Injectable composite gel as well as preparation method and application thereof

Abstract

The invention provides injectable composite gel as well as a preparation method and application thereof. The composite gel comprises a gel carrier and active microspheres which are suspended and dispersed in the gel carrier; wherein the gel carrier comprises a methacrylated hyaluronic acid gel, and the methacrylated hyaluronic acid gel is obtained by cross-linking methacrylated hyaluronic acid; the active microspheres comprise polylactic acid microspheres. The composite gel disclosed by the invention is simple in component, does not contain other components such as a chemical cross-linking agent, an auxiliary suspending agent and a surfactant, and has good injectability and heat resistance, and after moist heat sterilization, microspheres are basically maintained to be spherical, have an excellent dispersion effect in a gel carrier, do not have the conditions of deformation, precipitation and the like, and can be kept stable for a long time without sedimentation.

Description

Technical Field

[0001] The invention relates to an injectable composite gel and a preparation method and application thereof, belonging to the field of medical materials. Background Art

[0002] With the rapid development of regenerative medicine and minimally invasive clinical treatment, regenerative tissue filling materials are one of the important research fields. With the launch of several polymer regenerative tissue fillers such as the girl needle and the baby face needle, it also marks that the medical beauty field has gradually entered the "regeneration era" of material-induced tissue replacement from the "filling era" dominated by hyaluronic acid injection. Therefore, the development of a new generation of regenerative tissue filling materials has huge clinical demand and market space.

[0003] Polylactic acid (PLA) is a biodegradable polymer material approved by the FDA for use in the human body. PLA-based facial fillers have been widely used in the international market and can be used to treat facial fat atrophy associated with human immunodeficiency virus and remove wrinkles and fill depressions on the face of normal people. Currently, polylactic acid filler products in the industry are mainly divided into two forms: freeze-dried powder form and pre-filled injection form. Both forms of products have some defects and shortcomings.

[0004] Among them, polylactic acid fillers in the form of lyophilized powder need to be reconstituted before clinical use. However, due to the poor dispersibility of polylactic acid microspheres in aqueous solution and the long reconstitution time, it is easy to cause insufficient reconstitution or adhesion of polylactic acid microspheres, which makes injection more difficult and may even cause adverse reactions such as subcutaneous nodules or redness and swelling. In clinical use, the operator is also required to quickly inject the product after it is fully reconstituted to avoid the problem of microsphere sedimentation.

[0005] Prefilled injection products usually disperse polylactic acid microspheres directly in gel and can be directly injected. The gel commonly used is cross-linked sodium hyaluronate gel, which is mostly obtained by cross-linking sodium hyaluronate with chemical cross-linking agents such as divinyl sulfone and glycidyl ether. The cross-linking agent needs to be removed by dialysis to avoid affecting safety, and the preparation process is complicated. In addition, in order to prevent the polylactic acid microspheres from settling and agglomerating in the gel, auxiliary suspending agents such as poloxamer F127, glycerol, and sodium carboxymethyl cellulose are usually added, resulting in a complex product composition. For example, patent document CN115304788A discloses a hyaluronic acid hydrogel loaded with polylactic acid and a preparation method thereof. First, hyaluronic acid is added to a sodium hydroxide aqueous solution and allowed to stand for swelling and uniform dispersion to obtain a sodium hyaluronate solution. Then, polylactic acid microparticles are uniformly dispersed in a physiological saline solution containing an auxiliary suspending agent, the sodium hyaluronate solution is added, and after stirring evenly, a cross-linking agent is added, stirred evenly, filled into a hydrophobic mold, sealed and allowed to stand for cross-linking to complete, and finally a hyaluronic acid hydrogel loaded with polylactic acid is obtained after dialysis and swelling; wherein the auxiliary suspending agent is one or a mixture of two or more of glycerol, gum arabic, poloxamer F127, and sodium carboxymethyl cellulose; and the cross-linking agent is one or a mixture of two or more of 1,4-butanediol diglycidyl ether, polyethylene glycol diglycidyl ether, and ethylene glycol diglycidyl ether.

