Amphiphilic polyester microsphere as well as preparation method and application thereof

Abstract

The invention provides amphiphilic polyester microspheres as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) dissolving amphiphilic polyester in a good solvent of the amphiphilic polyester as an oil phase; (2) taking a water solution containing a surfactant and inorganic salt as a water phase, and adding the oil phase in the step (1) into the water phase under stirring for emulsification; wherein the emulsification temperature is 0-10 DEG C. The amphiphilic polyester microsphere disclosed by the invention is high in surface smoothness degree and high in sphericity degree; the preparation method of the amphiphilic polyester microspheres is simple to operate, and the particle size of the microspheres is easy to control so as to meet the requirements of different purposes on the particle size of the microspheres; the microsphere provided by the invention has a good application prospect in the fields of tumor embolism and tissue repair / regeneration.

Description

Technical Field

[0001] The present invention relates to the technical field of medical cosmetic or embolic preparations, and in particular to amphiphilic polyester microspheres and a preparation method and application thereof. Background Art

[0002] Microspheres, usually particles with a size in the range of 1 to 1000 μm, can be made of materials such as polymers, ceramics, lipids, proteins or cells. Their small size allows for tailored drug release, targeted delivery and functional amplification. From drug delivery systems in medicine to fillers in cosmetics, from diagnostic tools in biotechnology to lightweight fillers in materials science, they are widely used in industries such as pharmaceuticals, cosmetics, materials science and biotechnology.

[0003] Microspheres have many unique characteristics, which make them a hot research object in the field of tumor embolization and tissue repair / regeneration. According to the material properties, microspheres can be divided into two types: degradable and non-degradable. Among them, degradable microspheres have irreplaceable advantages in multiple application fields due to their degradable properties.

[0004] In the field of tumor embolization therapy, compared with non-degradable embolic microspheres, degradable microspheres can recanalize blood vessels after degradation, and tissues can recover from ischemic damage, avoiding the body's persistent inflammatory response and affecting the recovery of organ function, and reducing the risk of tumor metastasis and recurrence. After blood vessels are recanalized, large-area vascular occlusion caused by permanent embolism of non-degradable embolic agents can also be avoided, which hinders the subsequent catheter-based related treatment. In particular, degradable and drug-loaded embolic microspheres, in addition to the above advantages, can also slowly release chemotherapy drugs in specific parts of the body, thereby reducing systemic toxic side effects and improving efficacy.

[0005] In the field of tissue engineering, microspheres can be formed in situ at the injection site, reducing the risk of infection and improving the comfort of patients clinically. In addition, as a special tissue scaffold, degradable microspheres can fill irregular and complex-shaped tissue defects, replace damaged tissue structures and restore their biological functions. In the field of medical beauty filling, degradable microspheres with polycaprolactone (PCL) and polylactic acid (PLA) as the main materials have become a new star product in recent years and are widely used for filling soft tissues in the face, neck and body. When microspheres are injected into human tissues, they can not only directly play a role in physical filling, making skin wrinkles disappear and fuller; at the same time, the presence of microspheres will further cause subclinical foreign body inflammatory reactions, leading to the encapsulation of microparticles, fibrosis and deposition of type I collagen in the extracellular matrix to increase the volume of soft tissues, thereby promoting the regeneration of self-collagen cells, and playing a dual role of filling and repair. Compared with simple hydrogels, microspheres have a high specific surface area, which can provide sufficient space for cell growth. The gaps between microspheres can promote cell migration and proliferation to accelerate the formation of new tissues.

[0006] Related research results show that microparticles with poor hydrophilicity, rough surface and irregular shape are prone to foreign body granuloma after injection filling, causing long-term rejection reaction; on the contrary, microspheres with strong hydrophilicity, smooth surface and regular spherical shape form fibroblasts and collagen fibers around the microspheres after injection filling, thus producing the best tissue enhancement and filling effect. However, such microsphere products with PLA and PCL as the main regenerative materials are difficult to disperse evenly in hydrophilic gels such as sodium hyaluronate (HA) and sodium carboxymethyl cellulose (CMC-Na) due to their poor hydrophilicity. Therefore, there are risks such as easy needle blocking, difficult injection, and easy agglomeration during actual use; in addition, existing medical beauty filler products also have problems such as rough surface, irregular morphology, poor uniformity, and slow re-dissolution speed of microspheres. The irregular and rough morphology may cause the microspheres to be unable to pass through smaller injection needles (26G~30G), the pushing force is large, and the doctor is difficult to operate, causing problems such as uneven filling and unnatural filling. Therefore, improving the hydrophilicity, surface smoothness and sphericity of microspheres is crucial to improving the biocompatibility, filling effect and convenience of clinical operation of microsphere products. However, the preparation of microspheres with high surface smoothness has always been a technical difficulty, involving the physical and chemical properties of the material, the stability of the two-phase emulsification process, the control of the microsphere curing process and the drying process. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention aims to provide an amphiphilic polyester microsphere and a preparation method and application thereof; the amphiphilic polyester microsphere of the present invention has a high degree of surface smoothness and a high degree of sphericity; the preparation method of the amphiphilic polyester microsphere of the present invention is simple to operate and the particle size of the microsphere can be easily controlled to meet the requirements of different uses for the particle size of the microsphere; the microsphere of the present invention has good application prospects in the fields of tumor embolism and tissue repair / regeneration.

[0008] The purpose of the present invention is achieved through the following technical solutions: In a first aspect, the present invention provides a method for preparing polyester microspheres, the preparation method comprising the following steps: (1) dissolving the amphiphilic polyester in its good solvent as the oil phase; (2) Using an aqueous solution containing a surfactant and an inorganic salt as the aqueous phase, the oil phase of step (1) is added to the aqueous phase under stirring for emulsification; wherein the emulsification temperature is 0 to 10°C.

[0009] In some embodiments of the present invention, the amphiphilic polyester has both a hydrophobic segment and a hydrophilic segment.

[0010] In some embodiments of the present invention, the amphiphilic polyester is selected from branched amphiphilic polyesters and amphiphilic polyesters having a triblock structure.

[0011] In some embodiments of the present invention, the amphiphilic polyester is a biodegradable amphiphilic polyester. The biodegradable amphiphilic polyester may be a commercially available biodegradable amphiphilic polyester.

[0012] In some embodiments of the present invention, the triblock structure comprises a SQS structure or a QSQ structure, wherein S represents a hydrophobic segment and Q represents a hydrophilic segment.

[0013] In some embodiments of the present invention, the hydrophobic segment of the amphiphilic polyester having a triblock structure comprises a polyester formed by polymerization using one or more degradable lactone monomers as monomers.

[0014] In some embodiments of the present invention, the degradable lactone monomers include lactic acid, glycolic acid, glycolide, lactide, ε-caprolactone, and the like.

[0015] In some embodiments of the present invention, when the hydrophobic segment of the amphiphilic polyester having a triblock structure includes a polyester formed by polymerization of two or more degradable lactone monomers, the molar proportion of each monomer in the entire hydrophobic segment is between 5% and 95%.

[0016] In some embodiments of the present invention, the polymerization of the degradable lactone monomer is carried out in the presence of a polymerization catalyst; preferably, the polymerization catalyst is selected from one or more of tin-based, zinc-based, titanium-based, copper-based, iron-based, magnesium-based, and calcium-based metal catalysts, etc.; more preferably, the polymerization catalyst is a tin-based metal catalyst; most preferably, the polymerization catalyst is stannous octoate.

[0017] In some embodiments of the present invention, the hydrophilic segment of the amphiphilic polyester having a triblock structure is selected from diethylene glycol, butanol, polyethylene glycol, polypropylene glycol and the like.

