A mild sunscreen and a method of making the same

Abstract

The application discloses a mild sunscreen cream and a preparation method thereof, and relates to the technical field of skin care products. The mild sunscreen cream is composed of sunscreen agents and a cream base. The cream base comprises auxiliary sunscreen agents, emulsifiers, emollients, thickening agents, humectants, film formers, antioxidants, preservatives and solvents. The sunscreen agents are composite particles formed by covalently combining alkynyl-modified TiO2-HA composite particles with a lignin-cyclodextrin-aloe inclusion compound. The sunscreen cream prepared by the application has the effects of high-efficiency sun protection, mildness, low irritation, stable and long-lasting sun protection, and multiple skin care.

Description

Technical Field

[0001] This invention relates to the field of skincare technology, specifically to a mild sunscreen and its preparation method. Background Technology

[0002] Ultraviolet (UV) radiation from sunlight is one of the main causes of skin aging. Direct exposure can cause a range of skin problems, including blemishes, dermatitis, and even skin cancer. With the thinning of the ozone layer leading to a continuous increase in UV radiation intensity, and with people's growing demands for skin health and aesthetics, the development and application of sunscreen cosmetics has become an important research area in the daily chemical industry. Sunscreen agents are functional materials that protect the skin from sun damage by absorbing, reflecting, or scattering UV rays. Based on their mechanism of action, sunscreen agents can be divided into two main categories: chemical sunscreens and physical sunscreens. Chemical sunscreens achieve protection by absorbing UV rays and converting them into heat energy. They have advantages such as a lightweight texture and a pleasant feel on the skin, but their complex chemical formulations can easily irritate sensitive skin. Some chemical sunscreens, such as oxybenzone, also have issues such as photodegradation and environmental safety concerns. Physical sunscreens mainly consist of titanium dioxide and zinc oxide powders, two inorganic mineral powders. Compared to chemical sunscreens, physical sunscreens have significant advantages such as good photostability, low irritation, and broad-spectrum protection.

[0003] However, existing physical sunscreens still face a series of technical challenges in practical applications: First, titanium dioxide nanoparticles exhibit significant photocatalytic activity under ultraviolet irradiation, generating hydroxyl radicals, etc. These exogenous substances not only accelerate skin aging but may also degrade other organic components in sunscreen formulations, severely weakening the gentleness of physical sunscreens. Second, titanium dioxide nanoparticles and zinc oxide particles have large specific surface areas and high surface energies, making them prone to aggregation, resulting in poor dispersibility in the matrix. This not only affects ultraviolet shielding efficiency but also exacerbates the whitening effect after application. In addition, physical sunscreens offer relatively limited ultraviolet protection. Titanium dioxide nanoparticles provide strong protection against the UVB band (290-320nm) but are weaker against the UVA band, while zinc oxide performs better in the UVA band but has a more pronounced whitening problem. Neither can achieve ideal broad-spectrum protection on its own. Summary of the Invention

[0004] The purpose of this invention is to provide a mild sunscreen and its preparation method, thereby solving the following technical problems: Titanium dioxide nanoparticles offer strong protection against UVB but weak protection against UVA. Furthermore, titanium dioxide nanoparticles exhibit significant photocatalytic activity under ultraviolet radiation, making it difficult for sunscreens containing titanium dioxide nanoparticles to achieve ideal protective effects.

[0005] The objective of this invention can be achieved through the following technical solutions: A gentle sunscreen, consisting of sunscreen agents and a lotion base; The sunscreen is a composite particle formed by the covalent bonding of alkynyl-modified TiO2-HA composite particles and lignin-cyclodextrin-aloe inclusion complex.

[0006] As a further aspect of the present invention, the method for preparing the sunscreen agent includes the following steps: S1: Carboxylated lignin, aminolated β-cyclodextrin, and MES buffer were added to a reaction flask for dispersion. EDC·HCl and NHS were added, and the mixture was stirred at room temperature for 18-24 h. The reaction solution was dialyzed and freeze-dried to obtain lignin-β-cyclodextrin grafts. The lignin-β-cyclodextrin graft, aloe extract, and deionized water were added to a reaction vessel and mixed. The temperature was controlled at 35-40℃ and the reaction was kept at this temperature for 4-6 hours. After centrifugation, washing, and drying, the inclusion complex was obtained. S2: The inclusion complex and dimethyl sulfoxide were added to the reaction vessel and dispersed. Azide propionic acid, N,N'-diisopropylcarbodiimide and 4-dimethylaminopyridine were added. The temperature was controlled at 20-25℃ and the reaction was kept at this temperature for 12-24h. The reaction solution was poured into ice-cold ether to precipitate. The solid was collected by centrifugation, washed and dried to obtain the inclusion complex with azide groups on the surface. S3: Under light-proof and nitrogen atmosphere, alkynyl-modified TiO2-HA composite particles, inclusion complexes with azide groups on the surface, dimethyl sulfoxide, and deionized water are added to a reaction flask for dispersion. Sodium L-ascorbate and copper sulfate pentahydrate are added. The temperature is controlled at 25-35℃ and the reaction is kept at this temperature for 12-24 hours. After centrifugation, washing, and drying, the sunscreen agent is obtained.

[0007] As a further aspect of the present invention: the MES buffer in S1 is a 0.1M MES buffer with pH=6; the addition ratio of carboxylated lignin, aminolated β-cyclodextrin, MES buffer, EDC·HCl, and NHS is 10g:15-18g:400-600mL:8-16g:2-8g. The addition ratio of lignin-β-cyclodextrin graft, aloe extract, and deionized water is 10g: 2-4g: 100-200mL.

[0008] As a further embodiment of the present invention: the addition ratio of inclusion complex, dimethyl sulfoxide, azidopropionic acid, N,N'-diisopropylcarbodiimide, and 4-dimethylaminopyridine in S2 is 10g: 100-200mL: 4-8g: 6-10g: 0.4-1g.

[0009] As a further embodiment of the present invention: the addition ratio of alkynyl-modified TiO2-HA composite particles, surface-modified azide-based inclusion complex, dimethyl sulfoxide, deionized water, sodium L-ascorbate, and copper sulfate pentahydrate in S3 is 10g: 8-12g: 200-400mL: 100-200mL: 0.4-1.2g: 0.2-0.6g.

[0010] As a further aspect of the present invention, the preparation method of alkynyl-modified TiO2-HA composite particles includes the following steps: A1: Disperse diammonium hydrogen phosphate, deionized water I, and sodium citrate in a high-pressure reactor. Add calcium nitrate and deionized water II to the high-pressure reactor after mixing. Adjust the pH to 5-6 with nitric acid. Stir for 0.5-1 h, control the temperature at 140-150℃, and perform a hydrothermal reaction for 9-12 h. Centrifuge, wash, dry, and calcine to obtain hollow hydroxyapatite. A2: Under a nitrogen atmosphere, hollow hydroxyapatite and anhydrous ethanol were added to a reaction flask for dispersion. A mixture of aminopropyltriethoxysilane and deionized water was added to the reaction flask for dispersion. The mixture was heated to reflux for 6-9 hours, centrifuged, washed, and dried to obtain aminated hollow hydroxyapatite. A3: Aminated hollow hydroxyapatite and anhydrous ethanol were added to the reaction flask and dispersed. Tetrabutyl titanate and anhydrous ethanol were mixed and added to the reaction flask and dispersed. Nitric acid was added to adjust the pH to 3-4. The mixture was stirred at room temperature for 1-3 hours. Deionized water was added and stirred for 2-4 hours. The mixture was centrifuged, washed, and dried to obtain TiO2-HA composite particles. A4: Under a nitrogen atmosphere, TiO2-HA composite particles and MES buffer 1 were added to a reaction flask for dispersion. Succinic acid, EDC·HCl, NHS and MES buffer 2 were mixed and added to the reaction flask. The temperature was controlled at 20-25℃ and the reaction was kept at this temperature for 12-24h. After centrifugation, washing and drying, alkynyl-modified TiO2-HA composite particles were obtained.