[0006] In addition, the pre-filled injection products containing microspheres cannot be sterilized by irradiation because they are in a gel state. Irradiation sterilization will cause the pre-filled syringe to change color and the sodium hyaluronate gel to denature, and moist heat sterilization often causes the internal microspheres to deform. It is usually necessary to add surfactants such as carboxymethyl cellulose, methyl cellulose, tween, and dextrin to the mixed system of cross-linked sodium hyaluronate gel and microspheres to maintain the shape of the microspheres after sterilization. It plays a good protective role so that terminal sterilization can be performed, as disclosed in patent document CN110559489A. However, adding surfactants to sodium hyaluronate gel will not only increase the risk of side reactions of sodium hyaluronate gel, but also easily lead to the generation of bubbles during gel encapsulation. Summary of the invention

[0007] Problem that the invention aims to solve

[0008] In view of the technical problems existing in the prior art, the present invention first provides an injectable composite gel with good injectability and heat resistance. After wet heat sterilization, the microspheres basically maintain a spherical shape and have an excellent dispersion effect in the gel carrier without deformation, precipitation, etc., and can maintain long-term stability without sedimentation.

[0009] Furthermore, the composite gel of the present invention can be prepared into a pre-filled gel injection product, which can be used directly, thus avoiding the need for medical staff to perform re-dissolution operations before use, and is convenient for clinical use.

[0010] Furthermore, the present invention also provides a method for preparing an injectable composite gel, which is simple and easy to implement, and the raw materials are easy to obtain, and is suitable for mass production.

[0011] Solutions for solving problems

[0012] The present invention provides an injectable composite gel, wherein the composite gel comprises a gel carrier and active microspheres suspended and dispersed in the gel carrier; wherein:

[0013] The gel carrier comprises methacryloyl hyaluronic acid gel, and the methacryloyl hyaluronic acid gel is obtained by cross-linking methacryloyl hyaluronic acid;

[0014] The active microspheres include polylactic acid microspheres.

[0015] Furthermore, based on the total mass of the composite gel as 100%, the content of the gel carrier is 75% to 95%, preferably 85% to 90%; the content of the active microspheres is 5% to 25%, preferably 10% to 15%.

[0016] Furthermore, the mass ratio of the gel carrier to the active microspheres is (3-15):1; preferably (5-10):1.

[0017] Further, the raw materials for preparing the gel carrier include methacryloyl hyaluronic acid, a photoinitiator, a solvent and an optional analgesic. Preferably, the weight average molecular weight of the methacryloyl hyaluronic acid is 50 to 500 kDa, preferably 100 to 300 kDa; and / or,

[0018] The particle size of the polylactic acid microspheres is 20 to 55 μm, and the viscosity is above 1.0 dL / g.

[0019] Further, the photoinitiator is phenyl (2,4,6-trimethylbenzoyl) lithium phosphate and / or α-ketoglutaric acid;

[0020] The analgesic agent includes one or a combination of two or more of lidocaine hydrochloride, lidocaine carbonate, tetracaine, prilocaine, procaine, mepivacaine and bupivacaine;

[0021] The solvent includes one or a combination of two or more of purified water, water for injection or physiological saline.

[0022] The present invention also provides a method for preparing the composite gel according to the present invention, which comprises the steps of mixing a gel carrier precursor solution and active microspheres and then performing light cross-linking.

[0023] Furthermore, the preparation method comprises the following steps:

[0024] S1. The methacrylylated hyaluronic acid, the photoinitiator and the optional analgesic agent are mixed with a solvent to obtain a gel carrier precursor solution;

[0025] S2. The active microspheres are mixed with the gel carrier precursor solution and then subjected to light cross-linking to obtain a composite gel.

[0026] Furthermore, in the gel carrier precursor solution, the mass fraction of the methacryloyl hyaluronic acid is 0.5% to 2.5%, preferably 0.5% to 1.8%, the mass fraction of the photoinitiator is 0.09% to 0.3%, and the mass fraction of the analgesic is 0.02% to 0.08%; and / or,

[0027] The mixing in step S2 includes mixing by magnetic stirring; preferably, the speed of the magnetic stirring is 200 to 500 r / min, and the time of the magnetic stirring is 0.5 to 1.5 h.

[0028] Furthermore, the mass ratio of the gel carrier precursor solution to the active microspheres is (3-15):1, preferably (5-10):1; and / or,

[0029] The light cross-linking includes cross-linking under ultraviolet light irradiation. Preferably, the wavelength of the ultraviolet light irradiation is 365-425 nm, and the time of the ultraviolet light irradiation is 5-30 min, preferably 5-8 min.

[0030] The present invention also provides a use of the composite gel according to the present invention for preparing a tissue filling material.

[0031] Effects of the Invention

[0032] The composite gel of the present invention has simple ingredients, does not contain other ingredients such as chemical cross-linking agents, auxiliary suspending agents, surfactants, etc., and has good injectability and heat resistance. After wet heat sterilization, the microspheres basically maintain a spherical shape and have an excellent dispersion effect in the gel carrier without deformation, precipitation, etc., and can maintain long-term stability without sedimentation.

