Hydroxyapatite composite polyester microspheres, and preparation method and application thereof

Abstract

The application provides a hydroxyapatite composite polyester microsphere and a preparation method and application thereof, relates to the technical field of biomedical materials, and the microsphere is prepared from raw materials including bioabsorbable polyester 25-95 parts by mass and hydroxyapatite 5-18 parts by mass; the preparation method of the microsphere comprises the following steps: dissolving the bioabsorbable polyester in an organic solvent to obtain solution 1; adding the hydroxyapatite into the solution 1 to obtain solution 2; dissolving an emulsifier to obtain solution 3; dropping the solution 2 into the solution 3 to obtain an emulsified solution; and cleaning and drying to obtain the hydroxyapatite composite polyester microsphere; and the microsphere can be used for preparing a reagent for facial filling and wrinkle removal. The microsphere has a suitable size, clear boundaries, and can reduce the possibility of inflammation and other adverse symptoms after skin filling, and is stable and long-acting. The microsphere prepared by the preparation method has a suitable size, clear boundaries, and good supporting effect after filling the skin.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biomedical materials, in particular to a hydroxyapatite composite polyester microsphere and a preparation method and application thereof. BACKGROUND

[0002] There are various methods for preparing microspheres, among which the emulsion method can be used to prepare microspheres from high molecular materials. Through a corresponding synthesis route, various functional components can be attached to the microspheres and delivered to the required site by using a syringe. The microspheres can be injected into damaged or missing tissues, and the structure can play a supporting or protective role in the early stage. As the structure degrades, the load can play a role in repair, regeneration and the like. Hydroxyapatite (HA) is a material similar to the composition, structure and properties of the skeleton and teeth of the living body, and its chemical formula is Ca 10 (PO4)6(OH)2, and it has a precise chemical equivalent Ca / P=1.67, which is very similar to the bone mineral structure of the human body. Therefore, it has many properties, such as good bone binding property, biological activity, absorbability and excellent biocompatibility. More and more studies have shown that hydroxyapatite can also play an active role in the regeneration and repair of soft tissues such as skin.

[0003] Microplastic injection plays a role in wrinkle removal, shaping, skin tendering, anti-aging and anti-aging by injecting microsphere suspension subcutaneously, and is used for forehead augmentation, cheek augmentation, fullness of the temple, improvement of the marionette line, etc. As a filling material for bone defects, it can fill bone defects, support and stabilize bone structure. In addition, microspheres can accelerate the transport of substances in the area where they take effect, which is beneficial to angiogenesis and nerve repair in the area. Traditional injectable microspheres are mainly composed of polyester such as polylactic acid, which is a biodegradable material. This kind of absorbable medical polymer has been verified by theory and clinic for many years, and has no toxicity, low immunogenicity, good biocompatibility, and is widely used in tissue engineering, biological medicine and other fields. However, as a skin filler, polylactic acid alone has certain limitations: microspheres rely on the initial space-occupying effect to stimulate subcutaneous protein secretion, and its effect is sensitive to size. Although larger size microspheres can achieve better space-occupying effect, their long degradation period can stimulate cells to form fibrous capsule, making it difficult for the implant to be completely absorbed, resulting in complications such as cysts. Smaller microspheres can be easily absorbed, but the stimulating effect is not good, and the in vivo duration is short, so the treatment effect is not good. Therefore, while ensuring the initial space-occupying effect of microspheres and stimulating the secretion of subcutaneous fibrous tissue collagen, adjusting the overall degradation period of microspheres is the key to significantly improving the use effect of injectable microspheres. Among the polyester microspheres used for skin filling, hydroxyapatite has excellent bioactivity, can actively interact with human tissues, has a more suitable degradation time, avoids complications such as cysts, achieves a more stable and long-acting filling effect, and reduces the possibility of inflammation and other adverse tissue formation. However, the hydroxyapatite microspheres prepared by the method in the prior art have poor size stability, and the boundary of the microspheres is not clear, so the supporting effect and degradation effect are not ideal in the process of application to facial filling. SUMMARY

[0004] The application provides a hydroxyapatite composite polyester microsphere, a preparation method and application thereof, to solve the problems of poor size stability of hydroxyapatite microspheres prepared in the prior art, unclear boundary of the microspheres, and poor filling and degradation.

[0005] To solve the above-mentioned application purposes, the technical solutions provided by the application are as follows:

[0006] A hydroxyapatite composite polyester microsphere, raw materials of which include biodegradable polyester 25-95 parts and hydroxyapatite 5-18 parts by mass.

