A high-stability injectable soft tissue filling material and its preparation method and use

Abstract

The present invention belongs to the technical field of biomedical materials, and specifically relates to a highly stable injectable soft tissue filling material, a preparation method thereof, and a use thereof. The soft tissue filling material of the present invention is prepared by mixing an amphiphilic degradable polyether-polyester copolymer with water and annealing the mixture; the annealing process conditions are as follows: under the protection of an inert gas, pressurizing to 1.0-5.0 bar, heating to 110-158 ° C, slowly cooling to room temperature while maintaining the pressure, and finally reducing the pressure to standard atmospheric pressure. Experimental tests have shown that the soft tissue filling material of the present invention has excellent properties such as high concentration, high particle size and viscosity, good formulation stability, good stability between process batches, good needle permeability, no need for sterilization process, good safety, long-term retention effect in the body, and the ability to promote collagen production in skin tissue. It has good application effects in the fields of wound healing, tissue filling and / or repair, wrinkle removal, and anti-aging.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical materials, and in particular relates to a highly stable injectable soft tissue filling material, a preparation method thereof, and uses thereof. Background Art

[0002] Polymer microspheres, primarily made from polycaprolactone (PCL) and polylactic acid (PLA), are widely used in the biomedical field due to their excellent biocompatibility, biodegradability, controlled drug release, and the high safety and tissue absorbability of their degradation products. These applications include controlled drug delivery, dermal fillers, soft tissue repair, and the treatment of tumors and other diseases. However, these polymer microspheres, due to their material properties, have numerous limitations in practical applications, such as poor dispersion, easy aggregation, poor needle permeability, and potential side effects. These issues severely restrict their scope and effectiveness in clinical treatment.

[0003] Among them, amphiphilic block copolymers, defined as those formed from polyether and polyester segments (e.g., PCL and PLA), exhibit significant potential in drug delivery due to their excellent hydrophilicity and nano-self-assembly properties. Currently, existing technologies primarily utilize common methods such as solvent evaporation, dialysis, melt hydration, and freeze-thaw methods to formulate these amphiphilic block copolymers into self-assembled formulations. This improves drug encapsulation efficiency, stability, and bioavailability, while also enhancing drug release behavior and achieving more precise therapeutic effects.

[0004] However, self-assembled formulations prepared using these traditional methods typically have low solid content, small particle size, low viscosity, and short residence time, making it difficult to meet the requirements for filler durability and support. Furthermore, most of these preparation methods rely on organic solvents, which not only increases production costs but also poses an environmental burden and the risk of solvent residue. More critically, formulations prepared using these traditional methods have significant deficiencies in batch-to-batch stability, long-term stability, and stability at high concentrations, hindering large-scale production and quality control. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a highly stable injectable soft tissue filling material and a preparation method and use thereof.

[0006] A highly stable injectable soft tissue filling material is prepared by mixing an amphiphilic degradable polyether-polyester copolymer with water and annealing the mixture;

[0007] The annealing process conditions are: under inert gas protection, pressurized to 1.0-5.0 bar, heated to 110-158° C., slowly cooled to room temperature while maintaining the pressure, and finally reduced to standard atmospheric pressure.

[0008] Preferably, the feeding ratio of the amphiphilic degradable polyether-polyester copolymer to water is 1-5 kg:10 L.

[0009] Preferably, the mixing temperature is 60-95°C.

[0010] Preferably, the mixing method is: heating the amphiphilic degradable polyether-polyester copolymer to 60-95° C. to fully melt it, cooling it to form small pieces or particles, and adding water at 60-95° C. to mix it.

[0011] Preferably, the amphiphilic degradable polyether-polyester copolymer is a block copolymer consisting of a polyether block and a polyester block;

[0012] The polyether block is selected from at least one of polyethylene glycol or its derivatives;

[0013] The polyester block is selected from at least one of polycaprolactone, poly (L-lactic acid), poly (D-lactic acid), poly (racemic) lactic acid or poly (lactic acid-glycolic acid copolymer).

[0014] Preferably, the amphiphilic degradable polyether-polyester copolymer is a diblock copolymer or a triblock copolymer consisting of a polyether block and a polyester block;

[0015] The mass ratio of the polyether block to the polyester block in the amphiphilic degradable polyether-polyester copolymer is 1:1-1:8, preferably 1:1-1:5;

[0016] The weight average molecular weight of the amphiphilic degradable polyether-polyester copolymer is selected from 5000-140000 Da, preferably 10000-80000 Da.