[0033] Furthermore, the composite gel of the present invention can be prepared into a pre-filled gel injection product, which can be used directly, thus avoiding the need for medical staff to perform re-dissolution operations before use, and is convenient for clinical use.

[0034] Furthermore, the preparation method of the injectable composite gel of the present invention is simple and easy, the raw materials are easy to obtain, and it is suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1An optical microscope photograph of the composite gel product of Example 1 is shown (magnification 500 times).

[0036] Figure 2 Photographs of the composite gel of Example 1 before sterilization (left) and after sterilization (right) are shown.

[0037] Figure 3 Photographs of the composite gel of Example 2 before sterilization (left) and after sterilization (right) are shown.

[0038] Figure 4 The photographs of the composite gel products of Example 1 (left), Example 2 (middle), and Example 6 (right) when squeezed out with a syringe are shown.

[0039] Figure 5 Photos of the composite gel product of Example 1 before (left) and after (right) centrifugation are shown.

[0040] Figure 6 Photos of the composite gel product of Example 2 before (left) and after (right) centrifugation are shown.

[0041] Figure 7 Photographs of the product of Comparative Example 1 before (left) and after (right) centrifugation are shown.

[0042] Figure 8 Photographs of the product of Comparative Example 2 before (left) and after (right) centrifugation are shown.

[0043] Fig. 9 The photographs show the composite gel products of Example 1 (left) and Example 2 (right) after being left at room temperature for 3 months.

[0044] Fig.10 The photographs show the products of Comparative Example 1 (left) and Comparative Example 2 (right) after being left at room temperature for 1 month. DETAILED DESCRIPTION

[0045] Various exemplary embodiments, features and aspects of the present invention will be described in detail below. The word "exemplary" used here means "used as an example, embodiment or illustrative". Any embodiment described here as "exemplary" is not necessarily interpreted as being superior or better than other embodiments.

[0046] In addition, in order to better illustrate the present invention, numerous specific details are provided in the following specific embodiments. It should be understood by those skilled in the art that the present invention can be implemented without certain specific details. In other examples, methods, means, equipment and steps well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present invention.

[0047] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0048] In this specification, the word "may" means both performing a certain process and not performing a certain process.

[0049] In this specification, the references to "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", etc., mean that the specific elements (e.g., features, structures, properties and / or characteristics) described in connection with the embodiments are included in at least one embodiment described herein, and may or may not exist in other embodiments. In addition, it should be understood that the elements may be combined in various embodiments in any suitable manner.

[0050] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints numerical values ​​A and B.

[0051] <First aspect>

[0052] The first aspect of the present invention provides an injectable composite gel, the composite gel comprising a gel carrier and active microspheres suspended and dispersed in the gel carrier; wherein:

[0053] The gel carrier comprises methacryloyl hyaluronic acid gel, and the methacryloyl hyaluronic acid gel is obtained by cross-linking methacryloyl hyaluronic acid;

[0054] The active microspheres include polylactic acid microspheres.

[0055] The composite gel of the present invention has good injectability and heat resistance. After wet heat sterilization, the microspheres basically maintain a spherical shape and have an excellent dispersion effect in the gel carrier without deformation, precipitation, etc., and can maintain long-term stability without sedimentation. In addition, the composite gel of the present invention can be prepared into a pre-filled gel injection product that can be used directly, avoiding the need for medical staff to perform re-dissolution operations before use, and is convenient for clinical use.

[0056] The gel carrier of the composite gel of the present invention comprises methacryloyl hyaluronic acid gel, which is obtained by cross-linking methacryloyl hyaluronic acid; the active microspheres comprise polylactic acid microspheres. The composite gel of the present invention does not contain other components such as chemical cross-linking agents, auxiliary suspending agents, surfactants, etc., and the active microspheres are dispersed and suspended in the gel carrier, and the active microspheres can be fixed and dispersed inside the gel carrier by cross-linking, so that the active microspheres are not easily displaced and precipitated during storage and injection.

[0057] Further, in the present invention, the particle size of the polylactic acid microspheres is 20-55 μm, and the viscosity is above 1.0 dL / g. When the particle size of the polylactic acid microspheres is 20-55 μm, and the viscosity is above 1.0 dL / g, the polylactic acid microspheres can be better dispersed in the gel carrier without displacement and sedimentation.