[0011] As a further embodiment of the present invention, the preparation method of carboxylated lignin includes the following steps: sodium lignin sulfonate and dimethyl sulfoxide are added to a reaction flask for dispersion, succinic anhydride and 4-dimethylaminopyridine are mixed and added to the reaction flask for dispersion, the temperature is controlled at 80-90℃ and the reaction is kept at this temperature for 2-4 hours, ice-cold ether is added to precipitate, centrifuged, washed and dried to obtain carboxylated lignin. The addition ratio of sodium lignosulfonate, dimethyl sulfoxide, succinic anhydride, and 4-dimethylaminopyridine is 10g: 200-400mL: 12-13g: 0.5-1g.

[0012] As a further embodiment of the present invention, the preparation method of amino-β-cyclodextrin includes the following steps: β-cyclodextrin, dimethyl sulfoxide, p-toluenesulfonyl chloride, and triethylamine are added to a reaction vessel and dispersed, the temperature is controlled at 0-5℃ and the reaction is maintained for 3-6 hours, acetone is added to precipitate, centrifuged and dried to obtain an intermediate; the intermediate is mixed with ethylenediamine, the temperature is controlled at 50-60℃ and the reaction is maintained for 24-30 hours, the reaction solution is dialyzed and freeze-dried to obtain amino-β-cyclodextrin; The addition ratio of β-cyclodextrin, dimethyl sulfoxide, p-toluenesulfonyl chloride, and triethylamine is 10g:100-200mL:15-30g:15-25mL; the addition ratio of intermediate and ethylenediamine is 10g:80-120mL.

[0013] As a further embodiment of the present invention: the addition ratio of diammonium hydrogen phosphate, deionized water I, sodium citrate, calcium nitrate and deionized water II in A1 is 12-16g: 400-500mL: 4-6g: 22-29g: 300-600mL; The addition ratio of hollow hydroxyapatite, anhydrous ethanol, aminopropyltriethoxysilane, and deionized water in A2 is 10g: 100-200mL: 30-60mL: 1-2mL; The addition ratio of aminated hollow hydroxyapatite, anhydrous ethanol I, tetrabutyl titanate, anhydrous ethanol II, and deionized water in A3 is 10g: 400-600mL: 8-15mL: 100-200mL: 50-100mL. The MES buffer in A4 is a 0.1M MES buffer with pH=6; the addition ratio of TiO2-HA composite particles, MES buffer one, succinic acid, EDC·HCl, NHS and MES buffer two in A4 is 10g: 200-400mL: 5-10g: 8-12g: 3-6g: 100-150mL.

[0014] As a further aspect of the present invention, the method for preparing aloe vera extract includes the following steps: Fresh Aloe vera leaves are washed, peeled, and the transparent leaf pulp gel is obtained. The leaf pulp gel is mixed with trehalose solution and then freeze-dried under vacuum to obtain freeze-dried aloe vera powder. Aloe vera lyophilized powder was mixed with a citrate-sodium citrate buffer solution at pH 3.5 and extracted by sonication. After centrifugation, the supernatant was collected and eluted through a chromatography column using the following elution program: elution with 3 column volumes of deionized water, 30% ethanol aqueous solution, and 70% ethanol aqueous solution. The solution eluted with 30% ethanol was concentrated under reduced pressure at 40°C to 1 / 5-1 / 10 of its original volume to obtain solution component one. The solution eluted with 70% ethanol was ultrafiltered through an ultrafiltration membrane, and the retentate was collected. The retentate was dialyzed with distilled water and freeze-dried to obtain component two. The solution components 1 and 2, with a mass ratio of 1:3-5, were filtered and freeze-dried to obtain aloe vera extract.

[0015] As a further aspect of the present invention: the emulsion matrix includes auxiliary sunscreen agents, emulsifiers, emollients, thickeners, humectants, film-forming agents, antioxidants, preservatives, and solvents; The sunscreen comprises the following ingredients by weight percentage: 10-30 wt% sunscreen agent, 2-3 wt% auxiliary sunscreen agent, 2-4 wt% emulsifier, 10-20 wt% emollient, 0.1-3 wt% thickener, 1-15 wt% moisturizer, 0.3-1 wt% film-forming agent, 0.1-2 wt% antioxidant, 0.05-0.2 wt% preservative, and the balance being solvent; the sum of the weight percentages of the ingredients is 100%.

[0016] As a further aspect of the present invention: the solvent is water; the auxiliary sunscreen agent is methylenebis-benzotriazolyltetramethylbutylphenol; The emulsifier is obtained by combining one or more of the following: cetearyl glucoside, decyl glucoside, arachidonic glucoside, alkyl glucoside, olive oil polyglycerol-6 esters, polyglycerol-6 pentaoleate, polyglycerol-2 dihydroxystearate, polyglycerol-4 diisostearate / polyhydroxystearate / sebate, lauryl polyglycerol-3 polydimethylsiloxane, polyglycerol-3 polydimethylsiloxyethyl polydimethylsiloxane, hydrogenated lecithin, C12-20 alkyl glucoside, glyceryl stearate, PEG-100 stearate, sodium stearoyl glutamate, sorbitan sesquioleate, PEG-10 polydimethylsiloxane, and PEG-30 dihydroxystearate. The emollient is obtained by combining one or more of the following: coconut oil-caprylate / capric acid ester, squalane, jojoba seed oil, butyl octyl salicylate, dibutyl adipate, lauroyl sarcosine isopropyl ester, dioctyl carbonate, C12-15 alcohol benzoate, caprylic / capric triglyceride, isononyl isononanoate, propyl heptaethyl caprylate, cetyl alcohol, and cetearyl alcohol. The thickener is obtained by combining one or more of the following: xanthan gum, carbomer, ammonium acryloyl dimethyl taurate / VP copolymer, aluminum octenyl succinate starch, hydroxypropyl methylcellulose, sodium polyacrylate, and polymethyl silsesquioxane. The moisturizer is obtained by combining one or more of the following: glycerin, butylene glycol, 1,3-propanediol, sodium hyaluronate, glucosylrutin, polyethylene glycol-8, polybutylene glycol-8, and glyceryl polyether-26. The film-forming agent is obtained by combining one or more of the following: polyvinylpyrrolidone, trimethylsilyloxysilicate, polymethylsilsesquioxane, dextrin isostearate, dextrin palmitate, and glyceryl rosinate. The antioxidant is a mixture of one or more of the following: tocopheryl acetate, vitamin E, p-hydroxyacetophenone, sodium metabisulfite, pentaerythritol tetra(bis-tert-butylhydroxyhydrocinnamate), and tert-butylhydroquinone. The preservative is a mixture of one or more of phenoxyethanol, parabens, salicylic acid, 1,2-pentanediol, and ethylhexylglycerin.

[0017] The preparation method of a mild sunscreen includes the following steps: The auxiliary sunscreen agent, moisturizer, thickener, and solvent are mixed, heated, and stirred to obtain an aqueous phase; Sunscreen, emollient, emulsifier, and film-forming agent are mixed, heated and stirred to obtain the oil phase; The oil phase is added to the aqueous phase, homogenized and emulsified, cooled, and antioxidants and preservatives are added. The mixture is then stirred and homogenized to obtain sunscreen.

