Preparation method of injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microsphere composite dextran hydrogel filler

Abstract

The invention discloses a preparation method of an injectable dextran / poly (L-lactic acid) interpenetrating network microsphere composite hydrogel filler, comprising the following preparation steps: (1) synthesis of a polymerizable poly (L-lactic acid-dextran) copolymer; (2) preparation of a polymerizable dextran; (3) preparation of poly (L-lactic acid-dextran) interpenetrating network microspheres; (4) preparation of dextran microspheres; (5) preparation of an injectable poly (L-lactic acid-dextran) interpenetrating network microsphere and dextran microsphere composite hydrogel filler. The preparation method disclosed in the invention has the following beneficial effects: mild processing conditions, suitable for large-scale production, and the obtained injectable poly (L-lactic acid-dextran) interpenetrating network microsphere and dextran microsphere composite hydrogel filler has good biocompatibility and degradability, and is suitable for the field of soft tissue filling.

Description

Technical Field

[0001] The invention relates to the technical field of tissue filling and biomedical polymer materials, and in particular to a method for preparing an injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microsphere composite dextran hydrogel filler. Background Art

[0002] Everyone loves beauty. With the increasing demand for beauty and the preference for non-invasive beauty methods, injection beauty technology is becoming more and more popular. Injection beauty technology is a technology that improves appearance, reduces wrinkles, increases facial contours or improves other beauty problems by injecting fillers into the skin or tissues. At present, the main filler products on the market are sodium hyaluronate gel, polyester, calcium hydrogel, etc. Calcium hydrogels such as calcium hydroxyapatite gel have a long action time in the human body and good filling effect, but may cause calcium deposition and calcification problems. Especially after long-term injection, it may cause tissue discomfort and affect the appearance and texture of the injection area. Sodium hyaluronate gel has good biocompatibility, but due to gravity problems, sodium hyaluronate gel cannot be fixed, will slowly move over time, and has a short duration of action, so frequent repeated injections are required, which increases the pain of patients.

[0003] In recent years, the development of polyester fillers has made up for the defects of traditional tissue filling materials. For example, polycaprolactone (PCL) and poly-L-lactic acid (PLLA) have good biocompatibility. Because they degrade by their own hydrolysis and the degradation rate is relatively slow, the filling effect can last from several months to several years. At present, there are many PCL and PLLA products on the market for the correction of moderate and severe nasolabial wrinkles. In these products, PCL and PLLA are usually in the form of microspheres. However, since PCL and PLLA fillers cannot be degraded by enzymes in the human body, they are not easy to remove later. This can easily lead to a series of adverse reactions such as granulomas, and the hydrophobicity of the polyester material itself aggravates these symptoms. In addition, PCL and PLLA fillers are difficult to fill evenly and are prone to nodules, so there are certain physical limitations in shaping facial morphology. Therefore, the introduction of hydrophilic components that can be degraded by enzymes in PCL or PLLA microspheres can reduce the risk of granulomas and nodules. And even if adverse reactions occur, the symptoms can be quickly and effectively relieved by injecting degrading enzymes. Dextran is a bacterial polysaccharide present in the secretions of some microorganisms. It is non-toxic, biocompatible, biodegradable and has gelling properties. It has a long history as a plasma substitute in clinical practice. Therefore, it has great potential as a filling material. Dextran is copolymerized with caprolactone and L-lactic acid to prepare hydrophilic, enzyme-degradable ternary cross-linked interpenetrating network microspheres, which are then mixed with cross-linked dextran gel to prepare a composite injectable hydrogel. The hydrogel combines the advantages of dextran, caprolactone and L-lactic acid, and integrates long-term, immediate, safe and effective properties. It is an ideal injectable filling material.

[0004] CN114099772A discloses a material for facial shaping and filling and a preparation method thereof. This method directly mixes PLLA beads, cross-linked dextran, and sodium hyaluronate to achieve the effect of immediate filling and long-term filling. CN14601966A discloses a sodium hyaluronate gel lubricant, a filler, and a preparation method and application thereof. This method uses sodium hyaluronate as a lubricant to solve the problem of uneven dispersion of polycaprolactone beads in the filler. However, these two methods still have the risk of granulomas and nodules caused by the inability of polyester beads to be enzymatically degraded and the hydrophobicity of polyester materials. CN116832213A prepares binary interpenetrating network beads by copolymerizing dextran and L-lactide, which effectively avoids the risk of nodules and granulomas, but the single introduction of L-lactide, a hard segment, increases the modulus of the product, and the adjustable range of the modulus is reduced, thereby causing the product to lose its natural touch.

[0005] In summary, the technical problems to be solved by the present invention are:

[0006] An injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microsphere composite dextran hydrogel filler was developed and prepared. The filler has an adjustable degradation time and degradation mode and can adjust the modulus to meet the injection requirements of different parts. Summary of the invention

[0007] The objects of the present invention are:

[0008] A dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microsphere composite dextran hydrogel filler is prepared, which can be used for filling different tissue parts.

[0009] It is prepared by the following four steps:

[0010] S1 Synthesis of polymerizable polycaprolactone-poly(L-lactic acid) copolymer;

[0011] S2 Preparation of polymerizable dextran;

[0012] Preparation of S3 dextran-polycaprolactone-poly(L-lactic acid) ternary interpenetrating network microspheres;

[0013] S4 injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microspheres composite dextran hydrogel.

