, 2.0 mmol) were mixed thoroughly, and the mixture was reacted at 130 °C for 12 h under argon protection to obtain mesoblock polycaprolactone PCL. 10 -PCL 10 .

[0123] (2) The intermediate block polycaprolactone PCL 10 -PCL 10 (2.40 g, 1.0 mmol) was dissolved in a mixed solution of dichloromethane (100 mL) and triethylamine (10 mL) under argon protection. 2-Bromoisobutyryl bromide (1.38 g, 6.0 mmol) was added, and the reaction was carried out at 20 °C for 24 h. The reaction mixture was washed four times with 300 mL each time with hydrochloric acid solution (1.0 mol / L), saturated NaHCO3, and deionized water. The organic phase was dried overnight with anhydrous MgSO4. The supernatant was collected and concentrated by rotary evaporation. The product was precipitated with excess n-hexane (5 °C), and the solid product was dried at 50 °C for 24 h to obtain brominated polycaprolactone Br-PCL. 10 -PCL 10-Br.

[0124] (3) Br-PCL 10 -PCL 10 Br (2.65 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), and the mixture was reacted under argon protection at 65 °C for 48 h. The reaction mixture was then added to excess 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 10 -PCL 10 -PDEAEMA 60 (GPC curve as shown) Figure 6 Calculate Mn = 22410).

[0125] Example 11

[0126] One embodiment of the anti-aging EGCG nanocomposition of the present invention differs from Example 1 only in that the carrier is replaced with the block polymer PDEAEMA. 60 -PCL 50 -PCL 50 -PDEAEMA 60 (i.e., the degree of polymerization of the hydrophobic blocks is different), and its preparation method is as follows (taking the preparation of 1.0 mmol as an example):

[0127] (1) 1,6-hexanediol (118.17 mg, 1.0 mmol), ξ-caprolactone (11.4 g, 100 mmol), and stannous octoate (0.81 g, 2.0 mmol) were mixed thoroughly, and the mixture was reacted at 130 °C for 12 h under argon protection to obtain mesoblock polycaprolactone PCL. 50 -PCL 50 .

[0128] (2) The intermediate block polycaprolactone PCL 50 -PCL 5011.53 g (1.0 mmol) was dissolved in a mixed solution of dichloromethane (100 mL) and triethylamine (10 mL) under argon protection. 2-Bromoisobutyryl bromide (1.38 g, 6.0 mmol) was added, and the reaction was carried out at 20 °C for 24 h. The reaction mixture was washed four times with 300 mL each time with hydrochloric acid solution (1.0 mol / L), saturated NaHCO3, and deionized water. The organic phase was dried overnight with anhydrous MgSO4. The supernatant was collected and concentrated by rotary evaporation. The product was precipitated with excess n-hexane (5 °C), and the solid product was dried at 50 °C for 24 h to obtain brominated polycaprolactone Br-PCL. 50 -PCL 50 -Br.

[0129] (3) Br-PCL 50 -PCL 50 Br (11.78 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), and the mixture was reacted under argon protection at 65 °C for 48 h. The reaction mixture was then added to excess 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 50 -PCL 50 -PDEAEMA 60 (GPC curve as shown) Figure 6 Calculate Mn = 31540).

[0130] Examples 12-15

[0131] Examples 12-15 are examples of the anti-aging EGCG nanocomposition of the present invention, differing from Example 1 only in that the pH adjuster and the pH value of the nanocomposition are adjusted as follows:

[0132] In Example 12, 0.08% glutamic acid was replaced with 0.2% glutamic acid by mass, and the composition of the remaining components was kept unchanged by adjusting the balance with water. The pH of the B phase solution was 3, and the actual measured pH value of the anti-aging EGCG nanocomposite was 3.

[0133] In Example 13, 0.08% glutamic acid was replaced with 0.14% glutamic acid by mass, and the composition of the remaining components was kept unchanged by adjusting the balance with water. The pH of the B phase solution was 4, and the measured pH of the anti-aging EGCG nanocomposite was 4.1.

[0134] In Example 14, 0.08% glutamic acid was replaced with 0.04% glutamic acid by mass, and the composition of the remaining components was kept unchanged by adjusting the balance with water. The pH of the B phase solution was 6, and the measured pH of the anti-aging EGCG nanocomposite was 6.3.

[0135] In Example 15, 0.08% glutamic acid was replaced with 0.08% deionized water by mass, while the other components remained unchanged. The pH of the B phase solution was 7, and the measured pH of the anti-aging EGCG nanocomposite was 6.9.

[0136] Examples 16-18

[0137] Examples 16-18 are examples of the anti-aging EGCG nanocomposition of the present invention, which differ from Example 1 only in that the type of stabilizer used is changed.