[0018] In some embodiments of the present invention, the amphiphilic polyester having a triblock structure is selected from amphiphilic polyesters having an SQS structure, and the amphiphilic polyesters having an SQS structure include but are not limited to PLA-PEG-PLA, PGA-PEG-PGA, PLGA-PEG-PLGA, PCL-PEG-PCL, PLCL-PEG-PLCL, PGCL-PEG-PGCL, and PGLCL-PEG-PGLCL.

[0019] In some embodiments of the present invention, in the amphiphilic polyester having a triblock structure, the molecular weight of the hydrophobic segment is 500 to 5,000,000 Da, and the molecular weight of the hydrophilic segment is 100 to 5,000 Da.

[0020] In some embodiments of the present invention, the branched amphiphilic polyester is a branched amphiphilic polyester whose main part is a hydrophilic structure and the number of branches n≥3.

[0021] In some embodiments of the present invention, the hydrophilic segment of the branched amphiphilic polyester is selected from polyglycerol, polyethylene glycol monomethyl ether, multi-arm PEG, starch, cellulose, dextran, hyaluronic acid, sodium alginate, chitosan, carboxymethyl chitosan, plant polyphenols (such as tannins, tea polyphenols, etc.), hydroxyl-modified polylysine, hydroxyl-modified polyglutamic acid, etc.

[0022] In some embodiments of the present invention, the hydrophobic segment of the branched amphiphilic polyester comprises a polyester formed by polymerization of one or more degradable lactone monomers as monomers.

[0023] In some embodiments of the present invention, the degradable lactone monomers include lactic acid, glycolic acid, glycolide, lactide, ε-caprolactone, and the like.

[0024] In some embodiments of the present invention, when the hydrophobic segment of the branched amphiphilic polyester includes a polyester formed by polymerization of two or more degradable lactone monomers, the molar proportion of each monomer in the entire hydrophobic segment is between 5% and 95%.

[0025] In some embodiments of the present invention, in the molecular weight of the branched amphiphilic polyester, the molecular weight of the hydrophobic segment is 500 to 5,000,000 Da, and the molecular weight of the hydrophilic segment is 100 to 5,000 Da.

[0026] In some embodiments of the present invention, the molecular weight of the amphiphilic polyester is selected according to the different needs of different fields. For example, for the field of medical and aesthetic filling, the molecular weight of the amphiphilic polyester with a triblock structure is preferably 5000-1000000Da, and more preferably 50000-500000Da; for the field of vascular interventional treatment, the molecular weight of the amphiphilic polyester with a triblock structure is preferably 600-100000Da, and more preferably 1000-20000Da.

[0027] In some embodiments of the present invention, the amphiphilic polyester is obtained by polymerizing a polymerizable ester monomer and an initiator through ring-opening polymerization or polycondensation; preferably, the polymerization is carried out in the presence of a polymerization catalyst.

[0028] In some embodiments of the present invention, the polymerizable ester monomer is selected from one or more of lactic acid, glycolic acid, glycolide, lactide, ε-caprolactone and the like.

[0029] In some embodiments of the present invention, the initiator is a hydrophilic initiator, preferably selected from small molecules or polymers containing more than two hydroxyl groups; more preferably selected from diethylene glycol, butanol, glycerol, pentaerythritol, dipentaerythritol, trimethylolpropane, di(trimethylolpropane), polyglycerol, erythritol, xylitol, sorbitol, PPG, multi-arm PEG, starch, cellulose, dextran, hyaluronic acid, sodium alginate, chitosan, carboxymethyl chitosan, plant polyphenols (such as tannins, tea polyphenols, etc.), hydroxyl-modified polylysine, hydroxyl-modified polyglutamic acid, etc.

[0030] In some embodiments of the present invention, when the initiator is selected from a small molecule or a polymer containing two hydroxyl groups, an amphiphilic polyester having a triblock structure can be obtained.

[0031] In some embodiments of the present invention, when the initiator is selected from small molecules or polymers containing more than 3 hydroxyl groups, a branched amphiphilic polyester can be obtained.

[0032] In some embodiments of the present invention, the polymerization catalyst is selected from one or more of tin-based, zinc-based, titanium-based, copper-based, iron-based, magnesium-based, and calcium-based metal catalysts; preferably, the polymerization catalyst is a tin-based metal catalyst; more preferably, the polymerization catalyst is stannous octoate.

[0033] In some embodiments of the present invention, the amphiphilic polyester is prepared by a preparation method comprising the following steps: 1) Add polymerizable ester monomers into a reactor pre-loaded with initiators at 120-180°C under inert gas protection, and completely melt and mix the polymerizable ester monomers; 2) Add the polymerization catalyst into the reactor, seal the reactor, and stir the reaction for 5 minutes to 24 hours under the protection of inert gas.

[0034] In some embodiments of the present invention, the molar ratio of the initiator to the polymerizable ester monomer in step 1) is between 1:(1-500).

[0035] In some embodiments of the present invention, the polymerization catalyst in step 2) is first dissolved in dichloromethane or toluene, prepared into a catalyst solution and then added to the reaction system; preferably, the concentration of the polymerization catalyst in the catalyst solution is 0.5% to 50%, preferably 2 to 20%, and more preferably 5 to 10%.

[0036] In some embodiments of the present invention, the amount of the polymerization catalyst added in step 2) is 0.1% to 1% of the total molar amount of the monomer and the initiator.

[0037] In some embodiments of the present invention, the stirring speed in step 2) is 200-1000 rpm.

[0038] In some embodiments of the present invention, the inert gas is preferably nitrogen.

[0039] In some embodiments of the present invention, the method for preparing the amphiphilic polyester further comprises drying the initiator before step 1); preferably, drying is performed in a vacuum oven at 60-120° C.; more preferably, the drying time is 10 min to 24 h.

[0040] In some embodiments of the present invention, the method for preparing the amphiphilic polyester further comprises step 3): dissolving the reaction product obtained in step 2) in a good solvent thereof, then precipitating it with a poor solvent and collecting the precipitate; preferably, further drying the precipitate.

[0041] In some embodiments of the present invention, the good solvent in step 3) refers to a reagent that can dissolve the amphiphilic polyester.

[0042] In some embodiments of the present invention, the good solvent in step 3) can be selected from one or two of ethyl acetate, dichloromethane, chloroform, tetrahydrofuran and the like.

[0043] In some embodiments of the present invention, the poor solvent in step 3) refers to a reagent that cannot dissolve the amphiphilic polyester.

[0044] In some embodiments of the present invention, the poor solvent in step 3) can be selected from one or two of petroleum ether, diethyl ether, methanol and the like.

[0045] In some embodiments of the present invention, the molecular structure of the amphiphilic polyester can be regulated by the selection of initiators, the content of initiators and the selection of monomers and the content of monomers, thereby adjusting the physical and chemical properties of the amphiphilic polyester, which has rich structural and performance diversity.

[0046] In some embodiments of the present invention, the mass concentration of the amphiphilic polyester in the oil phase is 1% to 20%.

[0047] In some embodiments of the present invention, in the oil phase, the good solvent is an organic solvent that can dissolve the polyester, preferably dichloromethane (DCM).

[0048] In some embodiments of the present invention, the inorganic salt includes at least one of sodium chloride, potassium chloride, etc.

[0049] In some embodiments of the present invention, the surfactant is selected from at least one of common emulsifiers such as polyvinyl alcohol (PVA), polypropylene, paraffin, Span, sodium dodecyl sulfate (SDS), etc.

[0050] In some embodiments of the present invention, the mass concentration of the surfactant in the aqueous phase is 0.1% to 5%.

[0051] In some embodiments of the present invention, the mass concentration of the inorganic salt in the aqueous phase is 0.1% to 10%.