[0058] In some specific embodiments, based on the total mass of the composite gel as 100%, the content of the gel carrier is 75% to 95%, preferably 85% to 90%, for example: 78%, 80%, 82%, 85%, 88%, 90%, 92%, etc.; the content of the active microspheres is 5% to 25%, preferably 10% to 15%, for example: 12%, 15%, 18%, 20%, 22%, etc. When the content of the gel carrier is 75% to 95% and the content of the active microspheres is 5% to 25%, a composite gel with better performance can be obtained.

[0059] In some specific embodiments, the mass ratio of the gel carrier to the active microspheres is (3-15):1; preferably (5-10):1, for example: 4:1, 6:1, 8:1, 10:1, 12:1, 14:1, etc. The present invention can obtain a composite gel with good injectability, good microsphere dispersion effect, long-term stability and not easy to settle by adjusting the mass ratio of the gel carrier to the active microspheres.

[0060] In some specific embodiments, the raw materials for preparing the gel carrier include methacrylated hyaluronic acid, a photoinitiator, a solvent, and an optional analgesic, and do not contain a chemical cross-linking agent.

[0061] High molecular weight methacryloyl hyaluronic acid has an anti-inflammatory effect, but if the molecular weight is too high, the composite gel formed is relatively viscous and difficult to extrude. Therefore, in the present invention, the weight average molecular weight of the methacryloyl hyaluronic acid can be 50 to 500 kDa, preferably 100 to 300 kDa, for example: 80 kDa, 120 kDa, 150 kDa, 200 kDa, 250 kDa, 280 kDa, 350 kDa, 400 kDa, 450 kDa, etc. When the weight average molecular weight of the methacryloyl hyaluronic acid is 50 to 500 kDa, an injectable composite gel with good anti-inflammatory effect can be obtained.

[0062] The present invention can make the methacrylylated hyaluronic acid undergo photo-crosslinking reaction to form a gel carrier by using a photoinitiator, and the active microspheres can be better suspended and dispersed inside the gel carrier through photo-crosslinking.

[0063] Specifically, in the present invention, the photoinitiator is lithium phenyl (2,4,6-trimethylbenzoyl) phosphate (LAP) and / or α-ketoglutaric acid.

[0064] In addition, the present invention relieves the pain of the patient by using an analgesic. Specifically, the analgesic includes one or a combination of two or more of lidocaine hydrochloride, lidocaine carbonate, tetracaine, prilocaine, procaine, mepivacaine and bupivacaine.

[0065] Furthermore, the present invention has no particular limitation on the solvent, and it can be a commonly used solvent in the art. Specifically, the solvent includes one or a combination of two or more of purified water, water for injection, or physiological saline.

[0066] The injectable composite gel of the present invention also has good heat resistance. After wet heat sterilization, the polylactic acid microspheres still basically maintain a spherical shape and have an excellent dispersion effect in the gel carrier without deformation, precipitation, etc., and can maintain long-term stability without sedimentation, which can meet clinical needs.

[0067] <Second Aspect>

[0068] The second aspect of the present invention provides a method for preparing the composite gel according to the first aspect of the present invention, comprising the step of mixing a gel carrier precursor solution and active microspheres and then subjecting the mixture to photo-crosslinking.

[0069] The preparation method of the present invention does not require a dialysis gel carrier after cross-linking, thus shortening the preparation time, simplifying the preparation process, and not introducing chemical cross-linking agents, auxiliary suspending agents, surfactants, etc. during the preparation process, thereby improving the safety of the product.

[0070] In some specific embodiments, the preparation method comprises the following steps:

[0071] S1. The methacrylylated hyaluronic acid, the photoinitiator and the optional analgesic agent are mixed with a solvent to obtain a gel carrier precursor solution;

[0072] S2. The active microspheres are mixed with the gel carrier precursor solution and then subjected to light cross-linking to obtain a composite gel.

[0073] Furthermore, the method also includes the step of sterilizing the composite gel by wet heat.

[0074] Furthermore, the method also includes pre-filling the sterilized composite gel into a syringe to obtain an injectable composite gel product.

[0075] Specifically, methacryloyl hyaluronic acid can be dissolved in a solvent, and after being dissolved, a photoinitiator is added, and then an analgesic is optionally added. After stirring and dissolving evenly, the solution is protected from light to obtain a gel carrier precursor solution.

