KR101656066B1 - Biodegradable and elastic stent having various bioactive groups for drug delivery - Google Patents

Abstract

The present invention relates to a cardiovascular implant for drug delivery using a polyester block copolymer capable of regulating the introduction of various bioactive functional groups and having elasticity and having an adjustable biodegradation period. The polyester block copolymer according to the present invention is not only suitable for a living body but also has elasticity and its biodegradation half-life is controlled. Therefore, when applied to a body, the body's protein is adsorbed on the block copolymer surface and local accumulation It is possible to solve the problems such as side effects and thrombus formation.

Description

[0001] The present invention relates to a biodegradable and elastic stent having various bioactive groups for drug delivery with biodegradability and elasticity,

The present invention relates to a polyester block copolymer capable of regulating introduction of various bioactive functional groups with biodegradability and elasticity, and a cardiovascular graft for drug delivery using the same. More specifically, the present invention relates to a lactide, a caprolactone, And a polyester block copolymer comprising caprolactone having various functional groups.

In the early 1990s, a metal stent was inserted into a stenotic lesion of the coronary artery to expand the coronary artery by expanding the balloon by inserting a stent into the balloon and by inserting a wire net into the coronary artery wall. The incidence of restenosis was lower than that of balloon dilatation and the stent was used as a support for the inner wall of the vessel to prevent the contraction of the coronary artery and to reduce the restenosis rate to 20 ~ 30%. Stent implantation reduces the acute recoil and stenosis of the coronary artery, which was a fatal disadvantage of balloon dilatation. However, mechanical vascular injury occurs in the dilation process and neointimal formation occurs, resulting in stent restenosis. Many studies have been conducted to prevent stent restenosis and it has been reported that psilylimus, which was developed as an immunosuppressant, and paclitaxel, which is an anticancer agent, effectively inhibited neointimal formation. However, the problem is that systemic administration of these drugs can lead to serious adverse effects because the drug concentration is not maintained locally in the stent. In order to overcome these problems, studies have been carried out on the surface of the stent to release the drug locally. As a result of these research and development, drug-eluting stent was born, but also problems such as mechanical property of drug delivery, drug release control, maintenance of appropriate drug concentration, drug-induced cytotoxicity, and the incidence of thrombosis were raised.

In recent years, in order to overcome the problems of metals, many studies have been actively conducted on aliphatic polyesters having biodegradability due to their physical properties and hydrolytic properties, and they have been widely used for biocompatibility with substances approved by institutions such as the US FDA Studies are limited to known materials. Typically, there are Igaki-Tamai stents made of polylactide (PLA) and REVA biodegradable stents made of polycarbonate (PC) with Abbott's BVS everolimus-eluting stent. However, there is no structurally functional group in the above polyester, and the research is limited and has its limitations. In order to introduce a functional group into such a polyester, a process such as electric discharge, plasma treatment, or chemical treatment is required for the self or manufactured implant structure. However, since the basic structure of the structure is cut off, There is a difficulty in following.

The present inventors have made efforts to overcome the problems of the prior art as described above. As a result, they have found that by controlling the ratio of polyester block copolymer and molecular weight and introducing various bioactive functional groups, it is possible to control mechanical properties and biodegradation period, And the present invention has been completed.

Accordingly, the present invention is to provide a polyester block copolymer having a variety of bioactive functional groups and capable of controlling mechanical properties and biodegradation period, and a method for producing the same.

The present invention also provides a cardiovascular graft for drug delivery comprising the polyester block copolymer.

In order to solve the above problems, the present invention provides a polyester block copolymer having various functional groups introduced into a side chain or terminal and capable of controlling mechanical properties and biodegradation period, and a cardiovascular transplant recipient using the same.

As one aspect of the present invention, there is provided a thermoplastic resin composition comprising lactide (LA), caprolactone (CL), lactide (fLA) having a functional group and caprolactone (fCL) There is provided a cardiovascular implant comprising a polyester block copolymer having an adjustable biodegradation period:

[Chemical Formula 1]

In Formula 1, R is a methyl group, a benzyl ether group, a hydroxyl group, a carboxyl group, an amine group or a peptide; a, b, c and d are molar ratios of monomers, a = 0 to 99.9, b = 0.1 to 100, c = 0 to 50 and d = 0 to 50.

The main chain in the formula (1) is composed of a, and the ratio b is controlled according to the amount of the functional group introduced, and c and d are introduced in appropriate proportions according to the biodegradable property control.

And the molecular weight of the polyester block copolymer is 1,000 to 2,000,000 g / mole.

