Biomass microsphere for cosmetic injection and preparation method thereof

Abstract

The invention relates to the technical field of medical cosmetology, and particularly discloses biomass microspheres for cosmetic injection and a preparation method of the biomass microspheres. The biomass microsphere for cosmetic injection comprises a microsphere and a water-soluble polysaccharide coating, and the microsphere is one of a hydroxyapatite microsphere, a chitin microsphere, a chitosan microsphere and an acylated chitin / chitosan microsphere. The water-soluble polysaccharide coating is one of carboxyalkyl chitin, carboxyalkyl chitosan, hydroxyalkyl chitin, hydroxyalkyl chitosan, carboxyalkyl cellulose, sodium alginate, potassium alginate, sodium hyaluronate and potassium hyaluronate. The biomass microspheres for cosmetic injection prepared by the invention are used for filling pits, tightening skin, reducing wrinkles, reducing immune response and inflammatory response and improving the compactness and elasticity of the skin.

Description

Technical Field

[0001] The present application relates to the technical field of medical aesthetics. More specifically, it relates to a biomaterial microsphere for aesthetic injection and a preparation method thereof. Background Art

[0002] Aesthetic injection is a non-surgical plastic aesthetic method. By injecting specific biological materials or synthetic biocompatible materials into the dermis or subcutaneous tissue of the skin, it aims to reduce skin wrinkles, shape or improve the skin condition. Commonly used aesthetic injection materials include hyaluronic acid, collagen, polylactic acid, polymethyl methacrylate, biogenic hydroxyapatite, polycaprolactone, agarose dextran microspheres, etc.

[0003] Among them, microsphere materials are more commonly used as filling materials for aesthetic injection because they do not require incisions during surgery, are easy to operate, and cause less pain to patients. The prior art provides a kind of hydroxyapatite microsphere, which is prepared from nano-hydroxyapatite, collagen and a cross-linking agent to form a network structure composite gel with good strength and toughness, support the sunken skin, eliminate wrinkles, effectively extend the retention time in the human body, and maintain a long-term effect. In this raw material, a cross-linking agent is used, and there will be cross-linking agent residues, which will increase the probability of inflammatory reactions. Summary of the Invention

[0004] In order to improve the problem that cross-linking agent residues will exist when preparing microsphere materials, the present application provides a biomaterial microsphere for aesthetic injection and a preparation method thereof.

[0005] In the first aspect, the present application provides a biomaterial microsphere for aesthetic injection, adopting the following technical solution: A biomaterial microsphere for aesthetic injection includes a microsphere and a water-soluble polysaccharide coating. The microsphere is one of hydroxyapatite microspheres, chitin microspheres, chitosan microspheres, and acylated chitin / chitosan microspheres. The water-soluble polysaccharide coating is one of carboxyalkyl chitin, carboxyalkyl chitosan, hydroxyalkyl chitin, hydroxyalkyl chitosan, carboxyalkyl cellulose, sodium alginate, potassium alginate, sodium hyaluronate, and potassium hyaluronate.

[0006] By adopting the above technical solutions, the microspheres have excellent mechanical support performance. When injected into the skin, they can activate fibroblasts in the skin, promote the regeneration of collagen and elastic fibers, improve the density and elasticity of the skin, and are used for filling depressions, tightening the skin and reducing wrinkles. The water-soluble polysaccharide coating forms a film to coat the microspheres, improving the dispersibility of the microspheres and alleviating the discomfort of the human body to the microspheres in the aqueous environment. Moreover, for the microspheres coated with the water-soluble polysaccharide coating, after the microspheres reach the action site, with the dispersibility in water, it ensures the uniform distribution of the microspheres during injection, avoiding local over-aggregation that affects the degradation of the water-soluble polysaccharide or premature exposure of the microspheres due to the rapid degradation of the water-soluble polysaccharide, and prematurely playing the role of stimulating tissue regeneration.

[0007] Among the microspheres, hydroxyapatite microspheres, chitin microspheres, chitosan microspheres, and acylated chitin / chitosan microspheres all have good biocompatibility and biodegradability, can provide an immediate filling effect, improve facial wrinkles, fine lines and depressions, such as nasolabial folds, crow's feet, etc., making the skin look younger and smoother. Moreover, they can stimulate the activity of skin fibroblasts, promote the synthesis of collagen and elastic fibers, accelerate tissue repair and regeneration, and improve the firmness and elasticity of the skin.

[0008] Among the water-soluble polysaccharide coatings, carboxyalkyl chitin, carboxyalkyl chitosan, hydroxyalkyl chitin, hydroxyalkyl chitosan, carboxyalkyl cellulose, sodium alginate, potassium alginate, sodium hyaluronate, and potassium hyaluronate have good film-forming properties and can form a uniform film on the surface of the microspheres. This film can not only protect the microspheres, reduce direct contact with surrounding tissues, and reduce immune responses and inflammatory responses, but also improve their dispersibility in the aqueous environment, ensure the uniform distribution of the microspheres during injection, and avoid unnatural appearance or discomfort caused by local aggregation. Moreover, the raw materials used in this application do not contain cross-linking agents and will not increase the probability of inflammatory responses due to the residue of cross-linking agents in the body.

[0009] Further preferably, the chitosan microspheres are chitosan microspheres with a deacetylation degree of 50-60%.

[0010] Optionally, the preparation method of the hydroxyapatite microspheres includes the following steps: calcine bovine bone at a temperature of 500-1000 °C for 4-8 h to obtain hydroxyapatite, first perform a pulverization treatment on the hydroxyapatite, and after the pulverization is completed, sieve to obtain hydroxyapatite with a particle size of 30-70 μm, and then perform a spheroidization treatment on the sieved hydroxyapatite to obtain hydroxyapatite microspheres with a particle size of 20-40 μm.