[0138] In Example 16, the stabilizer isobutylamide thiazole resorcinol was replaced with phenylethyl resorcinol, while the mass percentage remained unchanged.

[0139] In Example 17, the stabilizer isobutylamidothiazole resorcinol was replaced with 4-butylresorcinol, with the mass percentage remaining unchanged.

[0140] In Example 18, the stabilizer isobutylamidothiazole resorcinol was replaced with 4-cyclohexylresorcinol, with the mass percentage remaining unchanged.

[0141] Examples 19-22

[0142] Examples 19-22 are examples of the anti-aging EGCG nanocomposition of the present invention. The only difference from Example 1 is that the amount of carrier or active ingredient is changed.

[0143] Example 19 shows a reduction in the block polymer PDEAEMA. 60 -PCL 30 -PCL 30 -PDEAEMA 60 The mass percentage is 0.5%.

[0144] Example 20 adds the block polymer PDEAEMA 60 -PCL 30 -PCL 30 -PDEAEMA 60 The mass percentage is 5%.

[0145] In Example 21, the mass percentage reduction of the active ingredient EGCG was 0.5%.

[0146] In Example 22, the mass percentage of the active ingredient EGCG was increased to 5%.

[0147] Comparative Example 1

[0148] The only difference between Comparative Example 1 and Example 1 is that the carrier is replaced with the block polymer PPEGMA. 60 -PCL 30 -PCL 30 -PPEGMA 60 Block polymer PPEGMA 60 -PCL 30 -PCL 30 -PPEGMA 60 The preparation method is as follows:

[0149] Steps (1) and (2) Brominated polycaprolactone Br-PCL 30 -PCL 30 The preparation of -Br is the same as in Example 1;

[0150] (3) 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), and N,N,N',N',N”-pentamethyldiethylenetriamine (2.08 g, 12 mmol) were added to tetrahydrofuran (100 mL), and the mixture was reacted under argon protection at 65 °C for 48 h. The reaction mixture was then added to excess 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 PPEGMA. 60 -PCL 30 -PCL 30 -PPEGMA 60 (Mn=66850).

[0151] Comparative Example 2

[0152] The only difference between Comparative Example 2 and Example 1 is that the carrier is replaced with the block polymer PDEAEMA. 10 -PCL 30 -PCL 30 -PDEAEMA 10 (i.e., further reducing the degree of polymerization of protonable blocks), block polymer PDEAEMA 10 -PCL 30 -PCL 30 -PDEAEMA 10 The preparation method is as follows:

[0153] Steps (1) and (2) Brominated polycaprolactone Br-PCL 30 -PCL30 The preparation of -Br is the same as in Example 1;

[0154] (3) 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), and N,N,N',N',N”-pentamethyldiethylenetriamine (0.35 g, 2 mmol) were added to tetrahydrofuran (100 mL), and the mixture was reacted under argon protection at 65 °C for 48 h. The reaction mixture was then added to excess 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. 10 -PCL 30 -PCL 30 -PDEAEMA 10 (Mn=10555).

[0155] Comparative Example 3

[0156] The only difference between Comparative Example 3 and Example 1 is that the carrier is replaced with the block polymer PDEAEMA. 60 -PCL 60 -PCL 60 -PDEAEMA 60 (i.e., further increasing the degree of polymerization of the hydrophobic blocks), the block polymer PDEAEMA 60 -PCL 60 -PCL 60 -PDEAEMA 60 The preparation method is as follows:

[0157] (1) 1,6-hexanediol (118.17 mg, 1.0 mmol), ξ-caprolactone (13.68 g, 120 mmol), and stannous octoate (4.86 g, 12.0 mmol) were mixed thoroughly, and the mixture was reacted at 130 °C for 12 h under argon protection to obtain mesoblock polycaprolactone PCL. 60 -PCL 60 .

[0158] (2) The intermediate block PCL 60 -PCL 6013.82 g (1.0 mmol) was dissolved in a mixed solution of dichloromethane (100 mL) and triethylamine (10 mL) under argon protection. 2-Bromoisobutyryl bromide (1.38 g, 6.0 mmol) was added, and the reaction was carried out at 20 °C for 24 h. The reaction mixture was washed four times with 300 mL each time with hydrochloric acid solution (1.0 mol / L), saturated NaHCO3, and deionized water. The organic phase was dried overnight with anhydrous MgSO4. The supernatant was collected and concentrated by rotary evaporation. The product was precipitated with excess n-hexane (5 °C), and the solid product was dried at 50 °C for 24 h to obtain brominated polycaprolactone Br-PCL. 60 -PCL 60 -Br.