[0018] The beneficial effects of this invention are: This application utilizes tetrabutyl titanate to deposit titanium dioxide on the surface of aminated hollow hydroxyapatite, and introduces alkynyl groups using succinic acid to obtain alkynyl-modified TiO2-HA composite particles. This application further utilizes carboxylated lignin and aminated β-cyclodextrin for grafting and inclusion of aloe extract, and introduces azido groups using azidopropionic acid to obtain an inclusion complex with azido groups on its surface. Finally, through click assembly, the alkynyl-modified TiO2-HA composite particles and the inclusion complex with azido groups on its surface are used to construct a core-shell structured sunscreen.

[0019] (1) Broad-spectrum sun protection performance and stability The sunscreen agent prepared in this application is covalently bonded to alkynyl-modified TiO2-HA composite particles and a lignin-cyclodextrin-aloe inclusion complex. Through the synergistic combination of lignin and titanium dioxide, TiO2 provides UVB shielding, while lignin, as a highly efficient natural UVA absorber and antioxidant, provides long-wave UV shielding, significantly improving UV protection and achieving full-band protection. The lignin coating modification of the titanium dioxide surface quenches reactive oxygen free radicals that may be generated by TiO2 under light, significantly improving the photostability of the sunscreen system.

[0020] This application utilizes click chemistry to covalently bond alkynyl-modified TiO2-HA composite particles with lignin-cyclodextrin-aloe inclusion complex, forming 1,2,3-triazole ring covalent bonds that firmly bind the organic active layer to the inorganic core. This avoids the migration and detachment of active ingredients in traditional physical mixing or simple coating, ensuring long-lasting sun protection performance.

[0021] (2) Mildness and skin affinity In this sunscreen application, titanium dioxide is loaded onto the surface of hollow hydroxyapatite. Hollow hydroxyapatite possesses excellent biocompatibility and bioactivity, and can release calcium and phosphorus ions transdermally, helping to soothe the skin. Its porous hollow structure physically isolates TiO2 internally, fundamentally preventing direct contact between TiO2 nanoparticles and the skin, thus eliminating the potential risk of photocatalytic irritation. The active ingredient of aloe vera is encapsulated in β-cyclodextrin cavities, allowing for slow and continuous release after application, providing long-lasting soothing, moisturizing, and repairing functions, instantly calming potentially irritated skin.

[0022] (3) Excellent formula compatibility and skin feel The outermost layer of the sunscreen agent in this application is an organic layer composed of lignin and aloe vera extract. It has good hydrophilicity, is easy to disperse in the aqueous phase, and has excellent compatibility with the emulsion matrix, making it less prone to aggregation or sedimentation. Furthermore, the hollow hydroxyapatite loaded with titanium dioxide used in the sunscreen agent has a low density, which helps to reduce the overall heaviness of the formulation, improves spreadability, and avoids the "fake white" and heavy sticky feeling commonly found in traditional physical sunscreens, resulting in a light, refreshing, and natural feel on the skin.

[0023] (4) It has skin care effects The lignin used in the sunscreen prepared in this application has free radical scavenging capabilities, combating UV-induced oxidative stress and preventing pigmentation and photoaging. Aloe vera extract, in synergy with hollow hydroxyapatite, provides immediate cooling, soothing, and moisturizing effects to the skin, making it particularly suitable for post-sun exposure repair. The minerals released by the hollow hydroxyapatite, along with the skin-moisturizing ingredients in the formula, collectively help maintain a healthy skin barrier. Therefore, this sunscreen achieves a unified triple effect of protection, repair, and skin nourishment. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1: The preparation method of aloe vera extract includes the following steps: Fresh Aloe vera leaves were washed, peeled, and the transparent leaf pulp gel was obtained. 100g of leaf pulp gel was mixed with 100mL of 5wt% trehalose solution and then freeze-dried under vacuum at -20℃ to obtain freeze-dried Aloe vera powder. 100g of lyophilized aloe vera powder was mixed with 1500mL of citrate-sodium citrate buffer solution (pH=3.5) and extracted with ultrasound at 4℃ and 300W for 20min. After centrifugation, the supernatant was collected and passed through a chromatography column packed with macroporous adsorption resin AB-8. The supernatant was eluted sequentially with 3 column volumes of deionized water, 30% ethanol aqueous solution, and 70% ethanol aqueous solution. The solution eluted with 30% ethanol was concentrated under reduced pressure at 40℃ to 1 / 10 of its original volume to obtain solution component one. The solution eluted with 70% ethanol was ultrafiltered using an ultrafiltration membrane with a molecular weight cutoff of 10kDa. The retentate was collected and dialyzed with distilled water for 24h. Then, it was freeze-dried at -50℃ to obtain component two. Solution components one and two, with a mass ratio of 1:3-5, were sterilely filtered through a 0.22 μm microporous membrane and freeze-dried at -20 °C to obtain aloe vera extract.

[0026] The preparation method of carboxylated lignin includes the following steps: 10g of sodium lignin sulfonate and 300mL of dimethyl sulfoxide are added to a reaction flask for dispersion. 12.5g of succinic anhydride and 0.7g of 4-dimethylaminopyridine are mixed and added to the reaction flask for dispersion. The temperature is controlled at 85℃ and the reaction is kept at this temperature for 3h. Ice-cold ether is added to precipitate the lignin, centrifuged, washed, and dried to obtain carboxylated lignin.

[0027] The preparation method of amino-β-cyclodextrin includes the following steps: 10g of β-cyclodextrin, 100mL of dimethyl sulfoxide, 25g of p-toluenesulfonyl chloride, and 20mL of triethylamine are added to a reaction vessel and dispersed. The temperature is controlled at 0℃ and the reaction is maintained for 4h. Acetone is added to precipitate the product, and the product is centrifuged and dried to obtain an intermediate. 10g of the intermediate is mixed with 100mL of ethylenediamine and the reaction is maintained at 55℃ for 27h. The reaction solution is dialyzed for 48h (MWCO 1000Da) and freeze-dried to obtain amino-β-cyclodextrin.

[0028] Example 2: The preparation method of alkynyl-modified TiO2-HA composite particles includes the following steps: A1: 12g of diammonium hydrogen phosphate, 400mL of deionized water and 4g of sodium citrate were dispersed in a high-pressure reactor. 22g of calcium nitrate and 300mL of deionized water were mixed and added to the high-pressure reactor. Nitric acid was added to adjust the pH to 5. The mixture was stirred for 0.5h, and the temperature was controlled at 140℃ for hydrothermal reaction for 9h. After centrifugation, washing, drying and calcination at 600℃ for 2h, hollow hydroxyapatite was obtained. A2: Under a nitrogen atmosphere, 10g of hollow hydroxyapatite and 100mL of anhydrous ethanol were added to a reaction flask for dispersion. 30mL of aminopropyltriethoxysilane and 1mL of deionized water were mixed and added to the reaction flask for dispersion. The mixture was heated to reflux for 6h, centrifuged, washed and dried to obtain aminated hollow hydroxyapatite. A3: 10g of aminated hollow hydroxyapatite and 400mL of anhydrous ethanol were added to the reaction flask for dispersion. 8-15mL of tetrabutyl titanate and 100mL of anhydrous ethanol were mixed and added to the reaction flask for dispersion. Nitric acid was added to adjust the pH to 3. The mixture was stirred at room temperature for 1h. 50mL of deionized water was added and stirred for 2h. The mixture was centrifuged, washed, and dried to obtain TiO2-HA composite particles. A4: Under a nitrogen atmosphere, 10g of TiO2-HA composite particles and 200mL of 0.1M MES buffer (pH=6) were added to the reaction flask for dispersion. 5g of succinic acid, 8g of EDC·HCl, 3g of NHS, and 100mL of 0.1M MES buffer (pH=6) were mixed and added to the reaction flask. The temperature was controlled at 20℃ and the reaction was maintained for 12h. After centrifugation, washing, and drying, alkynyl-modified TiO2-HA composite particles were obtained.