In another aspect of the present invention, the polyester block copolymer is characterized in that the functional group has a protein adsorption inhibitor or an anti-thrombogenic group.

In another aspect of the present invention, there is provided a method of preparing a cardiovascular implant comprising a polyester block copolymer, comprising the steps of:

(a) treating a mixture of toluene with an alcohol initiator selected from the group consisting of methanol, ethanol, ethylene glycol, propylene glycol, carbitol and polyethylene glycol with azeotropic distillation at 140 ° C for 3 hours to remove the toluene Obtaining an alcohol initiator;

(b) adding lactide (LA), caprolactone (CL), lactide (fLA) having a functional group and caprolactone (fCL) having a functional group to the dried initiator and conducting polymerization; And

(C) introducing a protein adsorption inhibitor or antithrombogenic agent into a part or all of the functional groups.

[Reaction Scheme 1]

In Formula 1, R is a methyl group, a benzyl ether group, a hydroxyl group, a carboxyl group, an amine group or a peptide; a, b, c and d are molar ratios of monomers, a = 0 to 99.9, b = 0.1 to 100, c = 0 to 50 and d = 0 to 50.

The main chain in the formula (1) is composed of a, and the ratio b is controlled according to the amount of the functional group introduced, and c and d are introduced in appropriate proportions according to the biodegradable property control.

In another embodiment of the present invention, the cardiovascular transplant is characterized by comprising a drug.

The polyester block copolymer of the present invention is not only suitable for a living body but also can be controlled in mechanical properties by introducing various bioactive functional groups and its biodegradation half life is controlled so that the protein in the body is adsorbed on the block copolymer surface And side effects caused by local accumulation of hydrolysis products in the body. In addition, it can contain drugs, and it is possible to release pharmacological drugs by controlling the duration of biodegradation, and it is not necessary to undergo biodegradation after a certain period of time after the procedure, Biologically active therapeutic substances, including inhibitory drugs, can be slowly released from the body for long-term delivery. In addition, since it exhibits elasticity in a specific ratio range, it is possible to maintain the physical properties at the time of stent expansion and also to reduce the thrombosis caused by the toxicity of the drug by introducing an antithrombotic agent into the functional group as a bioactive substance. Accordingly, the polyester block copolymer according to the present invention can be effectively used as a biocompatible biodegradable material for a medical material such as a cardiovascular implant material for drug delivery.

1 to 5 are ¹ H-NMR spectra of Examples 1 to 5 prepared by the present invention.
FIG. 6 is a graph showing thermal characteristics of the Example 2 and the Comparative Examples 1 to 4 produced by the present invention through a differential scanning calorimeter. FIG.
7 is a graph showing the measurement of the elastic force through the tensile strength tester of Example 2 produced by the present invention.
FIG. 8 is a photograph showing the elastic recovery force of a film of Example 2 produced by the present invention after filming. FIG.
FIG. 9 is a graph showing a GPC graph (in vitro) of biodegradation behavior of (a) Example 2 produced by the present invention and (b) a biodegradation half-life graph.
10 is a graph showing the results of measurement of pH change due to decomposition of Example 2 produced by the present invention with PLGA having FDA approval similar in biodegradation period.
Fig. 11 is a graph showing a GPC graph (in vivo) and (b) a biodegradation half-life graph of the biodegradation behavior of (a) Example 2 produced by the present invention.
FIG. 12 is a photograph showing the H & E staining of the graft prepared according to the present invention after being inserted into the rat subcutaneously.
FIG. 13 is a photograph showing an ED1 immunofluorescent staining of an implant prepared according to the present invention after being inserted into a rat subcutaneously. FIG.
14 is a graph showing the in vitro drug release behavior of a cardiovascular graft containing the drug of Example 2 and Comparative Examples 2 and 3 prepared by the present invention.
FIG. 15 is a photograph of the drug release behavior of drug-containing cardiovascular implants of Example 2 and Comparative Examples 2 and 3 prepared by the present invention through SEM. FIG.
16 is a graph showing the inhibition of the formation of neointima of Example 2 produced by the present invention and the film containing the drug through the activity of VSMCs cells.
17 is a photograph showing the degree of adhesion of anti-platelet on the copolymer film produced by Example 5 produced by the present invention.
18 is a diagram showing the overall schematic diagram of the present invention.

Hereinafter, the present invention will be described in more detail.

The biodegradable block copolymer of the present invention can appropriately control the decomposition period by controlling the molecular weight and the component ratio and can control the composition of the lactide and caprolactone in a specific ratio range, And the flexibility of the polycaprolactone are complemented with each other to produce a polymer having elasticity.