[0011] By adopting the above technical solution, the bovine bone is first calcined to remove organic substances to obtain hydroxyapatite, and then crushed to obtain hydroxyapatite with a smaller particle size. Then, spheroidization treatment is carried out to make the hydroxyapatite powder form spherical microspheres, improve the morphology of the microspheres, control the particle size distribution of the microspheres, and the obtained hydroxyapatite microspheres are applied in cosmetic injections, having a cosmetic filling effect and reducing skin wrinkles.

[0012] Optionally, the preparation method of the hydroxyapatite microspheres includes the following steps: Mix an aqueous solution of calcium nitrate and an ethanol solution of methyl phosphate in a ratio of calcium to phosphorus of 1.67, adjust the pH to 8 - 10 with ammonia water, react at 70 - 90 °C for 12 - 24 h until the solution becomes a gel state, dehydrate and dry the gel to obtain uniform small crystal particles, and calcine at 600 - 800 °C for 3 - 4 h to form a white powder, thus obtaining hydroxyapatite microspheres.

[0013] By adopting the above technical solution, according to the ratio of calcium to phosphorus of 1.67, an aqueous solution of calcium nitrate and an ethanol solution of methyl phosphate are mixed evenly. The calcium ions and phosphate ions in the mixed solution react to form a precursor of hydroxyapatite. Using ammonia water to adjust the pH value of the mixed solution to 8 - 10 is beneficial to the combination of calcium ions and phosphate ions, promotes the precipitation and crystal growth of hydroxyapatite, and improves the purity of hydroxyapatite. Dehydrate and dry the gel to obtain uniform small crystal particles. Finally, calcine the obtained crystal particles to remove any residual organic substances, improve the crystallinity and purity of hydroxyapatite, and finally obtain hydroxyapatite microspheres.

[0014] Optionally, the preparation method of the chitosan microspheres includes the following steps: Immerse chitosan in a dilute alkali solution for 1 - 3 h. After immersion, wash the chitosan with purified water / distilled water until the pH is neutral, dry it at 40 - 60 °C, crush the treated chitosan, perform a screening process after crushing, and then perform a spheroidization process on the screened chitosan to obtain chitosan microspheres with a particle size of 20 - 40 μm.

[0015] By adopting the above technical solution, chitosan is first immersed in a dilute alkali solution for purification treatment to remove impurities, ensure the purity of chitosan, and improve its biocompatibility and functionality. Perform a crushing process to break it into smaller particles, increase the surface area of chitosan, and improve the efficiency of subsequent spheroidization treatment. Perform a screening process on the chitosan particles to remove too large or too small particles to ensure the uniformity of the particle size. Then perform a spheroidization process to make the chitosan particles form chitosan microspheres with a particle size of 20 - 40 μm under the action of ball milling media, which is helpful for subsequent application in the field of cosmetic injections.

[0016] Optionally, chitin / chitosan is immersed in dilute alkali solution for 1-3 h, and after immersion, chitin / chitosan is washed with purified water / distilled water until the pH is neutral; chitin / chitosan, acetic anhydride solution and methanol are mixed and stirred evenly, the temperature is controlled at 0-5 °C, and then perchloric acid solution is added, and the mixture is stirred and reacted for 46-48 h. After the reaction is completed, filtration is carried out for solid-liquid separation. The solid is put into an NaOH aqueous solution for acid-base neutralization, centrifuged for solid-liquid separation, the solid is washed with water to remove salt, dehydrated with ethanol, and dried by heating at 50-55 °C to obtain acylated chitin / chitosan; after the reaction is completed, the acylated chitin / chitosan is added to a formic acid solution or tetrahydrofuran solution with a mass concentration of 70-90% for stirring and dissolution, and after the dissolution is completed, spray drying is carried out to obtain acylated chitin microspheres / chitosan microspheres with a particle size of 20-40 μm.

[0017] By adopting the above technical scheme, chitin / chitosan is purified to remove impurities and ensure its purity and biocompatibility. The purified chitin / chitosan is subjected to acylation reaction, and acyl groups are introduced onto the chitin molecules through chemical reactions, which changes the chemical properties of chitin / chitosan and improves its solubility and functionality. Then it is dissolved in a formic acid solution or a tetrahydrofuran solution to form a homogeneous solution. Spray drying can quickly dry the solution into tiny particles to obtain acylated chitin microspheres.

[0018] Optionally, the acylated chitin / chitosan is further processed: the acylated chitin / chitosan is dissolved in a tetrahydrofuran solution to obtain an acylated chitin / chitosan solution. The acylated chitin / chitosan solution is added to a saturated sodium chloride solution, and the acylated chitin / chitosan solution is evenly dispersed in the saturated sodium chloride solution. Distilled water is slowly added for precipitation treatment. After the precipitation is completed, filtration is carried out, and it is washed with distilled water to remove the excess solvent, and then dried to obtain acylated chitin microspheres / chitosan microspheres with a particle size of 20-40 μm.

[0019] By adopting the above technical solution, acyl chitin / chitosan is dissolved in a tetrahydrofuran solution to form a homogeneous solution, which is then added to a saturated sodium chloride solution. The high salt concentration of the saturated sodium chloride solution will change the solvent environment and reduce the solubility of acyl chitin / chitosan in the solution, thereby promoting the precipitation of acyl chitin / chitosan. The saturated sodium chloride solution evenly disperses the acyl chitin / chitosan solution to ensure uniform precipitation. Subsequently, distilled water is slowly added to further reduce the dissolution ability of the solution and promote the complete precipitation of acyl chitin / chitosan. The precipitated acyl chitin / chitosan is separated from the solution by filtration. Then, the acyl chitin / chitosan is washed with distilled water to remove the excess solvent and possibly residual sodium chloride, ensuring the purity of acyl chitin / chitosan, and dried to remove the residual moisture, obtaining acyl chitin microspheres.