[0052] In some embodiments of the present invention, the stirring speed in step (2) is 50 to 1800 rpm.

[0053] In some embodiments of the present invention, when preparing microspheres for use as medical cosmetic fillers, the stirring speed in step (2) is 800 to 1800 rpm.

[0054] In some embodiments of the present invention, when preparing embolic microspheres, the stirring speed in step (2) is 50 to 800 rpm.

[0055] In some embodiments of the present invention, the emulsification temperature is 0-4° C.; preferably, the emulsification can be performed in an ice bath.

[0056] In some embodiments of the present invention, the emulsification time is 1 to 60 minutes.

[0057] In some embodiments of the present invention, the preparation method further comprises removing the solvent from the product obtained after the emulsification.

[0058] In some embodiments of the present invention, the method of removing the solvent in the product obtained after emulsification includes stirring, volatilization and / or washing.

[0059] In some embodiments of the present invention, the stirring rate of the stirring volatilization is 100-1000 rpm.

[0060] In some embodiments of the present invention, when preparing microspheres for use as medical cosmetic fillers, the stirring rate of the stirring volatilization is 200 to 800 rpm.

[0061] In some embodiments of the present invention, when preparing embolic microspheres, the stirring rate of the stirring volatilization is 50-500 rpm.

[0062] In some embodiments of the present invention, the stirring and volatilization time is 2 hours to 24 hours.

[0063] In some embodiments of the present invention, the temperature of the stirring and volatilization is 20-50°C.

[0064] In some embodiments of the present invention, the cleaning is performed using pure water.

[0065] In some embodiments of the present invention, the method for removing the solvent from the product obtained after emulsification comprises first treating it by stirring and volatilizing for 2 to 24 hours, and then washing it with pure water for 3 to 6 times.

[0066] In some embodiments of the present invention, microspheres with different target particle size ranges can be obtained by adjusting the stirring rate during the emulsification process and / or the solvent volatilization process.

[0067] In some embodiments of the present invention, the preparation method further comprises freeze-drying the microspheres obtained after removing the solvent.

[0068] In some embodiments of the present invention, the preparation method further comprises screening the freeze-dried microspheres according to particle size.

[0069] In some embodiments of the present invention, when preparing microspheres for use in medical cosmetic fillers, microspheres of 30 to 50 μm are screened out as the final product.

[0070] In some embodiments of the present invention, when preparing embolic microspheres, microspheres of 70-150 μm, 100-300 μm, 300-500 μm, 500-700 μm, 700-900 μm and 900-1200 μm are screened out and stored as final products.

[0071] In a second aspect, the present invention provides a use of microspheres prepared by the preparation method described in the first aspect in the preparation of embolic microspheres or medical aesthetic fillers.

[0072] In a third aspect, the present invention provides an embolic microsphere, wherein the embolic microsphere comprises a microsphere prepared by the preparation method described in the first aspect, and the particle size of the microsphere is between 70 and 1200 μm.

[0073] In a fourth aspect, the present invention provides a medical cosmetic filler, comprising microspheres prepared by the preparation method described in the first aspect, wherein the particle size of the microspheres is between 30 and 50 μm.

[0074] In some embodiments of the present invention, based on the total amount of the medical cosmetic filler in a freeze-dried state, the mass percentage of the microspheres in the entire medical cosmetic filler is 10% to 70%.

[0075] In some embodiments of the present invention, based on the total amount of the medical cosmetic filler in a freeze-dried state, the mass percentage of the microspheres in the entire medical cosmetic filler is 30% to 60%.

[0076] In some embodiments of the present invention, the medical cosmetic filler further comprises a gel, and the storage modulus G' of the gel is between 10 and 1000 Pa, and the loss modulus G" of the gel is between 5 and 500 Pa.

[0077] In some embodiments of the present invention, the gel comprises a host material and optional additives.

[0078] In some embodiments of the present invention, the main material of the gel is selected from one or more of CMC-Na, HA, cross-linked HA, collagen, etc.

[0079] In some embodiments of the present invention, the additive comprises a pharmaceutical excipient and / or an anesthetic.

[0080] In some embodiments of the present invention, the pharmaceutical excipients are selected from common pharmaceutical excipients such as mannitol, glucose, protein, vitamins, glycerol, glycolic acid, amino acids, and lidocaine hydrochloride.

[0081] In some embodiments of the present invention, the gel comprises the following raw materials in percentage by weight, based on the total amount of the gel: 5% to 70% of main material, 0% to 50% of pharmaceutical excipients, and 0% to 0.5% of anesthetic.

[0082] In some embodiments of the present invention, the gel comprises the following raw materials in percentage by weight, based on the total amount of the gel: 10% to 40% of main material, 10% to 40% of pharmaceutical excipients, and 0% to 0.3% of anesthetic.

[0083] In some embodiments of the present invention, the dispersion medium of the gel is water for injection.

[0084] In a fifth aspect, the present invention provides a method for preparing the medical cosmetic filler described in the fourth aspect, comprising the following steps: mixing microspheres with a particle size between 30 and 50 μm prepared by the preparation method described in the first aspect with gel.

[0085] In some embodiments of the present invention, the method for preparing a medical cosmetic filler comprises the following steps: (a) adding microspheres with a particle size of 30 to 50 μm prepared by the preparation method described in the first aspect to a gel, dispersing the microspheres in the gel by stirring or vortexing, and then performing ultrasonic treatment to remove bubbles in the liquid; Optionally (b) freeze-drying and sterilizing the product obtained in step (a).

[0086] The beneficial effects of the present invention are as follows: The invention provides a method for preparing amphiphilic polyester microspheres by a W / O emulsification solidification method under low temperature and stirring conditions, using an amphiphilic polyester / good solvent as an oil phase and an aqueous solution containing a surfactant and an inorganic salt as a water phase. The amphiphilic polyester microspheres prepared by the preparation method have high surface smoothness and high sphericity, and the preparation method is simple to operate and can easily control the particle size of the microspheres to meet the requirements of different uses for the particle size of the microspheres.

[0087] The present invention further proposes to select biodegradable amphiphilic polyesters to prepare microspheres, thereby obtaining biodegradable microspheres to meet the degradation characteristics requirements of microspheres in some fields. Furthermore, the present invention proposes that the hydrophobic segment of the amphiphilic polyester includes a polyester formed by polymerization with one or more degradable lactone monomers as monomers. First, the hydrophobic segment can be degraded under certain conditions, so that the formed amphiphilic polyester can also be degraded; secondly, the degree of polymerization of the hydrophobic segment is controllable, and hydrophobic segments of different lengths (molecular weight) and different molecular structures can be obtained by controlling the type and content of the monomers. Moreover, the hydrophilic segment of the amphiphilic polyester of the present invention has a wide range of options, and different amphiphilic polyesters can be obtained by selecting different hydrophilic segments.

[0088] The microspheres of the present invention have good application prospects in the fields of tumor embolization and tissue repair / regeneration. The present invention also proposes an embolic microsphere or medical cosmetic filler containing the microspheres of the present invention, and proves that the medical cosmetic filler of the present invention has the characteristics of not being easy to block the needle and having a fast re-dissolution speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Figure 1 The NMR spectrum of polyester 6 is shown.

[0090] Figure 2 The NMR spectrum of polyester 9 is shown.

[0091] Figure 3 A microscopic photograph of microsphere 4 is shown.

[0092] Figure 4 A microscope photograph of microsphere 5 is shown.

[0093] Figure 5 A microscope photograph of microsphere 6 is shown.

[0094] Figure 6 The scanning electron microscope image of microsphere 6 is shown.

[0095] Figure 7 A microscope photograph of microsphere 9 is shown.

[0096] Figure 8 A microscope photograph of the microsphere 10 is shown.