[0076] In some specific embodiments, in order to better prepare the composite gel, the mass fraction of the methacryloyl hyaluronic acid in the gel carrier precursor solution is 0.5% to 2.5%, for example: 0.6%, 0.8%, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, 2.2%, 2.4%, etc. When the mass fraction of the methacryloyl hyaluronic acid in the gel carrier precursor solution is 0.5% to 2.5%, the active microspheres can be better suspended and dispersed in the gel carrier; further, in order to make the composite The gel product can be more easily extruded for convenient injection. The mass fraction of the methacryloyl hyaluronic acid is preferably 0.5% to 1.8%; the mass fraction of the photoinitiator is 0.09% to 0.3%, for example: 0.1%, 0.12%, 0.15%, 0.18%, 0.2%, 0.22%, 0.24%, 0.26%, 0.28%, etc.; the mass fraction of the analgesic is 0.02% to 0.08%, for example: 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, etc.

[0077] Furthermore, in the present invention, the mixing in step S2 includes mixing by magnetic stirring; preferably, the speed of the magnetic stirring is 200-500 r / min, for example: 250 r / min, 300 r / min, 350 r / min, 400 r / min, 450 r / min, etc.; the time of the magnetic stirring is 0.5-1.5 h, for example: 0.6 h, 0.8 h, 1 h, 1.2 h, 1.4 h.

[0078] In some specific embodiments, the mass ratio of the gel carrier precursor solution to the active microspheres is (3-15):1, preferably (5-10):1, for example: 4:1, 6:1, 8:1, 10:1, 12:1, 14:1, etc. When the mass ratio of the gel carrier precursor solution to the active microspheres is (3-15):1, a composite gel having good injectability, good microsphere dispersion effect and not easy to settle can be obtained.

[0079] Further, the active microspheres are mixed with the gel carrier precursor solution and then light-crosslinked to obtain a composite gel. In some specific embodiments, the light-crosslinking includes crosslinking under ultraviolet light irradiation, preferably, the wavelength of the ultraviolet light irradiation is 365-425nm, preferably 365-400nm, for example: 370nm, 380nm, 390nm, 400nm, etc.; the ultraviolet light irradiation time is 5-30min, preferably 5-8min, for example: 6min, 7min, 10min, 15min, 20min, 25min, etc.

[0080] Methacryloyl hyaluronic acid contains carboxyl and hydroxyl groups, and polylactic acid contains carbonyl groups. When the polylactic acid microspheres are pre-mixed with the gel carrier precursor solution, the polylactic acid microspheres and the methacryloyl hyaluronic acid interact with each other to form hydrogen bonds, so that the methacryloyl hyaluronic acid is wrapped on the surface of the polylactic acid microspheres, the dispersibility of the polylactic acid microspheres in the gel carrier precursor solution is improved, and the polylactic acid microspheres settle more slowly in the carrier precursor solution; then, light cross-linking is performed, and the gel carrier precursor solution is cured and cross-linked into a gel to obtain a composite gel, so that the polylactic acid microspheres are fixed and dispersed in the network structure of the cross-linked gel, avoiding the displacement and sedimentation of the polylactic acid microspheres.

[0081] Therefore, the preparation method of the composite gel of the present application not only reduces the difficulty of mixing the active microspheres in the gel carrier, but also enables the active microspheres to be well fixed and dispersed inside the gel carrier, and are not prone to displacement and sedimentation. In addition, only a small amount of safe and non-toxic photoinitiator is used in the preparation process to induce cross-linking and curing, and the ingredients are simple, without the need to add other ingredients such as chemical cross-linking agents, auxiliary suspending agents, surfactants, etc., and no dialysis is required after cross-linking, which shortens the preparation time and simplifies the preparation process.

[0082] The present invention also provides a use of the composite gel according to the present invention for preparing tissue filling materials, for example, for filling the face or the bridge of the nose.

[0083] Example

[0084] The embodiments of the present invention will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. If no specific conditions are specified in the examples, the conditions are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0085] In the embodiment, the polylactic acid microspheres are purchased from Bloomage Biotechnology Co., Ltd., and the particle size of the polylactic acid microspheres is 20 to 55 μm, and the viscosity is above 1.0 dL / g.

[0086] Example 1

[0087] S1: Take 0.1g of methacryloyl hyaluronic acid (weight average molecular weight is 150kDa) and add it to 10.1g of normal saline, stir until completely dissolved, then add 0.02g of photoinitiator LAP and stir to dissolve evenly, then add 0.006g of lidocaine powder and stir to dissolve evenly to obtain a gel carrier precursor solution.

[0088] S2: Take 1.5g of polylactic acid microspheres and add them to the gel carrier precursor solution of step S1, mix them by magnetic stirring at a speed of 300r / min and a magnetic stirring time of 1.5h. After mixing evenly, irradiate with ultraviolet light at a wavelength of 365nm for 5min to obtain a composite gel.