[0020] Optionally, the carboxyalkyl / hydroxyalkyl chitosan is pretreated, including the following steps: dispersing the carboxyalkyl / hydroxyalkyl chitosan in purified water, stirring evenly, suction filtering, precipitating and washing with absolute ethanol, drying to obtain the carboxyalkyl / hydroxyalkyl chitosan raw material, dispersing the carboxyalkyl / hydroxyalkyl chitosan raw material in purified water, adding modified seaweed fiber and sodium carboxymethylcellulose, stirring at a temperature of 60 - 65 °C for 1 - 2 h, and drying to obtain the pretreated carboxyalkyl / hydroxyalkyl chitosan.

[0021] By adopting the above technical solution, the carboxyalkyl / hydroxyalkyl chitosan is dispersed in purified water to dissolve the chitosan in the purified water. The impurities in the carboxyalkyl / hydroxyalkyl chitosan solution are separated by suction filtering, and then precipitated and washed with ethanol to remove the residual salt and possibly existing impurities, ensuring the purity of the carboxyalkyl / hydroxyalkyl chitosan.

[0022] The carboxyalkyl / hydroxyalkyl chitosan raw material is dissolved in purified water. Electrostatic interaction will occur between the carboxylate ions (-COO-) on the modified seaweed fiber and the amino groups (-NH 2 ) to form ionic bonds, thereby achieving crosslinking and forming a stable gel structure. Sodium carboxymethylcellulose improves the solubility of chitosan, increases the crosslinking degree of carboxyalkyl / hydroxyalkyl chitosan and modified seaweed fiber, improves the mechanical strength, biocompatibility and film-forming property of the system. Subsequently, microspheres are coated, and the obtained microspheres have good dispersibility, stability, antibacterial and anti-inflammatory effects, can enhance the adhesion of the material to the skin tissue, ensure that the microsphere filler remains in the target area after injection, and improve the treatment effect.

[0023] Optionally, the mass ratio of the carboxyalkyl / hydroxyalkyl chitosan, the modified seaweed fiber and the sodium carboxymethylcellulose is 1:0.4 - 0.6:0.1 - 0.2.

[0024] By adopting the above technical solution, further limiting the mass ratio of carboxyalkyl / hydroxyalkyl chitosan, modified seaweed fiber and sodium carboxymethylcellulose within a certain range can improve the solubility, biocompatibility and stability of carboxyalkyl / hydroxyalkyl chitosan. There is a synergistic effect among carboxyalkyl / hydroxyalkyl chitosan, modified seaweed fiber and sodium carboxymethylcellulose. Sodium carboxymethylcellulose improves the solubility of carboxyalkyl / hydroxyalkyl chitosan and enhances the cross-linking effect between carboxyalkyl / hydroxyalkyl chitosan and modified seaweed fiber. The carboxylate ions (-COO-) on the modified seaweed fiber cross-link with the amino groups (-NH 2 ) on chitosan to form a stable gel structure. The obtained system has good mechanical strength, film-forming property and stability, and is subsequently applied to microspheres to improve the corresponding properties of the microspheres.

[0025] Preferably, the preparation method of the modified seaweed fiber includes the following steps: dispersing the seaweed fiber in a sodium hydroxide solution, soaking for 20 - 25 min, washing with water, then dispersing in purified water, adding a PCL-PEG-PCL block copolymer and xanthan gum, stirring at 35 - 40 °C for 1 - 2 h, and drying to obtain the modified seaweed fiber.

[0026] By adopting the above technical solution, the surface of the seaweed fiber is treated with the sodium hydroxide solution, making the surface of the seaweed fiber uneven, increasing the specific surface area of the seaweed fiber, which is helpful for the subsequent mixing of the seaweed fiber with other components.

[0027] The PCL-PEG-PCL block copolymer is an amphiphilic block copolymer with hydrophilicity and hydrophobicity, which can be loaded on the surface and pores of the seaweed fiber, improving the hydrophilicity of the seaweed fiber, reducing the surface tension, while enhancing the biodegradability and mechanical strength of the seaweed fiber, and increasing the flexibility and hydrophilicity of the seaweed fiber.

[0028] As a thickening agent and stabilizer, xanthan gum plays a role in increasing the viscosity of the system and improving the dispersion stability, can increase the adhesion between the PCL-PEG-PCL block copolymer and the seaweed fiber, making the PCL-PEG-PCL block copolymer stably loaded on the surface of the seaweed fiber, thereby improving the hydrophilicity, mechanical strength, biodegradability and stability of the seaweed fiber. Subsequently applied to chitosan, it improves the corresponding properties and film-forming property of chitosan, which is helpful for the subsequent coating of microspheres.

[0029] In a second aspect, the present application provides a preparation method of a biomass microsphere for cosmetic injection, including the following steps: subjecting the microsphere to boiling dispersion treatment, dissolving a water-soluble polysaccharide in purified water to obtain an aqueous solution of the water-soluble polysaccharide, atomizing, and coating the microsphere to obtain the biomass microsphere.

[0030] By adopting the above technical solution, the method coats the microspheres, making the surface of the microspheres smoother and rounder, improving the dispersibility of the microspheres. Subsequently, the microspheres are injected into the skin to reduce the damage of the microspheres to the tissue. After the microspheres reach the action site, as the water-soluble polysaccharide degrades, the microspheres are exposed and play a role in stimulating tissue regeneration.

[0031] In summary, the present application has the following beneficial effects: 1. The microspheres in the present application have excellent mechanical support performance. When injected into the skin, they can activate fibroblasts in the skin, promote the regeneration of collagen and elastic fibers, improve the density and elasticity of the skin, and are used for filling depressions, tightening the skin and reducing wrinkles. The water-soluble polysaccharide coating forms a film to coat the microspheres, improving the dispersibility of the microspheres and alleviating the discomfort of the human body to the microspheres in the aqueous environment.