The polyester block copolymer constituting the cardiovascular implants of the present invention comprises lactide (LA), caprolactone (CL), lactide (fLA) having a functional group and caprolactone (fCL) segment having a functional group, 1.

[Chemical Formula 1]

In Formula 1, R is a methyl group, a benzyl ether group, a hydroxyl group, a carboxyl group, an amine group or a peptide; a, b, c and d are molar ratios of monomers, a = 0 to 99.9, b = 0.1 to 100, c = 0 to 50 and d = 0 to 50.

The main chain in the formula (1) is composed of a, and the ratio b is controlled according to the amount of the functional group introduced, and c and d are introduced in appropriate proportions according to the biodegradable property control.

The copolymer preferably has a molecular weight of 20,000 to 2,000,000 g / mole. If the molecular weight of the polyester is less than 20,000 g / mole, it is difficult to apply the biomaterial to the cardiovascular implants because of difficulty in maintaining the physical properties thereof. When the molecular weight exceeds 2,000,000 g / mole, the molecular weight becomes too large, And there is a large amount of lactide degradation products during the biodegradation, so that it is preferable to maintain the above range since it may damage the surrounding cells.

As the molecular weight of the polyester (F-PCLA) block copolymer increases, the biodegradation period increases. Therefore, the biodegradation period can be appropriately controlled according to the purpose of use. The biodegradation half-life period of the produced block copolymer is usually 1 to 6 months It is possible to control within. Further, since the biodegradation period and the mechanical properties can be controlled depending on the ratio of each segment used, a more detailed decomposition period and mechanical characteristics can be controlled through the combination thereof.

The protein adsorption inhibitor or antithrombotic agent to be introduced into the functional group of the present invention may include one or more selected from the group consisting of heparin, warfarin, aspirin, ticlopidine, floppy dog, dipyridamole, clostazol, can do.

In addition, the cardiovascular transplant according to the present invention may include a drug, and the drug may include a drug for cardiovascular diseases or a physiologically active substance. The drug or physiologically active substance for cardiovascular diseases includes at least one selected from the group consisting of actinomycin D, sialolimus, tacrolimus, everolimus, gutarolimus, paclitaxel, doxecell, dexamethasone and heparin can do.

The present invention also provides a method for preparing a cardiovascular implant comprising a polyester block copolymer comprising the steps of:

(a) treating a mixture of toluene with an alcohol initiator selected from the group consisting of methanol, ethanol, ethylene glycol, propylene glycol, carbitol and polyethylene glycol with azeotropic distillation at 140 ° C for 3 hours to remove the toluene Obtaining an alcohol initiator;

(b) adding lactide, caprolactone, lactide having a functional group and caprolactone having a functional group to the dried initiator and conducting polymerization; And

(C) introducing a protein adsorption inhibitor or an anti-thrombogenic agent into a part or all of the functional groups:

[Reaction Scheme 1]

In Formula 1, R is a methyl group, a benzyl ether group, a hydroxyl group, a carboxyl group, an amine group or a peptide; a, b, c and d are molar ratios of monomers, a = 0 to 99.9, b = 0.1 to 100, c = 0 to 50 and d = 0 to 50.

The process for producing the polyester block copolymer according to the present invention will be described in detail as follows.

In step (a), water, methanol, ethanol, ethylene glycol, propylene glycol, carbitol, polyethylene glycol and the like may be used as the step of drying the alcohol initiator. In the present invention, polyethylene glycol is preferable. Polyethylene glycol (PEG) is not toxic and has no immunological rejection reaction and is suitable for use in living bodies. In addition, it has an effect of inhibiting restenosis when it is used as a biotransplantable material because it has a protein adsorption inhibiting effect. In addition, since the mechanical properties of polyethylene glycol vary depending on the degree of polymerization, the mechanical properties can be controlled by using the same.

When polyethylene glycol is used as the alcohol initiator, the molecular weight of the polyethylene glycol is not limited, but it is preferably from 32 to 5,000 g / mole in terms of mechanical properties such as flexibility and elasticity, more preferably from 134 to 2,000 g / mole, most preferably 750 g / mole.

The step (b) is a step of ring-opening polymerization of an initiator, lactide, caprolactone, lactide having a functional group and caprolactone having a functional group together to prepare a copolymer. The ester monomer and toluene, which is a reaction solvent, Polymerization is carried out using Sn (Oct) ₂ as an activating agent. At this time, the polymerization reaction is carried out at 50 to 160, preferably 130 to 160 for about 12 to 48 hours, preferably about 20 to 28 hours.

