JP2020056020A - Biodegradable copolymer showing antiplatelet adhesiveness - Google Patents

Abstract

To provide a biodegradable copolymer showing antiplatelet adhesiveness that is of an unconventional novel structure and has both biodegradable and antithrombotic properties, and has excellent morphological stability.MEANS: A biodegradable copolymer showing antiplatelet adhesiveness comprises an aliphatic polyester as a copolymer of a hydrophobic component and a hydrophilic component, the hydrophilic component comprising at least one of poly (1,5-dioxepane-2-one), poly (1,4-dioxane-2-one), or polyethylene oxide, and a molar ratio of the hydrophilic component being 5% or more and 85% or less.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a biodegradable copolymer exhibiting antiplatelet adhesion.

Japan is leading the world in research on antithrombotic materials (materials exhibiting antiplatelet adhesion), and MPC polymers (JP-A-2002-181946) that have already imitated biological membranes and poly (2-methoxyethyl acrylate) (PMEA) (Patent Document 2) has been put to practical use for some applications.
Recently, Tanaka, Fukushima et al. Of Yamagata University have reported a polymer having an aliphatic polycarbonate as a main chain and having a hydrophilic side chain (Patent Documents 3 and 4).

JP 2008-280398 A JP 2013-121430A JP-A-2017-203062 JP 2014-161675 A

However, the materials of References 1 and 2 are polymers having a carbon-carbon bond from a vinyl monomer as a main chain, and do not exhibit biodegradability. Therefore, there is a worldwide demand for the development of a biodegradable and antithrombotic material that does not require reoperation for removal in the future.
Further, although the polymers of Patent Documents 3 and 4 are materials having both biodegradability and antithrombotic properties, they are copolymers having a hydrophilic site in a side chain, which is different from the copolymer of the present disclosure. It is a polymer based on the concept.
Further, the materials disclosed in Documents 1 and 2 and Patent Documents 3 and 4 are all soft at room temperature and sticky when absorbing water, and have a problem in terms of shape stability.
As described above, an object of the present invention is to provide a biodegradable copolymer having both biodegradability and antithrombotic properties and having excellent shape stability and exhibiting antiplatelet adhesiveness of a novel structure which has not been seen before. And

The present inventors have obtained the following findings as a result of intensive studies.
(1) Aliphatic polyesters are known to exhibit biodegradability and bioabsorbability, but may be poly (1,5-dioxepan-2-one) (hereinafter sometimes referred to as PDXO) as a hydrophilic component. ), Poly (1,4-dioxan-2-one) (hereinafter sometimes referred to as PDO), or an aliphatic polyester copolymer containing at least one of polyethylene oxide (hereinafter sometimes referred to as PEO) However, they also show low platelet adhesion and are very promising as antithrombotic materials.
In addition, polylactic acid and polylactic acid-polyglycolic acid copolymer, which are the most common biodegradable polymers, do not show antiplatelet adhesion. Further, poly (1,5-dioxepan-2-one) is a hydrophilic aliphatic polyester, and its synthesis itself was reported in 1989, but no antiplatelet adhesion has been reported so far.
(2) Cell culture is possible on the aliphatic polyester copolymer containing the specific hydrophilic component. The copolymer is a material having biodegradability, antithrombotic properties, and cell adhesion.
(3) The copolymer is expected to be developed in various fields in the medical field, such as coating on an implantable material in a living body and application as a cell culture substrate in the field of regenerative medicine.
(4) The copolymer may be in any form of a random copolymer, a block copolymer, or a multi-block copolymer (random multi-block copolymer, alternating multi-block copolymer). In any case, they show antithrombotic properties.
(5) When the PDXO, PDO, or PEO component is introduced in a predetermined molar ratio in the copolymer, better antithrombotic properties are exhibited.
(6) The copolymer exhibits better antithrombotic properties when it has a microphase-separated structure.
(7) In the case where the copolymer is a block copolymer or a multi-block copolymer, when the PDXO segment, PDO segment, or PEO segment has a predetermined length, better antithrombotic properties can be obtained. Show.

  Based on the above findings, the present application, as a first mode, is an aliphatic polyester which is a copolymer of a hydrophobic component and a hydrophilic component, wherein the hydrophilic component is a polystyrene. (1,5-dioxepan-2-one), poly (1,4-dioxan-2-one) or polyethylene oxide, and the molar ratio of the hydrophilic component (constituting the copolymer) A biodegradable copolymer exhibiting antiplatelet adhesiveness, wherein the proportion of the monomer constituting the hydrophilic component in the entire monomer is 5% or more and 85% or less.

  In the first embodiment, the hydrophobic component is at least one of poly (L-lactic acid), poly (D-lactic acid), poly (D, L-lactic acid), and a polylactic acid-polyglycolic acid copolymer. It is preferable to include

  In the first embodiment, the bond between the hydrophilic component and the hydrophobic component is preferably one of random, block, and multi-block.

  In the first embodiment, the bonding mode of the hydrophilic component may be random or block, but when the bonding mode is block, the hydrophilic component preferably has a pentamer or longer segment length.

  In order to solve the above problems, the present application discloses, as a second embodiment, a thin film having antiplatelet adhesion and biodegradability, which is made of the copolymer of the first embodiment.

  In order to solve the above problems, the present application discloses, as a third embodiment, a molded product having antiplatelet adhesion and biodegradability, which is made of the copolymer of the first embodiment.

  The present application discloses, as a fourth mode, a medical device in which the thin film or the molded body according to the second or third mode is provided at a position where the thin film or the formed body comes into contact with a living tissue.

  The copolymers of the present disclosure exhibit biodegradability and antiplatelet adhesion. In addition, cell culture is possible on the copolymer of the present disclosure.