[0032] 2. The hydroxyapatite microspheres, chitin microspheres, chitosan microspheres, and acylated chitin / chitosan microspheres in the present application all have good biocompatibility and biodegradability, can provide an immediate filling effect, improve facial wrinkles, fine lines and depressions, such as nasolabial folds, crow's feet, etc., make the skin look younger and smoother, stimulate the activity of skin fibroblasts, promote the synthesis of collagen and elastic fibers, accelerate tissue repair and regeneration, and improve the firmness and elasticity of the skin.

[0033] 3. The carboxyalkyl chitin, carboxyalkyl chitosan, hydroxyalkyl chitin, hydroxyalkyl chitosan, carboxyalkyl cellulose, sodium alginate, potassium alginate, sodium hyaluronate, and potassium hyaluronate in the present application have good film-forming properties and can form a uniform film on the surface of the microspheres. This film can not only protect the microspheres, reduce direct contact with the surrounding tissues, reduce immune responses and inflammatory responses, but also improve their dispersibility in the aqueous environment, ensure the uniform distribution of the microspheres during injection, and avoid unnatural appearance or discomfort caused by local aggregation. Detailed implementation mode

[0035] Example 1 A biomass microsphere for cosmetic injection, comprising a microsphere and a water-soluble polysaccharide coating. The microsphere is a hydroxyapatite microsphere, and the water-soluble polysaccharide coating is carboxymethyl chitin, which is purchased from Qingdao Boyite Biomaterials Co., Ltd.

[0036] A preparation method of hydroxyapatite microspheres, comprising the following steps: calcine 300 g of bovine bone at a temperature of 500 °C for 8 h to obtain hydroxyapatite, use a bead mill with a certain particle size to first crush the hydroxyapatite, the crushing time is 20 min, after crushing, sieve to obtain hydroxyapatite with a particle size of 30 - 70 μm, and then use a bead mill with a smaller particle size to spheroidize the sieved hydroxyapatite, the treatment time is 10 min / time, and perform 5 treatments to obtain hydroxyapatite microspheres with a particle size of 20 - 40 μm.

[0037] A preparation method of biomass microspheres for cosmetic injection, characterized by comprising the following steps: put 8 g of microspheres with a particle size of 20 - 40 μm into a multifunctional fluidized bed for boiling dispersion treatment, the treatment temperature is 70 °C, the treatment time is 30 min, dissolve 10 g of carboxymethyl chitin in 200 g of water to obtain an aqueous solution of water-soluble polysaccharide, atomize it into the cavity of the fluidized bed using a high-pressure spray gun to coat the microspheres, the atomization time is 15 min, to obtain biomass microspheres, and the particle size of the biomass microspheres is 30 - 60 μm.

[0038] Example 2 A kind of biomass microspheres for cosmetic injection, different from Example 1 in that the preparation method of hydroxyapatite microspheres comprises the following steps: calcine 340 g of bovine bone at a temperature of 1000 °C for 4 h to obtain hydroxyapatite, use a bead mill with a certain particle size to first crush the hydroxyapatite, the crushing time is 5 min, after crushing, sieve to obtain hydroxyapatite with a particle size of 30 - 70 μm, and then use a bead mill with a smaller particle size to spheroidize the sieved hydroxyapatite, the treatment time is 10 min / time, and perform 2 treatments to obtain hydroxyapatite microspheres with a particle size of 20 - 40 μm.

[0039] Example 3 A kind of biomass microspheres for cosmetic injection, different from Example 1 in that the preparation method of hydroxyapatite microspheres comprises the following steps: mix an aqueous solution of calcium nitrate (10 g of calcium nitrate dissolved in 100 g of water) and an ethanol solution of methyl phosphate (5.1 g of methyl phosphate dissolved in 60 g of ethanol) according to a calcium-phosphorus ratio of 1.67, adjust the pH to 10 with ammonia water, react at 70 °C for 24 h until the solution becomes a gel state (gel concentration is 20%), dehydrate and dry the gel using a spray dryer (the inlet air temperature of spray drying is 210 °C, the feeding speed time is 1.1 L / h, and the outlet air temperature is 110 °C) to obtain uniform crystal small particles, and then put them into a muffle furnace and calcine at 600 °C for 4 h to form a white powder to obtain hydroxyapatite microspheres, and the particle size of the microspheres is 15 - 45 μm.

[0040] Example 4 A kind of biomass microspheres for cosmetic injection, which is different from Example 1 in that the preparation method of hydroxyapatite microspheres includes the following steps: Mix an aqueous solution of calcium nitrate (10 g of calcium nitrate dissolved in 100 g of water) and an ethanol solution of methyl phosphate (5.1 g of methyl phosphate dissolved in 60 g of ethanol) according to a calcium-phosphorus ratio of 1.67, adjust the pH to 8 with ammonia water, react at 90 °C for 12 h until the solution becomes a gel state (gel concentration is 50%), dehydrate and dry the gel using a spray dryer (the inlet air temperature of spray drying is 180 °C, the feeding speed time is 0.9 L / h, and the outlet air temperature is 90 °C) to obtain uniform crystal small particles, then put them into a muffle furnace and calcine at 800 °C for 3 h to form a white powder, obtaining hydroxyapatite microspheres with a particle size of 15 - 45 μm.

[0041] Example 5 A kind of biomass microspheres for cosmetic injection, which is different from Example 1 in that the microspheres are chitosan microspheres. The preparation method of chitosan microspheres includes the following steps: Soak 20 g of chitosan in 60 mL of sodium hydroxide solution with a molar concentration of 0.1 mol / L for 3 h. After soaking, wash the chitosan with distilled water until the pH is neutral, dry it at 60 °C, crush the treated chitosan, with the crushing time being 30 min. After crushing, perform screening treatment using a sieve (particle size is 30 - 60 μm), and then use a small-particle-size pick bead ball mill to spheroidize the screened chitosan, with the treatment time being 15 min / time, and perform 5 treatments. After the treatment is completed, chitosan microspheres with a particle size of 20 - 40 μm are obtained.