[0159] (3) 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) were added to tetrahydrofuran (100 mL), and the mixture was reacted under argon protection at 65 °C for 48 h. The reaction mixture was then added to excess 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 60 -PCL 60 -PDEAEMA 60 (Mn=35930).

[0160] Comparative Example 4

[0161] The only difference between Comparative Example 4 and Example 1 is that 1% of the stabilizer by mass was replaced with 1% of deionized water.

[0162] Comparative Example 5

[0163] The only difference between Comparative Example 5 and Example 1 is that 0.04% glutamic acid was replaced with 0.1% concentrated hydrochloric acid by mass, the composition of the remaining components was kept unchanged by adjusting the balance with water, the pH of the B phase solution was 2, and the actual pH value of the nanocomposite was 2.

[0164] Comparative Example 6

[0165] The only difference between Comparative Example 6 and Example 1 is that 0.08% glutamic acid was replaced with 0.08% sodium glutamate by mass, the composition of the remaining components was kept unchanged by adjusting the balance with water, the pH of the B phase solution was 8, and the measured pH of the nanocomposite was 7.8.

[0166] Comparative Example 7

[0167] The only difference between Comparative Example 7 and Example 1 is the reduction of the block polymer PDEAEMA. 60 -PCL 30 -PCL 30 -PDEAEMA 60 The mass percentage is 0.1%.

[0168] Comparative Example 8

[0169] The only difference between Comparative Example 8 and Example 1 is that the mass percentage of the active ingredient EGCG is increased by 6%.

[0170] Comparative Example 9

[0171] The nanocomposite in Comparative Example 9 consisted of the following components by mass percentage: 2% active ingredient, 0.08% pH adjuster, and the balance being water. The active ingredient was EGCG, and the pH adjuster was glutamic acid. Its preparation method was as follows:

[0172] Add EGCG and glutamic acid to deionized water according to the mass percentage, stir at 300 rpm for 15 min until EGCG is completely dissolved, and obtain an EGCG aqueous solution with a pH of 5.

[0173] Example 1

[0174] To investigate the encapsulation effect of the anti-aging EGCG nanocomposition provided by the present invention, the particle size and encapsulation efficiency in the above examples and comparative examples 1-8 were tested, as follows:

[0175] Particle size determination: The particle size of the samples in the above examples and comparative examples 1-8 was characterized using a Malvern Nano-ZS90 dynamic light scattering particle size analyzer. The test angle was 90° and the test temperature was 25°C. Each group of experiments was conducted in triplicate, and the arithmetic mean of the experimental results was taken.

[0176] Encapsulation efficiency determination: 200 μL of samples from Examples 1-8 and Comparative Examples 1-8 were ultrafiltered and centrifuged (9000 rpm, 30 min). 5 μL of the filtrate was then analyzed using a high-performance liquid chromatograph (HPLC, Shimadzu, Japan) to determine the EGCG content in the filtrate. This yielded the content of unencapsulated EGCG in the nanocomposite. The analytical column used in the HPLC system was a non-polar C24 column. 18 The column was used with acetonitrile as the mobile phase, the flow rate was 1.0 ml / min, and the column temperature was 30 ℃. Each experiment was performed in triplicate, and the arithmetic mean of the results was taken.

[0177] In another example and comparative example, the nanocompositions were added to a methanol and water mixture, and ultrasonically demulsified for 30 min at a ratio of sample:methanol:water = 1:4:5 (v / v). After filtration through a 0.45 μm organic filter membrane, 5 μL of the sample solution was analyzed by high-performance liquid chromatography (HPLC, Shimadzu, Japan) to determine the EGCG content in the nanocomposition. The EGCG encapsulation efficiency (EE) in the nanocomposition was calculated using the following formula:

[0178]

[0179] Where C1 represents the concentration of unencapsulated EGCG in the sample; C0 represents the concentration of EGCG in the sample after ultrasonic demulsification using a mixture of methanol and deionized water.

[0180] The particle size and encapsulation efficiency test results of the above embodiments and comparative examples 1-8 are shown in Table 1 below; wherein the particle size and particle size distribution of the nanocomposite of Example 1 are as follows. Figure 7 .

[0181] Table 1. Test results of particle size and EGCG encapsulation efficiency of the nanocomposite.