[0089] S3: The composite gel obtained in S2 is sterilized by wet heat sterilization at 120° C. for 30 min, and then pre-filled into a syringe to obtain an injectable composite gel product.

[0090] Example 2

[0091] S1: Take 0.12g of methacryloyl hyaluronic acid (weight average molecular weight is 150kDa) and add it to 10.1g of normal saline, stir until completely dissolved, then add 0.02g of photoinitiator LAP and stir to dissolve evenly, then add 0.006g of lidocaine powder and stir to dissolve evenly to obtain a gel carrier precursor solution.

[0092] S2: 1.5 g of polylactic acid microspheres were added to the gel carrier precursor solution of step S1, and mixed by magnetic stirring at a speed of 400 r / min for 1 h. After the mixture was evenly mixed, a composite gel was obtained by irradiating the mixture with ultraviolet light at a wavelength of 365 nm for 5 min.

[0093] S3: The composite gel obtained in S2 is sterilized by wet heat at 120° C. for 40 min, and then pre-filled into a syringe to obtain an injectable composite gel product.

[0094] Example 3

[0095] S1: Take 0.06g of methacryloyl hyaluronic acid (weight average molecular weight is 500kDa) and add it to 10.1g of normal saline, stir until completely dissolved, then add 0.01g of photoinitiator LAP and stir to dissolve evenly, then add 0.003g of lidocaine powder and stir to dissolve evenly to obtain a gel carrier precursor solution.

[0096] S2: 3.2 g of polylactic acid microspheres were added to the gel carrier precursor solution of step S1, and mixed by magnetic stirring at a speed of 500 r / min for 1 h. After the mixture was evenly mixed, a composite gel was obtained by irradiating the mixture with ultraviolet light at a wavelength of 365 nm for 5 min.

[0097] S3: The composite gel obtained in S2 is sterilized by wet heat at 120° C. for 40 min, and then pre-filled into a syringe to obtain an injectable composite gel product.

[0098] Example 4

[0099] S1: Take 0.18g of methacryloyl hyaluronic acid (weight average molecular weight is 50kDa) and add it to 10.1g of normal saline, stir until completely dissolved, then add 0.03g of photoinitiator α-ketoglutaric acid and stir to dissolve evenly, then add 0.008g of lidocaine powder and stir to dissolve evenly to obtain a gel carrier precursor solution.

[0100] S2: Take 0.7 g of polylactic acid microspheres and add them to the gel carrier precursor solution of step S1, mix them by magnetic stirring, the speed of magnetic stirring is 200 r / min, the time of magnetic stirring is 1.5 h, after stirring and mixing evenly, use ultraviolet light with a wavelength of 365 nm for 30 min to obtain a composite gel;

[0101] S3: The composite gel obtained in S2 is sterilized by wet heat sterilization at 100° C. for 30 min, and then pre-filled into a syringe to obtain an injectable composite gel product.

[0102] Example 5

[0103] S1: Take 0.15g of methacryloyl hyaluronic acid (weight average molecular weight is 100kDa) and add it to 10.1g of normal saline, stir until completely dissolved, then add 0.02g of photoinitiator α-ketoglutaric acid and stir to dissolve evenly, then add 0.006g of lidocaine powder and stir to dissolve evenly to obtain a gel carrier precursor solution.

[0104] S2: 1.2 g of polylactic acid microspheres were added to the gel carrier precursor solution of step S1, and mixed by magnetic stirring at a speed of 400 r / min for 1 h. After the mixture was evenly mixed, a composite gel was obtained by irradiating the mixture with ultraviolet light at a wavelength of 365 nm for 5 min.

[0105] S3: The composite gel obtained in S2 is sterilized by wet heat sterilization at 100° C. for 50 min, and then pre-filled into a syringe to obtain an injectable composite gel product.

[0106] Example 6

[0107] S1: Take 0.2g of methacryloyl hyaluronic acid (weight average molecular weight is 150kDa) and add it to 10.1g of normal saline, stir until completely dissolved, then add 0.02g of photoinitiator LAP and stir to dissolve evenly, then add 0.009g of lidocaine powder and stir to dissolve evenly to obtain a gel carrier precursor solution.

[0108] S2: Take 1.5g of polylactic acid microspheres and add them to the gel carrier precursor solution of step S1, mix them by magnetic stirring at a speed of 400r / min and a magnetic stirring time of 1h. After mixing evenly, irradiate with ultraviolet light at a wavelength of 365nm for 5min to obtain a composite gel.

[0109] S3: The composite gel obtained in S2 is sterilized by wet heat sterilization at 100° C. for 50 min, and then pre-filled into a syringe to obtain a composite gel product.