[0042] Example 6 A kind of biomass microspheres for cosmetic injection, which is different from Example 1 in that the microspheres are chitosan microspheres. The preparation method of chitosan microspheres includes the following steps: Soak 15 g of chitosan in 150 mL of sodium hydroxide solution with a molar concentration of 0.5 mol / L for 1 h. After soaking, wash the chitosan with purified water until the pH is neutral, dry it at 40 °C, crush the treated chitosan, with the crushing time being 30 min. After crushing, perform screening treatment using a sieve (particle size is 30 - 60 μm), and then use a small-particle-size pick bead ball mill to spheroidize the screened chitosan, with the treatment time being 15 min / time, and perform 2 treatments. After the treatment is completed, chitosan microspheres with a particle size of 20 - 40 μm are obtained.

[0043] Example 7 A biomass microsphere for cosmetic injection, which is different from that of Example 1 in that the microsphere is an acylated chitin microsphere. The preparation method of the acylated chitin microsphere includes the following steps: Soak 30 g of chitin in 300 mL of sodium hydroxide solution with a molar concentration of 0.5 mol / L for 1 h. After soaking, wash the chitin with purified water until the pH is neutral. Weigh 10 g of chitin powder, add it to a glass reaction vessel, add 20 mL of an acylation reagent acetic anhydride solution, add 150 mL of methanol, stir evenly, control the temperature at 0 °C, then add 1 mL of perchloric acid solution with a mass concentration of 70% as a catalyst, stir and react for 48 h. After the reaction is completed, filter to separate the solid and liquid. Put the solid into an aqueous NaOH solution with a mass concentration of 5% for acid-base neutralization, centrifuge to separate the solid and liquid. Wash the solid with water to desalt, dehydrate with 95% ethanol by mass concentration, and dry by heating at 50 °C to obtain acylated chitin. After the reaction is completed, add the acylated chitin to a tetrahydrofuran solution with a mass concentration of 90% and stir to dissolve it to prepare a solution with a mass concentration of 15%. After dissolution is completed, use a spray dryer for spray drying. The inlet air temperature for spray drying is 210 °C, the feeding speed is 1.5 L / h, and the outlet air temperature is 105 °C to obtain acylated chitin microspheres with a particle size of 20 - 40 μm.

[0044] Example 8 A biomass microsphere for cosmetic injection, which is different from that of Example 1 in that the microsphere is an acylated chitin microsphere. The preparation method of the acylated chitin microsphere includes the following steps: Soak 36 g of chitin in 80 mL of sodium hydroxide solution with a molar concentration of 0.1 mol / L for 3 h. After soaking, wash the chitin with distilled water until the pH is neutral. Weigh 10 g of chitin powder, add it to a glass reaction vessel, add 20 mL of an acylation reagent acetic anhydride solution, add 150 mL of methanol, stir evenly, control the temperature at 5 °C, then add 1 mL of perchloric acid solution with a mass concentration of 65% as a catalyst, stir and react for 46 h. After the reaction is completed, filter to separate the solid and liquid. Put the solid into an aqueous NaOH solution with a mass concentration of 5% for acid-base neutralization, centrifuge to separate the solid and liquid. Wash the solid with water to desalt, dehydrate with 95% ethanol by mass concentration, and dry by heating at 50 °C to obtain acylated chitin. After the reaction is completed, add the acylated chitin to formic acid solution with a mass concentration of 70% and stir to dissolve it to prepare a solution with a mass concentration of 5%. After dissolution is completed, use a spray dryer for spray drying. The inlet air temperature for spray drying is 195 °C, the feeding speed is 1 L / h, and the outlet air temperature is 120 °C to obtain acylated chitin microspheres with a particle size of 20 - 40 μm.

[0045] Example 9 A kind of biomass microsphere for cosmetic injection, which is different from Example 8 in that the acylated chitin is further processed: 10 g of acylated chitin is dissolved in 100 mL of tetrahydrofuran solution to obtain an acylated chitin solution. The acylated chitin solution is added to a saturated sodium chloride solution (36.5 g of sodium chloride is dissolved in 100 mL of water at room temperature). The acylated chitin solution is evenly dispersed in the saturated sodium chloride solution using a liquid dispersion device (high-speed disperser). 4000 g of distilled water is slowly added for precipitation treatment. After precipitation, filtration is carried out, washed with distilled water to remove excess solvent, and dried to obtain acylated chitin microspheres with a particle size of 20 - 40 μm.

[0046] Example 10 A kind of biomass microsphere for cosmetic injection, which is different from Example 1 in that the water-soluble polysaccharide coating is carboxymethyl chitosan.

[0047] The pretreatment of carboxymethyl chitosan includes the following steps: 15 g of carboxymethyl chitosan is dispersed in 300 mL of purified water, stirred evenly, filtered by suction, precipitated and washed with absolute ethanol, and dried to obtain a chitosan raw material. The chitosan is dispersed in 300 mL of purified water, modified seaweed fiber and sodium carboxymethyl cellulose are added, and stirred at 60 °C for 2 h, and then dried to obtain pretreated carboxymethyl chitosan.

[0048] The mass ratio of carboxymethyl chitosan, modified seaweed fiber and sodium carboxymethyl cellulose is 1:0.6:0.1.

[0049] The preparation method of the modified seaweed fiber includes the following steps: 12 g of seaweed fiber is dispersed in 100 mL of sodium hydroxide solution with a mass concentration of 10%, soaked for 20 min, washed with water, and then dispersed in 200 mL of purified water. PCL-PEG-PCL block copolymer and xanthan gum are added, and stirred at 40 °C for 1 h, and then dried to obtain the modified seaweed fiber. Take the required amount for the preparation of carboxymethyl chitosan; the PCL-PEG-PCL block copolymer is purchased from Shanghai Sigma-Aldrich Biotechnology Co., Ltd.