[0182] sample Particle size (nm) EGCG encapsulation rate (%) 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 Regarding Example 2 315.4 32.6 Comparative Example 3 287.6 35.7 Regarding 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

[0183] The results in Table 1 show that:

[0184] Comparing Examples 1-5, it is evident that the type of protonable and hydrophobic blocks in the block polymers affects both the particle size and encapsulation efficiency of the product. In Examples 1-3, the protonable blocks in the block polymers were PDEAEMA, PDMAEMA, and PTBAEMA, respectively. When PDEAEMA (Example 1) was selected as the protonable block, the final product exhibited the smallest particle size, the highest encapsulation efficiency, and the best EGCG encapsulation effect. In Examples 1, 4, and 5, the hydrophobic blocks in the block polymers were PCL, PLA, and PGA, respectively. When PCL (Example 1) was selected as the hydrophobic block, the nanocomposite product exhibited the smallest particle size, the highest encapsulation efficiency, and a better EGCG encapsulation effect.

[0185] Comparing Examples 1, 6-11, and Comparative Examples 2 and 3, the different degrees of polymerization of the protonable blocks and hydrophobic blocks in the block polymers all affect the particle size and encapsulation efficiency of the products. In Examples 1, 6-9, and Comparative Example 2, the degrees of polymerization of the protonable blocks were 60, 20, 40, 80, 100, and 10, respectively. As the degree of polymerization of the protonable blocks in the block polymers gradually increased, the product particle size first decreased and then increased, while the encapsulation efficiency first increased and then decreased. In Example 1, when the degree of polymerization of the protonable blocks was selected as 60, the final product had the smallest particle size, the highest encapsulation efficiency, and the best encapsulation effect on EGCG. In Examples 1, 10-11, and Comparative Example 3, the degrees of polymerization of the hydrophobic blocks were 30, 10, 50, and 60, respectively. As the degree of polymerization of the hydrophobic blocks 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 blocks is selected as 30 (Example 1), the particle size of the product is the smallest, the encapsulation efficiency is the highest, and the encapsulation effect on EGCG is the best.

[0186] Comparing Examples 1, 12-15, and Comparative Examples 5-6, the pH value of the nanocomposite significantly affects the particle size and encapsulation efficiency of the product. The pH values ​​of the nanocomposite compositions in Examples 1, 12-15, and Comparative Examples 5-6 were 5.2, 3.0, 4.1, 6.3, 6.9, 2.0, and 7.8, respectively. As the pH value of the nanocomposite gradually increased, the particle size first decreased and then increased, while the encapsulation efficiency first increased and then decreased. When the pH was 5.2 (Example 1), the product had the smallest particle size, the highest encapsulation efficiency, and the best overall effect.

[0187] In Comparative Examples 1, 16-18, and Comparative Example 4, the stabilizers were isobutylamidothiazole resorcinol, phenylethyl resorcinol, 4-butylresorcinol, 4-cyclohexylresorcinol, and no stabilizer, respectively. The results showed that when isobutylamidothiazole resorcinol (Example 1) was selected as the stabilizer, the final product had a smaller particle size, higher encapsulation efficiency, and better EGCG encapsulation effect.

[0188] In Comparative Examples 1, 19-20, and 7, the block polymer addition amounts were 2%, 0.5%, 5%, and 0.1%, respectively. As the block polymer addition amount in the nanocomposite gradually increased, the particle size first decreased and then increased, while the encapsulation efficiency first increased and then decreased. When the block polymer addition amount was 2% (Example 1), the product had the smallest particle size and the highest encapsulation efficiency. In Comparative Examples 1, 21-22, and 8, the EGCG addition amounts in the nanocomposite compositions were 2%, 0.5%, 5%, and 6%, respectively. As the EGCG addition amount gradually increased, the particle size first decreased and then increased, while the encapsulation efficiency first increased and then decreased. The EGCG addition amount was most suitable at 2% (Example 1), at which point the product had the smallest particle size and the highest encapsulation efficiency. Considering all factors, a 2% EGCG mass percentage was chosen, and the cases of excessive or insufficient active ingredients were no longer investigated.

[0189] Compared with Comparative Example 1, compared with PPEGMA (non-protonated block), the block polymer prepared by using protonable block PDEAEMA and linked hydrophobic block PCL, which encapsulates EGCG, has a smaller particle size, higher encapsulation efficiency, and better EGCG encapsulation capacity.