 The polyester block copolymer according to the present invention is not only suitable for a living body but also can be controlled in mechanical properties by introducing various bioactive groups so that a copolymer having elasticity can be produced and a biodegradable half- Adsorption to the surface of the block copolymer and side effects due to local accumulation of hydrolysis products in the body can be solved.

In addition, the cardiovascular transplant of the present invention may contain a drug to control the release rate of the contained drug, and further, the degree of drug release can be controlled stepwise. Thus, the polyester block copolymers according to the present invention can be used as effective cardiovascular implants for drug delivery.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined by the appended claims. It will be obvious to you.

Preparation of methoxypolyethylene glycol- (polycaprolactone-co-poly F caprolactone-co-polylactide-co-poly F lactide) block copolymer

Preparation of block copolymer of methoxypolyethylene glycol- (polycaprolactone-co-poly F caprolactone-co-polylactide-co-poly F lactide) having a molecular weight of 50,000 g / mole [MPEG- (PCL- PfCL-co-PLLA-co-PLfLA) (caprolactone: F caprolactone: lactide: F lactide = 45: 45: 5: 5)

The initiator methoxypolyethylene glycol (0.6 g, 0.08 mmol) and 70 ml toluene were placed in a well-dried 100 ml round bottom flask and azeotropically distilled at 140 using a Deanstock trap for 3 hours. After distillation, 30 ml of toluene was removed and the prepolymerized caprolactone (CL) (1.47 g, 12.8 mmol), F caprolactone (fCL) (0.315 g, 1.43 mmol) and methoxypolyethylene glycol (MPEG) lactide (LA) (1.85g, 12.8mmol) and lactide F (fLA) (0.357g, 1.43mmol) to put into a pre-purified toluene as a reaction solvent and then 40ml, Sn (Oct) ₂ as a polymerization catalyst, 0.96 ml and stirred at 130 for 24 hours. All procedures were carried out under high purity nitrogen. After the reaction, the reactants were slowly added dropwise to 1,600 ml of hexane and 400 ml of ether to remove unreacted monomers and initiator. The precipitate was dissolved in methylene chloride (MC), filtered with filter paper, the solvent was removed through a rotary evaporator, and dried under reduced pressure to obtain the title copolymer. The molecular weight with respect to the molar ratio of the constituent components of the prepared copolymer was measured by ¹ H-NMR, and the measurement results are shown in FIG.

As shown in Fig. 1, the molecular weight of the prepared copolymer was 521.00 g / mole, which is similar to the theoretical predicted value. The polydispersity was found to be 1.3 by gel permeation chromatography (GPC) It was confirmed that it had a dispersion degree.

(PCL-co-PfCL-co-PLLA-co-PLfLA)] methoxypolyethylene glycol- (polycaprolactone-co-poly F caprolactone-co-polylactide-co-poly F lactide) Introduction of hydroxyl group into the side chain of the copolymer

2 g of the block copolymer of Example 1-1 and 1000 mg of palladium carbon (Pd / C) were placed in anhydrous tetrahydrofuran (THF) 200 and hydrogen bubbles were added using a syringe needle. The mixture was stirred for 16 hours at room temperature . After the reaction, the reaction mixture was filtered using celite, the solvent was removed using a rotary evaporator, and the filtrate was dried under reduced pressure to obtain the title copolymer. ¹ H-NMR was used to determine whether hydroxyl groups of the prepared copolymer were introduced, and the results are shown in FIG.

As shown in FIG. 2, the prepared copolymer showed no specific peak of the benzyl group at 7.3 ppm and confirmed that the hydroxyl group was introduced into the side chain.

Methoxypolyethylene glycol - ( Polycaprolactone - co - Poly F Caprolactone - co - Polylactide - co - Poly F Lactide ) [ MPEG - ( PCL - co - PfCL - co - PLLA - co - PLFLA )] Block copolymer On the side of the chain Carboxyl group  Introduction

2 g of the block copolymer of Example 2 and toluene 160 were placed in a well-dried 200-round bottom flask and azeotropically distilled at 140 using a Dean Stark trap for 3 hours. After distillation, all of 60 toluene was removed and the mixture was cooled to room temperature. 1.04 g of glutaric acid hydride (GA) was added thereto, and acetic acid (1.2 g) as a polymerization catalyst was reacted at 110 for 24 hours. All procedures were carried out under high purity nitrogen. After the reaction, the reaction was precipitated by slowly dropping the reaction into 800 hexanes and 200 ethers to remove unreacted monomer or initiator. The precipitate was dissolved in methylene chloride (MC), filtered with filter paper, the solvent was removed through a rotary evaporator, and dried under reduced pressure to obtain the title copolymer. In order to confirm whether or not the carboxyl group of the prepared copolymer was introduced, it was measured using ¹ H-NMR, and the measurement result is shown in FIG.