[0029] The preparation method of sunscreen agents includes the following steps: S1: 10g of carboxylated lignin prepared in Example 1, 15g of aminolated β-cyclodextrin prepared in Example 1, and 400mL of 0.1M MES buffer (pH=6) were added to a reaction flask for dispersion. 8g of EDC·HCl and 2g of NHS were added, and the mixture was stirred at room temperature for 18h. The reaction solution was dialyzed (MWCO 1000Da) and freeze-dried to obtain lignin-β-cyclodextrin grafts. S2: 10g of lignin-β-cyclodextrin graft, 2g of aloe extract prepared in Example 1, and 100mL of deionized water were added to the reaction vessel and mixed. The temperature was controlled at 35℃ and the reaction was kept at this temperature for 4h. After centrifugation, washing, and drying, the inclusion complex was obtained. S3: 10g of the inclusion compound and 100mL of dimethyl sulfoxide were added to the reaction vessel for dispersion. 4g of azidopropionic acid, 6g of N,N'-diisopropylcarbodiimide and 0.4g of 4-dimethylaminopyridine were added. The temperature was controlled at 20℃ and the reaction was kept at this temperature for 12h. The reaction solution was poured into ice-cold diethyl ether to precipitate. The solid was collected by centrifugation, washed and dried to obtain the inclusion compound with azido groups on its surface. S4: Under a light-protected, nitrogen atmosphere, 10g of alkynyl-modified TiO2-HA composite particles, 8g of inclusion complex with azide groups on the surface, 200mL of dimethyl sulfoxide, and 100mL of deionized water were added to a reaction flask for dispersion. 0.4g of sodium L-ascorbate and 0.2g of copper sulfate pentahydrate were added. The temperature was controlled at 25℃ and the reaction was maintained for 12h. After centrifugation, the mixture was washed twice with a pH=8.0, 0.1M EDTA aqueous solution, washed with water, and dried to obtain the sunscreen agent.

[0030] Example 3: The preparation method of alkynyl-modified TiO2-HA composite particles includes the following steps: A1: 15g of diammonium hydrogen phosphate, 400mL of deionized water and 5g of sodium citrate were dispersed in a high-pressure reactor. 26g of calcium nitrate and 400mL of deionized water were mixed and added to the high-pressure reactor. Nitric acid was added to adjust the pH to 5. The mixture was stirred for 1 hour, and the temperature was controlled at 145℃ for hydrothermal reaction for 9 hours. After centrifugation, washing, drying and calcination at 600℃ for 2 hours, hollow hydroxyapatite was obtained. A2: Under a nitrogen atmosphere, 10g of hollow hydroxyapatite and 100mL of anhydrous ethanol were added to a reaction flask for dispersion. 45mL of aminopropyltriethoxysilane and 2mL of deionized water were mixed and added to the reaction flask for dispersion. The mixture was heated to reflux for 7h, centrifuged, washed and dried to obtain aminated hollow hydroxyapatite. A3: 10g of aminated hollow hydroxyapatite and 500mL of anhydrous ethanol were added to the reaction flask for dispersion. 12mL of tetrabutyl titanate and 100mL of anhydrous ethanol were mixed and added to the reaction flask for dispersion. Nitric acid was added to adjust the pH to 3. The mixture was stirred at room temperature for 2h. 100mL of deionized water was added and stirred for 3h. The mixture was centrifuged, washed, and dried to obtain TiO2-HA composite particles. A4: Under a nitrogen atmosphere, 10g of TiO2-HA composite particles and 300mL of 0.1M MES buffer (pH=6) were added to the reaction flask for dispersion. 8g of succinic acid, 10g of EDC·HCl, 4.5g of NHS, and 100mL of 0.1M MES buffer (pH=6) were mixed and added to the reaction flask. The temperature was controlled at 20℃ and the reaction was maintained for 18h. After centrifugation, washing, and drying, alkynyl-modified TiO2-HA composite particles were obtained.

[0031] The preparation method of sunscreen agents includes the following steps: S1: 10g of carboxylated lignin prepared in Example 1, 16.5g of aminolated β-cyclodextrin prepared in Example 1, and 500mL of 0.1M MES buffer (pH=6) were added to a reaction flask for dispersion. 13g of EDC·HCl and 5g of NHS were added, and the mixture was stirred at room temperature for 21h. The reaction solution was dialyzed (MWCO 1000Da) and freeze-dried to obtain lignin-β-cyclodextrin grafts. S2: 10g of lignin-β-cyclodextrin graft, 3g of aloe extract prepared in Example 1, and 100mL of deionized water were added to the reaction vessel and mixed. The temperature was controlled at 35℃ and the reaction was kept at this temperature for 5h. After centrifugation, washing, and drying, the inclusion complex was obtained. S3: 10g of the inclusion compound and 100mL of dimethyl sulfoxide were added to the reaction vessel for dispersion. 6g of azide propionic acid, 8g of N,N'-diisopropylcarbodiimide and 0.8g of 4-dimethylaminopyridine were added. The temperature was controlled at 20℃ and the reaction was kept at this temperature for 18h. The reaction solution was poured into ice-cold diethyl ether to precipitate. The solid was collected by centrifugation, washed and dried to obtain the inclusion compound with azide groups on its surface. S4: Under a light-protected, nitrogen atmosphere, 10g of alkynyl-modified TiO2-HA composite particles, 10g of inclusion complex with azide groups on the surface, 300mL of dimethyl sulfoxide, and 100mL of deionized water were added to a reaction flask for dispersion. 0.8g of sodium L-ascorbate and 0.4g of copper sulfate pentahydrate were added. The temperature was controlled at 30℃ and the reaction was maintained for 18h. After centrifugation, the mixture was washed twice with a pH=8.0, 0.1M EDTA aqueous solution, washed with water, and dried to obtain the sunscreen agent.

[0032] Example 4: The preparation method of alkynyl-modified TiO2-HA composite particles includes the following steps: A1: 16g of diammonium hydrogen phosphate, 500mL of deionized water, and 6g of sodium citrate were dispersed in a high-pressure reactor. 29g of calcium nitrate and 600mL of deionized water were mixed and added to the high-pressure reactor. Nitric acid was added to adjust the pH to 6. The mixture was stirred for 1 hour, and the temperature was controlled at 150℃ for hydrothermal reaction for 12 hours. After centrifugation, washing, drying, and calcination at 600℃ for 2 hours, hollow hydroxyapatite was obtained. A2: Under a nitrogen atmosphere, 10g of hollow hydroxyapatite and 200mL of anhydrous ethanol were added to a reaction flask for dispersion. 60mL of aminopropyltriethoxysilane and 2mL of deionized water were mixed and added to the reaction flask for dispersion. The mixture was heated to reflux for 9h, centrifuged, washed and dried to obtain aminated hollow hydroxyapatite. A3: 10g of aminated hollow hydroxyapatite and 600mL of anhydrous ethanol were added to the reaction flask for dispersion. 15mL of tetrabutyl titanate and 200mL of anhydrous ethanol were mixed and added to the reaction flask for dispersion. Nitric acid was added to adjust the pH to 4. The mixture was stirred at room temperature for 3h. 100mL of deionized water was added and stirred for 4h. The mixture was centrifuged, washed, and dried to obtain TiO2-HA composite particles. A4: Under a nitrogen atmosphere, 10g of TiO2-HA composite particles and 400mL of 0.1M MES buffer (pH=6) were added to the reaction flask for dispersion. 10g of succinic acid, 12g of EDC·HCl, 6g of NHS, and 150mL of 0.1M MES buffer (pH=6) were mixed and added to the reaction flask. The temperature was controlled at 25℃ and the reaction was kept at this temperature for 24h. After centrifugation, washing, and drying, alkynyl-modified TiO2-HA composite particles were obtained.