[0017] Preferably, the weight average molecular weight of the polyether block is selected from 1000-20000 Da; the weight average molecular weight of the polyester block is selected from 1250-120000 Da;

[0018] Preferably, the polyether block is selected from at least one of polyethylene glycol 1000, polyethylene glycol 1500, polyethylene glycol 2000, polyethylene glycol 4000, polyethylene glycol 6000, polyethylene glycol 8000, polyethylene glycol 10000, polyethylene glycol 20000, polyethylene glycol monomethyl ether 1000, polyethylene glycol monomethyl ether 2000, polyethylene glycol monomethyl ether 5000, polyethylene glycol monomethyl ether 10000, and polyethylene glycol monomethyl ether 20000;

[0019] The polyester block is selected from at least one of polycaprolactone 1250, polycaprolactone 5000, polycaprolactone 10000, polycaprolactone 15000, polycaprolactone 20000, polycaprolactone 25000, polycaprolactone 30000, poly-L-lactic acid 4000, poly-L-lactic acid 25000, poly-D-lactic acid 120000, polyracemic lactic acid 5000, polylactic acid-glycolic acid copolymer 50000, and polylactic acid-glycolic acid copolymer 20000.

[0020] Preferably, the annealing further comprises the following process conditions: the heating and holding time is 10-40 min; the cooling process to room temperature under the condition of maintaining pressure is completed within 30-60 min;

[0021] And / or, the concentration of the soft tissue filling material is 15-40 wt. %;

[0022] and / or, the viscosity of the soft tissue filling material is 100-1000 mPa·s, preferably 200-450 mPa·s;

[0023] And / or, in the soft tissue filling material, the average particle size of the microspheres of the amphiphilic degradable polyether-polyester copolymer is 150 nm-250 nm, preferably 200 nm-250 nm.

[0024] The present invention also provides a method for preparing the above-mentioned high-stability injectable soft tissue filling material, which is characterized by comprising the following steps:

[0025] The amphiphilic degradable polyether-polyester copolymer is mixed with water and annealed;

[0026] The annealing process conditions are: under inert gas protection, pressurized to 1.0-5.0 bar, heated to 110-158° C., slowly cooled to room temperature while maintaining the pressure, and finally reduced to standard atmospheric pressure.

[0027] The present invention also provides use of the highly stable injectable soft tissue filling material in the preparation of medicines, cosmetics or medical aesthetic materials.

[0028] The drug has at least one of the following effects: promoting wound healing, tissue filling, promoting tissue repair, wrinkle removal, and anti-aging;

[0029] The cosmetic or medical cosmetic material has at least one of the following functions: tissue filling, promoting tissue repair, wrinkle removal, and anti-aging.

[0030] The present invention improves the preparation process of an injectable soft tissue filler material to provide a highly stable injectable soft tissue filler material. By performing annealing during the preparation process, the injectable soft tissue filler material of the present invention achieves the following beneficial technical effects:

[0031] (1) The present invention solves the problem of demulsification of self-assembled preparations during annealing treatment. By optimizing the pressure control program during the cooling process, the preparation temperature and pressure ranges are broadened, and the difficulty of controlling the production process is reduced.

[0032] (2) The high-stability injectable filler provided by the present invention has higher stability at room temperature than traditional preparations. At extremely high concentrations, the self-assembly formed does not aggregate or precipitate, and has a longer storage and effective time. It can be stored at room temperature for at least 24 months.

[0033] (3) The method for preparing a high-stability injectable filler provided by the present invention can obtain a high-viscosity injectable filler without adding other substances, thereby improving the immediate filling effect and retention time, while maintaining excellent needle permeability, and having a more stable pushing force during the injection process, which is beneficial to the injection operation and reduces the pain of the injector.

[0034] (4) The highly stable injectable filler and its preparation method provided by the present invention are easy to operate, and the obtained self-assembly has good batch stability in particle size and viscosity, which is suitable for large-scale production.

[0035] (5) The high-stability injectable filler provided by the present invention has better biocompatibility and storage stability, and avoids the complex sterilization process and its impact on the properties of the injectable filler.

[0036] The following further describes the above content of the present invention in detail through specific embodiments in the form of examples. However, this should not be construed as limiting the scope of the above subject matter of the present invention to the following examples. All technologies implemented based on the above content of the present invention fall within the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 These are optical images of the highly stable injectable fillers prepared in Examples 1-7 and the injectable fillers prepared in Comparative Examples 1-3.