[0190] Example 2

[0191] To investigate the transdermal absorption effect of the anti-aging EGCG nanocomposition provided by this invention, a transdermal absorption (penetration enhancement) experiment was used to evaluate the transdermal absorption capacity of the nanocomposition. The specific method is as follows:

[0192] In vitro transdermal experiments were conducted using a vertical diffusion cell, with nude mouse skin (abdominal skin, with subcutaneous fat and blood vessels removed) as the model. PBS solution was used as the receiving fluid. The skin patch was fixed between the supply and receiving cells, skin layer facing upwards, and equilibrated for 20 minutes. The nanocomposite samples from each example and comparative example were prepared into 10% (w / w) sample solutions, and these solutions were added to the supply cell. Receiving fluid was collected after 1 hour, 4 hours, 8 hours, and 24 hours. The receiving fluid was ultrasonically demulsified with a mixture of methanol and deionized water at a ratio of receiving fluid:methanol:water = 1:4:5 (V / V) for 30 minutes. After filtration through a 0.45 μm organic filter membrane, the EGCG content was determined by high-performance liquid chromatography (HPLC, Shimadzu, Japan), and the cumulative permeation per unit area was calculated. Each experiment was performed in triplicate, and the arithmetic mean of the results was taken. The formula for calculating the cumulative permeation per unit area on the skin patch is as follows:

[0193]

[0194] Among them, Q n The cumulative transmittance per unit area of ​​the sample at time t (μg / cm²) 2 ), A is the permeation area, C nC represents the concentration of the active ingredient measured at time t. i V represents the measured concentration of the active ingredient at time point t, V is the total volume of the receiving liquid, and V0 is the sampling volume at each time point. The results are shown in Table 2 below.

[0195] Table 2. Results of in vitro transdermal testing of the nanocomposition.

[0196]

[0197] The results in Table 2 show that:

[0198] Comparing Examples 1-5, the type of protonable and hydrophobic blocks in the block polymer affects the transdermal permeability of the product. When the protonable block was selected as PDEAEMA (Example 1), the cumulative permeation per unit area of ​​the final prepared EGCG nanocomposition (Example 1) was 2.91 μg / cm² at 1h, 4h, 8h, and 24h. 2 15.45 μg / cm 2 36.52 μg / cm 2 88.72 μg / cm 2 The permeability was higher than that of the samples in Examples 2-3, and the carrier selected in Example 1 had the best transdermal permeability. When the hydrophobic block was selected as PCL (Example 1), the cumulative permeability per unit area of ​​the final product was higher, indicating that its transdermal permeability was better.

[0199] Comparing Examples 1, 6-11, and 2 and 3, the degree of polymerization of the protonable and hydrophobic blocks in the block polymer affects the transdermal permeability of the product. When the degree of polymerization of the protonable block is selected as 60 (Example 1), the product has a higher cumulative permeation per unit area, indicating better transdermal permeability. When the degree of polymerization of the hydrophobic block is selected as 30 (Example 1), the product has a higher cumulative permeation per unit area, indicating better transdermal permeability.

[0200] Comparing Examples 1, 12-15, and 5-6, the pH value of the nanocomposite significantly affects the transdermal permeability of the product: In Example 1, when the pH of the nanocomposite was 5.2, the cumulative permeation per unit area of ​​the product was higher, resulting in superior transdermal permeability. Comparing Examples 1, 16-18, and 4, the type of stabilizer in the nanocomposite affects the transdermal permeability: When the stabilizer was isobutylamidothiazol resorcinol (Example 1), the cumulative permeation per unit area of ​​the product was higher, resulting in superior transdermal permeability. Comparing Examples 1, 19-20, and 7, the amount of block polymer added affects the transdermal permeability: When the amount of block polymer added was 2% (Example 1), the cumulative permeation per unit area was higher, resulting in superior transdermal permeability.

[0201] Comparing Example 1 and Comparative Example 1, it can be seen that, compared to PPEGMA (unprotonated block polymer), the block polymer prepared by linking the hydrophobic block PCL with the protonable block PDEAEMA of this invention, which encapsulates EGCG, has a higher cumulative permeation per unit area and better transdermal permeability. Comparing Example 1 and Comparative Example 9 (EGCG aqueous solution), it can be seen that, compared to unencapsulated free EGCG, the EGCG encapsulation strategy adopted in this application can significantly improve the transdermal permeability of EGCG.

[0202] Example 3

[0203] To investigate the effects of the anti-aging EGCG nanocomposition provided in this invention on cells after UV damage, the amount of ATP produced in the cells was measured to evaluate the function and activity of mitochondria, as detailed below:

[0204] ATP levels were detected using an ATP assay kit, which is available from Shanghai Beyotime Biotechnology Co., Ltd. The specific experimental method is as follows:

[0205] a. Preparation of ATP standard solution: Thaw the reagents to be used on an ice bath, and dilute the ATP standard solution with ATP detection lysis buffer to a certain concentration gradient (0.1nM, 0.3nM, 1nM, 3nM, 10nM, 30nM, 100nM).