[0014] As a further improvement of this scheme, the following preparation steps are included:

[0015] S1 Synthesis of polymerizable polycaprolactone-poly(L-lactic acid) copolymer;

[0016] S2 Preparation of polymerizable dextran;

[0017] Preparation of S3 dextran-polycaprolactone-poly(L-lactic acid) ternary interpenetrating network microspheres;

[0018] Preparation of injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microspheres composite dextran hydrogel;

[0019] As a further improvement of this solution, the detailed steps of S1, S2, S3, and S4 are as follows:

[0020] S1 Synthesis of polymerizable polycaprolactone-poly(L-lactic acid) copolymer;

[0021] At room temperature, caprolactone was dissolved in dimethyl sulfoxide at a solid-liquid ratio of 1 g:10 mL by stirring, and nitrogen was introduced for 30 minutes. Then, an appropriate amount of L-lactide was gradually injected into the solution, and stannous octoate and reaction aid A were added;

[0022] The reaction system was placed at 85°C for 12 hours. After the reaction was completed, the mixture was transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000-14000 g / mol;

[0023] First, dialysis was performed using dimethyl sulfoxide, with the dialysate replaced every 24 hours for 7 consecutive days. Subsequently, dialysis was performed using deionized water, with the dialysate replaced every 12 hours for 7 consecutive days.

[0024] After dialysis, freeze drying was performed to obtain a polymerizable polycaprolactone-poly-L-lactic acid copolymer;

[0025] Wherein, the added amount of stannous octoate is 3% of the mass of caprolactone;

[0026] Preparation of S2 polymerizable dextran

[0027] At room temperature, dextran was dissolved in dimethyl sulfoxide at a solid-liquid ratio of 1 g:10 mL with stirring and nitrogen flow for 30 minutes;

[0028] Subsequently, appropriate amounts of dimethylaminopyridine and modifier B were added to the reaction system and reacted at room temperature for 48 h;

[0029] After the reaction is completed, the reaction product is transferred to a dialysis bag of regenerated cellulose with a molecular weight cutoff of 8000 to 14000 g / mol, and dialyzed with deionized water. The deionized water is replaced every 12 hours for 7 consecutive days.

[0030] After dialysis is completed, the polymerizable dextran can be obtained by freeze drying;

[0031] Preparation of S3 dextran-polycaprolactone-poly(L-lactic acid) ternary interpenetrating network microspheres

[0032] The polymerizable polycaprolactone-poly(L-lactic acid) copolymer obtained in step (1) and the polymerizable dextran obtained in step (2) are mixed and dissolved in a certain amount of deionized water at room temperature with a proper amount of ammonium persulfate in a certain proportion, and stirred sufficiently to form a dispersed phase solution A. At the same time, a proper amount of emulsifier is added to the oil phase, and mixed uniformly to obtain a continuous phase solution B;

[0033] Next, at room temperature, dispersed phase solution A was added dropwise to continuous phase solution B, and nitrogen was passed through and stirred continuously for 0.5 h until the emulsification was stable, and then a certain amount of tetramethylethylenediamine was added, and the reaction was continued for 3 h. After the reaction was completed, air was passed through to terminate the polymerization reaction, and the stratification was fully allowed to stand;

[0034] Subsequently, the upper liquid phase is removed, and the lower liquid phase is filtered to obtain a filter cake. The obtained filter cake is dispersed with ethanol and washed thoroughly, and then filtered again, and the obtained filter cake is redispersed in deionized water. The obtained dispersion is transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000-14000 g / mol, and dialyzed with deionized water for 7 days, with the water replaced every 12 hours. After the dialysis is completed, freeze-drying is performed to obtain poly (L-lactic acid-dextran) interpenetrating network microspheres. Among them, the amounts of ammonium persulfate and tetramethylethylenediamine are 2% and 0.5% of the mass of the polymerizable polycaprolactone-poly (L-lactic acid) copolymer, respectively;

[0035] Preparation of S4 injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microspheres composite dextran hydrogel

[0036] The polymerizable dextran obtained in step (2) and the dextran-polycaprolactone-poly-L-lactic acid ternary interpenetrating network microspheres obtained in step (3) are dissolved in deionized water, N2 is passed through at room temperature for 30 min, and a certain amount of ammonium persulfate and tetramethylethylenediamine are added, and the mixture is stirred thoroughly;

[0037] After 3 h of reaction, the obtained product was transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000 to 14000 g / mol and dialyzed with deionized water for 7 days, during which the deionized water was replaced every 12 h;

[0038] After the dialysis is completed, the injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microsphere composite dextran hydrogel is obtained by storing at low temperature;

[0039] The dosage of ammonium persulfate and tetramethylethylenediamine is 1% and 0.25% of the mass of polymerizable dextran, respectively.

[0040] As a further improvement of this solution, the mass ratio of L-lactide to caprolactone in S1 is 1:1 to 1:15.

[0041] As a further improvement of this solution, the reaction aid A in S1 is any one or more of acryl alcohol, N-hydroxyethyl acrylamide, hydroxyethyl methacrylate, and hydroxypropyl methacrylate, and the added amount of the reaction aid A is 5% to 15% of the mass of caprolactone.

[0042] As a further improvement of this solution, in step (2), the modifier B is any one or more of glycidyl methacrylate, methacryloyl chloride, and acryloyl chloride, and the added amount of the modifier B is 5% to 15% of the mass of the dextran.

[0043] As a further improvement of this solution, the mass ratio of the polymerizable dextran to the polymerizable polycaprolactone-poly-L-lactic acid copolymer in S3 is 1:1 to 1:20;

[0044] In the step (3), the volume ratio of the dispersed phase solution to the continuous phase solution is 3:7, and the mass concentration of the polymerizable polycaprolactone-poly (L-lactic acid) copolymer in the dispersed phase solution is 5% to 30%.

[0045] As a further improvement of this solution, the oil phase in S3 is one or more of n-hexane, cyclohexane, dichloromethane, n-pentane, and white oil;

[0046] The emulsifier in S3 is one or more of Span 80, sodium oleate, lauryl alcohol polyoxyethylene ether, lecithin, polyoxyethylene castor oil; the amount of the emulsifier is 0.5% to 5% of the oil phase.