[0038] Figure 2 This is a TEM image of the highly stable injectable filler prepared in Example 1.

[0039] Figure 3 The particle size and viscosity of the highly stable injectable filler obtained in Example 1 are shown in FIG.

[0040] Figure 4The curves of particle size change over time of the highly stable injectable filler obtained in Example 1 and the preparation obtained in Comparative Example 1 are shown.

[0041] Figure 5 The graph shows the pushing force curve when a 27G injection needle is used to inject the highly stable injectable filler obtained in Example 1.

[0042] Figure 6 This is an image showing the diffusion of the highly stable injectable filler obtained in Example 1 in vivo.

[0043] Figure 7 This is a graph showing the collagen content in rat back skin after the highly stable injectable filler obtained in Examples 1-7 was injected into rat skin. DETAILED DESCRIPTION

[0044] In the following examples and experimental examples, all unspecified reagents and raw materials are commercially available. In the following examples, polyether raw materials, such as MPEG5000, MPEG2500, MPEG2000, MPEG20000, MPEG1000, and MPEG10000, were purchased from Shanghai Myrrel Biochemical Technology Co., Ltd.

[0045] Example 1:

[0046] This example provides a method for preparing a highly stable injectable filler of polyethylene glycol monomethyl ether 5000-polycaprolactone 20000 (MPEG5000-PCL20000). The specific steps of the preparation are as follows:

[0047] 1.00 kg of polyethylene glycol monomethyl ether 5000 (MPEG5000) and 4.02 kg of ε-caprolactone (ε-CL) were added to a reactor. After azeotropic removal of water, stannous octoate was added and the mixture was reacted at 130°C for 48 hours. After completion of the reaction, the product was dissolved in dichloromethane and purified by extraction with distilled water and then brine. After precipitation with diethyl ether, the product was dried in an oven to constant weight. The NMR integrated areas of 3.38 ppm (attributable to methoxy protons on the MPEG backbone) and 4.07 ppm (attributable to methylene protons on the PCL backbone) were calculated from the NMR spectrum, confirming that the product was a MPEG5000-PCL20000 diblock copolymer.

[0048] 4.00 kg of MPEG5000-PCL20000 copolymer was fully melted at 60°C and cooled to form small pieces or pellets. The mixture was then added to a reactor, and 10 L of 60°C distilled water was added. After thorough soaking and stirring, the mixture was cooled to room temperature. Nitrogen was introduced into the reactor, pressurized to 3.5 bar, and heated to 135°C for 10 minutes. The pressure was then maintained and slowly reduced to room temperature over a 30-minute cooling period. Finally, the pressure was reduced to standard atmospheric pressure to produce a highly stable injectable filler.

[0049] Example 2:

[0050] This example provides a method for preparing a highly stable injectable filler of polycaprolactone 1250-polyethylene glycol 2500-polycaprolactone 1250 (PCL1250-PEG2500-PCL1250). The specific steps of the preparation are as follows:

[0051] 1.00 kg of polyethylene glycol 2500 (MPEG2500) and 1.01 kg of ε-caprolactone (ε-CL) were added to a reactor. After azeotropic removal of water with anhydrous toluene, the catalyst, stannous octoate, was added and the mixture was reacted at 130°C for 48 hours. After completion of the reaction, the product was dissolved in dichloromethane and purified by extraction with distilled water and then brine. After precipitation with diethyl ether, the product was dried in an oven to constant weight. The integrated NMR areas of 3.64 ppm (attributable to ethoxy protons on the MPEG backbone) and 4.07 ppm (attributable to methylene protons on the PCL backbone) were calculated from the NMR spectrum, confirming that the product was a PCL1250-PEG2500-PCL1250 triblock copolymer.

[0052] 5.00 kg of PCL1250-PEG2500-PCL1250 was fully melted at 70°C and cooled to form small pieces or granules. Subsequently, the mixture was added to a reactor and 10 L of 70°C distilled water was added. After thorough soaking and stirring, the mixture was cooled to room temperature. Nitrogen was introduced into the reactor, pressurized to 1 bar, heated to 110°C, and held at this temperature for 15 minutes. The pressure was then maintained and slowly lowered to room temperature over a 35-minute cooling period. Finally, the pressure was reduced to standard atmospheric pressure to produce a highly stable injectable filler.