[0206] b. Sample preparation: Human skin keratinocytes (HaCaT cells) were digested and prepared into a cell suspension, which was then seeded into 6-well plates at a density of 5.0 × 10⁶ cells per well. 5 -10.0×10 5 Cells were cultured in DMEM medium for 24 hours, followed by UVA irradiation (6-10 J / cm²) on both the control and experimental groups. 2 After the light exposure ended, the culture medium was replaced, and 50 μL of the nanocomposite sample from the examples and comparative examples (experimental group) or PBS solution (blank group and control group) was added respectively, and the cells were cultured for another 24 h. The cell culture medium was removed, and the cells were washed three times with PBS. The cells were collected by centrifugation and washed once with PBS. After aspirating all the PBS, the cells were appropriately dispersed. 200 μL of lysis buffer was added to each well to lyse the cells. After lysis, the cells were centrifuged at 4°C for 5 min (12000 rpm), and the supernatant was collected for analysis.

[0207] c. Determination of ATP concentration: Add 100 μL of ATP detection working solution to the detection tube and let it stand at room temperature for 3-5 minutes to allow all background ATP to be consumed, thereby reducing the background. Add 20 μL of the test sample or ATP standard solution to the detection tube, mix well with a micropipette, and measure the RLU value using a chemiluminescence analyzer. Plot an ATP standard curve with the ATP content of the ATP standard solution as the x-axis and the RLU value as the y-axis. The ATP content of the test sample can be calculated from the ATP standard curve. The results are shown in Table 3 below. Table 3 ATP content test results of UV-damaged cells treated with nanocomposite

[0208] The results in Table 3 show that:

[0209] Comparing Examples 1-5, the different types of protonable and hydrophobic blocks in the block polymers both affect the protective effect of the product on mitochondria. After co-incubating UV-damaged cells with the sample from Example 1, the ATP content in the mitochondria was the highest, at 0.357 nM, which could restore the cells to 92.97% of the level of normal healthy cells. Example 1 showed the best mitochondrial protective effect from the protonable block PDEAEMA. When the hydrophobic block was PCL (Example 1), the nanocomposition prepared and co-incubated with UV-damaged cells showed the highest ATP content in the mitochondria, indicating the best mitochondrial protective effect.

[0210] Comparing Examples 1, 6-11, and 2 and 3, the degree of polymerization of the protonable and hydrophobic blocks in the block polymer affects the protective effect of the product on mitochondria. When the degree of polymerization of the protonable block was selected as 60 (Example 1), the nanocomposite prepared and co-incubated with UV-damaged cells showed the highest ATP content in the mitochondria, indicating the best mitochondrial protective effect. When the degree of polymerization of the hydrophobic block was selected as 30 (Example 1), the nanocomposite prepared and co-incubated with UV-damaged cells also showed the highest ATP content in the mitochondria, indicating the best mitochondrial protective effect.

[0211] The pH of the nanocompositions in Comparative Examples 1, 12-15, and 5-6 affected the protective effect of the products on mitochondria. When the pH of the nanocomposition was 5.2 (Example 1), the ATP content in the mitochondria was the highest after co-incubation with UV-damaged cells, indicating the best mitochondrial protective effect. Comparative Examples 1, 16-18, and Comparative Example 4 showed that the addition and type of stabilizer had a significant impact. When the stabilizer was isobutylamidothiazol resorcinol (Example 1), the nanocomposition showed the highest ATP content in the mitochondria and the best mitochondrial protective effect after co-incubation with UV-damaged cells. Comparative Examples 1, 19-20, and Comparative Example 7, the amount of block polymer added to the nanocomposition significantly affected the protective effect of the products on mitochondria; when the amount of block polymer added was 2% (Example 1), the nanocomposition showed the best mitochondrial protective effect.

[0212] Compared to Example 1 and Comparative Example 1, compared to PPEGMA (unprotonated block), the block polymer prepared by linking the protonable block PDEAEMA with the hydrophobic block PCL to encapsulate EGCG, after co-incubation with UV-damaged cells, showed higher ATP content in mitochondria and better mitochondrial protection. Compared to Example 1 and Comparative Example 9 (EGCG aqueous solution), compared to unencapsulated free EGCG, the nanocomposition prepared using the encapsulation strategy of this invention showed higher ATP content in mitochondria after co-incubation with UV-damaged cells, indicating better mitochondrial protection.