5 is a microscope observation image (dark field) of the material obtained in Example 1. 4 is a graph showing the platelet adhesion number of the material obtained in Example 1. 7 is a microscope observation image (dark field) of the material obtained in Example 2. 5 is a graph showing the platelet adhesion number of the material obtained in Example 2. 9 is a microscope observation image (dark field) of the material obtained in Example 3. 9 is a graph showing the platelet adhesion number of the material obtained in Example 3. 9 is a phase image of the material obtained in Example 3 by an atomic force microscope (AFM). 9 is a microscope observation image (dark field) of the material obtained in Example 4. 9 is a graph showing the platelet adhesion number of the material obtained in Example 4. 9 is a shape image and a phase image of the material obtained in Example 4 by an atomic force microscope (AFM). 13 is a microscope observation image (dark field) of the material obtained in Example 5. 14 is a graph showing the platelet adhesion number of the material obtained in Example 5. 14 is a microscope observation image (dark field) of the material obtained in Example 6. 11 is a graph showing the platelet adhesion number of the material obtained in Example 6. 9 is a graph showing the platelet adhesion number of the material obtained in Example 7. 14 is a graph showing the platelet adhesion number of the material obtained in Example 8. 19 is a microscope observation image (dark field) of the material obtained in Example 9. 14 is a graph showing the platelet adhesion number of the material obtained in Example 9. 17 is a microscope observation image (dark field) of the material obtained in Example 10. 14 is a graph showing the platelet adhesion number of the material obtained in Example 10. It is an image which shows a state of HeLa cell culture on the material obtained by Example 11 (cell culture test, Hela cells, PLGA-PDXO alternate MBC). It is a graph which shows the culture behavior of the HeLa cell by the cell count on the material obtained by Example 11 (cell culture test, Hela cell, PLGA-PDXO alternate MBC). It is a graph which shows the culture behavior of the HeLa cell by the WST test on the material obtained by Example 11 (cell culture test, Hela cell, PLGA-PDXO alternate MBC). It is an image which shows the mode of HUVEC cell culture on the material obtained by Example 11 (cell culture test, HUVEC cell, PLGA-PDXO alternate MBC). It is a graph which shows the culture behavior of the HUVEC cell by the cell count on the material obtained by Example 11 (cell culture test, HUVEC cell, PLGA-PDXO alternate MBC). It is a graph which shows the culture | cultivation behavior of the HUVEC cell by the WST test on the material obtained by Example 11 (cell culture test, HUVEC cell, PLGA-PDXO alternate MBC). It is an image which shows the state of HeLa cell culture on the material obtained by Example 11 (cell culture test, HeLa cell, PLGA-PDO alternating MBC). It is an image showing a state of HeLa cell culture on a material obtained in Example 11 (cell culture test, HeLa cells, PLGA-PDXO alternate MBC). It is a graph which shows the culture behavior of the HeLa cell by the cell count on the material obtained in Example 11 (cell culture test, HeLa cell, PLGA-PDXO alternating MBC, PLGA-PDO alternating MBC). It is a graph which shows the culture behavior of the HeLa cell by the WST test on the material obtained by Example 11 (cell culture test, HeLa cell, PLGA-PDXO alternating MBC, PLGA-PDO alternating MBC). It is an image which shows the mode of the HUVEC cell culture on the material obtained by Example 11 (cell culture test, HUVEC cell, PLGA-PDO alternating MBC). It is an image which shows the mode of HUVEC cell culture on the material obtained by Example 11 (cell culture test, HUVEC cell, PLGA-PDXO alternate MBC). It is a graph which shows the culture | cultivation behavior of the HUVEC cell by the cell count on the material obtained by Example 11 (cell culture test, HUVEC cell, PLGA-PDXO alternating MBC, PLGA-PDO alternating MBC). It is a graph which shows the culture | cultivation behavior of the HUVEC cell by WST test on the material obtained by Example 11 (cell culture test, HUVEC cell, PLGA-PDXO alternating MBC, PLGA-PDO alternating MBC). 14 is a graph showing the change in contact angle of the material obtained in Example 12 due to hydrolysis (pH 7.4). 19 is a graph showing a change in molecular weight of a residual component of the material obtained in Example 12 due to hydrolysis (pH 7.4). 13 is an image of a free-standing film made of the copolymer obtained in Example 13. 13 is a stress-strain curve of a free-standing film made of a copolymer obtained in Example 13.

<Biodegradable copolymer showing antiplatelet adhesion>
The copolymer of the present disclosure is an aliphatic polyester copolymer having a hydrophobic component and a hydrophilic component as constituent components.
The anti-platelet adhesion is a property that platelets do not easily adhere to the material surface.After a predetermined platelet solution is brought into contact with the material surface and incubated at a predetermined temperature and for a predetermined time, the number of platelets on the material is measured on a microscopic image. It can be evaluated by counting with.
The anti-platelet adhesion of the copolymer of the present invention is determined by contacting a platelet solution having a platelet concentration of 5.0 × 10 ⁷ platesets / mL, incubating at 37 ° C. for 1 hour, and performing a predetermined treatment such as washing. Although the number of platelets on the surface of the material is evaluated by counting it on a microscope image, the number of platelets cannot be evaluated based on the absolute value of the number of platelets because the number of platelets varies depending on the state of the used platelet solution. In the platelet adhesion test in the present application, an experiment was performed simultaneously with the control (surface PLGA-PCL alternate MBC on which platelets are likely to adhere and surface PMEA on which platelets are unlikely to adhere), and a significant difference test was performed to evaluate.

  Biodegradable means that it can be chemically degraded by the action of hydrolysis, enzymatic degradation, microbial degradation and the like. The copolymer of the present disclosure, for example, shows a weight loss of preferably 10% or more, more preferably 20% or more after 14 weeks in a hydrolysis test in a phosphate buffer (pH 7.4).

(Hydrophilic component)
The copolymer of the present disclosure includes, as hydrophilic components, poly (1,5-dioxepan-2-one) represented by the following formula (1) and poly (1,4-dioxane-one) represented by the following formula (2). 2-one) or a polyethylene oxide represented by the following formula (3), or may include a plurality selected from these.

(Hydrophobic component)
The copolymer of the present disclosure includes, as a hydrophobic component, poly (L-lactic acid) (PLLA), poly (D-lactic acid) (PDLA), poly (D, L-lactic acid) (PDLLA), or polylactic acid- It contains at least one of polyglycolic acid copolymer (PLGA).

(Coupling form of copolymer)
The bonding form of the hydrophilic component and the hydrophobic component may be any of random, block (diblock, triblock), and multiblock (random multiblock, alternate multiblock).
However, the hydrophilic component and the hydrophobic component need to be copolymerized, and a polymer blend of a polymer composed of a hydrophilic component and a polymer composed of a hydrophobic component does not exhibit the effects of the present invention.

(Molar ratio of hydrophilic component)
The lower limit of the molar ratio of the hydrophilic component (the ratio of the monomer constituting the hydrophilic component to the entire monomer constituting the copolymer) in the copolymer of the present disclosure is preferably 5% or more. , More preferably at least 6%, further preferably at least 19%, particularly preferably at least 29%, and the upper limit is preferably at most 85%, more preferably at most 74%, even more preferably at most 60%. In general, when the molar ratio of the hydrophilic component is increased, the antiplatelet adhesion tends to be improved. However, when the molar ratio exceeds the upper limit, the antiplatelet adhesion is greatly reduced. This is considered to be because the domain diameter of the hydrophilic component became large, and the predetermined microphase-separated structure could not be maintained.