[0053] Example 3:

[0054] This embodiment provides a method for preparing a highly stable injectable filler of polyethylene glycol monomethyl ether 2000-poly L-lactic acid 6000 (MPEG2000-PLLA6000). The specific steps of the preparation are as follows:

[0055] 1.00 kg of polyethylene glycol monomethyl ether 2000 (MPEG2000) and 3.01 kg of L-lactide (L-LA) were added to a reactor. After azeotropic removal of water, stannous octoate was added and the mixture was reacted at 130°C for 56 hours. After completion of the reaction, the product was dissolved in dichloromethane and purified by extraction with distilled water and then brine. After precipitation with ether, the product was dried in an oven to constant weight. The NMR integrated areas of 3.38 ppm (attributable to methoxy protons on the MPEG backbone) and 1.58 ppm (attributable to methyl protons on the LA side chains) were calculated from the NMR spectrum, confirming that the product was an MPEG2000-PLLA6000 copolymer.

[0056] 3.00 kg of MPEG2000-PLLA6000 copolymer was fully melted at 80°C and cooled to form small pieces or pellets. The mixture was then added to a reactor, and 10 L of 80°C distilled water was added. After thorough soaking and stirring, the mixture was cooled to room temperature. Nitrogen was introduced into the reactor, pressurized to 1.5 bar, and heated to 115°C for 20 minutes. The pressure was then maintained and slowly reduced to room temperature over a 40-minute cooling period. Finally, the pressure was reduced to standard atmospheric pressure to produce a highly stable injectable filler.

[0057] Example 4:

[0058] This example provides a method for preparing a highly stable injectable filler of polyethylene glycol monomethyl ether 20,000-poly (D-lactic acid) 120,000 (MPEG20,000-PDLA120,000). The specific steps of the preparation are as follows:

[0059] 1.00 kg of polyethylene glycol monomethyl ether 20000 (MPEG20000) and 6.03 kg of D-lactide (D-LA) were added to a reactor. After azeotropic removal of water, stannous octoate was added and the mixture was reacted at 130°C for 72 hours. After completion of the reaction, the product was dissolved in dichloromethane and purified by extraction with distilled water and then brine. After precipitation with ether, the product was dried in an oven to constant weight. The NMR integrated areas of 3.38 ppm (attributable to methoxy protons on the MPEG backbone) and 1.58 ppm (attributable to methyl protons on the LA side chains) were calculated from the NMR spectrum, confirming that the product was an MPEG20000-PDLA120000 diblock copolymer.

[0060] 3.50 kg of MPEG20000-PDLA120000 copolymer was fully melted at 90°C and cooled to form small pieces or pellets. The mixture was then added to a reactor, and 10 L of 90°C distilled water was added. After thorough soaking and stirring, the mixture was cooled to room temperature. Nitrogen was introduced into the reactor, pressurized to 2 bar, and heated to 120°C for 25 minutes. The pressure was then maintained and slowly reduced to room temperature over a 45-minute cooling period. Finally, the pressure was reduced to standard atmospheric pressure to produce a highly stable injectable filler.

[0061] Example 5:

[0062] This example provides a method for preparing a highly stable injectable filler of polyethylene glycol monomethyl ether 1000-poly (ethylene glycol monomethyl ether) 5000 (MPEG1000-PDLLA5000). The specific steps of the preparation are as follows:

[0063] 1.00 kg of polyethylene glycol monomethyl ether 1000 (MPEG1000) and 5.02 kg of DL-lactide (DL-LA) were added to a reactor. After azeotropic removal of water, stannous octoate was added and the reaction was carried out at 130°C for 60 h. After completion of the reaction, the product was dissolved in dichloromethane and purified by extraction with distilled water and then brine. After precipitation with diethyl ether, the product was dried in an oven to constant weight. The NMR integrated areas of 3.38 ppm (attributable to methoxy protons on the MPEG backbone) and 1.58 ppm (attributable to methyl protons on the LA side chains) were calculated from the NMR spectrum, confirming that the product was an MPEG1000-PDLLA5000 diblock copolymer.

[0064] 6.00 kg of MPEG1000-PDLLA5000 copolymer was fully melted at 65°C and cooled to form small pieces or pellets. The mixture was then added to a reactor, followed by 10 L of 60°C distilled water. After thorough soaking and stirring, the mixture was cooled to room temperature. Nitrogen was introduced into the reactor to pressurize it to 3 bar. The system was then heated to 140°C and held at this temperature for 30 minutes. The pressure was then maintained and slowly reduced to room temperature over a 50-minute cooling period. Finally, the pressure was reduced to standard atmospheric pressure to produce a highly stable injectable filler.