[0097] Fig. 9 A microscope photograph of the microsphere 11 is shown.

[0098] Fig.10 This is a photograph showing 1 mL of filler 4 after reconstitution with a syringe.

[0099] Fig.11 The graph shows the variation curve of the pushing force during the 1st to 3rd push injection process of fillers 1 to 6.

[0100] Fig.12 Microscope photographs of the microspheres 5 prepared in Example 5 after degradation for 1 month (upper figure) and 3 months (lower figure) are shown.

[0101] Fig.13 The results show the effects of microsphere extracts at different dilution multiples on cell activity. DETAILED DESCRIPTION

[0102] The following examples further illustrate the technology of the present invention. These examples are for illustration and example of the present invention and are not intended to limit the scope of the present invention in any form.

[0103] 1. Synthesis of amphiphilic polyester The amphiphilic polyester material is synthesized by ring-opening polymerization. By selecting different types of monomers and adjusting the ratio of initiator to monomer, products with different molecular structures and molecular weights can be obtained. The details are as follows: Polyester Synthesis Example 1 (Synthesis of PLA-PEG1000-PLA with M=10,000) 10.0 g (10.00 mmol) of PEG1000 was weighed into a reaction bottle, and the bottle was placed in a vacuum drying oven for drying and dehydration for 2 h. Then, 45 g (624.50 mmol) of lactide was weighed and added into the reaction bottle, nitrogen was introduced for deoxygenation, and the temperature was raised to 150°C. After all monomers were melted, 0.7 g (1.74 mmol) of stannous octoate was weighed and added into the reaction bottle. Under nitrogen protection, the reaction was carried out at 150°C for 3 h. Then, the reaction product was cooled to room temperature, and the product was dissolved with dichloromethane, and then the dissolved product was precipitated in petroleum ether. The precipitate was separated, redissolved with dichloromethane, and then placed in petroleum ether for precipitation again. The precipitate was separated again, redissolved with dichloromethane, and then placed in petroleum ether for precipitation again. The precipitate was collected, and the solvent was removed by vacuum drying to obtain polyester 1.

[0104] Polyester Synthesis Example 2 (Synthesis of PLA-PEG1000-PLA with M=50,000) Weigh 1.0 g (1.00 mmol) of PEG1000 into a reaction bottle, and place it in a vacuum drying oven for drying and dehydration for 2 hours; then weigh 49 g (680 mmol) of lactide and add it to the above reaction bottle, introduce nitrogen to deoxygenate, and heat to 150°C; after all monomers are melted, weigh 0.7 g (1.74 mmol) of stannous octoate and add it to the above reaction bottle; react at 150°C for 3 hours under nitrogen protection; then cool the reaction product to room temperature, dissolve the product with dichloromethane, and then precipitate the dissolved product in petroleum ether; separate the precipitate, dissolve it with dichloromethane again, and precipitate it in petroleum ether again; separate the precipitate again, dissolve it with dichloromethane again, and continue to precipitate it in petroleum ether, collect the precipitate, and remove the solvent by vacuum drying to obtain polyester 2.

[0105] Polyester Synthesis Example 3 (Synthesis of PLA-PEG1000-PLA with M=90,000) Weigh 0.5 g (0.50 mmol) of PEG1000 into a reaction bottle, and place it in a vacuum drying oven for drying and dehydration for 2 h; then weigh 749 g (680 mmol) of lactide and add it to the above reaction bottle, introduce nitrogen to deoxygenate, and heat to 150°C; after all monomers are melted, weigh 0.7 g (1.74 mmol) of stannous octoate and add it to the above reaction bottle; react at 150°C for 3 h under nitrogen protection; then cool the reaction product to room temperature, dissolve the product with dichloromethane, and then precipitate the dissolved product in petroleum ether; separate the precipitate, dissolve it with dichloromethane, and then precipitate it in petroleum ether again; separate the precipitate again, dissolve it with dichloromethane, and then precipitate it in petroleum ether again, collect the precipitate, and remove the solvent by vacuum drying to obtain polyester 3.

[0106] Polyester Synthesis Example 4 (Synthesis of PLGA7525-PEG600-PLGA7525 with M=5,000) 12.0 g (20.00 mmol) of PEG600 was weighed into a reaction bottle and placed in a vacuum drying oven for drying and dehydration for 2 h; then 74.1 g (1028.4 mmol) of lactide and 19.9 g (342.8 mmol) of glycolide were weighed and added to the above reaction bottle, nitrogen was introduced for deoxygenation, and the temperature was raised to 150°C; after all monomers were melted, 1.44 g (3.55 mmol) of stannous octoate was weighed and added to the above reaction bottle; under nitrogen protection, the reaction was carried out at 150°C for 3 h; then the reaction product was cooled to room temperature, and the product was dissolved with dichloromethane, and then the dissolved product was precipitated in petroleum ether; the precipitate was separated and redissolved with dichloromethane and then placed in petroleum ether for precipitation; the precipitate was separated again and redissolved with dichloromethane and then placed in petroleum ether for precipitation, the precipitate was collected, and the solvent was removed by vacuum drying to obtain polyester 4.

[0107] Polyester Synthesis Example 5 (Synthesis of PLGA9010-PEG600-PLGA9010 with M=5,000) 12.0 g (20.00 mmol) of PEG600 was weighed into a reaction bottle and placed in a vacuum drying oven for drying and dehydration for 2 h; then 86.3 g (1330.40 mmol) of lactide and 7.7 g (133.04 mmol) of glycolide were weighed and added into the above reaction bottle, nitrogen was introduced for deoxygenation, and the temperature was raised to 150°C; after all monomers were melted, 1.39 g (3.44 mmol) of stannous octoate was weighed and added into the above reaction bottle; under nitrogen protection, the reaction was carried out at 150°C for 3 h; then the reaction product was cooled to room temperature, and the product was dissolved with dichloromethane, and then the dissolved product was precipitated in petroleum ether; the precipitate was separated and redissolved with dichloromethane and then placed in petroleum ether for precipitation; the precipitate was separated again and redissolved with dichloromethane and then placed in petroleum ether for precipitation, the precipitate was collected, and the solvent was removed by vacuum drying to obtain polyester 5.

[0108] Polyester Synthesis Example 6 (Synthesis of PLGA9010-PEG600-PLGA9010 with M=40,000) Weigh 1.2g (2.00mmol) of PEG600 into a reaction bottle, and place it in a vacuum drying oven to dry and remove water for 2h; then weigh 86.3g (1330.40mmol) of lactide and 7.7g (133.04mmol) of glycolide and add them to the above reaction bottle, introduce nitrogen to deoxygenate, and heat to 150°C; after all monomers are melted, weigh 1.39g (3.44mmol) of stannous octoate and add it to the above reaction bottle; react at 150°C for 2h under nitrogen protection; then cool the reaction product to room temperature, dissolve the product with dichloromethane, and then precipitate the dissolved product in petroleum ether; separate the precipitate, dissolve it with dichloromethane, and then place it in petroleum ether for precipitation; separate the precipitate again, dissolve it with dichloromethane, and then place it in petroleum ether for precipitation, collect the precipitate, and remove the solvent by vacuum drying to obtain polyester 6. The NMR spectrum obtained by NMR analysis of polyester 6 is as follows Figure 1 shown.