[0033] The preparation method of sunscreen agents includes the following steps: S1: 10g of carboxylated lignin prepared in Example 1, 18g of aminolated β-cyclodextrin prepared in Example 1, and 600mL of 0.1M MES buffer (pH=6) were added to a reaction flask for dispersion. 16g of EDC·HCl and 8g of NHS were added, and the mixture was stirred at room temperature for 24h. The reaction solution was dialyzed (MWCO 1000Da) and freeze-dried to obtain lignin-β-cyclodextrin grafts. S2: 10g of lignin-β-cyclodextrin graft, 4g of aloe extract prepared in Example 1, and 200mL of deionized water were added to the reaction vessel and mixed. The temperature was controlled at 40℃ and the reaction was kept at this temperature for 6h. After centrifugation, washing, and drying, the inclusion complex was obtained. S3: 10g of the inclusion compound and 200mL of dimethyl sulfoxide were added to the reaction vessel for dispersion. 8g of azide propionic acid, 10g of N,N'-diisopropylcarbodiimide and 1g of 4-dimethylaminopyridine were added. The temperature was controlled at 25℃ and the reaction was kept at this temperature for 24h. The reaction solution was poured into ice-cold ether to precipitate. The solid was collected by centrifugation, washed and dried to obtain the inclusion compound with azide groups on its surface. S4: Under a light-protected, nitrogen atmosphere, 10g of alkynyl-modified TiO2-HA composite particles, 12g of inclusion complex with azide groups on the surface, 400mL of dimethyl sulfoxide, and 200mL of deionized water were added to a reaction flask for dispersion. 1.2g of sodium L-ascorbate and 0.6g of copper sulfate pentahydrate were added. The temperature was controlled at 35℃ and the reaction was maintained for 24h. After centrifugation, the mixture was washed twice with a pH=8.0, 0.1M EDTA aqueous solution, washed with water, and dried to obtain the sunscreen agent.

[0034] Example 5: A method for preparing a mild sunscreen, comprising the following steps: 2wt% methylenebis-benzotriazolyltetramethylbutylphenol, 5wt% butanediol, 3wt% glycerol, 2wt% sodium hyaluronate, 0.2wt% xanthan gum, 0.2wt% carbomer, and 44.7wt% water were mixed and homogenized at 80°C to obtain an aqueous phase. 18 wt% of the sunscreen prepared in Example 1, 7 wt% squalane, 5 wt% jojoba seed oil, 5 wt% dioctyl carbonate, 3 wt% C12-15 alcohol benzoate, 2 wt% cetearyl glucoside, 1 wt% polyglycerol-6 pentaoleate, and 1 wt% dextrin isostearate were mixed and stirred at 85°C to obtain the oil phase. Add the oil phase to the aqueous phase, homogenize and emulsify, cool to 40°C, add 0.8 wt% tocopherol, 0.05 wt% p-hydroxybenzoate, and 0.05 wt% 1,2-pentanediol, stir and homogenize to obtain sunscreen.

[0035] Example 6: Preparation method of mild sunscreen. Compared with Example 5, the only difference is that the sunscreen agent prepared in Example 2 is replaced in equal amounts with the sunscreen agent prepared in Example 3. The remaining components and preparation method are completely the same as in Example 5.

[0036] Example 7: Preparation method of mild sunscreen. Compared with Example 5, only the sunscreen agent prepared in Example 2 was replaced in equal amounts with the sunscreen agent prepared in Example 4. The remaining components and preparation method are completely the same as in Example 5.

[0037] Comparative Example 1: The preparation method of alkynyl-modified TiO2 particles includes the following steps: A1: Under a nitrogen atmosphere, 10g of nano-titanium dioxide and 100mL of anhydrous ethanol were added to a reaction flask for dispersion. 45mL of aminopropyltriethoxysilane and 2mL of deionized water were mixed and added to the reaction flask for dispersion. The mixture was heated to reflux for 7h, centrifuged, washed and dried to obtain aminated nano-titanium dioxide. A2: Under a nitrogen atmosphere, 10g of aminated nano-titanium dioxide and 300mL of 0.1M MES buffer (pH=6) were added to the reaction flask for dispersion. 8g of succinic acid, 10g of EDC·HCl, 4.5g of NHS and 100mL of 0.1M MES buffer (pH=6) were mixed and added to the reaction flask. The temperature was controlled at 20℃ and the reaction was maintained for 18h. After centrifugation, washing and drying, alkynyl-modified TiO2 particles were obtained.

[0038] The preparation method of sunscreen agents includes the following steps: S1: 10g of carboxylated lignin prepared in Example 1, 16.5g of aminolated β-cyclodextrin prepared in Example 1, and 500mL of 0.1M MES buffer (pH=6) were added to a reaction flask for dispersion. 13g of EDC·HCl and 5g of NHS were added, and the mixture was stirred at room temperature for 21h. The reaction solution was dialyzed (MWCO 1000Da) and freeze-dried to obtain lignin-β-cyclodextrin grafts. S2: 10g of lignin-β-cyclodextrin graft, 3g of aloe extract prepared in Example 1, and 100mL of deionized water were added to the reaction vessel and mixed. The temperature was controlled at 35℃ and the reaction was kept at this temperature for 5h. After centrifugation, washing, and drying, the inclusion complex was obtained. S3: 10g of the inclusion compound and 100mL of dimethyl sulfoxide were added to the reaction vessel for dispersion. 6g of azide propionic acid, 8g of N,N'-diisopropylcarbodiimide and 0.8g of 4-dimethylaminopyridine were added. The temperature was controlled at 20℃ and the reaction was kept at this temperature for 18h. The reaction solution was poured into ice-cold diethyl ether to precipitate. The solid was collected by centrifugation, washed and dried to obtain the inclusion compound with azide groups on its surface. S4: Under a light-protected, nitrogen atmosphere, 10g of alkynyl-modified TiO2 particles, 10g of an inclusion compound with azide-modified surface, 300mL of dimethyl sulfoxide, and 100mL of deionized water were added to a reaction flask for dispersion. 0.8g of sodium L-ascorbate and 0.4g of copper sulfate pentahydrate were added. The temperature was controlled at 30℃ and the reaction was maintained for 18h. After centrifugation, the mixture was washed twice with a pH=8.0, 0.1M EDTA aqueous solution, washed with water, and dried to obtain the sunscreen agent.

[0039] The preparation method of the mild sunscreen is the same as that of Example 5, except that the sunscreen agent prepared in Example 2 is replaced in equal amounts with the sunscreen agent prepared in Comparative Example 1. The other components and preparation methods are completely consistent with those of Example 5.

[0040] Comparative Example 2: The preparation method of the sunscreen agent includes the following steps: S1: 10g of carboxylated lignin prepared in Example 1, 16.5g of aminolated β-cyclodextrin prepared in Example 1, and 500mL of 0.1M MES buffer (pH=6) were added to a reaction flask for dispersion. 13g of EDC·HCl and 5g of NHS were added, and the mixture was stirred at room temperature for 21h. The reaction solution was dialyzed (MWCO 1000Da) and freeze-dried to obtain lignin-β-cyclodextrin grafts. S2: 10g of lignin-β-cyclodextrin graft and 100mL of dimethyl sulfoxide were added to a reaction vessel for dispersion. 6g of azide propionic acid, 8g of N,N'-diisopropylcarbodiimide and 0.8g of 4-dimethylaminopyridine were added. The temperature was controlled at 20℃ and the reaction was kept at this temperature for 18h. The reaction solution was poured into ice-cold ether to precipitate. The solid was collected by centrifugation, washed and dried to obtain lignin-β-cyclodextrin graft with azide group modified on the surface. S3: Under a light-protected, nitrogen atmosphere, 10g of the alkynyl-modified TiO2-HA composite particles prepared in Example 3, 10g of lignin-β-cyclodextrin grafts with azide-modified surfaces, 300mL of dimethyl sulfoxide, and 100mL of deionized water were added to a reaction flask for dispersion. 0.8g of sodium L-ascorbate and 0.4g of copper sulfate pentahydrate were added. The temperature was controlled at 30℃ and the reaction was maintained for 18h. After centrifugation, the sample was washed twice with a pH=8.0, 0.1M EDTA aqueous solution, washed with water, and dried to obtain the sunscreen agent.