[0047] As a further improvement of this solution, the stirring method in S3 is mechanical stirring, and the stirring speed is 300 rpm.

[0048] As a further improvement of the present solution, the mass concentration of the dextran-polycaprolactone-poly-L-lactic acid ternary interpenetrating network microspheres in S4 is 3% to 10%, and the mass concentration of the polymerizable dextran is 10% to 20%.

[0049] Compared with the prior art, the beneficial effects of the present invention are:

[0050] 1. The present invention firstly introduces double bonds into the polycaprolactone-L-lactide binary block copolymer by ring-opening polymerization of caprolactone and L-lactide through a reaction aid with double bonds. Subsequently, double bonds are introduced into dextran by the reaction of the active hydroxyl group of dextran. Finally, the two are mixed and reacted to prepare ternary cross-linked network microspheres. Compared with single polycaprolactone or poly-L-lactic acid, this ternary copolymer combines the advantages of dextran, polycaprolactone, and poly-L-lactic acid, which can stimulate the phagocytosis of macrophages to produce collagen tissue, and has better biocompatibility and enzyme degradation performance to reduce the appearance of nodules and granulomas. Since dextran with double bonds itself can be used as a cross-linking agent, the subsequent cross-linking reaction does not require the addition of additional cross-linking agents, thereby avoiding the risks caused by residual cross-linking agents.

[0051] 2. The particle size of the dextran-polycaprolactone-poly-L-lactic acid ternary interpenetrating network microspheres synthesized by inverse emulsion polymerization in the present invention is controllable and uniformly distributed.

[0052] 3. The dextran-polycaprolactone-poly-L-lactic acid ternary interpenetrating network microspheres in the present invention can be degraded by enzyme action, which can effectively reduce the risk of nodules and granulomas. By adjusting the ratio of dextran, caprolactone, and L-lactide, the degradation time of the microspheres can be effectively regulated to meet different filling requirements. At the same time, the cross-linked dextran gel can effectively fix the dextran-polycaprolactone-poly-L-lactic acid ternary interpenetrating network microspheres so that they are not free.

[0053] 4. The injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microsphere composite dextran hydrogel filler obtained by the present invention has excellent biocompatibility and stability, and can be suitable for filling different tissue parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 Scanning electron microscope image of Example 1 of the present invention;

[0055] Figure 2 Another scanning electron microscope image of Example 1 of the present invention. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described below in conjunction with the accompanying drawings and the best embodiments:

[0057] Example 1

[0058] (1) At room temperature, weigh 10g of caprolactone, stir and dissolve it in 100mL of dimethyl sulfoxide, and pass nitrogen for 30 minutes. Then, add 10g of L-lactide, 0.3g of stannous octoate and 0.5g of propylene alcohol as reaction aid A to the solution respectively. Place the reaction system at 85°C for 12h. After the reaction is completed, transfer the mixture to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000-14000g / mol. First, dialyze with dimethyl sulfoxide, replace the dialysis solution every 24h, and dialyze continuously for 7 days. Subsequently, dialyze with deionized water, replace the dialysis solution every 12h, and dialyze continuously for 7 days. After the dialysis is completed, freeze-dry to obtain a polymerizable polycaprolactone-poly-L-lactic acid copolymer.

[0059] (2) At room temperature, 10 g of dextran with a molecular weight of 70,000 g / mol was weighed and dissolved in 100 g of dimethyl sulfoxide, and nitrogen was introduced for 30 minutes. Subsequently, 0.5 g of dimethylaminopyridine and Modifier B0.5g of glycidyl methacrylate was added and reacted at room temperature for 48h. After the reaction, the reaction product was transferred to a dialysis bag of regenerated cellulose with a molecular weight cutoff of 8000-14000g / mol and dialyzed with deionized water. The deionized water was replaced every 12h for 7 consecutive days. After the dialysis was completed, the polymerizable dextran was obtained by freeze drying.

[0060] (3) At room temperature, 4.5 g of the polymerizable polycaprolactone-poly-L-lactic acid copolymer obtained in step (1) and 4.5 g of the polymerizable dextran obtained in step (2) were weighed and dissolved in 30 mL of deionized water with 90 mg of ammonium persulfate, to form a dispersed phase solution A. At the same time, 70 mL of cyclohexane was measured and 0.35 g of Span 80 was added, and mixed evenly to obtain a continuous phase solution B. Then, at room temperature, the dispersed phase solution A was added dropwise to the continuous phase solution B, and nitrogen was continuously mechanically stirred for 0.5 h at a speed of 300 rpm until the emulsification was stable, and then 22.5 mg of tetramethylethylenediamine was added and the reaction continued for 3 h. After the reaction was completed, air was introduced to terminate the polymerization reaction, and the reaction was allowed to stand for a long time to separate. Subsequently, the upper liquid phase was removed, and the lower liquid phase was filtered to obtain a filter cake. The obtained filter cake was dispersed and washed with ethanol and then filtered again, and the obtained filter cake was redispersed in deionized water. The obtained dispersion was transferred to a regenerated cellulose dialysis bag with a molecular weight cut-off of 8000-14000 g / mol, and dialyzed with deionized water for 7 days, with the water replaced every 12 hours. After the dialysis was completed, the dispersion was freeze-dried to obtain poly-L-lactic acid-dextran interpenetrating network microspheres.

[0061] (4) Weigh 10 g of the polymerizable dextran obtained in step (2) and 3 g of the dextran-polycaprolactone-poly(L-lactic acid) ternary interpenetrating network microspheres obtained in step (3) respectively, dissolve them in deionized water, pass N2 at room temperature for 30 min, add 100 mg of ammonium persulfate and 25 mg of tetramethylethylenediamine, and stir them thoroughly. After reacting for 3 h, transfer the obtained product to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000-14000 g / mol and dialyze it with deionized water for 7 days, during which the deionized water is replaced every 12 h. After the dialysis is completed, store it at low temperature to obtain an injectable dextran / polycaprolactone / poly(L-lactic acid) ternary interpenetrating network microsphere composite dextran hydrogel.