[0050] The mass ratio of seaweed fiber, PCL-PEG-PCL block copolymer and xanthan gum is 1:0.3:0.09.

[0051] Example 11 A kind of biomass microsphere for beauty injection, which is different from Example 10 in that the carboxymethyl chitosan is pretreated, including the following steps: Disperse 18 g of carboxymethyl chitosan in 360 mL of purified water, stir evenly, filter by suction, precipitate and wash with absolute ethanol, and dry to obtain the carboxymethyl chitosan raw material. Disperse the carboxymethyl chitosan in 300 mL of purified water, add modified seaweed fiber and sodium carboxymethyl cellulose, stir at 65 °C for 1 h, and dry to obtain the pretreated carboxymethyl chitosan.

[0052] The mass ratio of carboxymethyl chitosan, modified seaweed fiber and sodium carboxymethyl cellulose is 1:0.4:0.2.

[0053] The preparation method of the modified seaweed fiber includes the following steps: Disperse 14 g of seaweed fiber in 100 mL of sodium hydroxide solution with a mass concentration of 10%, soak for 25 min, wash with water, then disperse in 200 mL of purified water, add PCL-PEG-PCL block copolymer and xanthan gum, stir at 35 °C for 2 h, and dry to obtain the modified seaweed fiber, and take the required amount for the preparation of carboxymethyl chitosan.

[0054] The mass ratio of seaweed fiber, PCL-PEG-PCL block copolymer and xanthan gum is 1:0.1:0.07.

[0055] Example 12 A kind of biomass microsphere for beauty injection, which is different from Example 10 in that in the pretreatment of carboxymethyl chitosan, no modified seaweed fiber is added.

[0056] Example 13 A kind of biomass microsphere for beauty injection, which is different from Example 10 in that in the pretreatment of carboxymethyl chitosan, no sodium carboxymethyl cellulose is added.

[0057] Example 14 A kind of biomass microsphere for beauty injection, which is different from Example 10 in that the mass ratio of carboxymethyl chitosan, modified seaweed fiber and sodium carboxymethyl cellulose is 1:0.4 - 0.6:0.1 - 0.2.

[0058] Example 15 A kind of biomass microsphere for beauty injection, which is different from Example 10 in that in the preparation method of the modified seaweed fiber, no PCL-PEG-PCL block copolymer is added.

[0059] Example 16 A kind of biomass microsphere for beauty injection, which is different from Example 10 in that in the preparation method of the modified seaweed fiber, no xanthan gum is added.

[0060] Example 17 A biomass microsphere for cosmetic injection, which is different from Example 10 in that the mass ratio of the algal fiber, PCL-PEG-PCL block copolymer and xanthan gum is 1:0.05:0.13.

[0061] Example 18 A biomass microsphere for cosmetic injection, which is different from Example 1 in that the microsphere is a chitosan microsphere with a deacetylation degree of 50%. The preparation method of the chitosan microsphere with a deacetylation degree of 50% includes the following steps: putting 30 g of chitosan with a deacetylation degree of 50% into 80 mL of sodium hydroxide solution with a molar concentration of 0.2 mol / L and soaking for 2 h. After soaking, washing the chitosan with distilled water until the pH is neutral, drying at 60 °C, crushing the treated chitosan, with the crushing time being 35 min. After crushing, screening with a sieve (particle size of 40 - 50 μm), and then using a small-particle-size bead mill to spheroidize the screened chitosan, with the treatment time being 10 min / time and performing 4 treatments. After the treatment, chitosan microspheres with a particle size of 20 - 30 μm are obtained.

[0062] Comparative Example 1 A biomass microsphere for cosmetic injection, which is different from Example 1 in that no water-soluble polysaccharide coating is added.

[0063] Performance detection test Perform performance tests on the biomass microspheres for cosmetic injection prepared in Examples 1 - 18 and Comparative Example 1; 1. Sphericity test: Use the image-pro plus software (version number 6.0.0.260 for Windows 2000 / XP Professional) of Media Cybernetics to measure the average perimeter and average area of the hydroxyapatite microspheres in the examples and comparative examples, and calculate the sphericity using the following formula:

[0064] In the formula, S is the sphericity (%); A is the average surface area of the microsphere measured by the software (mm 2 ), C is the average perimeter of the microsphere measured by the software (mm), and the test results are shown in Table 1.

[0065] 2. Stability test: Disperse the hydroxyapatite microspheres in the examples and comparative examples in an aqueous solution for stability testing. The testing process is as follows: mechanical stirring at 360 rpm for 15 min; homogenization at 3500 rpm for 4 min; then standing at 35 °C. The test results are shown in Table 1.

[0066] 3. The injectables prepared in the examples and comparative examples were tested as follows. The preparation method of the preparation includes the following: 9 g of the microspheres prepared in the examples and comparative examples were respectively mixed evenly with 100 g of normal saline with a mass fraction of 0.9% to obtain the injectable for filling containing microspheres.

[0067] 4. Enhancement effectiveness test: Male Wistar rats were randomly divided into 19 groups with 10 rats in each group. The injectable was injected into the same area on the back of all rats. The control group was injected with 5 mL of normal saline, and the other groups were respectively injected with 5 mL of the injectables of the examples and comparative examples. After injection, the rats were fed normally. The injection sites were observed 3 days, 5 days, and 10 days later. A skin elasticity tester was used to test the tightness of the injection area for effectiveness evaluation.

[0068] 5. The elastic modulus and dynamic viscosity of the biomass microspheres prepared in the examples and comparative examples were tested. The elastic modulus and dynamic viscosity were measured for viscoelasticity by a rotational rheometer (TA Instruments DHR-1 model) at 25 °C using a clamp with a 25 mm diameter plate geometry. The deformation pressure was 0.1%, and frequency scanning was performed to obtain the modulus and viscosity of each sample at 1 Hz. Each sample was tested in parallel 3 times and the average value was calculated.