[0110] Comparative Example 1

[0111] 0.1 g of hyaluronic acid (weight average molecular weight: 150 kDa) was added to 10.1 g of normal saline and stirred until completely dissolved. Then, 0.006 g of lidocaine powder was added and stirred to dissolve evenly to obtain a mixed solution.

[0112] S2: 1.5 g of polylactic acid microspheres were mixed with the mixed solution of step S1 by magnetic stirring at a speed of 300 r / min for 1.5 h to obtain a viscous composite after uniform mixing;

[0113] S3: The complex obtained in S2 is sterilized by moist heat at 120° C. for 30 min, and then pre-filled into a syringe to obtain the final product.

[0114] Comparative Example 2:

[0115] S1: Take 0.12 g of hyaluronic acid (weight average molecular weight is 150 kDa) and add it to 10.1 g of normal saline, stir until completely dissolved, then add 0.006 g of lidocaine powder and stir to dissolve evenly to obtain a mixed solution.

[0116] S2: 1.5 g of polylactic acid microspheres were mixed with the mixed solution of step S1 by magnetic stirring at a speed of 400 r / min for 1 h, and a viscous composite was obtained after mixing evenly;

[0117] S3: The complex obtained in S2 is sterilized by moist heat at 120° C. for 40 min, and then pre-filled into a syringe to obtain the final product.

[0118] Performance Testing

[0119] 1. Optical microscope

[0120] The morphology of the composite gel product of Example 1 was observed using an optical microscope. Figure 1 shown.

[0121] Depend on Figure 1It can be seen that after wet heat sterilization, the polylactic acid microspheres in Example 1 can maintain a good dispersion state in the methacryloyl hyaluronic acid gel, and the microspheres basically maintain a spherical shape without deformation. In addition, in the composite gel products of Examples 2 to 5, the polylactic acid microspheres can also be uniformly dispersed in the methacryloyl hyaluronic acid gel, and the microspheres basically maintain a spherical shape without deformation.

[0122] 2. Comparison before and after sterilization

[0123] The morphology of the composite gels of Example 1 and Example 2 was compared before and after moist heat sterilization. The results are as follows: Figure 2 and 3 shown.

[0124] Depend on Figure 2 and Figure 3 It can be seen that the composite gels of Examples 1 and 2 had no significant changes before and after moist heat sterilization, and the microspheres did not precipitate. In addition, the composite gels of Examples 3 to 6 also did not precipitate the microspheres after moist heat sterilization.

[0125] 3. Syringe extrusion test

[0126] The composite gel products of Example 1, Example 2 and Example 6 were squeezed out using a syringe with the same thrust. The results are as follows: Figure 4 shown.

[0127] Depend on Figure 4 It can be seen that under the same thrust, the composite gel products of Examples 1 and 2 can be extruded well, but the composite gel product of Example 6 is not easy to extrude. This indicates that when the mass concentration of methacryloyl hyaluronic acid in the gel carrier precursor solution is high, the composite gel product formed is thicker and not easy to extrude. In addition, the composite gel products of Examples 3 to 5 can also be extruded well.

[0128] 4. Comparative test before and after centrifugation

[0129] The composite gel products of Example 1 and Example 2 and the products of Comparative Example 1 and Comparative Example 2 were placed in different centrifuge tubes and centrifuged at 5000 r / min for 30 min. Figures 5 to 8 shown.

[0130] Depend on Figure 5 and 6 It can be seen that the composite gel products of Examples 1 and 2 have no obvious changes before and after centrifugation, and no sedimentation occurs, indicating that the composite gel products have good stability and can ensure that the polylactic acid microspheres have a good long-term dispersion effect and do not settle. In addition, the composite gel products of Examples 3 to 6 have no obvious changes before and after centrifugation, indicating that the samples are very stable.

[0131] Depend on Figure 7 and 8 It can be seen that the products of Comparative Examples 1 and 2 were evenly dispersed before centrifugation, but were stratified after centrifugation, indicating that the stability of polylactic acid microspheres in hyaluronic acid was poor.

[0132] 5. Placement stability test

[0133] The composite gel products of Example 1 and Example 2 and the products of Comparative Example 1 and Comparative Example 2 were placed in different closed containers and placed at room temperature for 3 months. The results are as follows: Figures 9-10 shown.

[0134] Depend on Fig. 9 It can be seen that the composite gel products of Examples 1 and 2 have no significant changes after being placed at room temperature for 3 months, and the microspheres have a good dispersion effect in the gel. In addition, the composite gel products of Examples 3 to 6 also have no significant changes after being placed at room temperature for 3 months, and the microspheres have a good dispersion effect in the gel.