[0007] Preferably, the D50 of the hydroxyapatite composite polyester microsphere is 6.1-29.1 μm.

[0008] Generally, the effect and clinical performance of the microspheres can be judged by the appearance integrity and size of the microspheres. The size of the polyester microspheres commonly used in the clinic is 20-60 μm, which is the best, which can play a role in occupying and stimulating effect, and will not increase the risk of cyst due to being too large. The D50 of the polyester microspheres of the present application is 6.1 μm ~29.1 μm.

[0009] Preferably, the particle size of the hydroxyapatite is 20 nm-45 nm.

[0010] Preferably, the bioabsorbable polyester is one of polylactic acid, polyglycolic acid, and polycaprolactone.

[0011] A preparation method of the hydroxyapatite composite polyester microspheres described in the foregoing, comprising the following steps:

[0012] S1, dissolving the bioabsorbable polyester in an organic solvent to obtain a solution 1 with a mass-volume concentration of 5%-20%;

[0013] S2, adding the hydroxyapatite to the solution 1 to obtain an oil phase suspension, i.e. a solution 2;

[0014] S3, dissolving the emulsifier to obtain an emulsified aqueous solution, i.e. a solution 3;

[0015] S4, adjusting the stirring speed of the solution 3 to 400-1000 rpm, and simultaneously dropping the solution 2 into the solution 3 at a speed of 1000-3000 mL / h to obtain an emulsified solution;

[0016] In the preparation method of the present application, the liquid in the solution 2 is made into small balls through the shear force generated during the rotation of the solution 3 liquid. In this process, the stirring speed of the solution 3 and the dropping speed of the solution 2, as well as the volume concentration of the related solutes in the solution 2 and the solution 3, are the key parameters for obtaining microspheres of appropriate size. Only under the conditions of the present application, can hydroxyapatite composite polyester microspheres of qualified size and clear appearance be obtained.

[0017] S5, after the emulsification is completed, adjusting the stirring speed of the emulsified solution to 150-200 rpm, and reducing the temperature to 20-25℃, to volatilize the organic solvent;

[0018] S6, after standing, obtaining a precipitate, and washing and drying the precipitate to obtain the hydroxyapatite composite polyester microspheres.

[0019] Preferably, the organic solvent in S1 is one of dichloromethane, trichloromethane, ethyl acetate, dimethyl sulfoxide, and acetone.

[0020] Preferably, the mass-volume concentration of the solute in the solution 3 in S3 is 2%-3%.

[0021] Preferably, the emulsifier in S3 is one of polyvinylpyrrolidone, Span 80, and polyvinyl alcohol, and the mass ratio of the bioabsorbable polyester in S1 to the emulsifier in S3 is (5-19):(12-18).

[0022] Preferably, the drying in S6 is vacuum drying or freeze drying.

[0023] Use of the hydroxyapatite composite polyester microspheres as described above in the preparation of a facial filling and wrinkle-removing agent.

[0024] The microspheres are generally used for facial filling in the early stage to improve facial wrinkles by occupying space, and in the middle and late stages to achieve cosmetic effects by stimulating subcutaneous tissue to generate collagen. However, single polylactic acid microspheres often have uneven sizes, leading to difficulty in degradation and absorption of oversized microspheres, and ultimately forming cysts, causing local inflammation and other serious consequences. In the present application, hydroxyapatite is added as an additional component. Hydroxyapatite (HAP) is a biocompatible and biologically active inorganic material that is the main inorganic component of human and animal bones. It has a certain solubility in the body and can participate in the metabolic process in the body. Hydroxyapatite can promote the proliferation of adult human dermal fibroblasts (hADF), and can significantly promote the neogenesis of type I and type III collagen after injection, and increase the collagen density of the dermal layer, thus showing potential in skin repair and regeneration. Hydroxyapatite shows biological activity by stimulating the regeneration of collagen and promoting the repair of damaged tissue. In addition, due to its good biocompatibility and biodegradability, hydroxyapatite can be gradually replaced by newly formed tissue in the body, and ultimately degraded into harmless calcium and phosphate, without the risk of residual. The introduction of hydroxyapatite component can increase the overall degradation performance of the microspheres, make the degradation period more reasonable, and reduce the probability of complications such as fibrous cysts. At the same time, it increases the secretion of collagen and improves the overall use effect.