[0065] Example 6:

[0066] This example provides a method for preparing a highly stable injectable filler of polyethylene glycol monomethyl ether 10000-polylactic acid-glycolic acid copolymer 50000 (MPEG10000-PLGA50000). The specific steps of the preparation are as follows:

[0067] 1.00 kg of polyethylene glycol monomethyl ether 10000 (MPEG10000) and 5.02 kg of DL-lactide (DL-LA) and glycolide (GA) were added to a reactor. After azeotropic removal of water, stannous octoate was added and the mixture was reacted at 130°C for 60 h. After completion of the reaction, the product was dissolved in dichloromethane and purified by extraction with distilled water and then brine. After precipitation with diethyl ether, the product was dried in an oven to constant weight. The integrated NMR areas of 3.38 ppm (attributed to methoxy protons on the MPEG backbone), 1.58 ppm (attributed to methyl protons on the LA side chains), and 4.80 ppm (attributed to methylene protons on the GA chains) were calculated from the NMR spectrum, confirming that the product was an MPEG10000-PLGA50000 diblock copolymer.

[0068] 2.50 kg of MPEG10000-PLGA50000 was fully melted at 75°C and cooled to form small pieces or pellets. The mixture was then added to a reactor, and 10 L of 70°C distilled water was added. After thorough soaking and stirring, the mixture was cooled to room temperature. Argon was introduced into the reactor, pressurized to 4 bar, and heated to 150°C for 35 minutes. The pressure was then maintained and slowly reduced to room temperature over a 55-minute cooling period. Finally, the pressure was reduced to standard atmospheric pressure to produce a highly stable injectable filler.

[0069] Example 7:

[0070] This embodiment provides a method for preparing a highly stable injectable filler of polyethylene glycol monomethyl ether 5000-polylactic acid-co-glycolic acid copolymer 20000-polyethylene glycol monomethyl ether 5000 (MPEG5000-PLGA20000-MPEG5000). The specific preparation steps are as follows:

[0071] 2.00 kg of polyethylene glycol monomethyl ether 5000 (MPEG5000) and 4.01 kg of DL-lactide (DL-LA) and glycolide (GA) were added to a reactor. After azeotropic removal of water, stannous octoate was added and the mixture was reacted at 130°C for 48 hours. After completion of the reaction, the product was dissolved in dichloromethane and purified by extraction with distilled water and then brine. After precipitation with diethyl ether, the product was dried in an oven to constant weight. The integrated NMR areas of 3.38 ppm (attributed to methoxy protons on the MPEG backbone), 1.58 ppm (attributed to methyl protons on the LA side chains), and 4.80 ppm (attributed to methylene protons on the GA chains) were calculated from the NMR spectrum, confirming that the product was an MPEG5000-PLGA10000 diblock copolymer.

[0072] 5.00 kg of MPEG5000-PLGA10000 and hexamethylene diisocyanate (HDI) were added to a reactor. After dehydration and deoxygenation, stannous octoate was added and the mixture was reacted at 130°C for 72 hours. After completion of the reaction, the product was dissolved in dichloromethane and purified by extraction with distilled water and then brine. After precipitation with diethyl ether, the product was dried in an oven to constant weight. The integrated NMR areas of 3.38 ppm (attributed to methoxy protons on the MPEG backbone), 1.58 ppm (attributed to methyl protons on the LA side chains), and 4.80 ppm (attributed to methylene protons on the GA chains) were calculated from the NMR spectrum, confirming that the product was a MPEG5000-PLGA20000-MPEG5000 triblock copolymer.

[0073] 2.00 kg of MPEG5000-PLGA20000-MPEG5000 was fully melted at 95°C and cooled to form small pieces or pellets. The mixture was then added to a reactor and thoroughly soaked with 10 L of 95°C distilled water. After stirring, the mixture was cooled to room temperature. Nitrogen was introduced into the reactor, pressurized to 5 bar, and heated to 158°C for 40 minutes. The pressure was then maintained and slowly lowered to room temperature over a 60-minute cooling period. Finally, the pressure was reduced to standard atmospheric pressure to produce a highly stable injectable filler.

[0074] Comparative Example 1:

[0075] 4.00 kg of MPEG5000-PCL20000 copolymer (prepared according to Example 1) was fully melted at 60°C and cooled to form small pieces or granules. The mixture was then added to a reactor and 10 L of 60°C distilled water was added. After thorough soaking and stirring, the mixture was cooled to room temperature to obtain an injectable filler.