As shown in Fig. 3, it was confirmed that a carboxyl group was introduced into the side chain of the produced copolymer.

(PCL-co-PfCL-co-PLLA-co-PLfLA)] methoxypolyethylene glycol- (polycaprolactone-co-poly F caprolactone-co-polylactide-co-poly F lactide) Introduction of amine groups of the copolymer

2 g of the block copolymer from Example 3 and toluene 160 were placed in a well-dried 200-round bottom flask and azeotropic distillation was carried out at 140 for 3 hours using a Dean Stark trap. After distillation, all of 60 toluene was removed and the mixture was cooled to room temperature. After adding 1.04 g of 2-methyl aziridine, acetic acid (1.2 g) was added as a polymerization catalyst and reacted at 50 to 24 hours. All procedures were carried out under high purity nitrogen. After the reaction, the reaction was precipitated by slowly dropping the reaction in 700 hexane and 300 ether to remove unreacted monomers and initiator. The precipitate was dissolved in methylene chloride (MC), filtered with filter paper, the solvent was removed through a rotary evaporator, and dried under reduced pressure to obtain the title copolymer. The ¹ H-NMR was used to confirm whether or not an imine group was introduced into the prepared copolymer. The measurement results are shown in FIG.

As shown in Fig. 4, it was confirmed that an amine device was introduced into the side chain of the produced copolymer.

(PCL-co-PfCL-co-PLLA-co-PLfLA)] methoxypolyethylene glycol- (polycaprolactone-co-poly F caprolactone-co-polylactide-co-poly F lactide) Introduction of heparin to the side chain of the copolymer

To 1 g of heparin sodium, 1 g of NHS (N-Hydroxysuccinimide), 1.8 g of DCC (N, N'-Dicyclohexylcarbodiimide) and 0.007 g of DMAP (4-Dimethylaminopyridine) were dissolved in dimethylformamide (DMF) 20 and reacted at room temperature for 24 hours. All procedures were carried out under high purity nitrogen. After completion of the reaction, the reaction mixture was filtered to remove unreacted NHS and DCC, and 4 g of the copolymer of Example 4 was dissolved in DMF 10 and dropped therein. The reaction mixture was reacted at room temperature for 24 hours. After completion of the reaction, the polymer was precipitated at 500 DW and then precipitated in 500 ether to obtain a copolymer. The ¹ H-NMR was used to confirm whether or not the prepared copolymer was introduced with heparin. The measurement result is shown in FIG.

As shown in Fig. 5, it was confirmed that a heparin group was introduced into the side chain of the produced copolymer.

[Comparative Example 1]

Preparation of a methoxypolyethylene glycol (MPEG) - (polylactide-co-poly F lactide) block copolymer having a molecular weight of 50,000 g / mole [lactide: F lactide = 95: 5]

Methoxypolyethylene glycol (MPEG) as an initiator and 70 ml of toluene were placed in a well dried 100 ml round bottom flask and azeotropically distilled at 140 for 3 hours using a Dean Stark trap. After distillation, 40 ml of toluene was removed, and pre-purified lactide (LA) (4 g, 27.75 mmol) and F lactide (fLA) (0.357 g, 1.43 mmol) were added after cooling methoxypolyethylene glycol 30 ml of preliminarily purified toluene was added as a reaction solvent, and Sn (Oct) ₂ was added as a polymerization catalyst, followed by stirring at 130 for 24 hours. All procedures were carried out under high purity nitrogen. After completion of the reaction, the reaction was precipitated by slowly dropping the reaction into 1,600 ml of hexane and 400 ml of ether to remove unreacted monomers and initiator. The precipitate was dissolved in methylene chloride (MC) and filtered through filter paper. The solvent was removed through a rotary evaporator and dried under reduced pressure to obtain the title copolymer.