[0062] Example 2

[0063] (1) At room temperature, weigh 10 g of caprolactone, stir and dissolve it in 100 mL of dimethyl sulfoxide, and pass nitrogen for 30 minutes. Then, add 15 g of L-lactide, 0.45 g of stannous octoate and 0.75 g of hydroxypropyl methacrylate as reaction aid A to the solution respectively. Place the reaction system at 85°C for 12 hours. After the reaction is completed, transfer the mixture to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000-14000 g / mol. First, dialyze with dimethyl sulfoxide, replace the dialysis solution every 24 hours, and dialyze continuously for 7 days. Subsequently, dialyze with deionized water, replace the dialysis solution every 12 hours, and dialyze continuously for 7 days. After the dialysis is completed, freeze-dry to obtain a polymerizable dextran-polycaprolactone-poly-L-lactic acid copolymer.

[0064] (2) At room temperature, 10 g of dextran with a molecular weight of 70,000 g / mol was weighed and dissolved in 100 g of dimethyl sulfoxide, and nitrogen was introduced for 30 minutes. Subsequently, 0.5 g of dimethylaminopyridine and Modifier B 0.7g methacryloyl chloride was added and reacted at room temperature for 48h. After the reaction, the reaction product was transferred to a dialysis bag of regenerated cellulose with a molecular weight cutoff of 8000-14000g / mol and dialyzed with deionized water. The deionized water was replaced every 12h for 7 consecutive days. After the dialysis was completed, the polymerizable dextran was obtained by freeze drying.

[0065] (3) At room temperature, 9 g of the polymerizable polycaprolactone-poly(L-lactic acid) copolymer obtained in step (1) and 4.5 g of the polymerizable dextran obtained in step (2) were weighed and dissolved in 30 mL of deionized water with 180 mg of ammonium persulfate, and the mixture was stirred and dissolved to form a dispersed phase solution A. At the same time, 70 mL of white oil was measured and 0.7 g of Span 80 was added, and the mixture was mixed evenly to obtain a continuous phase solution B. Then, at room temperature, the dispersed phase solution A was added dropwise to the continuous phase solution B, and nitrogen was continuously mechanically stirred for 0.5 h at a speed of 300 rpm until the emulsification was stable, and then 45 mg of tetramethylethylenediamine was added and the reaction was continued for 3 h. After the reaction was completed, air was introduced to terminate the polymerization reaction, and the mixture was allowed to stand for stratification. Subsequently, the upper liquid phase was removed, and the lower liquid phase was filtered to obtain a filter cake. The obtained filter cake was dispersed and washed with ethanol and then filtered again, and the obtained filter cake was redispersed in deionized water. The obtained dispersion was transferred to a regenerated cellulose dialysis bag with a molecular weight cut-off of 8000-14000 g / mol, and dialyzed with deionized water for 7 days, with the water replaced every 12 hours. After the dialysis was completed, the dispersion was freeze-dried to obtain poly-L-lactic acid-dextran interpenetrating network microspheres.

[0066] (4) Weigh 12 g of the polymerizable dextran obtained in step (2) and 4 g of the dextran-polycaprolactone-poly(L-lactic acid) ternary interpenetrating network microspheres obtained in step (3), respectively, dissolve them in deionized water, pass N2 at room temperature for 30 min, add 120 mg of ammonium persulfate and 30 mg of tetramethylethylenediamine, and stir them thoroughly. After reacting for 3 h, transfer the obtained product to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000-14000 g / mol and dialyze it with deionized water for 7 days, during which the deionized water is replaced every 12 h. After the dialysis is completed, store it at low temperature to obtain an injectable dextran / polycaprolactone / poly(L-lactic acid) ternary interpenetrating network microsphere composite dextran hydrogel.

[0067] Example 3

[0068] (1) At room temperature, weigh 20g of caprolactone and stir and dissolve it in 200mL of dimethyl sulfoxide, and pass nitrogen for 30 minutes. Then, add 10g of L-lactide, 0.6g of stannous octoate and 0.2g of hydroxyethyl methacrylate as reaction aid A to the solution respectively. Place the reaction system at 85°C for 12h. After the reaction is completed, transfer the mixture to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000-14000g / mol. First, dialyze with dimethyl sulfoxide, replace the dialysis solution every 24h, and dialyze continuously for 7 days. Subsequently, dialyze with deionized water, replace the dialysis solution every 12h, and dialyze continuously for 7 days. After the dialysis is completed, freeze-dry to obtain a polymerizable dextran-polycaprolactone-poly-L-lactic acid copolymer.

[0069] (2) At room temperature, weigh 10 g of dextran with a molecular weight of 80,000 g / mol and dissolve it in 100 g of dimethyl sulfoxide, stirring it thoroughly, and then introduce nitrogen for 30 minutes. Then, add 0.5 g of dimethylaminopyridine and Modifier B 1 g of methacrylic anhydride was added and reacted at room temperature for 48 hours. After the reaction, the reaction product was transferred to a dialysis bag of regenerated cellulose with a molecular weight cutoff of 8000-14000 g / mol and dialyzed with deionized water. The deionized water was replaced every 12 hours for 7 consecutive days. After the dialysis was completed, the polymerizable dextran was obtained by freeze drying.