[0213] Example of effect 4

[0214] Further investigation was conducted into the cellular uptake and bioavailability of the anti-aging EGCG nanocomposition provided by this invention, as detailed below:

[0215] Exponentially growing HACAT cells (density 5×10⁻⁶) 4Cells were seeded in six-well plates with coverslips pre-mounted and cultured in DMEM solution (2 mL). The plates were incubated at 37°C, saturated humidity, and 5% CO2 for 24 h. The culture medium was removed, and 2 mL of sample solution (1% by mass aqueous solution of the nanocomposites from Examples 1, 12-15, and Comparative Examples 1, 4-6, and 9, respectively) was added to each well. The plates were incubated at 37°C, saturated humidity, and 5% CO2 for 30 min, 1 h, 2 h, and 4 h, respectively. The culture medium was removed, and the cells were washed twice with PBS solution and fixed with 4% paraformaldehyde for 0.5 h. The paraformaldehyde solution was removed, and the cells were washed twice with PBS solution. The plates were incubated with DAPI (4',6-diamidinyl-2-phenylindole) for 30 min, washed three times with PBS solution, and then mounted on coverslips. The fluorescence intensity of the coverslip was measured under a laser confocal microscope (CLSM, Leica SP8, Leica Microsystems, USA). The excitation wavelength was 488 nm and the emission wavelength was 525 nm. The results are shown in Table 4.

[0216] Table 4. Cell endocytosis test results of the nanocomposite

[0217]

[0218] As shown in Table 4, the fluorescence intensity in the experimental groups of Example 1, Examples 12-15, Comparative Examples 1, Comparative Examples 4-6, and Comparative Example 9 gradually increased with the increase of reaction time, indicating that more samples entered the cells and cell nuclei via endocytosis. Compared with Example 12 (pH 3.0), Example 13 (pH 4.1), Example 14 (pH 6.3), Example 15 (pH 6.9), Comparative Example 5 (pH 2.0), and Comparative Example 6 (pH 7.8), the sample of Example 1 (pH 5.2) showed the highest fluorescence intensity in HACAT cells during co-incubation periods of 30 min, 1 h, 2 h, and 4 h, indicating that the EGCG nanocomposite in Example 1 entered the cells and reached the cell nucleus in the largest quantity, and was taken up by the cells in the largest amount. Compared to Comparative Examples 1 and 4, the block polymer of this invention uses the protonable block PDEAEMA and the hydrophobic block PCL to encapsulate EGCG, and selects isobutylamidothiazol resorcinol as a stabilizer. The resulting nanocomposite exhibits the highest fluorescence intensity in HACAT cells during co-incubation at 30 min, 1 h, 2 h, and 4 h, indicating that the greater the number of nanocomposites in Example 1 that enters the cell nucleus, the greater the amount taken up by the cells. Furthermore, compared to the EGCG aqueous solution in Comparative Example 9, the anti-aging EGCG nanocomposite prepared by this application using a specific block polymer to encapsulate EGCG significantly increases the amount of EGCG entering the cell nucleus, resulting in a significantly greater amount taken up by the cells and a significantly better effect.

[0219] Example 5

[0220] To further explore the anti-aging application effect of the anti-aging EGCG nanocomposition of the present invention, anti-aging creams were prepared according to the formulations in Table 5 below using the nanocompositions of Example 1, Comparative Example 1, Comparative Example 4, and Comparative Example 9. The preparation methods are as follows: According to the formulations in Table 5, caprylic / capric triglyceride, 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 homogenized at 11000 rpm for 10 min, and cooled to 45°C; finally, the nanocompositions of Example 1, Comparative Example 1, Comparative Example 4, and Comparative Example 9 were added respectively, and stirred at 300 rpm for 20 min to obtain the corresponding anti-aging creams. The cream base was prepared by replacing the nanocomposition with an equal amount of deionized water, while keeping the rest unchanged.

[0221] Table 5 Anti-aging Cream Formula Table

[0222]

[0223] The testing method is as follows: 120 volunteers (aged 30-45) with facial wrinkles were selected as volunteers for the anti-aging efficacy test. They were randomly divided into 4 groups of 30 each. The anti-aging creams from Example 1, Comparative Example 1, Comparative Example 4, and Comparative Example 9 were applied to both sides of the face of each of the 4 groups of volunteers. The test lasted for five weeks, with tests conducted at the initial stage (week 0), after 2 weeks of use, after 4 weeks of use, and after 1 week of discontinuation. Skin firmness (face), skin elasticity (face), and wrinkle area (eyes) were measured. The results are shown in Table 6 below. The distribution of eye wrinkles in the volunteers of Example 1 and Comparative Example 1 after 2 weeks, 4 weeks, and 1 week of discontinuation of the anti-aging cream is shown in Table 6 below. Figure 8 .

[0224] Table 6. Test results of skin firmness, skin elasticity, and wrinkle area indicators of anti-aging creams.