[0069] Table 1 Test data of the examples and comparative examples

[0070] Table 2 Test data of the examples and comparative examples

[0071] Combined with the data in the examples and Tables 1-2, it can be seen that the sphericity of the biomass microspheres prepared in Examples 1-9 and Example 18 is between 88.3% and 91.0%. In the stability test of the biomass microspheres in aqueous solution, a uniform suspension was formed within 3 h, and aggregation sedimentation occurred at 5 h, indicating that the biomass microspheres prepared in this application have good forming rate and stability; when made into the injectable for filling containing hydroxyapatite microspheres for the enhancement effectiveness test, the elastic modulus is between 842 and 856 Pa, the dynamic viscosity range is 512-525 Pa·s, the enhancement effectiveness of the tightness at 3 days is 90-95%, the enhancement effectiveness of the tightness at 5 days is 90-94%, and the enhancement effectiveness of the tightness at 10 days is 80-84%, indicating that the prepared biomass microspheres have good biocompatibility, can provide an immediate filling effect, and enhance the tightness and elasticity of the skin.

[0072] Comparative Example 1 only used microspheres without adding water-soluble polysaccharide coating. The sphericity of the prepared biomass microspheres was 80.1%. In the stability test of the biomass microspheres in aqueous solution, a uniform suspension was formed within 0 min, aggregation and sedimentation occurred at 1 h, continued sedimentation at 3 h, and complete sedimentation at 5 h. This indicates that the biomass microspheres prepared in this application have good sphericity and stability, and coating the microspheres improves the forming rate and dispersion stability in aqueous solution. An injectable filler containing hydroxyapatite microspheres was prepared for the effectiveness improvement test. The elastic modulus was 821 Pa, the dynamic viscosity was 492 Pa·s, the effectiveness of improving compactness at 3 d was 80%, the effectiveness of improving compactness at 5 d was 75%, and the effectiveness of improving compactness at 10 d was 65%. The effectiveness of improving compactness at 3 d, 5 d, and 10 d in the control group was 0. This shows that coating the microspheres in this application can provide an immediate filling effect, improve the compactness and elasticity of the skin, while the filling effect and the effect of improving skin compactness of the uncoated biomass microspheres become worse.

[0073] In Examples 10 - 11, carboxymethyl chitosan was pretreated. The sphericity of the prepared biomass microspheres was 95.5 - 95.7%. In the stability test of the biomass microspheres in aqueous solution, a uniform suspension was formed within 5 h. This indicates that the biomass microspheres prepared by coating with the carboxymethyl chitosan obtained by pretreatment in this application have good sphericity and stability.

[0074] An injectable filler containing hydroxyapatite microspheres was prepared for the effectiveness improvement test. The elastic modulus was 877 - 879 Pa, the dynamic viscosity was 547 - 549 Pa·s, the effectiveness of improving compactness at 3 d was 100%, the effectiveness of improving compactness at 5 d was 100%, and the effectiveness of improving compactness at 10 d was 98%. The effectiveness of improving compactness at 3 d, 5 d, and 10 d in the control group was 0. This shows that electrostatic interaction occurs between the carboxylate ions on the modified seaweed fiber and the amino groups on chitosan in this application, forming an ionic bond, thereby achieving crosslinking and forming a stable gel structure. Sodium carboxymethyl cellulose improves the solubility of chitosan, increases the crosslinking degree of chitosan and the modified seaweed fiber, improves the mechanical strength, biocompatibility, and film-forming property of the system. Subsequently, microspheres are coated, and the obtained microspheres have good dispersibility, stability, antibacterial, and anti-inflammatory effects, effectively improving the compactness and elasticity of the skin.

[0075] In Examples 12-13, modified seaweed fiber and sodium carboxymethylcellulose were not added respectively during the pretreatment of carboxymethyl chitosan. In Example 14, the mass ratios of carboxymethyl chitosan, modified seaweed fiber and sodium carboxymethylcellulose were changed. It can be seen from Table 1-2 that the performance test results of the sphericity, elastic modulus, dynamic viscosity, 3d, 5d and 10d compactness improvement effectiveness of the biomass microspheres prepared in Examples 12-13 were all worse than those in Examples 10-11, but better than those in Examples 1-9. The corresponding performance test results of Example 14 were better than those in Examples 12-13, but worse than those in Examples 10-11, indicating that there is a synergistic effect among carboxymethyl chitosan, modified seaweed fiber and sodium carboxymethylcellulose. Sodium carboxymethylcellulose improves the solubility of carboxymethyl chitosan and enhances the cross-linking effect between carboxymethyl chitosan and modified seaweed fiber. The carboxylate ions on the modified seaweed fiber and the amino groups on chitosan cross-link to form a stable gel structure. The obtained system has good mechanical strength, film-forming property and stability. When applied to microspheres subsequently, the corresponding properties of the microspheres are improved, thereby enhancing the compactness and elasticity of the skin.

[0076] In Examples 15-16, PCL-PEG-PCL block copolymer and xanthan gum were not added respectively during the preparation method of modified seaweed fiber. In Example 17, the mass ratios of seaweed fiber, PCL-PEG-PCL block copolymer and xanthan gum were changed. It can be seen from Table 1-2 that the performance test results of the sphericity, elastic modulus, dynamic viscosity, 3d, 5d and 10d compactness improvement effectiveness of the biomass microspheres prepared in Examples 15-16 were all better than those in Example 12, but worse than those in Examples 10-11. The corresponding performance test results of Example 17 were better than those in Examples 15-16, but worse than those in Examples 10-11, indicating that xanthan gum can increase the adhesion between PCL-PEG-PCL block copolymer and seaweed fiber, improve the hydrophilicity, mechanical strength, biodegradability and stability of seaweed fiber. When applied to chitosan subsequently, the corresponding properties and film-forming property of chitosan are improved, and the corresponding properties of the biomass microspheres are improved.