[0109] Polyester Synthesis Example 7 (Synthesis of PLGA9010-PEG600-PLGA9010 with M=80,000) 0.6 g (1.00 mmol) of PEG600 was weighed into a reaction bottle and placed in a vacuum drying oven for drying and dehydration for 2 h; then 86.3 g (1330.40 mmol) of lactide and 7.7 g (133.04 mmol) of glycolide were weighed and added into the above reaction bottle, nitrogen was introduced for deoxygenation, and the temperature was raised to 150°C; after all monomers were melted, 1.39 g (3.44 mmol) of stannous octoate was weighed and added into the above reaction bottle; under nitrogen protection, the reaction was carried out at 150°C for 6 h; then the reaction product was cooled to room temperature, and the product was dissolved with dichloromethane, and then the dissolved product was precipitated in petroleum ether; the precipitate was separated, redissolved with dichloromethane, and then placed in petroleum ether for precipitation; the precipitate was separated again, redissolved with dichloromethane, and then placed in petroleum ether for precipitation, the precipitate was collected, and the solvent was removed by vacuum drying to obtain polyester 7.

[0110] Polyester Synthesis Example 8 (Synthesis of PLGA9010-PEG600-PLGA9010 with M=170,000) 0.24 g (0.40 mmol) of PEG600 was weighed into a reaction bottle and placed in a vacuum drying oven for drying and dehydration for 2 h; then 86.3 g (1330.40 mmol) of lactide and 7.7 g (133.04 mmol) of glycolide were weighed and added to the above reaction bottle, nitrogen was introduced for deoxygenation, and the temperature was raised to 150°C; after all monomers were melted, 1.39 g (3.44 mmol) of stannous octoate was weighed and added to the above reaction bottle; under nitrogen protection, the reaction was carried out at 150°C for 1 h; then the reaction product was cooled to room temperature, and the product was dissolved with dichloromethane, and then the dissolved product was precipitated in petroleum ether; the precipitate was separated, redissolved with dichloromethane, and then placed in petroleum ether for precipitation; the precipitate was separated again, redissolved with dichloromethane, and then placed in petroleum ether for precipitation, the precipitate was collected, and the solvent was removed by vacuum drying to obtain polyester 8.

[0111] Polyester Synthesis Example 9 (Synthesis of PLGA9010-PEG600-PLGA9010 with M=250,000) Weigh 0.10g (0.17mmol) of PEG600 into a reaction bottle, and place it in a vacuum drying oven to dry and remove water for 2h; then weigh 86.3g (1330.40mmol) of lactide and 7.7g (133.04mmol) of glycolide and add them to the above reaction bottle, introduce nitrogen to deoxygenate, and heat to 150°C; after all monomers are melted, weigh 1.39g (3.44mmol) of stannous octoate and add it to the above reaction bottle; react at 150°C for 1h under nitrogen protection; then cool the reaction product to room temperature, dissolve the product with dichloromethane, and then precipitate the dissolved product in petroleum ether; separate the precipitate, dissolve it with dichloromethane, and then place it in petroleum ether for precipitation; separate the precipitate again, dissolve it with dichloromethane, and then place it in petroleum ether for precipitation, collect the precipitate, and remove the solvent by vacuum drying to obtain polyester 9. The NMR spectrum obtained by NMR analysis of polyester 9 is as follows Figure 2 shown.

[0112] Polyester Synthesis Example 10 (Synthesis of PLCL5050-PEG600-PLCL5050 with M=50,000) 0.6 g (1.00 mmol) of PEG600 was weighed into a reaction bottle and placed in a vacuum drying oven for drying and dehydration for 2 h; then 19.67 g (272.95 mmol) of lactide and 27.33 g (272.95 mmol) of ε-caprolactone were weighed and added to the above reaction bottle, nitrogen was introduced for deoxygenation, and the temperature was raised to 150°C; after all monomers were melted, 0.58 g (1.42 mmol) of stannous octoate was weighed and added to the above reaction bottle; under nitrogen protection, the reaction was carried out at 150°C for 1 h; then the reaction product was cooled to room temperature, and the product was dissolved with dichloromethane, and then the dissolved product was precipitated in petroleum ether; the precipitate was separated and redissolved with dichloromethane and then placed in petroleum ether for precipitation; the precipitate was separated again and redissolved with dichloromethane and then placed in petroleum ether for precipitation, the precipitate was collected, and the solvent was removed by vacuum drying to obtain polyester 10.

[0113] Polyester Synthesis Example 11 (Synthesis of Branched Amphiphilic Polyester DGL-PLA with M=10,000) Weigh 7.6 g (10.00 mmol) of decaglycerol into a reaction bottle, and place it in a vacuum drying oven for drying and dehydration for 2 hours; then weigh 92.4 g (1.28 mol) of lactide and add it to the above reaction bottle, introduce nitrogen to deoxygenate, and heat to 150°C; after all monomers are melted, weigh 1.3 g (3.3 mmol) of stannous octoate and add it to the above reaction bottle; react at 150°C for 1 hour under nitrogen protection; then cool the reaction product to room temperature, dissolve the product with dichloromethane, and then precipitate the dissolved product in petroleum ether; separate the precipitate, dissolve it with dichloromethane, and then precipitate it in petroleum ether again; separate the precipitate again, dissolve it with dichloromethane, and then precipitate it in petroleum ether again, collect the precipitate, and remove the solvent by vacuum drying to obtain polyester 11.

[0114] 2. Preparation of biodegradable amphiphilic polyester microspheres Biodegradable amphiphilic polyester microspheres are prepared by emulsification and solidification. The surface smoothness, sphericity and particle size distribution of the microspheres are adjusted by regulating parameters such as the oil phase / water phase formula, oil-water ratio, stirring rate, stirring method, emulsification / solidification temperature and other parameters.

[0115] Microsphere Preparation Example 1 Weigh polyester 4, add dichloromethane to dissolve it, and prepare a polyester solution with a polyester mass concentration of 20% as the oil phase, and then prepare an aqueous solution containing a PVA mass concentration of 1% and a NaCl mass concentration of 5% as the water phase. Under stirring at 200rpm, slowly add the oil phase to the water phase, and the oil-water ratio is 1:7.5. Keep the closed condition and stir in an ice bath for emulsification for 30min. Then adjust the speed to 500rpm, first evaporate the solvent at room temperature for 30min, then increase the temperature to 35℃ to continue evaporating the solvent for 4h, then recover the microspheres by filtration and wash them, and then recover the microspheres with a particle size in the range of 50 to 1200μm by sieving, and finally freeze-dry the microspheres to obtain microspheres 1.

[0116] Microsphere Preparation Example 2 Weigh polyester 5, add dichloromethane to dissolve it, and prepare a polyester solution with a polyester mass concentration of 10% as the oil phase, and then prepare an aqueous solution containing a PVA mass concentration of 1% and a NaCl mass concentration of 3% as the water phase. Under stirring at 200rpm, slowly add the oil phase to the water phase, and the oil-water ratio is 1:6. Keep the closed condition and stir in an ice bath for emulsification for 30min. Then adjust the speed to 500rpm, first evaporate the solvent at room temperature for 30min, then increase the temperature to 35℃ and continue to evaporate the solvent for 4h, then recover the microspheres by filtration and wash them, and then recover the microspheres with a particle size in the range of 50 to 1200μm by sieving, and finally freeze-dry the microspheres to obtain microspheres 2.

[0117] Microsphere Preparation Example 3 Weigh polyester 6, add dichloromethane to dissolve it, and prepare a polyester solution with a polyester mass concentration of 10% as the oil phase, and then prepare an aqueous solution containing a PVA mass concentration of 1% and a NaCl mass concentration of 5% as the water phase. Under stirring at 300rpm, slowly add the oil phase to the water phase, and the oil-water ratio is 1:7.5. Keep the closed condition and stir in an ice bath for emulsification for 30min. Then adjust the speed to 500rpm, first evaporate the solvent at room temperature for 30min, then increase the temperature to 35℃ and continue to evaporate the solvent for 4h, then recover the microspheres by filtration and wash them, and then recover the microspheres with a particle size in the range of 50 to 1200μm by sieving, and finally freeze-dry the microspheres to obtain microspheres 3.