(Surface structure of copolymer)
The copolymer of the present disclosure is preferably that the hydrophobic component and the hydrophilic component have a uniform surface structure, or a microphase-separated structure, from the viewpoint of exhibiting good antiplatelet adhesion, More preferably, a phase separation structure is formed.
As long as a hydrophilic component (at least one selected from PDXO, PDO, or PEO) is introduced into the copolymer, the copolymer may be any of a random copolymer and a block copolymer. However, in the case of only a polymer composed of a hydrophilic component, or in the case of a blend of a polymer composed of a hydrophilic component and a polymer composed of a hydrophobic component, the antiplatelet adhesion is inferior. For example, FIG. As shown, it has been found that a large domain structure of a hydrophilic component of 0.5 μm or more is not preferable.

(Segment length of hydrophilic component)
Further, when the copolymer of the present disclosure is a block copolymer or a multi-block copolymer, the segment length of the hydrophilic component is preferably pentamer or more, more preferably 10 or more. preferable. By setting the segment length of the hydrophilic component to pentamer or more, good antiplatelet adhesion can be exhibited.

(Molecular weight)
The number average molecular weight of the copolymer of the present disclosure is preferably 10,000 to 150,000, more preferably 20,000 to 100,000, and still more preferably 30,000 to 80,000. When the molecular weight is at least the lower limit, mechanical properties can be improved, and when the molecular weight is at most the upper limit, hydrolyzability can be improved.

<Method for producing copolymer>
The copolymer of the present application is a ring-opening polymerization using at least one of 1,5-dioxepan-2-one or 1,4-dioxan-2-one as a monomer forming a hydrophilic component. Can be formed. In addition, polyethylene oxide as the hydrophilic component may be formed by polymerizing ethylene glycol, or commercially available polyethylene oxide may be used. Further, as the monomer forming the hydrophobic component, L-lactic acid, D-lactic acid, DL-lactic acid, glycolic acid, or a mixture thereof may be used to form the monomer by performing dehydration condensation. -Lactide, D-lactide, DL-lactide, glycolide, or a mixture thereof may be used to perform ring-opening polymerization.
The polymerization method is not particularly limited, and a known polymerization method (initiator, solvent, polymerization temperature, and the like) can be appropriately used so that a desired polymerization form such as random, block, or multiblock is obtained.

<Membrane, antithrombotic material>
The copolymer of the present disclosure is prepared by dissolving the copolymer in a solvent capable of dissolving the copolymer, for example, chloroform to prepare a solution, and applying the solution on a substrate (for example, a glass substrate) by a suitable means. In order to remove the solvent in the solution, the film can be appropriately dried by using a vacuum oven or the like to form a film. The thickness of the film is not particularly limited and can be appropriately adjusted depending on the required use, but it is generally preferably 0.5 to 60 μm. Further, the drying time is appropriately adjusted depending on the thickness.
The above membrane may be used together with the substrate as an antithrombotic material, or the membrane may be isolated from the substrate and used as a free-standing membrane.
In addition to the film, the copolymer of the present disclosure can be formed into various three-dimensional shapes using the copolymer of the present disclosure, and can be used as a molded product. The shape of the molded body is not particularly limited, and various shapes can be adopted depending on the application. As a molding method for various molded articles, a known resin material molding method can be employed.
(Application)
The membrane of the present disclosure, as an application of the antithrombotic material, when used in contact with a tissue or blood in a living body, is a use for suppressing foreign body reaction to blood or tissue until it is decomposed. For example, hemostatic agents, adhesives for living tissues, repair materials for tissue regeneration, anti-adhesion membranes, carriers for sustained drug release systems, matrices for scaffolds for cell engineering, surface coating of stent materials, fibrous artificial blood vessels And the like.

(Mechanical properties)
Films or molded articles containing the copolymer of the present disclosure exhibit various mechanical properties depending on the copolymer composition and segment length. In particular, a copolymer having a hydrophobic segment of 10-mers or more forms a microphase-separated structure and enables the formation of a free-standing film, and exhibits the following mechanical properties.
-The Young's modulus (25 ° C) is preferably 5 MPa or more, more preferably 20 MPa or more, and still more preferably 50 MPa or more.
-Elongation at break (25 ° C) is preferably 100% or more, more preferably 300% or more, and further preferably 500% or more.
-The tensile strength (25 ° C) is preferably 10 MPa or more, more preferably 20 MPa or more.
As described above, the film and the molded article made of the copolymer of the present disclosure can form a self-standing film at room temperature (25 to 45 ° C), particularly at body temperature (35 to 40 ° C), and are easy to handle. It stretches well and is a tough film. Therefore, the membrane and the molded body made of the copolymer of the present disclosure have mechanical properties suitable as a biocompatible material.

<Medical equipment>
A thin film or a molded article made of the copolymer of the present disclosure can be provided at a location in a medical device that comes into contact with a living tissue. Examples of the medical device include a catheter, a stent, an artificial blood vessel, an anti-adhesion membrane, an artificial organ, and an implantable device in a living body. Among them, the thin film or molded article of the present disclosure is applied to artificial blood vessels for bioimplantation, anti-adhesion membranes, surface coating materials for stents, and sealants for fibrous artificial blood vessels from the viewpoint of having both biodegradability and anti-platelet adhesion. Is more preferable.
In addition, the thin film or the molded body of the present disclosure is preferably used as a material of a portion that comes into contact with blood in these devices, particularly as a part, preferably all of a portion that comes into contact with blood.

<Synthesis example 1>
Synthesis of poly (L-lactide-co-glycolide) 25-mer-poly (1,5-dioxepan-2-one) 25-mer alternating multiblock copolymer (PLGA-PDXO alternating MBC) (Step 1) Synthesis of 1,5-dioxepan-2-one) oligomer 25-mer

DPP (diphenyl phosphate) (0.344 g, 1.37 mmol) was added to a Schlenk tube which was baked with a heat gun and purged with nitrogen, and 32 mL of dehydrated toluene was added and dissolved. DXO (3.98 g, 34.3 mmol) and benzyl alcohol (144 μL, 1.37 mmol) were added thereto and reacted at room temperature for 18 h. After the reaction, Amberlyst A21 was added and shaken for 30 minutes, and Amberlyst A21 was removed by filtration. The filtrate was dried with an evaporator and dried at 40 ° C. overnight to obtain a benzyl-terminated poly (1,5-dioxepan-2-one) oligomer 25-mer (yield: 4.31 g, yield: 104) %, GPC (CHCl ₃ ): M _w / M _n = 1.14,
^{1 H NMR (500 MHz, CDCl} 3): 7.38 (m, 5H, Ar H), 5.14 (s, 2H, ArC H 2), 4.25 (t, 2H, OCH 2 C H 2 O), 3.78 (t, _{2H, COCH 2 C H 2 O} ) 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 (t, 2H, COC H 2 CH 2 O)).