[0077] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A biomass microsphere for cosmetic injection, characterized in that: The invention comprises microspheres and water-soluble polysaccharide coatings, wherein the microspheres are one of hydroxyapatite microspheres, chitin microspheres, chitosan microspheres, and acylated chitin / chitosan microspheres, and the water-soluble polysaccharide coating is one of carboxyalkyl chitosan, carboxyalkyl chitosan, hydroxyalkyl chitosan, hydroxyalkyl chitosan, carboxyalkyl cellulose, sodium alginate, potassium alginate, sodium hyaluronate, and potassium hyaluronate.

2. The biomass microspheres for cosmetic injection according to claim 1, characterized in that: The preparation method of hydroxyapatite microspheres comprises the following steps: calcining cattle bones at a temperature of 500-1000°C for 4-8h to obtain hydroxyapatite, firstly crushing the hydroxyapatite, sieving to obtain hydroxyapatite with a particle size of 30-70 μm after the crushing, and then spheroidizing the sieved hydroxyapatite to obtain hydroxyapatite microspheres with a particle size of 20-40 μm.

3. The biomass microspheres for cosmetic injection according to claim 1, characterized in that: The preparation method of hydroxyapatite microspheres comprises the following steps: mixing an aqueous solution of calcium nitrate and an ethanol solution of methyl phosphate at a calcium-phosphorus ratio of 1.67, adjusting the pH to 8-10 with aqueous ammonia, reacting at 70-90° C. for 12-24 hours until the solution becomes a gel state, dehydrating and drying the gel to obtain uniform small crystal particles, and calcining at 600-800° C. for 3-4 hours to form white powder to obtain hydroxyapatite microspheres.

4. The biomass microspheres for cosmetic injection according to claim 1, characterized in that: The preparation method of chitosan microspheres comprises the following steps: soaking chitosan in a dilute alkali solution for 1-3 hours, washing the chitosan with purified water / distilled water to a neutral pH after soaking, drying the chitosan at 40-60° C., crushing the processed chitosan, sieving the chitosan after crushing, and spheroidizing the sieved chitosan to obtain chitosan microspheres with a particle size of 20-40 μm.

5. The biomass microspheres for cosmetic injection according to claim 1, characterized in that: The preparation method of acylated chitosan / chitosan microspheres comprises the following steps: placing chitosan / chitosan in a dilute alkali solution for soaking for 1-3 hours, washing the chitosan / chitosan with purified water / distilled water to neutralize the pH after soaking; mixing chitosan / chitosan, acetic anhydride solution and methanol, stirring evenly, controlling the temperature to be 0-5°C, adding a perchloric acid solution, stirring and reacting for 46-48 hours, filtering, solid-liquid separation after the reaction is completed, placing a solid in a NaOH aqueous solution, acid-base neutralization, centrifugation, solid-liquid separation, washing and desalting the solid with water, dehydrating with ethanol, and heating and drying at 50-55°C to obtain acylated chitosan / chitosan; after the reaction is completed, adding the acylated chitosan / chitosan to a formic acid solution or a tetrahydrofuran solution with a mass concentration of 70-90%, stirring and dissolving, and spray drying after the dissolution is completed to obtain acylated chitosan / chitosan microspheres with a particle size of 20-40 μm.

6. The biomass microspheres for cosmetic injection according to claim 5, characterized in that: The acylated chitosan / chitosan is further treated by dissolving the acylated chitosan / chitosan in a tetrahydrofuran solution to obtain an acylated chitosan / chitosan solution, adding the acylated chitosan / chitosan solution to a saturated sodium chloride solution, uniformly dispersing the acylated chitosan / chitosan solution in the saturated sodium chloride solution, slowly adding distilled water for precipitation treatment, filtering after the precipitation is completed, washing with distilled water, removing excess solvent, and drying to obtain acylated chitosan microspheres / chitosan microspheres with a particle size of 20-40 μm.

7. The biomass microspheres for cosmetic injection according to claim 1, characterized in that: The method comprises the following steps of: dispersing the carboxyalkyl / hydroxyalkyl chitosan in purified water, stirring evenly, filtering, precipitating and washing with anhydrous ethanol, and drying to obtain a carboxyalkyl / hydroxyalkyl chitosan raw material; dispersing the carboxyalkyl / hydroxyalkyl chitosan raw material in purified water, adding modified seaweed fiber and sodium hydroxymethyl cellulose, stirring at a temperature of 60-65°C for 1-2 hours, and drying to obtain a pretreated carboxyalkyl / hydroxyalkyl chitosan.

8. The biomass microspheres for cosmetic injection according to claim 7, characterized in that: The mass ratio of the carboxyalkyl / hydroxyalkyl chitosan, the modified seaweed fiber and sodium hydroxymethyl cellulose is 1:0.4-0.6:0.1-0.

2.

9. The biomass microspheres for cosmetic injection according to claim 7, characterized in that: The preparation method of the modified seaweed fiber comprises the following steps: dispersing the seaweed fiber in a sodium hydroxide solution, soaking for 20-25 minutes, washing with water, and then dispersing it in purified water, adding PCL-PEG-PCL block copolymer and xanthan gum, stirring at 35-40° C. for 1-2 hours, and drying to obtain the modified seaweed fiber.

10. The method for preparing biomass microspheres for cosmetic injection according to claim 1, characterized in that: The method comprises the following steps: subjecting microspheres to boiling dispersion treatment, dissolving water-soluble polysaccharides in purified water to obtain a water-soluble polysaccharide aqueous solution, atomizing, and coating the microspheres to obtain biomass microspheres.

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