[0118] Microsphere Preparation Example 4 Weigh polyester 7, add dichloromethane to dissolve it, and prepare a polyester solution with a polyester mass concentration of 10% as the oil phase, and then prepare an aqueous solution containing a PVA mass concentration of 1% and a NaCl mass concentration of 5% as the water phase. Under stirring at 1600rpm, slowly add the oil phase dropwise to the water phase with an oil-water ratio of 1:10. Keep the closed conditions and stir in an ice bath for emulsification for 10 minutes. Then increase the temperature to 35°C and adjust the speed to 500rpm to evaporate the solvent for 4 hours, then recover the microspheres by filtration and wash them, and then recover the microspheres with a particle size in the range of 30 to 50μm by sieving. Finally, freeze-dry the microspheres to obtain microspheres 4. The picture of microspheres 4 under a microscope is shown below. Figure 3 shown.

[0119] Microsphere Preparation Example 5 Weigh polyester 8, add dichloromethane to dissolve it, and prepare a polyester solution with a polyester mass concentration of 10% as the oil phase, and then prepare an aqueous solution containing a PVA mass concentration of 1% and a NaCl mass concentration of 5% as the water phase. Under stirring at 1500rpm, slowly add the oil phase dropwise to the water phase with an oil-water ratio of 1:8. Keep the closed conditions and stir in an ice bath for emulsification for 30 minutes. Then adjust the speed to 500rpm, first evaporate the solvent at room temperature for 30 minutes, then increase the temperature to 35°C and continue to evaporate the solvent for 4 hours, then recover the microspheres by filtration and wash them, and then recover the microspheres with a particle size in the range of 30 to 50μm by sieving, and finally freeze-dry the microspheres to obtain microspheres 5. The picture of microspheres 5 under a microscope is shown below. Figure 4 shown.

[0120] Microsphere Preparation Example 6 Weigh polyester 9, add dichloromethane to dissolve it, and prepare a polyester solution with a polyester mass concentration of 10% as the oil phase, and then prepare an aqueous solution containing a PVA mass concentration of 1% and a NaCl mass concentration of 3% as the water phase. Under stirring at 1800rpm, slowly add the oil phase dropwise to the water phase with an oil-water ratio of 1:10. Keep the closed conditions and stir in an ice bath for emulsification for 30 minutes. Then adjust the speed to 500rpm, first evaporate the solvent at room temperature for 30 minutes, then increase the temperature to 35°C and continue to evaporate the solvent for 4 hours, then recover the microspheres by filtration and wash them, and then recover the microspheres with a particle size in the range of 30 to 50μm by sieving, and finally freeze-dry the microspheres to obtain microspheres 6. The picture of microspheres 6 under a microscope is shown below. Figure 5 As shown, the image of microsphere 6 under scanning electron microscope is as follows Figure 6 shown.

[0121] Microsphere Preparation Example 7 Weigh polyester 10, add dichloromethane to dissolve it, and prepare a polyester solution with a polyester mass concentration of 5% as the oil phase, and then prepare an aqueous solution containing a PVA mass concentration of 1% and a NaCl mass concentration of 6% as the water phase. Under stirring at 1500rpm, slowly add the oil phase to the water phase, and the oil-water ratio is 1:10. Keep the closed condition and stir in an ice bath for emulsification for 30min. Then adjust the speed to 500rpm, first evaporate the solvent at room temperature for 30min, then increase the temperature to 35℃ to continue evaporating the solvent for 4h, then recover the microspheres by filtration and wash them, and then recover the microspheres with a particle size in the range of 30 to 50μm by sieving, and finally freeze-dry the microspheres to obtain microspheres 7.

[0122] Microsphere Preparation Example 8 Weigh polyester 11, add dichloromethane to dissolve it, and prepare a polyester solution with a polyester mass concentration of 5% as the oil phase, and then prepare an aqueous solution containing a PVA mass concentration of 1% and a NaCl mass concentration of 6% as the water phase. Under stirring at 1500rpm, slowly add the oil phase dropwise to the water phase, and the oil-water ratio is 1:10. Keep the closed condition and stir in an ice bath for emulsification for 30min. Then adjust the speed to 500rpm, first evaporate the solvent at room temperature for 30min, then increase the temperature to 35℃ and continue to evaporate the solvent for 4h, then recover the microspheres by filtration and wash them, and then recover the microspheres with a particle size in the range of 30 to 50μm by sieving, and finally freeze-dry the microspheres to obtain microspheres 8.

[0123] Microsphere Preparation Comparative Example 1 Weigh polyester 9, add dichloromethane to dissolve it, and prepare a polyester solution with a polyester mass concentration of 10% as the oil phase, and then prepare an aqueous solution containing a PVA mass concentration of 1% as the water phase. Under stirring at 1800rpm, slowly add the oil phase dropwise to the water phase, and the oil-water ratio is 1:10. Keep the closed conditions and stir and emulsify at room temperature for 30 minutes. Then adjust the speed to 500rpm, first evaporate the solvent at room temperature for 30 minutes, then increase the temperature to 35°C and continue to evaporate the solvent for 4 hours, then recover the microspheres by filtration and wash them, and then recover the microspheres with a particle size in the range of 30 to 50μm by sieving, and finally freeze-dry the microspheres to obtain microspheres 9. The picture of microspheres 9 under a microscope is shown below. Figure 7 shown.

[0124] Microsphere Preparation Comparative Example 2 Weigh polyester 9, add dichloromethane to dissolve it, and prepare a polyester solution with a polyester mass concentration of 10% as the oil phase, and then prepare an aqueous solution containing a PVA mass concentration of 1% and a NaCl mass concentration of 3% as the water phase. Under stirring at 1800rpm, slowly add the oil phase dropwise to the water phase with an oil-water ratio of 1:10. Keep the sealed conditions and stir and emulsify at room temperature for 30 minutes. Then adjust the speed to 500rpm, first evaporate the solvent at room temperature for 30 minutes, then increase the temperature to 35°C and continue to evaporate the solvent for 4 hours, then recover the microspheres by filtration and wash them, and then recover the microspheres with a particle size in the range of 30 to 50μm by sieving, and finally freeze-dry the microspheres to obtain microspheres 10. The picture of microspheres 10 under a microscope is shown below. Figure 8 shown.

[0125] Microsphere Preparation Comparative Example 3 Weigh polyester 9, add dichloromethane to dissolve it, and prepare a polyester solution with a polyester mass concentration of 10% as the oil phase, and then prepare an aqueous solution containing a PVA mass concentration of 1% as the water phase. Under stirring at 1800rpm, slowly add the oil phase dropwise to the water phase, and the oil-water ratio is 1:10. Keep the closed conditions and stir in an ice bath for emulsification for 30 minutes. Then adjust the speed to 500rpm, first evaporate the solvent at room temperature for 30 minutes, then increase the temperature to 35°C and continue to evaporate the solvent for 4 hours, then recover the microspheres by filtration and wash them, and then recover the microspheres with a particle size in the range of 30 to 50μm by sieving, and finally freeze-dry the microspheres to obtain microspheres 11. The picture of microspheres 11 under a microscope is shown below. Fig. 9 shown.

[0126] 3. Preparation of medical cosmetic fillers Fillers with different formulas are prepared by adjusting the type of gel carrier, the molecular parameters of the gel carrier, the mass percentage between the microspheres and the gel carrier, and the content of other pharmaceutical excipients.