[0041] The preparation method of the mild sunscreen is the same as that of Example 5, except that the sunscreen agent prepared in Example 2 is replaced in equal amounts with the sunscreen agent prepared in Comparative Example 2. The remaining components and preparation methods are completely consistent with those of Example 5.

[0042] The preparation method of TiO2-HA composite particles in Comparative Example 3 includes the following steps: A1: 15g of diammonium hydrogen phosphate, 400mL of deionized water and 5g of sodium citrate were dispersed in a high-pressure reactor. 26g of calcium nitrate and 400mL of deionized water were mixed and added to the high-pressure reactor. Nitric acid was added to adjust the pH to 5. The mixture was stirred for 1 hour, and the temperature was controlled at 145℃ for hydrothermal reaction for 9 hours. After centrifugation, washing, drying and calcination at 600℃ for 2 hours, hollow hydroxyapatite was obtained. A2: Under a nitrogen atmosphere, 10g of hollow hydroxyapatite and 100mL of anhydrous ethanol were added to a reaction flask for dispersion. 45mL of aminopropyltriethoxysilane and 2mL of deionized water were mixed and added to the reaction flask for dispersion. The mixture was heated to reflux for 7h, centrifuged, washed and dried to obtain aminated hollow hydroxyapatite. A3: 10g of aminated hollow hydroxyapatite and 500mL of anhydrous ethanol were added to the reaction flask for dispersion. 12mL of tetrabutyl titanate and 100mL of anhydrous ethanol were mixed and added to the reaction flask for dispersion. Nitric acid was added to adjust the pH to 3. The mixture was stirred at room temperature for 2h. 100mL of deionized water was added and stirred for 3h. The mixture was centrifuged, washed, and dried to obtain TiO2-HA composite particles.

[0043] The preparation method of sunscreen agents includes the following steps: S1: 10g of carboxylated lignin prepared in Example 1, 16.5g of aminolated β-cyclodextrin prepared in Example 1, and 500mL of 0.1M MES buffer (pH=6) were added to a reaction flask for dispersion. 13g of EDC·HCl and 5g of NHS were added, and the mixture was stirred at room temperature for 21h. The reaction solution was dialyzed (MWCO 1000Da) and freeze-dried to obtain lignin-β-cyclodextrin grafts. S2: 10g of lignin-β-cyclodextrin graft, 3g of aloe extract prepared in Example 1, and 100mL of deionized water were added to the reaction vessel and mixed. The temperature was controlled at 35℃ and the reaction was kept at this temperature for 5h. After centrifugation, washing, and drying, the inclusion complex was obtained. S3: Mix 10g of TiO2-HA composite particles and 10g of inclusion complex to obtain a sunscreen agent.

[0044] The preparation method of the mild sunscreen is the same as that of Example 5, except that the sunscreen agent prepared in Example 2 is replaced in equal amounts with the sunscreen agent prepared in Comparative Example 3. The other components and preparation methods are completely consistent with those of Example 5.

[0045] Comparative Example 4: The preparation method of the sunscreen agent includes the following steps: S1: 10g of carboxylated lignin prepared in Example 1, 16.5g of aminolated β-cyclodextrin prepared in Example 1, and 500mL of 0.1M MES buffer (pH=6) were added to a reaction flask for dispersion. 13g of EDC·HCl and 5g of NHS were added, and the mixture was stirred at room temperature for 21h. The reaction solution was dialyzed (MWCO 1000Da) and freeze-dried to obtain lignin-β-cyclodextrin grafts. S2: 10g of lignin-β-cyclodextrin graft, 3g of aloe extract prepared in Example 1, and 100mL of dimethyl sulfoxide were added to a reaction vessel for dispersion. 6g of azide propionic acid, 8g of N,N'-diisopropylcarbodiimide, and 0.8g of 4-dimethylaminopyridine were added. The temperature was controlled at 20℃ and the reaction was kept at this temperature for 18h. The reaction solution was poured into ice-cold ether to precipitate. The solid was collected by centrifugation, washed, and dried to obtain a mixture with azide groups on its surface. S3: Under a light-protected, nitrogen atmosphere, 10g of the alkynyl-modified TiO2-HA composite particles prepared in Example 3, 10g of the mixture with azide-modified surface, 300mL of dimethyl sulfoxide, and 100mL of deionized water were added to a reaction flask for dispersion. 0.8g of sodium L-ascorbate and 0.4g of copper sulfate pentahydrate were added. The temperature was controlled at 30℃ and the reaction was maintained for 18h. After centrifugation, the mixture was washed twice with a pH=8.0, 0.1MEDTA aqueous solution, washed with water, and dried to obtain the sunscreen agent.

[0046] The preparation method of the mild sunscreen is the same as that of Example 5, except that the sunscreen agent prepared in Example 2 is replaced in equal amounts with the sunscreen agent prepared in Comparative Example 4. The other components and preparation methods are completely the same as those of Example 5.

[0047] Comparative Example 5: The preparation method of the sunscreen agent includes the following steps: S1: 10g of β-cyclodextrin graft, 3g of aloe extract prepared in Example 1, and 100mL of deionized water were added to the reaction vessel and mixed. The temperature was controlled at 35℃ and the reaction was kept at this temperature for 5h. After centrifugation, washing, and drying, the inclusion complex was obtained. S2: 10g of the inclusion compound and 100mL of dimethyl sulfoxide were added to the reaction vessel for dispersion. 6g of azidopropionic acid, 8g of N,N'-diisopropylcarbodiimide and 0.8g of 4-dimethylaminopyridine were added. The temperature was controlled at 20℃ and the reaction was kept at this temperature for 18h. The reaction solution was poured into ice-cold ether to precipitate. The solid was collected by centrifugation, washed and dried to obtain the inclusion compound with azido groups on its surface. S3: Under a light-protected, nitrogen atmosphere, 10g of the alkynyl-modified TiO2-HA composite particles prepared in Example 3, 10g of the inclusion compound with azide groups on the surface, 300mL of dimethyl sulfoxide, and 100mL of deionized water were added to a reaction flask for dispersion. 0.8g of sodium L-ascorbate and 0.4g of copper sulfate pentahydrate were added. The temperature was controlled at 30℃ and the reaction was maintained for 18h. After centrifugation, the mixture was washed twice with a pH=8.0, 0.1MEDTA aqueous solution, washed with water, and dried to obtain the sunscreen agent.

[0048] The preparation method of the mild sunscreen is the same as that of Example 5, except that the sunscreen agent prepared in Example 2 is replaced in equal amounts with the sunscreen agent prepared in Comparative Example 5. The other components and preparation methods are completely consistent with those of Example 5.