[0070] (3) At room temperature, 12 g of the polymerizable polycaprolactone-poly-L-lactic acid copolymer obtained in step (1) and 4 g of the polymerizable dextran obtained in step (2) were weighed and dissolved in 30 mL of deionized water with 240 mg of ammonium persulfate, and the mixture was stirred and dissolved to form a dispersed phase solution A. At the same time, 70 mL of dichloromethane was measured and 0.6 g of Span 80 and 0.1 g of polyoxyethylene castor oil were added, and the mixture was mixed evenly to obtain a continuous phase solution B. Then, at room temperature, the dispersed phase solution A was added dropwise to the continuous phase solution B, and nitrogen was continuously mechanically stirred for 0.5 h at a speed of 300 rpm until the emulsification was stable, and then 60 mg of tetramethylethylenediamine was added and the reaction was continued for 3 h. After the reaction was completed, air was introduced to terminate the polymerization reaction, and the mixture was allowed to stand for stratification. Subsequently, the upper liquid phase was removed, and the lower liquid phase was filtered to obtain a filter cake. The obtained filter cake was dispersed and washed with ethanol and then filtered again, and the obtained filter cake was redispersed in deionized water. The obtained dispersion was transferred to a regenerated cellulose dialysis bag with a molecular weight cut-off of 8000-14000 g / mol, and dialyzed with deionized water for 7 days, with the water replaced every 12 hours. After the dialysis was completed, the dispersion was freeze-dried to obtain poly-L-lactic acid-dextran interpenetrating network microspheres.

[0071] (4) Weigh 10 g of the polymerizable dextran obtained in step (2) and 3 g of the dextran-polycaprolactone-poly(L-lactic acid) ternary interpenetrating network microspheres obtained in step (3) respectively, dissolve them in deionized water, pass N2 at room temperature for 30 min, add 100 mg of ammonium persulfate and 25 mg of tetramethylethylenediamine, and stir them thoroughly. After reacting for 3 h, transfer the obtained product to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000-14000 g / mol and dialyze it with deionized water for 7 days, during which the deionized water is replaced every 12 h. After the dialysis is completed, store it at low temperature to obtain an injectable dextran / polycaprolactone / poly(L-lactic acid) ternary interpenetrating network microsphere composite dextran hydrogel.

[0072] Example 4

[0073] (1) At room temperature, weigh 20g of caprolactone, stir and dissolve it in 200mL of dimethyl sulfoxide, and pass nitrogen for 30 minutes. Then, add 2g of L-lactide, 0.6g of stannous octoate and 0.2g of N-hydroxyethyl acrylamide as reaction aid A to the solution respectively. Place the reaction system at 85°C for 12h. After the reaction is completed, transfer the mixture to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000-14000g / mol. First, dialyze with dimethyl sulfoxide, replace the dialysis solution every 24h, and dialyze continuously for 7 days. Subsequently, dialyze with deionized water, replace the dialysis solution every 12h, and dialyze continuously for 7 days. After the dialysis is completed, freeze-dry to obtain a polymerizable dextran-polycaprolactone-poly-L-lactic acid copolymer.

[0074] (2) At room temperature, 10 g of dextran with a molecular weight of 100,000 g / mol was weighed and dissolved in 100 g of dimethyl sulfoxide, and nitrogen was introduced for 30 minutes. Subsequently, 0.5 g of dimethylaminopyridine and Modifier B 1 g of methacrylic anhydride was added and reacted at room temperature for 48 hours. After the reaction, the reaction product was transferred to a dialysis bag of regenerated cellulose with a molecular weight cutoff of 8000-14000 g / mol and dialyzed with deionized water. The deionized water was replaced every 12 hours for 7 consecutive days. After the dialysis was completed, the polymerizable dextran was obtained by freeze drying.

[0075] (3) At room temperature, 25 g of the polymerizable polycaprolactone-poly-L-lactic acid copolymer obtained in step (1) and 5 g of the polymerizable dextran obtained in step (2) were weighed and dissolved in 30 mL of deionized water with 500 mg of ammonium persulfate, and the mixture was stirred and dissolved to form a dispersed phase solution A. At the same time, 40 mL of n-hexane and 30 mL of cyclohexane were measured and 0.6 g of lecithin and 0.6 g of sodium oleate were added and mixed evenly to obtain a continuous phase solution B. Then, at room temperature, the dispersed phase solution A was added dropwise to the continuous phase solution B, and nitrogen was continuously mechanically stirred for 0.5 h at a speed of 300 rpm until the emulsification was stable, and then 125 mg of tetramethylethylenediamine was added and the reaction continued for 3 h. After the reaction was completed, air was introduced to terminate the polymerization reaction, and the mixture was allowed to stand for stratification. Subsequently, the upper liquid phase was removed, and the lower liquid phase was filtered to obtain a filter cake. The obtained filter cake was dispersed and washed with ethanol and filtered again, and the obtained filter cake was redispersed in deionized water. The obtained dispersion was transferred to a regenerated cellulose dialysis bag with a molecular weight cut-off of 8000-14000 g / mol, and dialyzed with deionized water for 7 days, with the water replaced every 12 hours. After the dialysis was completed, the dispersion was freeze-dried to obtain poly-L-lactic acid-dextran interpenetrating network microspheres.

[0076] (4) Weigh 10 g of the polymerizable dextran obtained in step (2) and 3 g of the dextran-polycaprolactone-poly(L-lactic acid) ternary interpenetrating network microspheres obtained in step (3) respectively, dissolve them in deionized water, pass N2 at room temperature for 30 min, add 100 mg of ammonium persulfate and 25 mg of tetramethylethylenediamine, and stir them thoroughly. After reacting for 3 h, transfer the obtained product to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000-14000 g / mol and dialyze it with deionized water for 7 days, during which the deionized water is replaced every 12 h. After the dialysis is completed, store it at low temperature to obtain an injectable dextran / polycaprolactone / poly(L-lactic acid) ternary interpenetrating network microsphere composite dextran hydrogel.