[0025] Compared with the prior art, the above technical solution has at least the following beneficial effects:

[0026] The hydroxyapatite composite polyester microspheres in the present application are composed of hydroxyapatite and absorbable polyester, with appropriate size, which can reduce the possibility of inflammation and other adverse symptoms after the polyester microsphere product is used for skin filling, and make its efficacy more stable and long-acting. The present application also provides a preparation method for hydroxyapatite composite polyester microspheres, which strictly controls various parameters, attaches hydroxyapatite to polyester microspheres by emulsification and makes it uniformly distributed, so as to obtain a suitable degradation rate, improve the activity of microspheres in stimulating skin regeneration, and the prepared microspheres have appropriate size, clear boundary, and good supporting effect after filling the skin. The prepared hydroxyapatite composite polyester microspheres can be applied to the field of facial filling and wrinkle removal. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 A microstructure diagram of a hydroxyapatite composite polyester microsphere prepared in Example 1;

[0028] Figure 2 A microstructure diagram of a hydroxyapatite composite polyester microsphere prepared in Example 2;

[0029] Figure 3 A microstructure diagram of a hydroxyapatite composite polyester microsphere prepared in Example 3;

[0030] Figure 4 A microstructure diagram of a hydroxyapatite composite polyester microsphere prepared in Comparative Example 1;

[0031] Figure 5 A microstructure diagram of a hydroxyapatite composite polyester microsphere prepared in Comparative Example 2. DETAILED DESCRIPTION

[0032] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the described embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without any creative effort belong to the scope of protection of the present application.

[0033] Example 1

[0034] A hydroxyapatite composite polyester microsphere, raw materials of which include 95 parts of bioabsorbable polyester and 5 parts of hydroxyapatite in terms of mass, and the particle size of the hydroxyapatite is 20 nm. The bioabsorbable polyester is polyglycolic acid.

[0035] A preparation method of the hydroxyapatite composite polyester microsphere described in the present embodiment, comprising the following steps:

[0036] S1, 95 g of polyglycolic acid is weighed and dissolved in ethyl acetate, and magnetic stirring is used to accelerate dissolution, and the dissolution time is 8 hours. After dissolution is completed, a solution with a total volume of 475 mL is obtained, and a solution 1 with a mass-volume concentration of 20% is obtained;

[0037] S2, 5 g of hydroxyapatite is added to the solution 1 to obtain an oil phase suspension, i.e., a solution 2;

[0038] S3, 60 g of polyvinylpyrrolidone is weighed and configured into an aqueous solution with a total volume of 3000 mL using pure water, and stirring and heating are started to accelerate dissolution, and the dissolution time is 6 hours, and an emulsified aqueous solution, i.e., a solution 3 with a mass-volume concentration of 2% of solute, is obtained;

[0039] S4, adjust the stirring speed of solution 3 to 600 rpm, adjust the stirring speed of solution 2 to 200 rpm, and drop solution 2 into solution 3 at a speed of 1000 mL / h to obtain an emulsified solution;

[0040] S5, after the emulsification is completed, the stirring speed of the emulsified solution is adjusted to 200 rpm, the temperature is reduced to 25°C, and the evaporation of the organic solvent is performed, and the evaporation is continued for 16 hours;

[0041] S6, after the organic phase is completely volatilized, the stirring is stopped, and the solution is placed for 10 hours, and after the microspheres are naturally settled, the supernatant is discarded, and the emulsion product is washed by resuspending and centrifuging with pure water, the centrifuge speed is set to 4000 rpm, and each time 4 minutes, and after the washing is repeated for 3 times, the anhydrous ethanol is replaced for washing once, and the supernatant is collected and discarded by centrifugal separation;

[0042] S7, the washed and dried hydroxyapatite composite polyester microspheres are obtained, and the drying method can be vacuum drying or freeze drying, and the suitable drying parameters are that the temperature of freeze drying is -120°C to -80°C, the vacuum degree is 1 to 100 Pa, the temperature of vacuum drying is 30°C to 60°C, and the vacuum degree is 1 to 100 Pa, and in this embodiment, the vacuum drying method is used to dry the washed microspheres, the vacuum degree is set to not more than 30 Pa, the temperature is 45°C, and the drying is performed for 4 hours.

[0043] The microstructure diagram of the hydroxyapatite composite polyester microspheres prepared in this embodiment is shown in Figure 1 .

[0044] The hydroxyapatite composite polyester microspheres prepared in this embodiment are used as main raw materials to prepare a reagent for facial filling and wrinkle removal.