[0127] Filler Preparation Example 1 (CMC-based) Weigh 200 mg of CMC-Na (substitution degree 0.9, viscosity (NF: 1%): 2500-4500 mPa·s) and 100 mg of mannitol, add 10 mL of water for injection, stir to fully dissolve CMC-Na and mannitol, then add 300 mg of microspheres 4 prepared in microsphere preparation example 4 with a particle size range of 30-50 μm, stir again to disperse the microspheres evenly in the gel, then put into an ultrasonic device, and perform ultrasonication at room temperature to remove bubbles in the microsphere gel. The microsphere gel is freeze-dried and sterilized by irradiation to obtain filler 1.

[0128] Filler Preparation Example 2 (CMC-based) Weigh 200 mg of CMC-Na (substitution degree 0.7, viscosity (NF: 1%): 2500-4500 mPa·s) and 100 mg of mannitol, add 10 mL of water for injection, stir to fully dissolve CMC-Na and mannitol, then add 300 mg of microspheres 6 prepared in microsphere preparation example 6 with a particle size range of 30-50 μm, stir again to evenly disperse the microspheres in the gel, then put into an ultrasonic device, and perform ultrasonication at room temperature to remove bubbles in the microsphere gel. The microsphere gel is freeze-dried and sterilized by irradiation to obtain filler 2.

[0129] Filler Preparation Example 3 (CMC-based) Weigh 150 mg of CMC-Na (substitution degree 0.7, viscosity (NF: 1%): 2500-4500 mPa·s) and 150 mg of mannitol, add 10 mL of water for injection, stir to fully dissolve CMC-Na and mannitol, then add 300 mg of microspheres 6 prepared in microsphere preparation example 6 with a particle size range of 30-50 μm, stir again to evenly disperse the microspheres in the gel, then put into an ultrasonic device, and perform ultrasonication at room temperature to remove bubbles in the microsphere gel. The microsphere gel was freeze-dried and irradiated to obtain filler 3.

[0130] Filler Preparation Example 4 (CMC-based) Weigh 50 mg of CMC-Na (substitution degree 0.7, viscosity (NF: 1%): 2500-4500 mPa·s) and 150 mg of mannitol respectively, add 10 mL of water for injection, stir to fully dissolve CMC-Na and mannitol, then add 300 mg of microspheres 7 prepared in microsphere preparation example 7 with a particle size range of 30-50 μm, stir again to disperse the microspheres evenly in the gel, then put it into an ultrasonic device and perform ultrasound at room temperature to remove bubbles in the microsphere gel. The microsphere gel was freeze-dried and irradiated to obtain filler 4. The freeze-dried filler 4 was mixed with normal saline at a ratio of 1 g of freeze-dried filler: 10 mL of normal saline, and 1 mL was drawn with a syringe and photographed as shown below. Fig.10 shown.

[0131] Filler Preparation Example 5 (HA-based) Weigh 200 mg of HA and 100 mg of mannitol, add 10 mL of water for injection, stir to fully dissolve CMC-Na and mannitol, then add 300 mg of microspheres 6 prepared in microsphere preparation example 6 with a particle size range of 30 to 50 μm, stir again to evenly disperse the microspheres in the gel, then put into an ultrasonic device and perform ultrasound at room temperature to remove bubbles in the microsphere gel. The microsphere gel is freeze-dried and sterilized by irradiation to obtain filler 5.

[0132] Comparative Example 1 of Filler Preparation (CMC-based) Weigh 150 mg of CMC-Na (substitution degree 0.7, viscosity (NF: 1%): 2500-4500 mPa·s) and 150 mg of mannitol, add 10 mL of water for injection, stir to fully dissolve CMC-Na and mannitol, then add 300 mg of microspheres 11 prepared in microsphere preparation comparative example 3 with a particle size range of 30-50 μm, stir again to evenly disperse the microspheres in the gel, then put into an ultrasonic device, and perform ultrasonication at room temperature to remove bubbles in the microsphere gel. The microsphere gel is freeze-dried and sterilized by irradiation to obtain filler 6.

[0133] IV. Related Characterization Tests 1. Filler needle blocking and pushing force test: (1) Determine the pH value of the filler before lyophilization prepared according to filler preparation examples 1 to 5 and filler preparation comparative example 1; then refer to standard YY / T096-2021 "Appendix A of Cross-linked Sodium Hyaluronate Gel for Plastic Surgery: Determination of Pushing Force" to evaluate the pushing force and needle blocking of the filler before lyophilization. Repeat the pushing of each filler 20 times, and record the pushing force and the number of needle blocking times. The results of pH value, number of needle blocking times, and average pushing force are shown in Table 1 below.

[0134] (2) Use normal saline to reconstitute the freeze-dried fillers 1 to 6 respectively, and record the reconstitution time of fillers 1 to 6; the reconstitution method is: mix the freeze-dried filler with normal saline at a ratio of 1g freeze-dried filler: 10mL normal saline. Then determine the pH value of the reconstituted filler; then refer to the standard YY / T096-2021 "Appendix A of Cross-linked Sodium Hyaluronate Gel for Plastic Surgery: Determination of Pushing Force" to evaluate the pushing force and needle blockage of the reconstituted filler. Repeat the pushing of each filler 20 times, and record the pushing force and the number of needle blockages; among them, the pushing force change curve of the 1st to 3rd push process of fillers 1 to 6 is as follows Fig.11 shown.

[0135] The specific operation of the above pushing force measurement is: use a syringe to draw 1mL of filler, add a 26G needle, set the test distance to full scale (1mL); at room temperature, use an electronic universal testing machine to push at a speed of 30mm / min.

[0136] The results of pH value, needle blocking times and average pushing force of fillers 1 to 6 before freeze-drying and after reconstitution are shown in Table 1 below.

[0137] Table 1 Results of pH value, needle blocking times and average pushing force

[0138] 2. Determination of in vitro degradation performance of microspheres: Sorensen buffer was prepared with reference to the standard of IS013781:1997, and the pH value was 7.4±0.2. Microspheres 1 to 11 were weighed respectively, mixed with Sorensen buffer at an extraction ratio of 30:1 (mL:g), and placed at 37°C for several days. The degradation of the microspheres was observed and recorded daily. Microscope photos of microspheres 5 prepared in microsphere preparation example 5 after degradation for 1 month and 3 months are shown in the figure below. Fig.12 shown.

[0139] 3. Microsphere cytocompatibility: The cytotoxicity of the microspheres was evaluated by extraction. Physiological saline was used as the extraction liquid. 200 mg of microspheres were weighed and placed in 1 mL of saline. The microspheres were then placed in a 37°C shaker at 500 rpm for 72 h. The extraction liquid was diluted with saline to obtain microsphere extraction liquids of different dilution multiples. L929 mouse fibroblasts were selected as the test object. 1×10 4 cells, and cultured them in DMEM medium with 10 vol% fetal bovine serum (FBS) and 1 vol% penicillin-streptomycin for 24 hours to allow the cells to adhere to the wall and grow. The culture medium was then replaced with an equal volume of microsphere extract with different dilution multiples. After continuing to culture for 24 hours, the extract was replaced with DMEM medium (serum-free) with 10 vol% CCK-8. The well plate was placed in the incubator and continued to incubate for 2 hours, and then its absorbance at 450nm was measured with a microplate reader. The positive control was DMEM medium without inoculated cells, and the negative control was normal saline. The cell viability was calculated by the following formula, and the results were as follows: Fig.13 shown.

[0140] Cell viability = (OD 450 nm Sample-OD 450 nm positive control) / (OD 450 nm negative control - OD 450 nm positive control) It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation of the present invention. The present invention has been described with reference to the embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A method for preparing amphiphilic polyester microspheres, characterized in that: The preparation method comprises the following steps: (1) dissolving the amphiphilic polyester in its good solvent as the oil phase; (2) Using an aqueous solution containing a surfactant and an inorganic salt as the aqueous phase, the oil phase of step (1) is added to the aqueous phase under stirring for emulsification; wherein the emulsification temperature is 0 to 10°C.