[0077] Example 5

[0078] (1) At room temperature, weigh 10 g of caprolactone and dissolve it in 100 mL of dimethyl sulfoxide, stir it thoroughly, and pass nitrogen for 30 minutes. Then, add 5 g of L-lactide, 0.3 g of stannous octoate and 0.2 g of propylene alcohol as reaction aid A to the solution respectively. Place the reaction system at 85°C for 12 hours. After the reaction is completed, transfer the mixture to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000-14000 g / mol. First, dialyze with dimethyl sulfoxide, replace the dialysis solution every 24 hours, and dialyze continuously for 7 days. Subsequently, dialyze with deionized water, replace the dialysis solution every 12 hours, and dialyze continuously for 7 days. After the dialysis is completed, freeze-dry to obtain a polymerizable dextran-polycaprolactone-poly-L-lactic acid copolymer.

[0079] (2) At room temperature, 10 g of dextran with a molecular weight of 40,000 g / mol was weighed and dissolved in 100 g of dimethyl sulfoxide, and nitrogen was introduced for 30 minutes. Subsequently, 0.5 g of dimethylaminopyridine and Modifier B 1 g of methacrylic anhydride was added and reacted at room temperature for 48 hours. After the reaction, the reaction product was transferred to a dialysis bag of regenerated cellulose with a molecular weight cutoff of 8000-14000 g / mol and dialyzed with deionized water. The deionized water was replaced every 12 hours for 7 consecutive days. After the dialysis was completed, the polymerizable dextran was obtained by freeze drying.

[0080] (3) At room temperature, 24 g of the polymerizable polycaprolactone-poly-L-lactic acid copolymer obtained in step (1) and 4 g of the polymerizable dextran obtained in step (2) were weighed and dissolved with 480 mg of ammonium persulfate in 30 mL of deionized water, forming a dispersed phase solution A. At the same time, 70 mL of n-pentane was measured and 1 g of lauryl alcohol polyoxyethylene ether was added, and mixed evenly to obtain a continuous phase solution B. Then, at room temperature, the dispersed phase solution A was added dropwise to the continuous phase solution B, and nitrogen was continuously mechanically stirred for 0.5 h at a speed of 300 rpm until the emulsification was stable, and then 120 mg of tetramethylethylenediamine was added and the reaction continued for 3 h. After the reaction was completed, air was introduced to terminate the polymerization reaction, and the reaction was allowed to stand for a long time to separate. Subsequently, the upper liquid phase was removed, and the lower liquid phase was filtered to obtain a filter cake. The obtained filter cake was dispersed and washed with ethanol and then filtered again, and the obtained filter cake was redispersed in deionized water. The obtained dispersion was transferred to a regenerated cellulose dialysis bag with a molecular weight cut-off of 8000-14000 g / mol, and dialyzed with deionized water for 7 days, with the water replaced every 12 hours. After the dialysis was completed, the dispersion was freeze-dried to obtain poly-L-lactic acid-dextran interpenetrating network microspheres.

[0081] (4) Weigh 10 g of the polymerizable dextran obtained in step (2) and 3 g of the dextran-polycaprolactone-poly(L-lactic acid) ternary interpenetrating network microspheres obtained in step (3) respectively, dissolve them in deionized water, pass N2 at room temperature for 30 min, add 100 mg of ammonium persulfate and 25 mg of tetramethylethylenediamine, and stir them thoroughly. After reacting for 3 h, transfer the obtained product to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000-14000 g / mol and dialyze it with deionized water for 7 days, during which the deionized water is replaced every 12 h. After the dialysis is completed, store it at low temperature to obtain an injectable dextran / polycaprolactone / poly(L-lactic acid) ternary interpenetrating network microsphere composite dextran hydrogel.

[0082] Example 6

[0083] (1) At room temperature, weigh 10 g of caprolactone and dissolve it in 100 mL of dimethyl sulfoxide, stir it thoroughly, and pass nitrogen for 30 minutes. Then, add 5 g of L-lactide, 0.3 g of stannous octoate and reaction aid A, 0.1 g of propylene alcohol, and 0.1 g of hydroxyethyl methacrylate to the solution respectively. The reaction system is placed at 85°C for 12 hours. After the reaction is completed, the mixture is transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000-14000 g / mol. First, dialyze with dimethyl sulfoxide, replace the dialysis solution every 24 hours, and dialyze continuously for 7 days. Subsequently, dialyze with deionized water, replace the dialysis solution every 12 hours, and dialyze continuously for 7 days. After the dialysis is completed, freeze-drying is performed to obtain a polymerizable dextran-polycaprolactone-poly-L-lactic acid copolymer.

[0084] (2) At room temperature, weigh 10 g of dextran with a molecular weight of 150,000 g / mol and dissolve it in 100 g of dimethyl sulfoxide, stirring it thoroughly, and then introduce nitrogen for 30 minutes. Then, add 0.5 g of dimethylaminopyridine and Modifier B 1 g of methacrylic anhydride was added and reacted at room temperature for 48 hours. After the reaction, the reaction product was transferred to a dialysis bag of regenerated cellulose with a molecular weight cutoff of 8000-14000 g / mol and dialyzed with deionized water. The deionized water was replaced every 12 hours for 7 consecutive days. After the dialysis was completed, the polymerizable dextran was obtained by freeze drying.