[0045] Embodiment 2

[0046] A hydroxyapatite composite polyester microsphere, the raw materials of which include 25 g of bioabsorbable polyester and 16.7 g of hydroxyapatite by mass parts, and the particle size of the hydroxyapatite is 30 nm. The bioabsorbable polyester is polycaprolactone.

[0047] A preparation method of the hydroxyapatite composite polyester microsphere described in the foregoing, including the following steps;

[0048] S1, 25 g of polycaprolactone is weighed and dissolved in acetone, and the magnetic stirring is accelerated to accelerate the dissolution, and the dissolution time is 8 hours, and after the dissolution is completed, a solution with a total volume of 500 mL is obtained, and the mass-volume concentration of the solution is 5% to obtain solution 1;

[0049] S2, 16.7 g of hydroxyapatite is added to the solution 1 to obtain an oil phase suspension, i.e. solution 2;

[0050] S3, 75 g Span 80 is weighed out, and a water solution with a total volume of 3000 mL is prepared by using pure water, stirring and heating are started to accelerate the dissolution, and the dissolution time is 8 hours, to obtain an emulsified water solution, i.e., a solution 3 with a mass-volume concentration of 2.5%;

[0051] S4, the stirring speed of the solution 3 is adjusted to 1000 rpm, the stirring speed of the solution 2 is adjusted to 600 rpm, and the solution 2 is dropped into the solution 3 at a speed of 3000 mL / h, to obtain an emulsified solution;

[0052] S5, after the emulsification is completed, the stirring speed of the emulsified solution is adjusted to 150 rpm, and the temperature is reduced to 20℃, to perform the volatilization of the organic solvent;

[0053] S6, after the volatilization of the organic phase is completed, the stirring is stopped, and the solution is left to stand for 10 hours, after the microspheres are naturally settled, the supernatant is discarded, and the emulsified product is cleaned by using the way of resuspension and centrifugation, the centrifuge speed is set to 4000 rpm, and each time is 5 minutes, the cleaning is repeated for 5 times, and then the anhydrous ethanol is used for cleaning once, and the supernatant is discarded by using the centrifugal separation collection;

[0054] S7, the cleaned microspheres are dried by using the freeze-drying way, the vacuum degree is set to not more than 5 Pa, the cold trap temperature is -100℃, and the drying time is 12 hours, to obtain the hydroxyapatite composite polyester microspheres.

[0055] The microstructure diagram of the hydroxyapatite composite polyester microspheres prepared in this embodiment is shown in Figure 2 .

[0056] The hydroxyapatite composite polyester microspheres prepared in this embodiment are used as the main raw material to prepare a reagent for facial filling and wrinkle removal.

[0057] Embodiment 3

[0058] A hydroxyapatite composite polyester microsphere, raw materials of which include 62.5 parts of bioabsorbable polyester and 18 parts of hydroxyapatite by mass, and the particle size of the hydroxyapatite is 45 nm. The bioabsorbable polyester is polylactic acid.

[0059] A preparation method of the hydroxyapatite composite polyester microsphere described in the foregoing, including the following steps.

[0060] S1, 62.5 g of polylactic acid is weighed out and dissolved in dichloromethane, magnetic stirring is started to accelerate the dissolution, and the dissolution time is 8 hours, to obtain a solution with a total volume of 500 mL, i.e., a solution 1 with a mass-volume concentration of 12.5%;

[0061] S2, 18 g hydroxyapatite is added into the solution 1, and dispersed for more than 2 hours to obtain an oil phase suspension, i.e. solution 2;

[0062] S3, 90 g polyvinyl alcohol is configured into an aqueous solution with a total volume of 3000 mL, and stirring and heating are started to accelerate dissolution, and the dissolution time is 8 hours to obtain an emulsified aqueous solution, i.e. solution 3 with a mass-volume concentration of 3%;

[0063] S4, the stirring speed of the solution 3 is adjusted to 400 rpm, the stirring speed of the solution 2 is adjusted to 300 rpm, and the solution 2 is dropped into the solution 3 at a speed of 2700 mL / h to obtain an emulsified solution;

[0064] S5, after the emulsification is completed, the stirring speed of the emulsified solution is adjusted to 200 rpm, and the temperature is reduced to 24℃, and the organic solvent is volatilized, and the volatilization is continued for 36 hours;

[0065] S6, after the organic phase is completely volatilized, the stirring is stopped, and the solution is left to stand for 10 hours, and after the microspheres are naturally settled, the supernatant is discarded, and the emulsified product is washed by resuspending and centrifuging with pure water, the centrifuge speed is set to 3500 rpm, and each time is 5 minutes, and the washing is repeated 5 times, and then the washed microspheres are dried by vacuum drying, the vacuum degree is not more than 30 Pa, and the temperature is 45℃, and the drying is continued for 4 hours to obtain the hydroxyapatite composite polyester microspheres.