[0049] Comparative Example 6: The preparation method of the sunscreen agent includes the following steps: S1: 10g of amino-β-cyclodextrin and 100mL of dimethyl sulfoxide were added to a reaction vessel for dispersion. 6g of azidopropionic acid, 8g of N,N'-diisopropylcarbodiimide, and 0.8g of 4-dimethylaminopyridine were added. The temperature was controlled at 20℃ and the reaction was maintained for 18h. The reaction solution was poured into ice-cold diethyl ether to precipitate. The solid was collected by centrifugation, washed, and dried to obtain azido-β-cyclodextrin. S2: 10g of azide-β-cyclodextrin and 3g of aloe extract prepared in Example 1 were mixed to obtain a mixture; S3: Under a light-protected, nitrogen atmosphere, 10g of the alkynyl-modified TiO2-HA composite particles prepared in Example 3, 10g of the mixture, 300mL of dimethyl sulfoxide, and 100mL of deionized water were added to a reaction flask for dispersion. 0.8g of sodium L-ascorbate and 0.4g of copper sulfate pentahydrate were added. The temperature was controlled at 30℃ and the reaction was maintained for 18h. After centrifugation, the mixture was washed twice with a pH=8.0, 0.1M EDTA aqueous solution, washed with water, and dried to obtain the sunscreen agent.

[0050] The preparation method of the mild sunscreen is the same as that of Example 5, except that the sunscreen agent prepared in Example 2 is replaced in equal amounts with the sunscreen agent prepared in Comparative Example 6. The other components and preparation methods are completely the same as those of Example 5.

[0051] Performance testing (1) Sun Protection Factor Using PMMA plates as substrates, the sunscreens prepared in Examples 5-7 and Comparative Examples 1-6 were coated onto the substrate surface at a coating amount of 2 mg / cm². 2 After being placed at room temperature for 30 minutes, the absorbance of the sample to wavelengths of 290-400 nm was measured using a UV spectrophotometer, and the theoretical SPF value was calculated. The wavelength value at which the absorbance integral from 290 nm to λc reaches 90% of the total absorbance integral (290-400 nm) was calculated. When λc ≥ 370 nm, it is considered to have broad-spectrum protection capability. The detection results are shown in Table 1. (2) Light stability Using PMMA plates as substrates, the sunscreens prepared in Examples 5-7 and Comparative Examples 1-6 were coated onto the substrate surface at a coating amount of 2 mg / cm². 2 Using a sunlight simulator containing UVA / UVB at a rate of 4J / cm 2 Irradiation was performed for 1 hour. After irradiation, the absorbance of the sample to wavelengths of 290-400 nm was measured using an ultraviolet spectrophotometer. The theoretical SPF value was calculated, and the SPF decay rate was also calculated. The test results are shown in Table 1. (3) Water resistance Using PMMA plates as substrates, the sunscreens prepared in Examples 5-7 and Comparative Examples 1-6 were coated onto the substrate surface at a coating amount of 2 mg / cm². 2 The substrate coated with the sample was immersed in a flowing water bath for 40 minutes and the SPF value before and after rinsing was recorded. The SPF retention rate was calculated and the test results are shown in Table 1. Table 1: Statistical Table of Sunscreen Performance Test Data for Examples 5-7 and Comparative Examples 1-6

[0052] As shown in Table 1, the sunscreen agent prepared in this application, when added to sunscreen, imparts broad-spectrum protective properties to the material and exhibits good photostability.

[0053] (4) Human skin patch A closed patch test was conducted according to the "Cosmetic Safety Technical Specifications" (2015 edition). Ninety volunteers were recruited. Approximately 0.020g of the test substance was placed in a patch applicator and applied to the back of the subjects with hypoallergenic adhesive tape. The test substance was removed after 24 hours. Skin reactions were observed at 0.5, 24, and 48 hours after removal, and the results were recorded according to the skin reaction grading standards in the "Cosmetic Safety Technical Specifications" (2015 edition). Human skin patch test results showed that 0 out of 90 people experienced adverse skin reactions.

[0054] (5) Security testing Phototoxicity: Singlet oxygen was detected using an SOSG probe. The sample was dispersed in water and tested with 10 mW / cm². 2 The sample was irradiated with UVA light of high intensity for 30 min, and the fluorescence intensity was measured. The relative amount of ROS generated was calculated according to the following formula: Relative amount of ROS generated = (fluorescence value of irradiated group - background of irradiated group) / (fluorescence value of light-shielded control group - background of light-shielded control group). The blank PBS group was set as the baseline value of 1.0. The detection results are shown in Table 2. In vitro cytotoxicity: Human immortalized keratinocytes (HaCaT) were co-cultured with the sample at a concentration of 100 ug / mL for 48 h using the CCK-8 assay. Cell viability was then assessed, and the results are shown in Table 2. Table 2: Statistical Table of Safety Test Data for Examples 5-7 and Comparative Examples 1-6

[0055] As shown in Table 2, the sunscreen prepared in this application is non-cytotoxic.

[0056] (6) In vitro antioxidant: Prepare a 0.1 mM DPPH methanol solution and store it in the dark. Dilute the sample with DMSO to obtain a test sample with a concentration of 50 μg / mL. Take 2 mL of the test sample and mix it with 2 mL of DPPH solution. After shaking, react at room temperature in the dark for 30 min and measure the absorbance at 517 nm.

[0057] DPPH radical scavenging rate (%) = [1−(A s -A e ) / A0]×100%, Where A0 is the absorbance of the blank control (DPPH solution + solvent); A s To detect the absorbance of the sample group, A e The background absorbance of the sample is calculated, and the IC is also calculated. 50 Values ​​and test results are shown in Table 3; (7) In vitro anti-inflammatory: The inhibition rate of inflammatory factors was calculated using the LPS-induced NO production inhibition model of RAW264.7 macrophages. The results are shown in Table 3. Table 3: Statistical Table of Anti-inflammatory and Antioxidant Test Data of Examples 5-7 and Comparative Examples 1-6

[0058] As shown in Table 3, the sunscreen prepared in this application has good anti-inflammatory and antioxidant capabilities.

[0059] The sunscreen agent prepared in this invention is obtained by click reaction bonding of alkynyl-modified TiO2-HA composite particles with an inclusion compound surface-modified with azide groups. The sunscreen agent prepared in this invention achieves synergistic sun protection, excellent photostability, and water resistance. The inclusion of aloe vera extract in the sunscreen agent provides additional UVA protection, antioxidant activity, and soothing effects. The lignin framework in the sunscreen agent serves as the core for UVA absorption, antioxidant activity, and structural support.

[0060] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A mild sunscreen, characterized in that, The sunscreen is composed of sunscreen agents and a lotion base; The sunscreen agent is a composite particle formed by the covalent bonding of alkynyl-modified TiO2-HA composite particles and lignin-cyclodextrin-aloe inclusion complex.

2. The mild sunscreen according to claim 1, characterized in that, The preparation method of the sunscreen agent includes the following steps: S1: Carboxylated lignin, aminolated β-cyclodextrin, and MES buffer were added to a reaction flask for dispersion. EDC·HCl and NHS were added, and the mixture was stirred at room temperature for 18-24 h. The reaction solution was dialyzed and freeze-dried to obtain lignin-β-cyclodextrin grafts. The lignin-β-cyclodextrin graft, aloe extract, and deionized water were added to a reaction vessel and mixed. The temperature was controlled at 35-40℃ and the reaction was kept at this temperature for 4-6 hours. After centrifugation, washing, and drying, the inclusion complex was obtained. S2: The inclusion complex and dimethyl sulfoxide were added to the reaction vessel and dispersed. Azide propionic acid, N,N'-diisopropylcarbodiimide and 4-dimethylaminopyridine were added. The temperature was controlled at 20-25℃ and the reaction was kept at this temperature for 12-24h. The reaction solution was poured into ice-cold ether to precipitate. The solid was collected by centrifugation, washed and dried to obtain the inclusion complex with azide groups on the surface. S3: Under light-proof and nitrogen atmosphere, alkynyl-modified TiO2-HA composite particles, inclusion complexes with azide groups on the surface, dimethyl sulfoxide, and deionized water are added to a reaction flask for dispersion. Sodium L-ascorbate and copper sulfate pentahydrate are added. The temperature is controlled at 25-35℃ and the reaction is kept at this temperature for 12-24 hours. After centrifugation, washing, and drying, the sunscreen agent is obtained.