[0085] (3) At room temperature, 10 g of the polymerizable polycaprolactone-poly-L-lactic acid copolymer obtained in step (1) and 5 g of the polymerizable dextran obtained in step (2) were weighed and dissolved with 200 mg of ammonium persulfate in 30 mL of deionized water, forming a dispersed phase solution A. At the same time, 35 mL of cyclohexane and 35 mL of n-pentane were measured and 1.4 g of Span 80 was added and mixed evenly to obtain a continuous phase solution B. Then, at room temperature, the dispersed phase solution A was added dropwise to the continuous phase solution B, and nitrogen was continuously mechanically stirred for 0.5 h at a speed of 300 rpm until the emulsification was stable, and then 50 mg of tetramethylethylenediamine was added and the reaction continued for 3 h. After the reaction was completed, air was introduced to terminate the polymerization reaction, and the mixture was allowed to stand for sufficient stratification. Subsequently, the upper liquid phase was removed, and the lower liquid phase was filtered to obtain a filter cake. The obtained filter cake was dispersed and fully washed with ethanol and then filtered again, and the obtained filter cake was redispersed in deionized water. The obtained dispersion was transferred to a regenerated cellulose dialysis bag with a molecular weight cut-off of 8000-14000 g / mol, and dialyzed with deionized water for 7 days, with the water replaced every 12 hours. After the dialysis was completed, the dispersion was freeze-dried to obtain poly-L-lactic acid-dextran interpenetrating network microspheres.

[0086] (4) Weigh 10 g of the polymerizable dextran obtained in step (2) and 3 g of the dextran-polycaprolactone-poly(L-lactic acid) ternary interpenetrating network microspheres obtained in step (3) respectively, dissolve them in deionized water, pass N2 at room temperature for 30 min, add 100 mg of ammonium persulfate and 25 mg of tetramethylethylenediamine, and stir them thoroughly. After reacting for 3 h, transfer the obtained product to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000-14000 g / mol and dialyze it with deionized water for 7 days, during which the deionized water is replaced every 12 h. After the dialysis is completed, store it at low temperature to obtain an injectable dextran / polycaprolactone / poly(L-lactic acid) ternary interpenetrating network microsphere composite dextran hydrogel.

[0087] Table 1 Examples 1 to 6 Step 1) Step 1) Formula selection of reaction aid A and modifier B

[0088]

[0089] Table 2 Test results of products prepared in Examples 1 to 6:

[0090]

[0091] Among them, in Table 2:

[0092] Test Item 4 is specifically: Transmittance of injectable dextran-polycaprolactone-poly-L-lactic acid ternary interpenetrating network microspheres composite dextran hydrogel filler (%)

[0093] Test Item 5 is as follows: Dynamic viscosity of injectable dextran-polycaprolactone-poly-L-lactic acid ternary interpenetrating network microspheres composite dextran hydrogel filler (mPa s)

[0094] Test Item 6 is specifically: Elastic modulus (Pa) of injectable dextran-polycaprolactone-poly-L-lactic acid ternary interpenetrating network microspheres composite dextran hydrogel filler

[0095] Test Item 7 is specifically: Degradation time of injectable dextran-polycaprolactone-poly-L-lactic acid ternary interpenetrating network microspheres composite dextran hydrogel filler (days)

[0096] It can be seen from the above examples 1-6 that the degradation time of examples 1-6 ranges from 25 to 200 days; and the elastic modulus ranges from 107 to 893 Pa. This product can effectively regulate the degradation time and elastic modulus of the product by adjusting the ratio of lactide, dextran, and L-lactide, thereby meeting the filling requirements of different parts. From the electron microscope picture, this product has a spherical structure, uniform size distribution, and controllable particle size.

[0097] The amount and activity of auxiliary agent A will affect the molecular weight and cross-linking ability of the polymerizable polycaprolactone-L-lactide copolymer; the type and amount of auxiliary agent B will affect the cross-linking ability of the polymerizable dextran. The combined effect of the above two will result in different degradation time, dynamic viscosity, and elastic modulus of the product. Example 4 has the longest degradation time, so that this product has a long-lasting and stable filling effect, but its dynamic viscosity is large, which will make the sample difficult to be squeezed out; Example 1, Example 2, and Example 5 have a smaller dynamic viscosity, but a short degradation time, and cannot play a long-term filling role; Example 3 has a lower dynamic viscosity, a longer degradation time, and a moderate elastic modulus, and is the best formula choice for this product.

[0098] In the present invention, the ring-opening polymerization of caprolactone and L-lactide is synergistically initiated by a special reaction auxiliary agent with a double bond at the terminal group, and a double bond compound with an active functional group is added at the same time, and a polymerizable polycaprolactone-poly L-lactic acid copolymer and a polymerizable dextran are prepared respectively by a one-step method. The copolymer has excellent hydrophilicity and biocompatibility. Since it has its own double bonds, the polydextran-polycaprolactone-poly L-lactic acid ternary interpenetrating network microspheres can be prepared without adding a crosslinking agent in the subsequent inverse emulsion polymerization. Finally, the microspheres are blended with the polymerizable dextran, and the microspheres are fixed by the bulk gel formed by the polymerizable dextran.

[0099] The preparation method of the injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microsphere composite dextran hydrogel filler disclosed in the present invention is simple and efficient. The obtained injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microsphere composite dextran hydrogel filler has excellent biocompatibility and degradability, and can effectively reduce the risk of nodules and granulomas.

[0100] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent changes made using the present invention are within the patent protection scope of the present invention.