(Step 2) Synthesis and deprotection of poly (L-lactide-co-glycolide) 25-mer-poly (1,5-dioxepan-2-one) 25-mer diblock copolymer

L-lactide (1.266 g, 8.78 mmol), glycolide (0.113 g, 0.98 mmol), and thiourea (0.180 g, 0.49 mmol) were added to a Schlenk tube which had been air-baked with a heat gun and purged with nitrogen. A benzyl-terminated PDXO oligomer 25 (1.00 g, 0.39 mmol) was placed in an Eppendorf tube, dissolved in 2 mL of dehydrated dichloromethane, added to a Schlenk tube, dissolved in 3 mL of dehydrated dichloromethane, and dissolved in Me ₆ TREN (124. (8 μL, 0.49 mmol) and reacted at room temperature for 3 h. After the reaction, the reaction was quenched by adding 0.12 g of benzoic acid, reprecipitated with methanol, filtered by suction, dried in vacuo at 40 ° C. overnight, and poly (L-lactide-co-glycolide) 25-mer was obtained as a white solid. A poly (1,5-dioxepan-2-one) 25-mer diblock copolymer was obtained (yield: 1.97 g, yield: 82%, GPC (CHCl ₃ ): M _w / M _n = 1.12, ¹⁾ _{H NMR (500 MHz, CDCl 3} ): 7.38 (m, 5H, Ar H), 5.18 (q, 1H, COC H (CH 3) O), 5.14 (s, 2H, ArC H 2), 4.81 (m, _{2H, COC H 2 O),} 4.25 (t, 2H, OCH 2 C H 2 O), 3.78 (t, 2H, COCH 2 C H 2 O) 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 _{(t, 2H, COC H 2} CH 2 O), 1.58 (d, 3H, COCH (C H 3) O)).

1.8 g of the diblock copolymer was dissolved in 80 mL of THF, and 0.18 g of Pd / C was added. After this was replaced with nitrogen, the mixture was reacted at room temperature under a hydrogen atmosphere for 24 hours. This was replaced with nitrogen, Pd / C was removed by Celite filtration, the filtrate was concentrated by an evaporator to reprecipitate methanol, collected by suction filtration, vacuum dried at 40 ° C., and deprotected. to obtain a polymer (yield: 1.74 g, ^{yield: 91%, 1 H NMR (} m, 500 MHz, CDCl 3): 5.18 (q, 1H, COC H (CH 3) O), 4.81 (m, 2H _{, COC H 2 O), 4.25} (t, 2H, OCH 2 C H 2 O), 3.78 (t, 2H, COCH 2 C H 2 O), 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 _{(t, 2H, COC H 2} CH 2 O), 1.58 (d, 3H, COCH (C H 3) O)).

(Step 3) Synthesis of poly (L-lactide-co-glycolide) 25-mer-poly (1,5-dioxepan-2-one) 25-mer alternating multi-block copolymer

A poly (L-lactide-co-glycolide) 25-mer-poly (1,5-dioxepan-2-one) 25-mer diblock copolymer (1.00 g, 0.138 mmol), dimethylaminopyridine p-toluenesulfonic acid (8.8 mg, 0.028 mmol) and dimethylaminopyridine (7.4 mg, 0.055 mmol) were added, and dissolved by adding 3 mL of dehydrated dichloromethane. Thereafter, molecular sieves were added for dehydration, and the mixture was shaken overnight. DIPCI (40.9 μL, 0.276 mmol) was added, and the mixture was reacted at room temperature with shaking for 24 hours. After the reaction, methanol was reprecipitated, followed by suction filtration and vacuum drying at 40 ° C. to obtain the desired product (yield: 0.699 g, yield: 68%, GPC (CDCl ₃ ): M _w = 72,000, M _w / ^{_{M n = 1.84, 1 H NMR}} (500 MHz, CDCl 3): 5.18 (q, 1H, COC H (CH 3) O), 4.81 (m, 2H, COC H 2 O), 4.25 (t, 2H, OCH _{2 C H 2 O), 3.78} (t, 2H, COCH 2 C H 2 O) 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 (t, 2H, COC H 2 CH 2 O), 1.58 ( d, 3H, COCH (C H 3) O)).

<Synthesis Example 2>
Synthesis of poly (L-lactide-co-glycolide) -poly (1,5-dioxepan-2-one) random multiblock copolymer (PLGA-PDXO RMBC 50:50) (Step 1) Poly (L-lactide- Synthesis of (co-glycolide) copolymer oligomer 25-mer

L-lactide (5.295 g, 36.7 mmol), glycolide (0.473 g, 4.07 mmol), thiourea (0.765 g, 2.04 mmol) were added to a Schlenk tube purged with a heat gun and purged with nitrogen, and dehydrated. 30 mL of dichloromethane was added and dissolved. After benzyl alcohol (144 μL, 1.38 mmol) was added and dissolved therein, Me ₆ TREN (522 μL, 1.86 mmol) was added, and the mixture was reacted at room temperature for 1 hour. After the reaction, the reaction was quenched by adding 0.5 g of benzoic acid, reprecipitated in methanol, and then dried in vacuo at 40 ° C. to give a benzyl-terminated poly (L-lactide-co-glycolide) copolymer (PLGA) as a white solid. An oligomer 25-mer was obtained (yield: 5.09 g, yield: 86%, GPC (CHCl ₃ ): M _w / M _n = 1.17,
^{1 H NMR (500 MHz, CDCl} 3):. 7 38 (m, 5H, Ar H), 5.18 (q, 1H, COC H (CH 3) O), 5.14 (s, 2H, ArC H 2), 4.81 _{(m, 2H, COC H 2} O), 1.58 (d, 3H, COCH (C H 3) O)).

(Step 2) Deprotection of poly (L-lactide-co-glycolide) copolymer oligomer 25-mer

2.5 g of PLGA oligomer having a benzyl end was dissolved in 100 mL of THF, and 0.25 g of Pd / C was added. After this was replaced with nitrogen, the mixture was reacted at room temperature under a hydrogen atmosphere for 48 hours. After replacing this with nitrogen, Pd / C was removed by celite filtration / membrane filtration, the filtrate was dried to dryness by an evaporator, redissolved in 15 mL of chloroform, reprecipitated in methanol in an ice bath, and dried in vacuo at 40 ° C. A benzyl-terminated poly (L-lactide-co-glycolide) copolymer oligomer 25-mer (PLGA25) was obtained as a white solid (yield: 2.32 g, 92%, ¹ H NMR (500 MHz, 500 MHz)). _{CDCl 3): 5.18 (q,} 1H, COC H (CH 3) O), 4.81 (m, 2H, COC H 2 O), 1.58 (d, 3H, COCH (C H 3) O)).