[0066] S7, the hydroxyapatite composite polyester microspheres prepared in the example are used as the main raw material to prepare a reagent for facial filling and wrinkle removal.

[0067] The microstructure diagram of the hydroxyapatite composite polyester microspheres prepared in the example is shown in Figure 3 .

[0068] The hydroxyapatite composite polyester microspheres prepared in the example are used as the main raw material to prepare a reagent for facial filling and wrinkle removal.

[0069] The hydroxyapatite composite polyester microspheres prepared in the example are used as the main raw material to prepare a reagent for facial filling and wrinkle removal.

[0070] Comparative Example 1

[0071] The comparative example is similar to the example 1, and the difference is that the preparation method in the comparative example is that the polyhydroxyacetic acid is 50 g, and the hydroxyapatite is 50 g, and the corresponding raw material of the hydroxyapatite composite polyester microspheres obtained includes 50 parts of bioabsorbable polyester and 50 parts of hydroxyapatite by mass.

[0072] The microstructure diagram of the hydroxyapatite composite polyester microspheres prepared in the example is shown in Figure 4 .

[0073] The particle size distribution of the hydroxyapatite composite polyester microspheres prepared in Examples 1-3 and Comparative Example 1 is shown in Table 1.

[0074] Table 1 Particle size distribution of hydroxyapatite composite polyester microspheres prepared in different ways

[0075]

[0076] It can be seen that the hydroxyapatite composite polyester microspheres prepared in Examples 1-3 have regular shape and clear boundary.

[0077] Comparative Example 2

[0078] This comparative example is similar to Example 1, except that 120 g of polyvinylpyrrolidone is added in S3 in this comparative example. The microstructure of the microspheres prepared in this comparative example is shown in Figure 5 It can be seen that the particle size of the microspheres prepared is too small.

[0079] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A hydroxyapatite composite polyester microsphere, characterized by, The raw materials include bioabsorbable polyester 25-95 parts by mass and hydroxyapatite 5-18 parts by mass; The D50 of the hydroxyapatite composite polyester microspheres is 6.1 μm-29.1 μm, and the particle size of the hydroxyapatite is 20 nm-45 nm; The hydroxyapatite composite polyester microspheres are prepared by the following steps: S1, dissolving bioabsorbable polyester in an organic solvent to obtain a solution 1 with a mass-volume concentration of 5%-20%; S2, adding hydroxyapatite to the solution 1 to obtain an oil phase suspension, i.e. a solution 2; S3, dissolving an emulsifier to obtain an emulsified aqueous solution, i.e. a solution 3; S4, adjusting the stirring speed of the solution 3 to 400-1000 rpm, and dropping the solution 2 into the solution 3 at a speed of 1000-3000 mL / h to obtain an emulsified solution; S5, after the emulsification is completed, adjusting the stirring speed of the emulsified solution to 150-200 rpm, and reducing the temperature to 20-25 ℃ to volatilize the organic solvent; S6, obtaining a precipitate after standing, and obtaining the hydroxyapatite composite polyester microspheres after washing and drying the precipitate.

2. The hydroxyapatite composite polyester microsphere according to claim 1, characterized in that, The bioabsorbable polyester is one of polylactic acid, polyhydroxyacetic acid and polycaprolactone.

3. The hydroxyapatite composite polyester microsphere according to claim 1, characterized in that, The organic solvent in S1 is one of dichloromethane, trichloromethane, ethyl acetate, dimethyl sulfoxide and acetone.

4. The hydroxyapatite composite polyester microsphere according to claim 1, wherein, The mass-volume concentration of the solute in the solution 3 in S3 is 2%-3%.

5. The hydroxyapatite composite polyester microsphere according to claim 1, wherein, The emulsifier in S3 is one of polyvinylpyrrolidone, span 80 and polyvinyl alcohol, and the mass ratio of the bioabsorbable polyester in S1 to the emulsifier in S3 is (5-19):(12-18).

6. The hydroxyapatite composite polyester microsphere of claim 1, wherein, The drying in S6 is vacuum drying or freeze-drying.

7. Use of the hydroxyapatite composite polyester microspheres in claim 1 or 2 in the preparation of a facial filling and wrinkle-removing agent.

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