Claims

1. A method for preparing an injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microsphere composite dextran hydrogel filler, It is characterized in that The method comprises the following preparation steps: S1 Synthesis of polymerizable polycaprolactone-poly(L-lactic acid) copolymer; S2 Preparation of polymerizable dextran; Preparation of S3 dextran-polycaprolactone-poly(L-lactic acid) interpenetrating network microspheres; Preparation of injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microspheres composite dextran hydrogel; The detailed steps of S1, S2, S3, and S4 are as follows: S1 Synthesis of polymerizable polycaprolactone-poly(L-lactic acid) copolymer; At room temperature, caprolactone was dissolved in dimethyl sulfoxide at a solid-liquid ratio of 1 g:10 mL by stirring, and nitrogen was introduced for 30 minutes. Then, an appropriate amount of L-lactide was gradually injected into the solution, and stannous octoate and reaction aid A were added; The reaction system was placed at 85°C for 12 hours. After the reaction was completed, the mixture was transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000 to 14000 g / mol; First, dialysis was performed using dimethyl sulfoxide, with the dialysate replaced every 24 hours for 7 consecutive days. Subsequently, dialysis was performed using deionized water, with the dialysate replaced every 12 hours for 7 consecutive days. After dialysis, freeze drying was performed to obtain a polymerizable polycaprolactone-poly-L-lactic acid copolymer; Wherein, the added amount of stannous octoate is 3% of the mass of caprolactone; Preparation of S2 polymerizable dextran At room temperature, dextran was dissolved in dimethyl sulfoxide at a solid-liquid ratio of 1 g:10 mL with stirring and nitrogen flow for 30 minutes; Subsequently, appropriate amounts of dimethylaminopyridine and modifier B were added to the reaction system and reacted at room temperature for 48 h; After the reaction is completed, the reaction product is transferred to a dialysis bag of regenerated cellulose with a molecular weight cutoff of 8000 to 14000 g / mol, and dialyzed with deionized water. The deionized water is replaced every 12 hours for 7 consecutive days. After dialysis is completed, the polymerizable dextran can be obtained by freeze drying; Preparation of S3 dextran-polycaprolactone-poly(L-lactic acid) ternary interpenetrating network microspheres The polymerizable polycaprolactone-poly(L-lactic acid) copolymer obtained in step (1) and the polymerizable dextran obtained in step (2) are mixed and dissolved in a certain amount of deionized water at room temperature with a proper amount of ammonium persulfate in a certain proportion, and stirred sufficiently to form a dispersed phase solution A; at the same time, a proper amount of emulsifier is added to the oil phase, and mixed uniformly to obtain a continuous phase solution B; Next, at room temperature, dispersed phase solution A was added dropwise into continuous phase solution B, and nitrogen was passed through and stirred continuously for 0.5 h until the emulsification was stable, and then a certain amount of tetramethylethylenediamine was added, and the reaction was continued for 3 h. After the reaction was completed, air was passed through to terminate the polymerization reaction, and the solution was allowed to stand for sufficient stratification; Subsequently, the upper liquid phase is removed, and the lower liquid phase is filtered to obtain a filter cake, the obtained filter cake is dispersed with ethanol and fully washed, and then filtered again, and the obtained filter cake is redispersed in deionized water, and the obtained dispersion is transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000-14000 g / mol, and dialyzed with deionized water for 7 days, and the water is replaced every 12 hours. After the dialysis is completed, freeze-drying is performed to obtain poly (L-lactic acid-dextran) interpenetrating network microspheres, wherein the amounts of ammonium persulfate and tetramethylethylenediamine are 2% and 0.5% of the mass of the polymerizable polycaprolactone-poly (L-lactic acid) copolymer, respectively; Preparation of S4 injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microspheres composite dextran hydrogel The polymerizable dextran obtained in step (2) and the dextran-polycaprolactone-poly-L-lactic acid ternary interpenetrating network microspheres obtained in step (3) are dissolved in deionized water, N2 is passed through at room temperature for 30 min, and a certain amount of ammonium persulfate and tetramethylethylenediamine are added, and the mixture is stirred thoroughly; After 3 h of reaction, the obtained product was transferred to a regenerated cellulose dialysis bag with a molecular weight cutoff of 8000 to 14000 g / mol and dialyzed with deionized water for 7 days, during which the deionized water was replaced every 12 h; After the dialysis is completed, the injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microsphere composite dextran hydrogel is obtained by storing at low temperature; The dosage of ammonium persulfate and tetramethylethylenediamine is 1% and 0.25% of the mass of polymerizable dextran, respectively; The reaction aid A in S1 is any one or more of acryl alcohol, N-hydroxyethyl acrylamide, hydroxyethyl methacrylate, and hydroxypropyl methacrylate, and the amount of the reaction aid A added is 5% to 15% of the mass of caprolactone. In the step (2), the modifier B is any one or more of glycidyl methacrylate, methacryloyl chloride, and acryloyl chloride, and the added amount of the modifier B is 5% to 15% of the mass of the dextran.

2. The method for preparing the injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microsphere composite dextran hydrogel filler according to claim 1, It is characterized in that The mass ratio of L-lactide to caprolactone in S1 is 1:1 to 1:

15.

3. The method for preparing the injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microsphere composite dextran hydrogel filler according to claim 1, It is characterized in that The mass ratio of the polymerizable dextran to the polymerizable polycaprolactone-poly-L-lactic acid copolymer in S3 is 1:1 to 1:20; In the step (3), the volume ratio of the dispersed phase solution to the continuous phase solution is 3:7, and the mass concentration of the polymerizable polycaprolactone-poly (L-lactic acid) copolymer in the dispersed phase solution is 5% to 30%.

4. The method for preparing the injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microsphere composite dextran hydrogel filler according to claim 1, It is characterized in that The oil phase in S3 is one or more of n-hexane, cyclohexane, dichloromethane, n-pentane, and white oil; The emulsifier in S3 is one or more of Span 80, sodium oleate, lauryl alcohol polyoxyethylene ether, lecithin, polyoxyethylene castor oil; the amount of the emulsifier is 0.5% to 5% of the oil phase.

5. The method for preparing the injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microsphere composite dextran hydrogel filler according to claim 1, It is characterized in that The stirring method in S3 is mechanical stirring, and the stirring speed is 300 rpm.

6. The method for preparing the injectable dextran / polycaprolactone / poly-L-lactic acid ternary interpenetrating network microsphere composite dextran hydrogel filler according to claim 1, It is characterized in that The mass concentration of the dextran-polycaprolactone-poly-L-lactic acid ternary interpenetrating network microspheres in S4 is 3% to 10%, and the mass concentration of the polymerizable dextran is 10% to 20%.

Images