[0135] Depend on Fig.10 It can be seen that the products of Comparative Examples 1 and 2 have already undergone stratification after being placed for one month, indicating that the polylactic acid microspheres have precipitated and have poor storage stability.

[0136] From the above results, it can be seen that the composite gel formed by methacryloyl hyaluronic acid and polylactic acid microspheres in the present application has good injectability and heat resistance, and moist heat sterilization has no obvious effect on the morphology of polylactic acid microspheres and their dispersion state in the composite gel; and during the centrifugation process and long-term storage at room temperature, the stability is good, and the polylactic acid microspheres do not precipitate. In contrast, the products formed by hyaluronic acid and polylactic acid microspheres in Comparative Examples 1 and 2, after centrifugation and storage for 1 month, the polylactic acid microspheres precipitate. This shows that the composite gel of the present application has good stability, which can ensure that the polylactic acid microspheres are dispersed in the methacryloyl hyaluronic acid gel for a long time without precipitation.

[0137] It should be noted that, although the technical solution of the present invention is introduced with specific examples, those skilled in the art will appreciate that the present invention should not be limited thereto.

[0138] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An injectable composite gel, characterized in that: The composite gel comprises a gel carrier and active microspheres suspended and dispersed in the gel carrier; wherein, The gel carrier comprises methacryloyl hyaluronic acid gel, and the methacryloyl hyaluronic acid gel is obtained by cross-linking methacryloyl hyaluronic acid; The active microspheres include polylactic acid microspheres.

2. The composite gel according to claim 1, characterized in that Taking the total mass of the composite gel as 100%, the content of the gel carrier is 75% to 95%, preferably 85% to 90%; the content of the active microspheres is 5% to 25%, preferably 10% to 15%.

3. The composite gel according to claim 1 or 2, characterized in that: The mass ratio of the gel carrier to the active microspheres is (3-15):1; preferably (5-10):

1.

4. The composite gel according to any one of claims 1 to 3, characterized in that The raw materials for preparing the gel carrier include methacryloyl hyaluronic acid, a photoinitiator, a solvent and an optional analgesic. Preferably, the weight average molecular weight of the methacryloyl hyaluronic acid is 50 to 500 kDa, preferably 100 to 300 kDa; and / or, The particle size of the polylactic acid microspheres is 20 to 55 μm, and the viscosity is above 1.0 dL / g.

5. The composite gel according to claim 4, characterized in that The photoinitiator is phenyl (2,4,6-trimethylbenzoyl) lithium phosphate and / or α-ketoglutaric acid; The analgesic agent includes one or a combination of two or more of lidocaine hydrochloride, lidocaine carbonate, tetracaine, prilocaine, procaine, mepivacaine and bupivacaine; The solvent includes one or a combination of two or more of purified water, water for injection or physiological saline.

6. A method for preparing a composite gel according to any one of claims 1 to 5, characterized in that: The method comprises the steps of mixing a gel carrier precursor liquid and active microspheres and then performing light cross-linking.

7. The preparation method according to claim 6, characterized in that: The preparation method comprises the following steps: S1. The methacrylylated hyaluronic acid, the photoinitiator and the optional analgesic agent are mixed with a solvent to obtain a gel carrier precursor solution; S2. The active microspheres are mixed with the gel carrier precursor solution and then subjected to light cross-linking to obtain a composite gel.

8. The preparation method according to claim 7, characterized in that: In the gel carrier precursor solution, the mass fraction of the methacryloyl hyaluronic acid is 0.5% to 2.5%, preferably 0.5% to 1.8%, the mass fraction of the photoinitiator is 0.09% to 0.3%, and the mass fraction of the analgesic is 0.02% to 0.08%; and / or, The mixing in step S2 includes mixing by magnetic stirring; preferably, the speed of the magnetic stirring is 200 to 500 r / min, and the time of the magnetic stirring is 0.5 to 1.5 h.

9. The preparation method according to claim 7 or 8, characterized in that: The mass ratio of the gel carrier precursor solution to the active microspheres is (3-15):1, preferably (5-10):1; and / or, The light cross-linking includes cross-linking under ultraviolet light irradiation. Preferably, the wavelength of the ultraviolet light irradiation is 365-425 nm, and the time of the ultraviolet light irradiation is 5-30 min, preferably 5-8 min.

10. Use of the composite gel according to any one of claims 1 to 5 for preparing tissue filling materials.

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