(Step 3) Synthesis of poly (1,5-dioxepan-2-one) oligomer 25-mer (deprotection)

Synthesis Example 1 4.3 g of a PDXO oligomer having a benzyl end synthesized in Step 1 was dissolved in 180 mL of THF, and 0.43 g of Pd / C was added. After this was replaced with nitrogen, the mixture was reacted at room temperature under a hydrogen atmosphere for 24 hours. After replacing this with nitrogen, Pd / C was removed by filtration through Celite, and the filtrate was dried by an evaporator and dried in vacuo at 40 ° C. overnight to remove poly (1,5-dioxepan-2-one) from which the benzyl terminal was removed. ) (to give a PDXO25) (yield: 4.72 g, ^{yield: 110%, 1 H NMR (} 500 MHz, CDCl 3): oligomer 25-mer _{4.25 (t, 2H, OCH 2} C H 2 O), 3.78 ( _{t, 2H, COCH 2 C H} 2 O) 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 (t, 2H, COC H 2 CH 2 O)).

(Step 4) Poly (L-lactide-co-glycolide) 25-mer-poly (1,5-dioxepan-2-one) 25-mer random multi-block copolymer (PLGA-PDXO RMBC) having a charge ratio of 50:50 50:50) Synthesis

PLGA25 (0.5 g, 0.138 mmol) and deprotected PDXO25 (0.388 g, 0.138 mmol) were added to a Schlenk tube which was baked with a heat gun and purged with nitrogen, and dimethylaminopyridine p-toluenesulfonic acid (15 g) was added. (1.6 mg, 0.055 mmol) and dimethylaminopyridine (13.1 mg, 0.110 mmol) were added and dissolved in 3 mL of dehydrated dichloromethane. Thereafter, molecular sieves were added for dehydration, and the mixture was shaken overnight. Diisopropylcarbodiimide (82.9 μL, 0.552 mmol) was added, and the mixture was shaken at room temperature for 24 hours to react. After the reaction, reprecipitation was performed with methanol, and the precipitate was collected by suction filtration and dried in vacuo at 40 ° C. to obtain the desired product as a white fibrous solid (yield: 0.70 g, 80%, GPC (CHCl ₃ )). : M _w = 89,000, M _w / M _n = 1.67,
^{1 H NMR (500 MHz, CDCl} 3): 5.18 (q, 1H, COC H (CH 3) O), 4.81 (m, 2H, COC H 2 O), 4.25 (t, 2H, OCH 2 C H 2 O ), 3.78 (t, 2H, COCH 2 C H 2 O) 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 (t, 2H, COC H 2 CH 2 O), 1.58 (d, 3H, COCH _{(C H 3) O),} PLGA / PDXO ratio: 64/36).

The following random multi-block copolymers having different charge ratios were synthesized by changing the charge ratio of PLGA25 and PDXO25.
PLGA-PDXO RMBC 13:87 (yield: 0.48 g, yield: 58%, GPC (CHCl ₃ ): M _w = 52,000, M _w / M _n = 1.98,
^{1 H NMR (500 MHz, CDCl} 3): 5.18 (q, 1H, COC H (CH 3) O), 4.81 (m, 2H, COC H 2 O), 4.25 (t, 2H, OCH 2 C H 2 O ), 3.78 (t, 2H, COCH 2 C H 2 O) 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 (t, 2H, COC H 2 CH 2 O), 1.58 (d, 3H, COCH _{(C H 3) O),} PLGA / PDXO ratio 13: 87).

PLGA-PDXO 26:74 (yield: 0.59 g, yield: 75%, GPC (CHCl ₃ ): M _w = 65,000, M _w / M _n = 1.48,
^{1 H NMR (500 MHz, CDCl} 3): 5.18 (q, 1H, COC H (CH 3) O), 4.81 (m, 2H, COC H 2 O), 4.25 (t, 2H, OCH 2 C H 2 O ), 3.78 (t, 2H, COCH 2 C H 2 O) 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 (t, 2H, COC H 2 CH 2 O), 1.58 (d, 3H, COCH (C H ₃ ) O), PLGA / PDXO ratio: 26:74).

PLGA-PDXO RMBC 40:60 (Yield: 0.27 g, Yield: 63%, GPC (CHCl ₃ ): M _w = 65,000, M _w / M _n = 1.76,
^{1 H NMR (500 MHz, CDCl} 3): 5.18 (q, 1H, COC H (CH 3) O), 4.81 (m, 2H, COC H 2 O), 4.25 (t, 2H, OCH 2 C H 2 O ), 3.78 (t, 2H, COCH 2 C H 2 O) 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 (t, 2H, COC H 2 CH 2 O), 1.58 (d, 3H, COCH (C H ₃ ) O), PLGA / PDXO ratio: 40/60).

PLGA-PDXO RMBC 50:50 (yield: 0.33 g, yield: 75%, GPC (CHCl ₃ ): M _w = 55,000, M _w / M _n = 1.55,
^{1 H NMR (500 MHz, CDCl} 3): 5.18 (q, 1H, COC H (CH 3) O), 4.81 (m, 2H, COC H 2 O), 4.25 (t, 2H, OCH 2 C H 2 O ), 3.78 (t, 2H, COCH 2 C H 2 O) 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 (t, 2H, COC H 2 CH 2 O), 1.58 (d, 3H, COCH _{(C H 3) O),} PLGA / PDXO ratio: 50/50).

PLGA-PDXO RMBC 71:29 (yield: 0.34 g, yield: 74%, GPC (CHCl ₃ ): M _w = 68,000, M _w / M _n = 1.57,
^{1 H NMR (500 MHz, CDCl} 3): 5.18 (q, 1H, COC H (CH 3) O), 4.81 (m, 2H, COC H 2 O), 4.25 (t, 2H, OCH 2 C H 2 O ), 3.78 (t, 2H, COCH 2 C H 2 O) 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 (t, 2H, COC H 2 CH 2 O), 1.58 (d, 3H, COCH _{(C H 3) O),} PLGA / PDXO ratio: 71/29).

PLGA-PDXO RMBC 81:19 (Yield: 0.40 g, Yield: 85%, GPC (CHCl ₃ ): M _w = 123,000, M _w / M _n = 1.65,
^{1 H NMR (500 MHz, CDCl} 3): 5.18 (q, 1H, COC H (CH 3) O), 4.81 (m, 2H, COC H 2 O), 4.25 (t, 2H, OCH 2 C H 2 O ), 3.78 (t, 2H, COCH 2 C H 2 O) 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 (t, 2H, COC H 2 CH 2 O), 1.58 (d, 3H, COCH _{(C H 3) O),} PLGA / PDXO ratio: 81/19).