2. The preparation method according to claim 1, characterized in that: The amphiphilic polyester has both a hydrophobic segment and a hydrophilic segment; and / or, the amphiphilic polyester is selected from branched amphiphilic polyesters and amphiphilic polyesters having a triblock structure; and / or, the amphiphilic polyester is a biodegradable amphiphilic polyester; and / or, the good solvent is an organic solvent capable of dissolving the polyester; And / or, the inorganic salt includes at least one of sodium chloride and potassium chloride; And / or, the surfactant is selected from at least one of polyvinyl alcohol, polypropylene, paraffin, Span, and sodium lauryl sulfate.

3. The preparation method according to claim 2, characterized in that: The triblock structure includes an SQS structure or a QSQ structure, wherein S represents a hydrophobic segment and Q represents a hydrophilic segment; And / or, the branched amphiphilic polyester is a branched amphiphilic polyester having a main hydrophilic structure and a branch number n≥3; And / or, the hydrophobic segment of the amphiphilic polyester having a triblock structure comprises a polyester formed by polymerization of one or more degradable lactone monomers as monomers; And / or, the hydrophilic segment of the amphiphilic polyester having a triblock structure is selected from diethylene glycol, butanol, polyethylene glycol, and polypropylene glycol; and / or, the hydrophilic segment of the branched amphiphilic polyester is selected from polyglycerol, polyethylene glycol monomethyl ether, multi-arm PEG, starch, cellulose, dextran, hyaluronic acid, sodium alginate, chitosan, carboxymethyl chitosan, plant polyphenols, hydroxyl-modified polylysine, hydroxyl-modified polyglutamic acid; And / or, the hydrophobic segment of the branched amphiphilic polyester comprises a polyester formed by polymerization of one or more degradable lactone monomers as monomers; and / or, in the amphiphilic polyester having a triblock structure, the molecular weight of the hydrophobic segment is 500 to 5,000,000 Da, and the molecular weight of the hydrophilic segment is 100 to 5,000 Da; And / or, in the branched amphiphilic polyester, the molecular weight of the hydrophobic segment is 500 to 5,000,000 Da, and the molecular weight of the hydrophilic segment is 100 to 5,000 Da.

4. The preparation method according to claim 3, characterized in that: The degradable lactone monomers include lactic acid, glycolic acid, glycolide, lactide, and ε-caprolactone; and / or, when the hydrophobic segment comprises a polyester formed by polymerization of two or more degradable lactone monomers, the molar proportion of each monomer in the entire hydrophobic segment is between 5% and 95%; And / or, the polymerization of the degradable lactone monomer is carried out in the presence of a polymerization catalyst, and the polymerization catalyst is selected from one or more of tin-based, zinc-based, titanium-based, copper-based, iron-based, magnesium-based, and calcium-based metal catalysts.

5. The preparation method according to claim 4, characterized in that: The amphiphilic polyester is obtained by polymerizing a polymerizable ester monomer and an initiator through ring-opening polymerization or condensation polymerization; wherein the polymerizable ester monomer is selected from one or more of lactic acid, glycolic acid, glycolide, lactide, and ε-caprolactone; and the initiator is selected from a small molecule or polymer containing more than two hydroxyl groups.

6. The preparation method according to claim 5, characterized in that: The molar ratio of the initiator to the polymerizable ester monomer is between 1:(1-500); and / or, the initiator is selected from diethylene glycol, butanol, glycerol, PEG, pentaerythritol, dipentaerythritol, trimethylolpropane, di(trimethylolpropane), polyglycerol, erythritol, xylitol, sorbitol, PPG, multi-arm PEG, starch, cellulose, dextran, hyaluronic acid, sodium alginate, chitosan, carboxymethyl chitosan, plant polyphenols, hydroxy-modified polylysine, hydroxy-modified polyglutamic acid; and / or, the polymerization is carried out in the presence of a polymerization catalyst; And / or, the polymerization temperature is 120-180°C.

7. The preparation method according to any one of claims 1 to 6, characterized in that: In the oil phase, the mass concentration of the amphiphilic polyester is 1% to 20%; And / or, in the aqueous phase, the mass concentration of the surfactant is 0.1% to 5%; And / or, in the aqueous phase, the mass concentration of the inorganic salt is 0.1% to 10%; And / or, the stirring speed in step (2) is 50 to 1800 rpm; And / or, the emulsification temperature is 0 to 4°C; And / or, the emulsification time is 1 to 60 minutes.

8. The preparation method according to claim 1, characterized in that: The preparation method further comprises removing the solvent from the product obtained after the emulsification, wherein the method of removing the solvent from the product obtained after the emulsification comprises stirring, volatilizing and / or washing.

9. The preparation method according to claim 8, characterized in that: The stirring rate of the stirring volatilization is 100 to 1000 rpm; And / or, the stirring and volatilization time is 2h to 24h; And / or, the temperature of the stirring and volatilization is 20 to 50°C; And / or, the cleaning is performed using pure water.

10. The preparation method according to claim 8 or 9, characterized in that: The preparation method further comprises freeze-drying the microspheres obtained after removing the solvent.

11. The preparation method according to claim 10, characterized in that: The preparation method further comprises screening the freeze-dried microspheres according to particle size.

12. Use of microspheres prepared by the preparation method according to any one of claims 1 to 11 in the preparation of embolic microspheres or medical aesthetic fillers.

13. An embolic microsphere, characterized in that: The embolic microspheres include microspheres prepared by the preparation method according to any one of claims 1 to 11, and the particle size of the microspheres is between 70 and 1200 μm.

14. A medical cosmetic filler, characterized in that: The medical cosmetic filler comprises microspheres prepared by the preparation method according to any one of claims 1 to 11, and the particle size of the microspheres is between 30 and 50 μm.

15. The medical cosmetic filler according to claim 14, characterized in that: Based on the total amount of the freeze-dried medical cosmetic filler, the mass percentage of the microspheres in the entire medical cosmetic filler is 10% to 70% or 30% to 60%.

16. The medical cosmetic filler according to claim 14, characterized in that: The medical cosmetic filler also includes a gel, and the storage modulus G' of the gel is between 10 and 1000 Pa, and the loss modulus G" is between 5 and 500 Pa.

17. The medical cosmetic filler according to claim 16, characterized in that: The gel comprises a main material and optional additives, wherein the main material is selected from one or more of CMC-Na, HA, cross-linked HA, and collagen solution; The additives include pharmaceutical excipients and / or anesthetics.

18. The medical cosmetic filler according to claim 17, characterized in that: Calculated on the total amount of gel, the gel comprises the following raw materials in percentage by weight: main material 5% to 70%, pharmaceutical excipients 0% to 50%, anesthetic 0% to 0.5%; or Calculated on the total amount of gel, the gel comprises the following raw materials in percentage by mass: main material 10% to 40%, pharmaceutical excipients 10% to 40%, and anesthetic 0% to 0.3%.

19. The method for preparing a medical cosmetic filler according to any one of claims 14 to 18, characterized in that: The method for preparing the medical cosmetic filler comprises the following steps: mixing microspheres with a particle size of 30 to 50 μm prepared by the preparation method according to any one of claims 1 to 11 with gel.

20. The method for preparing a medical cosmetic filler according to claim 19, characterized in that: The preparation method of the medical beauty filler comprises the following steps: (a) adding microspheres having a particle size of 30 to 50 μm prepared by the preparation method according to any one of claims 1 to 11 to a gel, dispersing the microspheres in the gel by stirring or vortexing, and then performing ultrasonic treatment to remove bubbles in the liquid; Optionally (b) freeze-drying and sterilizing the product obtained in step (a).

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