[Comparative Example 2]

Preparation of block copolymer of methoxypolyethylene glycol (MPEG) - (polycaprolactone-co-poly F caprolactone-co-polylactide-co-poly F lactide) having a molecular weight of 50,000 g / mole [caprolactone: F caprolactone Lactone: Lactide: F lactide and lactide = 15: 5: 75: 5]

Methoxypolyethylene glycol (MPEG) as an initiator and 70 ml of toluene were placed in a well dried 100 ml round bottom flask and azeotropically distilled at 140 for 3 hours using a Dean Stark trap. After distillation, 40 ml of toluene was removed and the pre-purified caprolactone (CL) (0.66 g, 5.78 mmol), F caprolactone (fCL) (0.315 g, 1.43 mmol) L lactide (LA) (3.339 g, 23.17 mmol) and F lactide (fLA) (0.357 g, 1.43 mmol) were charged and 30 ml of preliminarily purified toluene was added as a reaction solvent. Then, Sn (Oct) ₂ And stirred at 130 for 24 hours. All procedures were carried out under high purity nitrogen. After completion of the reaction, the reaction was precipitated by slowly dropping the reaction into 1,600 ml of hexane and 400 ml of ether to remove unreacted monomers and initiator. The precipitate was dissolved in methylene chloride (MC) and filtered through filter paper. The solvent was removed through a rotary evaporator and dried under reduced pressure to obtain the title copolymer.

[Comparative Example 3]

Preparation of block copolymer of methoxypolyethylene glycol (MPEG) - (polycaprolactone-co-poly F caprolactone-co-polylactide-co-poly F lactide) having a molecular weight of 50,000 g / mole [caprolactone: F caprolactone Lactone: Lactide: F Lactide and Lactide = 75: 5: 15: 5]

Methoxypolyethylene glycol (MPEG) as an initiator and 70 ml of toluene were placed in a well dried 100 ml round bottom flask and azeotropically distilled at 140 for 3 hours using a Dean Stark trap. After distillation, 40 ml of toluene was removed and the prepolymerized caprolactone (CL) (3.03 g, 2.65 mmol), F caprolactone (fCL) (0.315 g, 1.43 mmol) and methoxypolyethylene glycol (MPEG) (0.97 g, 6.73 mmol) and Flactide (fLA) (0.357 g, 1.43 mmol) were placed in a flask, and 30 ml of preliminarily purified toluene was added as a reaction solvent. Then, Sn (Oct) ₂ And stirred at 130 for 24 hours. All procedures were carried out under high purity nitrogen. After completion of the reaction, the reaction was precipitated by slowly dropping the reaction into 1,600 ml of hexane and 400 ml of ether to remove unreacted monomers and initiator. The precipitate was dissolved in methylene chloride (MC) and filtered through filter paper. The solvent was removed through a rotary evaporator and dried under reduced pressure to obtain the title copolymer.

[Comparative Example 4]

Molecular weight 50,000 g / mole of Methoxypolyethylene glycol ( MPEG ) - ( Polycaprolactone - co - Poly F Caprolactone ) Preparation of block copolymer [ Caprolactone : F Caprolactone  = 95: 5]

Methoxypolyethylene glycol (MPEG) as an initiator and 70 ml of toluene were placed in a well dried 100 ml round bottom flask and azeotropically distilled at 140 for 3 hours using a Dean Stark trap. After distillation, all of the toluene was removed and the pre-purified caprolactone (CL) (4 g, 35.04 mmol) and F caprolactone (fCL) (0.315 g, 1.43 mmol) were added after methoxypolyethylene glycol (MPEG) 30 ml of preliminarily purified methylene chloride (MC) was added as a reaction solvent, and HCL was added as a polymerization catalyst, followed by stirring at room temperature for 24 hours. All procedures were carried out under high purity nitrogen. After completion of the reaction, the reaction was precipitated by slowly dropping the reaction into 2,000 ml of hexane to remove unreacted monomers and initiator. The precipitate was dissolved in methylene chloride (MC) and filtered through filter paper. The solvent was removed through a rotary evaporator and dried under reduced pressure to obtain the title copolymer.

The monomer molar ratios of Example 1 and Comparative Examples 1 to 4 are shown in Table 1 below.

[Table 1]

As shown in Table 1, the theoretical molecular weight of the prepared copolymer was similar to the measured molecular weight, and it was confirmed that the ratio of the monomer was not significantly different from the theoretical ratio.

Experimental Example 1. Determination of Thermal Properties of Drug Delivery Material by Monomer Ratio

6 mg of each of the copolymers of Example 2 and Comparative Examples 1 to 4 was prepared and the thermal properties of the copolymer were ascertained by raising the temperature to -50 to 200 ° C for 5 minutes using a differential scanning calorimeter (DSC) Is shown in Fig.

Experimental Example  2. Identification of mechanical properties of drug delivery materials

According to Example 2, a silicon mold having a thickness of 1 cm 5 cm and a thickness of 1 mm was filled with a certain pressure to prepare a tensile strength specimen. Tensile strength and elongation according to the molecular weight of the prepared specimen were measured by pulling the UTM (H5KT) at a rate of 3 mm / min. The measurement results are shown in FIG.