PLGA-PDXO RMBC 94: 6 (yield: 0.83 g, yield: 79%, GPC (CHCl ₃ ): M _w = 78,000, M _w / M _n = 1.96,
^{1 H NMR (500 MHz, CDCl} 3): 5.18 (q, 1H, COC H (CH 3) O), 4.81 (m, 2H, COC H 2 O), 4.25 (t, 2H, OCH 2 C H 2 O ), 3.78 (t, 2H, COCH 2 C H 2 O) 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 (t, 2H, COC H 2 CH 2 O), 1.58 (d, 3H, COCH _{(C H 3) O),} PLGA / PDXO ratio: 94/6).

<Synthesis Example 3>
Synthesis of poly (L-lactide-co-glycolide) -poly (1,5-dioxepan-2-one) diblock copolymer (PLGA-PDXO DBC) (Step 1) Bn-OH (benzyl alcohol) as initiator Of polished poly (1,5-dioxepan-2-one) oligomer

After heating and drying the 20 ml Schlenk tube using a heat gun, the tube was degassed and replaced with nitrogen using a diaphragm pump. DXO (815 µL, 7.75 mmol), DPP (diphenyl phosphate) (19.4 mg, 0.078 mmol) as a catalyst, and Bn-OH (8.03 µL, 0.078 mmol, 10-fold diluted with dehydrated toluene) as an initiator were added. The mixture was stirred and reacted at 80 ° C. for 7.5 hours in an oil bath. After completion of the reaction, Amberlyst A21 and dichloromethane were added and shaken for 30 minutes. Thereafter, the mixture was filtered, washed with dichloromethane, concentrated with an evaporator, and then reprecipitated with hexane in an eggplant-shaped flask in an ice bath. Thereafter, decantation was performed, and the whole flask was vacuum-dried at 100 ° C. for 1 hour, and then vacuum-dried overnight while returning to room temperature to obtain a liquid poly (1,5-dioxepan-2-one) oligomer. (Yield: 0.905 g, yield: 100%). ¹ H NMR (500 MHz, CDCl ₃ ): 7.35 (m, 5 H, C ₆ H ₅ ), 5.13 (s, 2 H, C ₆ H ₅ C H ₂ O), 4.23 (t, 2 H, OCH ₂ C H ₂ O ), 3.75 (t, 2H, COCH 2 CH 2 O), 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 (t, 2H, COC H 2 CH 2), degree of polymerization n = 110 (NMR) .

(Step 2) Synthesis of poly (L-lactide-co-glycolide) -poly (1,5-dioxepan-2-one) diblock copolymer (PLGA-PDXO DBC)

After heating and drying the 20 ml Schlenk tube using a heat gun, the tube was degassed and replaced with nitrogen using a diaphragm pump. Benzyl-terminated poly (1,5-dioxepan-2-one) oligomer (degree of polymerization: 110, 0.905 g, 0.703 mmol) synthesized in step 1 as an initiator, and L-lactide (1.00 g, 6 .96 mmol) and glycolide (897 mg, 0.773 mmol), DBU (1,8-diazabicyclo [5.4.0] undec-7-ene) (58.9 μL, 0.386 mmol) as a catalyst, dehydrated THF (4 ml) And stirred for 1 hour at room temperature to react. Thereafter, benzoic acid (53.9 mg, 0.445 mmol) was added and stirred for 10 minutes. After inactivation of DBU, methanol was reprecipitated in an ice bath, suction filtration, vacuum drying at 40 ° C. overnight, and white powder A benzyl-terminated poly (L-lactide-co-glycolide) -poly (1,5-dioxepan-2-one) diblock copolymer was obtained as a solid. (Yield: 1.77 g, Yield: 88.5%)
_{^{1 H NMR (500MHz, CDCl 3}} ): 7.35 (m, 5H, C 6 H 5), 5.16 (q, 1H, COC H (CH 3) O), 4.83 (m, 2H, COC H 2 O), 4.23 _{(t, 2H, OCH 2 C} H 2 O), 3.76 (t, 2H, COCH 2 CH 2 O), 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 (t, 2H, COC H 2 CH _{2), 1.58 (d, 3H} , COCH (C H 3) O), the degree of polymerization n = 125, x = 112, y = 12 (NMR)

(Step 3) Deprotection of PLGA-PDXO DBC

A benzyl-terminated PLGA-PDXO DBC (1.77 g), THF (tetrahydrofuran) (75 ml), and Pd / C (0.20 g) were placed in an eggplant flask and degassed and purged with a diaphragm pump using a diaphragm pump. Replaced. Thereafter, a hydrogen balloon was attached and the mixture was vigorously stirred at room temperature overnight. After completion of the reaction, the mixture was evaporated to dryness, the solvent was replaced with chloroform, and the mixture was stirred for 3 hours. Thereafter, the mixture was filtered through Celite, the filtrate was concentrated under reduced pressure, reprecipitated in methanol in an ice bath, suction filtered, and dried in vacuo at 40 ° C. overnight to obtain a white powdery solid of PLGA-PDXO DBC from which benzyl terminals had been removed. (Yield: 1.65 g, yield: 93.2%)
_{^{1 H NMR (500MHz, CDCl 3}} ): 5.16 (q, 1H, COC H (CH 3) O), 4.83 (m, 2H, COC H 2 O), 4.23 (t, 2H, OCH 2 C H 2 O) , 3.76 (t, 2H, COCH 2 CH 2 O), 3.66 (t, 2H, OC H 2 CH 2 O), 2.66 (t, 2H, COC H 2 CH 2), 1.58 (d, 3H, COCH (C H ₃ ) O)

<Synthesis example 4>
Synthesis of poly (L-lactide-co-glycolide) -poly (1,5-dioxepan-2-one) -poly (L-lactide-co-glycolide) triblock copolymer (PLGA-PDXO-PLGA TBC) ( Step 1) Synthesis of OH poly (1,5-dioxepan-2-one) oligomer at both ends using 2-methyl-1,3-propanediol as an initiator