3. A mild sunscreen according to claim 2, characterized in that, S1 contains 0.1 MES buffer at pH 6; the addition ratio of carboxylated lignin, aminolated β-cyclodextrin, MES buffer, EDC·HCl, and NHS is 10g: 15-18g: 400-600mL: 8-16g: 2-8g. The addition ratio of lignin-β-cyclodextrin graft, aloe extract, and deionized water is 10g: 2-4g: 100-200mL.

4. A mild sunscreen according to claim 2, characterized in that, The addition ratio of inclusion complex, dimethyl sulfoxide, azidopropionic acid, N,N'-diisopropylcarbodiimide, and 4-dimethylaminopyridine in S2 is 10g: 100-200mL: 4-8g: 6-10g: 0.4-1g.

5. A mild sunscreen according to claim 2, characterized in that, The addition ratio of S3 to alkynyl-modified TiO2-HA composite particles, surface-modified azide-based inclusion complex, dimethyl sulfoxide, deionized water, sodium L-ascorbate, and copper sulfate pentahydrate is 10g: 8-12g: 200-400mL: 100-200mL: 0.4-1.2g: 0.2-0.6g.

6. A mild sunscreen according to claim 2, characterized in that, The preparation method of the alkynyl-modified TiO2-HA composite particles includes the following steps: A1: Disperse diammonium hydrogen phosphate, deionized water I, and sodium citrate in a high-pressure reactor. Add calcium nitrate and deionized water II to the high-pressure reactor after mixing. Adjust the pH to 5-6 with nitric acid. Stir for 0.5-1 h, control the temperature at 140-150℃, and perform a hydrothermal reaction for 9-12 h. Centrifuge, wash, dry, and calcine to obtain hollow hydroxyapatite. A2: Under a nitrogen atmosphere, hollow hydroxyapatite and anhydrous ethanol were added to a reaction flask for dispersion. A mixture of aminopropyltriethoxysilane and deionized water was added to the reaction flask for dispersion. The mixture was heated to reflux for 6-9 hours, centrifuged, washed, and dried to obtain aminated hollow hydroxyapatite. A3: Aminated hollow hydroxyapatite and anhydrous ethanol were added to the reaction flask and dispersed. Tetrabutyl titanate and anhydrous ethanol were mixed and added to the reaction flask and dispersed. Nitric acid was added to adjust the pH to 3-4. The mixture was stirred at room temperature for 1-3 hours. Deionized water was added and stirred for 2-4 hours. The mixture was centrifuged, washed, and dried to obtain TiO2-HA composite particles. A4: Under a nitrogen atmosphere, TiO2-HA composite particles and MES buffer 1 were added to a reaction flask for dispersion. Succinic acid, EDC·HCl, NHS and MES buffer 2 were mixed and added to the reaction flask. The temperature was controlled at 20-25℃ and the reaction was kept at this temperature for 12-24h. After centrifugation, washing and drying, alkynyl-modified TiO2-HA composite particles were obtained.

7. A mild sunscreen according to claim 6, characterized in that, The addition ratio of diammonium hydrogen phosphate, deionized water I, sodium citrate, calcium nitrate, and deionized water II in A1 is 12-16g: 400-500mL: 4-6g: 22-29g: 300-600mL; The addition ratio of hollow hydroxyapatite, anhydrous ethanol, aminopropyltriethoxysilane, and deionized water in A2 is 10g: 100-200mL: 30-60mL: 1-2mL; The addition ratio of aminated hollow hydroxyapatite, anhydrous ethanol I, tetrabutyl titanate, anhydrous ethanol II, and deionized water in A3 is 10g: 400-600mL: 8-15mL: 100-200mL: 50-100mL. The MES buffer in A4 is a 0.1M MES buffer with pH=6; the addition ratio of TiO2-HA composite particles, MES buffer one, succinic acid, EDC·HCl, NHS and MES buffer two in A4 is 10g: 200-400mL: 5-10g: 8-12g: 3-6g: 100-150mL.

8. A mild sunscreen according to claim 1, characterized in that, The emulsion matrix includes auxiliary sunscreens, emulsifiers, emollients, thickeners, humectants, film-forming agents, antioxidants, preservatives, and solvents; The sunscreen comprises the following ingredients by weight percentage: 10-30 wt% sunscreen agent, 2-3 wt% auxiliary sunscreen agent, 2-4 wt% emulsifier, 10-20 wt% emollient, 0.1-3 wt% thickener, 1-15 wt% moisturizer, 0.3-1 wt% film-forming agent, 0.1-2 wt% antioxidant, 0.05-0.2 wt% preservative, with the balance being solvent; the sum of the weight percentages of the ingredients is 100%.

9. A mild sunscreen according to claim 8, characterized in that, The solvent is water; the auxiliary sunscreen agent is methylenebis-benzotriazolyltetramethylbutylphenol; The emulsifier is obtained by combining one or more of the following: cetearyl glucoside, decyl glucoside, arachidonic glucoside, alkyl glucoside, olive oil polyglycerol-6 esters, polyglycerol-6 pentaoleate, polyglycerol-2 dihydroxystearate, polyglycerol-4 diisostearate / polyhydroxystearate / sebate, lauryl polyglycerol-3 polydimethylsiloxane, polyglycerol-3 polydimethylsiloxyethyl polydimethylsiloxane, hydrogenated lecithin, C12-20 alkyl glucoside, glyceryl stearate, PEG-100 stearate, sodium stearoyl glutamate, sorbitan sesquioleate, PEG-10 polydimethylsiloxane, and PEG-30 dihydroxystearate. The emollient is obtained by one or more of the following: coconut oil alcohol-caprylate / capric acid ester, squalane, jojoba seed oil, butyl octyl salicylate, dibutyl adipate, lauroyl sarcosine isopropyl ester, dioctyl carbonate, C12-15 alcohol benzoate, caprylic / capric triglyceride, isononyl isononanoate, propyl heptaethyl caprylate, cetyl alcohol, and cetearyl alcohol. The thickener is obtained by combining one or more of the following: xanthan gum, carbomer, ammonium acryloyl dimethyl taurate / VP copolymer, aluminum octenyl succinate starch, hydroxypropyl methylcellulose, sodium polyacrylate, and polymethyl silsesquioxane. The moisturizer is obtained by combining one or more of the following: glycerin, butylene glycol, 1,3-propanediol, sodium hyaluronate, glucosylrutin, polyethylene glycol-8, polybutylene glycol-8, and glyceryl polyether-26. The film-forming agent is obtained by combining one or more of the following: polyvinylpyrrolidone, trimethylsilyloxysilicate, polymethylsilsesquioxane, dextrin isostearate, dextrin palmitate, and glyceryl rosinate. The antioxidant is a mixture of one or more of the following: tocopheryl acetate, vitamin E, p-hydroxyacetophenone, sodium metabisulfite, pentaerythritol tetra(bis-tert-butylhydroxyhydrocinnamate), and tert-butylhydroquinone. The preservative is a mixture of one or more of phenoxyethanol, p-hydroxybenzoate, salicylic acid, 1,2-pentanediol, and ethylhexylglycerin.

10. The method for preparing a mild sunscreen according to any one of claims 1-9, characterized in that, Includes the following steps: The auxiliary sunscreen agent, moisturizer, thickener, and solvent are mixed, heated, and stirred to obtain an aqueous phase; Sunscreen, emollient, emulsifier, and film-forming agent are mixed, heated and stirred to obtain the oil phase; The oil phase is added to the aqueous phase, homogenized and emulsified, cooled, and antioxidants and preservatives are added. The mixture is then stirred and homogenized to obtain sunscreen.

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