In addition, FIG. 8 shows a state in which the original image is restored while enlarging the image of Example 2, and the image is shown as a picture.

As shown in Figs. 6, 7 and 8, the present invention of Example 2 compared to Comparative Examples 1 to 4 has excellent mechanical properties of polylactide and flexibility of polycaprolactone. I have confirmed that I have.

Experimental Example 3: Biodegradation of drug delivery materials (in vitro)

In Example 2, the copolymer was dissolved in a weight: methylene chloride (MC) volume of 30:70. The polymer solution was spread widely using a 3 mm thick applicator, dried at low temperature for 2 days, dried at room temperature for 4 days, and cut into a square shape of 11 cm ² . The prepared film was placed in a 20 ml vial, and a phosphate buffered saline (PBS) of pH 7.4 was added thereto, and the mixture was rotated at 37 rpm at 100 rpm. The sample was lyophilized for a certain time up to 6 weeks while keeping the temperature constant, and the decrease in molecular weight was confirmed by GPC at each time, and the result is shown in FIG. FIG. 9A is a GPC graph (in vitro) of the biodegradation behavior of Example 2, and FIG. 9B is a biodegradation half-life graph of Example 2. FIG.

As shown in Fig. 9, it was confirmed that the half-life of the produced film was about 25 days.

EXPERIMENTAL EXAMPLE 3. Experimental Study on pH Change by Biodegradation of Drug Delivery Material

The FDA-approved PLGA film prepared by the same method as that of the film prepared in Experimental Example 3 was placed in a 20 ml vial and the plate was rotated at 100 rpm at 37 with phosphate buffered saline (PBS). The pH was measured at constant time intervals until 40 days while the temperature was kept constant. The results are shown in FIG.

As shown in FIG. 10, the carrier prepared in Example 2 was less biodegradable than PLGA-approved PLGA, confirming biocompatibility.

Experimental Example 4 Biodegradation according to the molecular weight and composition of the copolymer (in vivo)

The film prepared in Experimental Example 2 was sterilized with ethylene oxide gas, and inserted into a male rat eight-week-old model subcutaneously. At 1, 2, 4, and 6 weeks after lapse of 1 week, 2 weeks, 4 weeks, and 6 weeks, the formulations removed from the subcutaneous rats were lyophilized and the decrease in molecular weight at each time was confirmed by GPC. The results are shown in FIG. FIG. 11A is a GPC graph (in vitro) of the biodegradation behavior of Example 2, and FIG. 11B is a biodegradation half-life graph of Example 2. FIG.

As shown in Fig. 11, it was confirmed that the half-life time of the produced film was about 12 days.

Experimental Example 5. Histological Evaluation of Film Formulation

The film prepared in Experimental Example 2 was sterilized with ethylene oxide gas, and inserted into a male rat eight-week-old model subcutaneously. At 1, 2, 4, and 6 weeks after the injection, the formulation removed from the subcutaneous tissue of the rat was fixed to 10% formalin. The fixed formulation was made into a paraffin block and cut into 4 thicknesses. H & E and ED1 staining were performed. H & E staining is the most basic staining method, using hematoxylin which is specifically stained in the nucleus of cells and eosin which is stained by cytoplasm. It is a staining method which can confirm the nature of nucleus and cytoplasm. Cell morphology and morphology. The decomposition behavior of the hydrophobic part was confirmed by the above H & E staining. The results are shown in FIG.

Expression of ED1 (mouse anti rat CD68; Serotec, UK) was also confirmed to confirm the inflammatory response of the implanted formulation, and the results are shown in FIG.

As shown in FIG. 12 and FIG. 13, it was confirmed that the cardiovascular implants of the present invention had biocompatibility and almost no immune response.

Experimental Example 6. Evaluation of Drug Release of Drug-Containing Film (in vitro)

In Example 2 and Comparative Examples 2 and 3, paclitaxel was mixed as a physiologically active substance to prepare a film as in Experimental Example 2, and 3 mg of drug was loaded on the film. The prepared film was placed in a sample tube of 2.5 cm in diameter and 3.6 cm in height, placed in a 50 ml tube containing 10 ml of PBS, rotated at 37 rpm at 100 rpm, and the amount of drug released per hour was measured by HPLC. 13.

As shown in FIG. 14, it was confirmed that the drug release appeared to be in a sustained release form, and it was confirmed that drug release was the fastest when the ratio of caprolactone to lactide was similar to each other. Also, it was confirmed in FIG. 15 that the drug was observed out of the film by SEM observation.