After heating and drying the 20 ml Schlenk tube using a heat gun, the tube was degassed and replaced with nitrogen using a diaphragm pump. DXO (815 μL, 7.75 mmol), DPP (diphenyl phosphate) (3.88 mg, 17.2 mmol) as catalyst, 2-methyl-1,3-propanediol (9.70 mg, 3.88 × 10 8) as initiator ^(-5 mol, diluted 10-fold with THF) and stirred at 80 ° C. for 7.5 hours to react. After completion of the reaction, Amberlyst A21 and dichloromethane were added and shaken for 30 minutes. Thereafter, the mixture was filtered, washed with dichloromethane, concentrated by an evaporator, and reprecipitated in ice bath with hexane. After reprecipitation, the solution was decanted and evaporated to dryness. Thereafter, the mixture was heated to 100 ° C. in an oil bath under reduced pressure, dried for 3 hours, and then dried in vacuum at room temperature overnight to obtain a liquid OH poly (1,5-dioxepan-2-one) oligomer having both ends OH. . (Yield: 0.780 g, Yield: 86.7%)
_{^{1 H NMR (500MHz, CDCl 3}} ): 4.23 (t, 2H, OCH 2 C H 2 O), 3.75 (t, 2H, COCH 2 CH 2 O), 3.66 (t, 2H, OC H 2 CH 2 O) , 2.62 (t, 2H, COC H 2 CH 2), 0.99 (d, 3H, CH 2 CH (C H 3) CH 2), polymerization degree 2n = 295 (NMR)

(Step 2) Poly (L-lactide-co-glycolide) -poly (1,5-dioxepan-2-one) -poly (L-lactide-co-glycolide) triblock copolymer (PLGA-PDXO-PLGA TBC) Synthesis of)

After heating and drying the 20 ml Schlenk tube using a heat gun, the tube was degassed and replaced with nitrogen using a diaphragm pump. Both ends OH poly (1,5-dioxepan-2-one) oligomer (0.719 g, 0.0212 mmol) as an initiator, L-lactide (823 mg, 5.71 mmol) and glycolide (73.1 mg, 0.12 g) as monomers. 634 mmol), DBU (48.3 μL, 0.317 mmol) as a catalyst, and dehydrated THF (4 ml) were added, and the mixture was stirred at room temperature for 1 hour to react. Thereafter, benzoic acid (77.4 mg, 0.635 mmol) was added and the mixture was stirred for 10 minutes to inactivate DBU. Then, methanol was reprecipitated in an ice bath, suction filtration, vacuum drying at 40 ° C. overnight, and white powder were obtained. Of PLGA-PDXO-PLGA TBC was obtained. (Yield: 1.54 g, yield: 95.2%)
_{^{1 H NMR (500MHz, CDCl 3}} ): 5.17 (q, 1H, COC H (CH 3) O), 4.83 (m, 2H, COC H 2 O), 4.23 (t, 2H, OCH 2 C H 2 O) , 3.76 (t, 2H, COCH 2 CH 2 O), 3.66 (t, 2H, OC H 2 CH 2 O), 2.62 (t, 2H, COC H 2 CH 2), 1.58 (d, 3H, COCH (C _{H 3) O), 0.99 (} d, 3H, CH 2 CH (C H 3) CH 2), degree of polymerization n = 300, m = 262, l = 28.1 (NMR)

<Synthesis example 5>
Synthesis of poly (L-lactide) -poly (1,5-dioxepan-2-one) random copolymer (PLLA-PDXORC)

After heating and drying the 20 ml Schlenk tube using a heat gun, the tube was degassed and replaced with nitrogen using a diaphragm pump. DXO (583 μL, 5.55 mmol), L-lactide (0.800 g, 5.55 mmol), Sn (Oct) ₂ (5.08 μL, L-lactide × 0.4 wt%) as a catalyst were added, and the mixture was placed in an oil bath. Stirred at 100 ° C. for 0.5 hour. Thereafter, the mixture was stirred at 130 ° C. for 8 hours to be reacted. After completion of the reaction, a few drops of acetic acid and 4 ml of chloroform were added to deactivate the catalyst. Thereafter, diethyl ether was reprecipitated in an ice bath. Thereafter, the solution was decanted and vacuum-dried at room temperature overnight to obtain a viscous semi-liquid PLLA-PDXORC. (Yield: 1.28 g, yield: 88.8%)
_{^{1 H NMR (500MHz, CDCl 3}} ): 5.16 (m, 1H, COC H (CH 3) O), 4.29 (m, 2H, OCH 2 C H 2 O), 4.23 (t, 2H, OCH 2 C H 2 O), 3.76 (t, 2H , COCH 2 CH 2 O), 3.66 (t, 2H, OC H 2 CH 2 O), 2.68 (m, 2H, COC H 2 CH 2), 2.62 (t, 2H, COC _{H 2 CH 2), 1.59 (} d, 3H, COCH (C H 3) O), 1.52 (m, 3H, COCH (C H 3) O), Mw = 53000, Mw / Mn = 1.65 (GPC)

<Synthesis example 6>
Synthesis of poly (L-lactide-co-glycolide) -poly (1,4-dioxan-2-one) alternating multiblock copolymer (PLGA-PDO alternating MBC) (Step 1) Bn-OH (benzyl alcohol) Synthesis of poly (1,4-dioxan-2-one) oligomer as initiator

After heating and drying the 20 ml Schlenk tube using a heat gun, the tube was degassed and replaced with nitrogen using a diaphragm pump. 1,4-dioxan-2-one (2.8 mL, 34.7 mmol), DPP (diphenylphosphate) (434.6 mg, 1.74 mmol) as a catalyst, Bn-OH (179.5 μL, (1.74 mmol) was added thereto, and the mixture was stirred and reacted at 110 ° C. for 1 hour in an oil bath. After completion of the reaction, Amberlyst A21 and dichloromethane were added and shaken for 30 minutes. Thereafter, the amber list was removed by filtration, the filtrate was concentrated by an evaporator, reprecipitated in methanol, and collected by filtration. Vacuum drying was performed at 40 ° C. for 12 hours to obtain a poly (1,4-dioxan-2-one) (PDO) oligomer. (Yield: 66%). ¹ H NMR (500 MHz, CDCl ₃ ): 7.36 (m, 5 H, C ₆ H ₅ ), 5.18 (s, 2 H, C ₆ H ₅ C H ₂ O), 4.35 (t, 2 H, OCH ₂ C H ₂ OCO ), 4.18 (s, 2H, COC H 2 O), 3.79 (t, 2H, OC H 2 CH 2 OCO), GPC (CHCl 3): M w / M n = 1.47, degree of polymerization n = 22.5 (NMR) .