[0076] Compared with the above embodiment, the difference of Comparative Example 1 is that no annealing step is performed.

[0077] Comparative Example 2:

[0078] 4.00 kg of MPEG5000-PCL20000 copolymer (prepared according to Example 1) was fully melted at 60°C and cooled to form small pieces or pellets. The mixture was then added to a reactor and 10 L of 60°C distilled water was added. After thorough soaking and stirring, the mixture was cooled to room temperature. Nitrogen was introduced into the reactor and pressurized to 2.5 bar. The mixture was heated to 135°C and held at this temperature for 10 minutes. The temperature and pressure were then simultaneously lowered, slowly dropping to room temperature and then to standard atmospheric pressure. The cooling period lasted 30 minutes.

[0079] Comparative Example 3:

[0080] 4.00 kg of MPEG5000-PCL20000 copolymer (prepared according to Example 1) was fully melted at 60°C and cooled to form small pieces or pellets. The mixture was then added to a reactor and 10 L of 60°C distilled water was added. After thorough soaking and stirring, the mixture was cooled to room temperature. Nitrogen was introduced into the reactor and pressurized to 3.5 bar. The reactor was heated to 125°C and held at this temperature for 10 minutes. The temperature and pressure were then simultaneously lowered, slowly cooling to room temperature and then to standard atmospheric pressure. The cooling period lasted 30 minutes.

[0081] Compared with the above embodiment, the difference between Comparative Examples 2 and 3 is that the annealing stage does not perform pressure maintenance and temperature reduction, but performs temperature reduction and pressure reduction simultaneously.

[0082] The technical solution of the present invention is further illustrated by experiments below. The samples used are all samples prepared in Examples 1-7 and Comparative Examples 1-3.

[0083] Test Example 1: Morphology Observation

[0084] A small amount of the high stability injectable fillers prepared in Examples 1-7 and the preparations prepared in Comparative Examples 1-3 were placed in a glass bottle and optical images were taken using a mobile phone camera. Figure 1 As shown, the high stability injectable fillers prepared in Examples 1-7 are uniform white transparent liquid preparations. A small amount of the high stability injectable filler prepared in Example 1 was taken and fully diluted before observation using TEM. Figure 2 As shown, it appears as uniform spherical nanoparticles. In contrast, the injectable filler prepared in Comparative Example 1 has higher transparency and lower apparent viscosity. The preparation processes of Comparative Examples 2-3 will cause the polymer to demulsify, resulting in aggregation and precipitation, forming a large particle precipitate phase.

[0085] Test Example 2: Particle size and viscosity test

[0086] Particle size test: Take 10 μL of sample, dilute 100 times with deionized water, mix thoroughly, and then take 1 mL and add it to the test dish. Use a Malvern Zetasizer Nano ZS dynamic light scattering instrument to measure the particle size and particle size distribution according to the 2020 edition of the "Pharmacopoeia of the People's Republic of China" (Volume IV) (0982 Method 3).

[0087] Viscosity test: Take 10 mL of sample and test it using a rotational rheometer at (25±0.2)℃ and a shear rate of 100 (1 / s).

[0088] Table 1 shows the particle size and viscosity test results for the formulations obtained in Examples 1-7 and Comparative Examples 1-3. Examples 1-7 successfully prepared injectable fillers with particle sizes ranging from 200-250 nm and viscosities from 350-450 mPa·s, demonstrating the universal applicability of the preparation methods provided herein for preparing fillers with varying molecular weights, hydrophilic-hydrophobic ratios, and chemical structures. Furthermore, the highly stable injectable fillers exhibited uniform particle size and high viscosity. In contrast, the formulation prepared in Comparative Example 1 exhibited low particle size and viscosity, while the preparation methods used in Comparative Examples 2-3 resulted in excessively large and highly non-uniform polymer particle size and low viscosity.

[0089] Table 1 Particle size and viscosity of the high stability injectable fillers obtained in Examples 1-7 and Comparative Examples 1-3

[0090]

[0091] Test Example 3: Preparation Stability

[0092] Example 1 was prepared 6 times, as Figure 3 As shown, the particle size of the resulting injectable filler varied within a range of 225-235 nm, with a fluctuation range of no more than 10 nm, and the viscosity was within a range of 380-400 mPa·s, with a fluctuation range of no more than 20 mPa·s. These experimental results demonstrate that the high-stability injectable filler prepared in Example 1 has stable particle size and viscosity, with minimal batch-to-batch variability, making it suitable for large-scale, standardized production.