[0225] As shown in Table 6, the anti-aging cream of Example 1 has a better anti-aging effect than Comparative Example 1, further verifying that the block polymer encapsulation strategy with specific protonable blocks used in this application has superior anti-aging efficacy. The comparison between the anti-aging creams of Example 1 and Comparative Example 4 verifies that the specific isobutylamidothiazole resorcinol stabilizer of this invention has a significant impact on the anti-aging efficacy of the prepared cream. The comparison between the anti-aging cream of Example 1 and Comparative Example 9 shows that the overall strategy of block polymer encapsulation used in this invention can effectively improve the bioavailability of EGCG and better exert its efficacy. Furthermore, after volunteers discontinued the product for one week, only the skin condition of the Example 1 group showed significantly better elasticity, firmness, and wrinkle reduction compared to the others, indicating that the application of the anti-aging EGCG nanocomposition of this invention in cosmetics has significant and lasting anti-aging efficacy.

[0226] In summary, this invention selects protonable block copolymers with a certain degree of polymerization to link hydrophobic blocks to prepare block polymers with specific structures. By selecting suitable stabilizers and adjusting the pH value, an anti-aging EGCG nanocomposition is formed through self-assembly and encapsulation of the active ingredient EGCG. This achieves high encapsulation efficiency and high transdermal penetration, exhibiting high cellular uptake and excellent mitochondrial protection for UV-damaged cells. Furthermore, the nanocomposition provided by this invention possesses long-lasting anti-aging properties. Cosmetics or topical medications made using this nanocomposition maintain good skin elasticity, firmness, and wrinkle reduction even after one week of discontinuation, demonstrating high application value.

[0227] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention 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, comprises 0.5-5% of a carrier, 0.5-2% of a stabilizer, 0.5-5% of an active ingredient, 10-30% of a polyol, 0.02-0.2% of a pH regulator, and the rest of water; 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 , the X m is a hydrophobic block, the Y n is a protonatable block; the m is the polymerization degree of the hydrophobic block, m = 10-50; the n is the polymerization degree of the protonatable block, n = 20-100; the block polymer 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; the stabilizer is at least one of phenylethyl resorcinol, 4-butyl resorcinol, isobutyl amidothiazole resorcinol, and 4-cyclohexyl resorcinol; the preparation method of the block polymer comprises the following steps: (1) mixing dihydric alcohol, polyester monomer, and ROP reaction catalyst in a molar ratio of 1: (20-100) : (2-10), and reacting at 80-150 ℃ for 6-18 h under an inert atmosphere to obtain an intermediate block; (2) mixing the intermediate block and bromo initiator in a molar ratio of 1: (2-8) in an organic solvent, and reacting at 0-25 ℃ for 8-72 h under an inert atmosphere to obtain a bromo-treated intermediate block; (3) mixing methacrylic monomer, the bromo-treated intermediate block, ATRP reaction catalyst, and catalyst ligand in a molar ratio of 1: (40-200) : (0.4-2) : (4-20) in an organic solvent, and reacting at 60-100 ℃ for 12-48 h under an inert atmosphere to obtain the block polymer; the polyester monomer is at least one of ξ-caprolactone, D, L-lactide, and glycolide; and the methacrylic monomer is at least one of dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and 2-tert-butylaminoethyl methacrylate; the preparation method of the anti-aging EGCG nano-composition comprises the following steps: S1, adding carrier, stabilizer, and active ingredient into polyol, mixing to obtain phase A solution; adding pH regulator into water, mixing to obtain phase B solution; the pH of the phase B solution is 3-7; S2, dropping the phase A solution into the phase B solution, and simultaneously performing high shear treatment to obtain a mixed solution; S3, subjecting the mixed solution to microfluidic homogenization treatment to obtain the anti-aging EGCG nano-composition.

2. The anti-aging EGCG nano-composition as claimed in claim 1, wherein, the dihydric alcohol 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-icosanediol; and / or the ROP reaction catalyst is at least one of stannous octoate, stannous isooctoate, stannous tartrate, and stannous stearate. and / or the brominated initiator is at least one of 2-bromoisobutyryl bromide, bis[2-(2'- bromoisobutyryloxy)ethyl] disulfide, tert-butyl 2-bromoisobutyrate, ethyl 2-bromoisovalerate; and / or the ATRP reaction catalyst is at least one of CuBr, CuCl, CuI; and / or the catalyst ligand is at least one of N,N-diisopropylethylamine, ethanolamine, N,N,N',N',N"-pentamethyldiethylenetriamine, tetrabutylammonium bromide.

3. The anti-aging EGCG nano-composition as claimed in claim 1, wherein, the polyol is at least one of 1,3-butanediol, 1,4-butanediol, 1,2-propanediol, 1,3- propanediol, glycerol, 1,2-hexanediol, ethoxydiglycol, octyldodecanol; and / or the pH adjuster is at least one of glutamic acid, aspartic acid, asparagine, glutamine, hydrochloric acid, citric acid, lactic acid, sulfuric acid, oxalic acid.

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