Experimental Example  7. Measurement of cell activity of the drug-containing film in vitro )

The vascular smooth muscle cells (VSMCs), the main cause of neointimal formation, were cultured on a film, and the activity of the cells was measured with a CCK8 reagent The measurement results are shown in FIG.

As shown in FIG. 16, it was confirmed that VSMCs were inhibited from growing and mediating neointimal formation upon drug release.

Experimental Example  8. In functional groups  Of heparin-introduced films Anti-platelet  Attachment experiment in vitro )

Fresh blood was collected from a male 8-week-old model and 10% Na-citrate (3.2%) was added to prevent clotting. The collected blood was centrifuged at 1500 rpm for 10 minutes, and then the supernatant was collected and further centrifuged at 3000 rpm for 20 minutes to collect platelet rich plasma (PRP). 1 X 10 ⁶ platelets were treated on the film made in Example 5 and reacted in an incubator. Scanning electron microscopy was used to confirm the adhesion pattern with time, and the results are shown in Fig.

As shown in FIG. 17, it was observed that the cardiovascular transplantation film of the present invention had a smaller number of platelets adhered and fewer impurities adhering to plasma than the film without the basic functional group.

Claims (14)

(1), comprising a lactide (LA), a caprolactone (CL), a lactide (fLA) having a functional group and a caprolactone (fCL) A cardiovascular graft comprising a block copolymer.
[Chemical Formula 1]

In Formula 1, R is a methyl group, a benzyl ether group, a hydroxyl group, a carboxyl group, an amine group or a peptide; a, b, c and d are molar ratios of monomers, a = 0.1 to 43, b = 0.1 to 5, c = 0.1 to 47 and d = 0.1 to 5.
The cardiovascular graft according to claim 1, wherein the polyester block copolymer has a molecular weight of 1,000 to 2,000,000 g / mole.
The cardiovascular graft according to claim 1, wherein the biodegradation half-life of the polyester block copolymer is 1 week to 24 weeks.
The cardiovascular graft according to claim 1, wherein some or all of the functional groups are introduced with a protein adsorption inhibitor or an anti-thrombotic agent. 5. The cardiovascular transplantation drug according to claim 4, wherein the protein adsorption inhibitor or antithrombotic agent is at least one selected from the group consisting of heparin, warfarin, aspirin, ticlopidine, clopidogrel, dipyridamole, clostazol and trifurus.
The cardiovascular graft according to claim 1, further comprising a drug for cardiovascular diseases or a physiologically active substance.
The pharmaceutical composition according to claim 6, wherein the drug or physiologically active substance for cardiovascular disease is selected from the group consisting of actinomycin D, sialolimus, tacrolimus, everolimus, gutarolimus, paclitaxel, doxecell, dexamethasone and heparin Wherein the cardiovascular graft is one or more of the following.
(a) treating a mixture of toluene with an alcohol initiator selected from the group consisting of methanol, ethanol, ethylene glycol, propylene glycol, carbitol and polyethylene glycol with azeotropic distillation at 140 ° C for 3 hours to remove the toluene Obtaining an alcohol initiator;
(b) adding lactide (LA), caprolactone (CL), lactide (fLA) having a functional group and caprolactone (fCL) having a functional group to the dried initiator and conducting polymerization; And
(LA), caprolactone (CL), lactide (fLA) having a functional group represented by the following formula (1), which comprises introducing a protein adsorption inhibitor or an antithrombogenic group into a part or all of the functional groups (C) And a caprolactone (fCL) having a functional group.
[Chemical Formula 1]

In Formula 1, R is a methyl group, a benzyl ether group, a hydroxyl group, a carboxyl group, an amine group or a peptide; a, b, c and d are molar ratios of monomers, a = 0.1 to 43, b = 0.1 to 5, c = 0.1 to 47 and d = 0.1 to 5.
delete The process according to claim 8, wherein the polyethylene glycol has a molecular weight of 32 to 2,000 g / mole. The method according to claim 8, wherein the polymerization of step (b) is performed at a temperature of 50 to 160 ° C for 12 to 48 hours.
The pharmaceutical composition according to claim 6, wherein the drug or physiologically active substance for cardiovascular disease is selected from the group consisting of actinomycin D, sialolimus, tacrolimus, everolimus, gutarolimus, paclitaxel, doxecell, dexamethasone and heparin Or more.
9. The method according to claim 8, further comprising the step of loading a drug for cardiovascular disease or a physiologically active substance.
14. The method according to claim 13, wherein the drug or physiologically active substance for cardiovascular disease is selected from the group consisting of actinomycin D, sialolimus, tacrolimus, everolimus, gutarolimus, paclitaxel, doxecell, dexamethasone and heparin Or more.

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