[0093] The high-stability injectable filler prepared in Example 1 and the preparation prepared in Comparative Example 1 were placed in a constant temperature and humidity chamber. Samples were taken out at regular intervals and subjected to particle size testing. The particle size testing method was the same as that in Test Example 2.

[0094] like Figure 4 As shown in the figure, during the 24-month test period, the particle size of the sample prepared in Example 1 fluctuated slightly around 225 nm, indicating that its particle size remained essentially unchanged and the preparation properties were stable. The results show that the preparation prepared in Example 1 did not change significantly after being stored at room temperature for 24 months. This indicates that in actual use, after long-term storage, the stability of the preparation will not affect its actual use effect. In contrast, the particle size of the sample prepared in Comparative Example 1 decreased significantly over time, from 149.34 nm to 102.09 nm. Its preparation properties are unstable, and after long-term storage, it will affect its actual use effect.

[0095] Test Example 4: Needle-passing

[0096] The high-stability injectable filler obtained in Example 1 was placed in a 1 mL syringe and subjected to a pushing force test using a 27 G injection needle (two samples were prepared in parallel). The pushing force curve is shown in FIG. Figure 5 The results show that the pushing force remained within the range of 12-14 N throughout the injection process, with minimal fluctuations. There was no accumulation of material at the needle tip during late injection, leading to increased injection pressure. This demonstrates that the highly stable injectable filler prepared by the method provided by this patent has excellent needle permeability, facilitating clinical procedures for physicians.

[0097] Test Example 5: Colony Count

[0098] The results of the assay should comply with the requirements of 2.2.12 in accordance with the gel method in 1143 Bacterial Endotoxin Test Methods of the 2020 edition of the Chinese Pharmacopoeia (Part IV). The results of the assay should comply with the requirements of 2.2.13 in accordance with the direct inoculation method in 1101 Sterility Test Methods of the 2020 edition of the Chinese Pharmacopoeia (Part IV).

[0099] The results showed that the bacterial endotoxin content of the highly stable injectable fillers obtained in Examples 1-7 was less than 0.5 EU / g, meeting national standards. Sterility tests also confirmed sterility, meeting the requirements for production, product marketing approval, and quality management. These results demonstrate that the highly stable injectable fillers prepared in this patent can be used without requiring complex sterilization processes, thus avoiding the effects of sterilization on the properties of the injectable filler material.

[0100] Test Example 6: Diffusion Experiment

[0101] In vivo imaging was used to test the retention time of the highly stable injectable fillers prepared in Examples 1-7 in the back skin of rats. The highly stable injectable fillers prepared in Examples 1-7 were first coupled with Cy5 fluorescent molecules to prepare fluorescently labeled injection solutions, which were then injected into the back skin of six-week-old SD rats. In vivo imaging was used to track the diffusion of the fluorescently labeled injection solutions in the rat skin. The results showed that the fluorescence of the highly stable injectable fillers prepared in Examples 1-7 completely disappeared after about 5 months of injection. The in vivo imaging results of the highly stable injectable fillers prepared in Example 1 are shown in Figure 2. Figure 6 shown.

[0102] Test Example 7: Filling Effect

[0103] The highly stable injectable fillers provided in Examples 1-7 were injected intradermally into the dermis of the back skin of 8-week-old SD rats. The back skin was taken for Masson staining analysis. The results were as follows: Figure 7The results showed that compared with the normal control group, the highly stable injectable fillers provided in Examples 1-7 were able to effectively promote the production of collagen in skin tissue and achieve good filling effects.

[0104] The above examples and experimental examples demonstrate that the highly stable injectable soft tissue filler material prepared by the present invention exhibits excellent properties, including high concentration, large particle size and viscosity, good formulation stability, excellent batch-to-batch stability, good needle permeability, no need for sterilization, excellent safety, long-term in vivo retention, and the ability to promote collagen production in skin tissue. Therefore, the injectable soft tissue filler material of the present invention has excellent application effects in the fields of wound healing, tissue augmentation and / or repair, wrinkle removal, and anti-aging, and has a promising application prospect.

Claims

1. A highly stable injectable soft tissue filling material, characterized in that: It is made by mixing an amphiphilic degradable polyether-polyester copolymer with water and annealing it; The annealing process conditions are: under inert gas protection, pressurized to 1.0-5.0 bar, heated to 110-158° C., slowly cooled to room temperature while maintaining the pressure, and finally reduced to standard atmospheric pressure.

2. The highly stable injectable soft tissue filling material according to claim 1, characterized in that: The feeding ratio of the amphiphilic degradable polyether-polyester copolymer to water is 1-5 kg:10 L.

3. The highly stable injectable soft tissue filling material according to claim 1, characterized in that: The mixing temperature is 60-95°C.

4. The highly stable injectable soft tissue filling material according to claim 3, characterized in that: The mixing method comprises heating the amphiphilic degradable polyether-polyester copolymer to 60-95° C. to fully melt the copolymer, cooling the copolymer to form small blocks or particles, and adding water at 60-95° C. to mix the mixture.

5. The highly stable injectable soft tissue filling material according to claim 1, characterized in that: The amphiphilic degradable polyether-polyester copolymer is a block copolymer consisting of a polyether block and a polyester block; The polyether block is selected from at least one of polyethylene glycol or its derivatives; The polyester block is selected from at least one of polycaprolactone, poly (L-lactic acid), poly (D-lactic acid), poly (racemic) lactic acid or poly (lactic acid-glycolic acid copolymer).

6. The highly stable injectable soft tissue filling material according to claim 5, characterized in that: The amphiphilic degradable polyether-polyester copolymer is a diblock copolymer or a triblock copolymer consisting of a polyether block and a polyester block; The mass ratio of the polyether block to the polyester block in the amphiphilic degradable polyether-polyester copolymer is 1:1-1:8; The weight average molecular weight of the amphiphilic degradable polyether-polyester copolymer is selected from 5000-140000 Da.

7. The highly stable injectable soft tissue filling material according to claim 6, characterized in that: The weight average molecular weight of the polyether block is selected from 1000-20000 Da; the weight average molecular weight of the polyester block is selected from 1250-120000 Da.

8. The highly stable injectable soft tissue filling material according to claim 7, characterized in that: The polyether block is selected from at least one of polyethylene glycol 1000, polyethylene glycol 1500, polyethylene glycol 2000, polyethylene glycol 4000, polyethylene glycol 6000, polyethylene glycol 8000, polyethylene glycol 10000, polyethylene glycol 20000, polyethylene glycol monomethyl ether 1000, polyethylene glycol monomethyl ether 2000, polyethylene glycol monomethyl ether 5000, polyethylene glycol monomethyl ether 10000, and polyethylene glycol monomethyl ether 20000; The polyester block is selected from at least one of polycaprolactone 1250, polycaprolactone 5000, polycaprolactone 10000, polycaprolactone 15000, polycaprolactone 20000, polycaprolactone 25000, polycaprolactone 30000, poly-L-lactic acid 4000, poly-L-lactic acid 25000, poly-D-lactic acid 120000, polyracemic lactic acid 5000, polylactic acid-glycolic acid copolymer 50000, and polylactic acid-glycolic acid copolymer 20000.

9. The highly stable injectable soft tissue filling material according to claim 1, characterized in that: The annealing process also includes the following process conditions: the heating and holding time is 10-40 minutes; the cooling process to room temperature under the condition of maintaining pressure is completed within 30-60 minutes; And / or, the concentration of the soft tissue filling material is 15-40 wt. %; and / or, the viscosity of the soft tissue filling material is 100-1000 mPa·s; And / or, in the soft tissue filling material, the average particle size of the microspheres of the amphiphilic degradable polyether-polyester copolymer is 150 nm-250 nm.

10. The method for preparing the highly stable injectable soft tissue filling material according to any one of claims 1 to 9, characterized in that: The steps include: The amphiphilic degradable polyether-polyester copolymer is mixed with water and annealed; The annealing process conditions are: under inert gas protection, pressurized to 1.0-5.0 bar, heated to 110-158° C., slowly cooled to room temperature while maintaining the pressure, and finally reduced to standard atmospheric pressure.

11. Use of the highly stable injectable soft tissue filling material according to any one of claims 1 to 9 in the preparation of medicines, cosmetics or medical aesthetic materials, characterized in that: The drug has at least one of the following effects: promoting wound healing, tissue filling, promoting tissue repair, wrinkle removal, and anti-aging; The cosmetic or medical cosmetic material has at least one of the following functions: tissue filling, promoting tissue repair, wrinkle removal, and anti-aging.

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