(Step 2) Synthesis and deprotection of poly (L-lactide-co-glycolide) -poly (1,4-dioxan-2-one) diblock copolymer

A Phenol-terminated PDO oligomer (degree of polymerization 22.5, 1.843 g, 0.767 mmol), L-lactide (2.633 g, 18.27 mmol), glycolide (0 .2356 g, 2.03 mmol) and 10 mL of dehydrated dichloromethane. Dissolve everything by heating and stirring the Schlenk tube with a drier, cool to room temperature, and then use DBU (1,8-diazabicyclo [5.4.0] undec-7-ene) (147.7 μL, 1. 02 mmol), and the mixture was stirred at room temperature for 1 hour to react. After the reaction, the reaction was quenched by adding 0.12 g of benzoic acid, methanol was reprecipitated, filtered by suction, dried in vacuo at 40 ° C. overnight, and poly (L-lactide-co-glycolide) -poly (1,4- A dioxan-2-one) diblock copolymer was obtained (yield: 83%, ¹ H NMR (500 MHz, CDCl ₃ ): 7.35 (m, 5H, C ₆ H ₅ ), 5.18 (s, 2H, _{C 6 H 5 C H 2 O} ), 5.16 (q, 1H, COC H (CH 3) O), 4.83 (m, 2H, COC H 2 OCO), 4.35 (t, 2H, OCH 2 C H 2 OCO) , 4.18 (s, 2H, COC H 2 O), 3.79 (t, 2H, OC H 2 CH 2 OCO), 1.58 (d, 3H, COCH (C H 3) O)), GPC (CHCl 3): M _w / _Mn = 1.48. PDO polymerization degree (n) = 21.5, PLGA polymerization degree (x + y) = 23.1 (NMR)
In a eggplant flask, 4.789 g of a diblock copolymer having a benzyl group was dissolved in 200 mL of hexafluoroisopropanol, and 0.479 g of Pd / C was added. After this was replaced with nitrogen, the mixture was reacted at room temperature under a hydrogen atmosphere for 20 hours. After completion of the reaction, the atmosphere was replaced with nitrogen, and then concentrated to dryness using an evaporator, chloroform was added, and the solvent was replaced. This was filtered through celite to remove Pd / C, and the filtrate was concentrated with an evaporator to reprecipitate methanol in an ice bath and collected by suction filtration. After vacuum drying at 40 ° C. for 12 hours, a deblocked diblock copolymer (PLGA-PDO DBC) was obtained (yield: 81%, ¹ H NMR (500 MHz, CDCl ₃ ): 5.16 (q, 1H, _{COC H (CH 3) O)} , 4.83 (m, 2H, COC H 2 OCO), 4.35 (t, 2H, OCH 2 C H 2 OCO), 4.18 (s, 2H, COC H 2 O), 3.79 (t _{, 2H, OC H 2 CH 2} OCO), 1.58 (d, 3H, COCH (C H 3) O)), GPC (CHCl 3): M w / M n = 1.30.

(Step 3) Synthesis of poly (L-lactide-co-glycolide) -poly (1,4-dioxan-2-one) alternating multi-block copolymer

PLGA-PDO DBC (1.00 g), dimethylaminopyridine p-toluenesulfonic acid (8.7 mg), dimethylaminopyridine (2.2 mg), and 10 mL of dehydrated dichloromethane were added to a Schlenk tube which was baked with a heat gun and purged with nitrogen. Dissolved. Thereafter, molecular sieves were added for dehydration, and the mixture was shaken overnight. DIPCI (55.4 μL) was added, and the mixture was reacted at room temperature with shaking for 3 hours. After the reaction, reprecipitation of methanol was performed, followed by suction filtration, followed by vacuum drying at 40 ° C. for 12 hours to obtain the desired product (yield: 96%, GPC (CDCl ₃ ): M _w = 120,000, M _w / M _n = ^{1.63, 1 H NMR (500 MHz} , CDCl 3): 5.16 (q, 1H, COC H (CH 3) O), 4.83 (m, 2H, COC H 2 OCO), 4.35 (t, 2H, OCH 2 C H _{2 OCO), 4.18 (s,} 2H, COC H 2 O), 3.79 (t, 2H, OC H 2 CH 2 OCO), 1.58 (d, 3H, COCH (C H 3) O)).

<Synthesis Example 7>
Synthesis of poly (L-lactide) 50-mer-polyethylene oxide copolymer (PLLA-PEO alternating MBC) (Step 1) poly (L-lactide) 25-mer-polyethylene oxide-poly (L-lactide) 25-mer Synthesis of triblock copolymer (PLLA25-PEO-PLLA25 TBC)

Polyethylene glycol (molecular weight: 2050) (1.424 g, 0.694 mmol) was added to a 100 mL Schlenk tube which was baked with a heat gun and purged with nitrogen, and stirred at 100 ° C. overnight in an oil bath to dehydrate. After cooling to room temperature, L-lactide (5.00 g, 34.7 mmol) was added, and 25 mL of dehydrated dichloromethane was added and dissolved. DBU (diazabicycloundecene) (260 μL, 0.175 mmol) was added thereto as a catalyst, and the mixture was stirred at room temperature for 1 hour to be reacted. After the reaction, benzoic acid (0.423 g, 0.347 mmol) was added, and the mixture was stirred for 10 minutes to inactivate DBU. Then, diethyl ether was reprecipitated, suction-filtered, vacuum-dried at 40 ° C. overnight, and a white powder solid was obtained. As a result, a poly (L-lactide) 25-mer-polyethylene oxide-poly (L-lactide) 25-mer triblock copolymer (PLLA25-PEO-PLLA25 TBC) was obtained. (Yield: 4.77 g, _{yield: 74.4%, GPC (CHCl 3} ): M w / M n = 1.19, 1 H NMR (500 MHz, CDCl 3): 5.16 (q, 1H, COC H (CH 3) O ), 3.64 (s, 4H, OC 2 H 4), 1.59 (d, 3H, COCH (C H 3) O) a polymerization degree m = 51 ⁽¹ H NMR, lactic acid units)).

(Step 2) Succinic anhydride-terminated poly (L-lactide) 25-mer-polyethylene oxide-poly (L-lactide) 25-mer triblock copolymer (HOOC-PLLA25-PEO-PLLA25-COOH TBC) Synthesis of

The triblock copolymer (2.0 g, 0.216 mmol) synthesized in (Step 1), triethylamine (75.2 μL, 0.540 mmol), and succinic anhydride (0 0.054 g, 0.540 mmol) and DMAP (dimethylaminopyridine) (2.00 mg, 0.0173 mmol), 10 mL of dehydrated dichloromethane was added thereto, and the mixture was stirred and reacted at room temperature for 12 hours. Thereafter, the reaction solution was diluted with 100 mL of chloroform, and separated with 100 mL of distilled water three times and with a 0.5 wt% citric acid solution three times using a 500 mL separatory funnel. Thereafter, the chloroform solution was recovered, dried using an evaporator, and dried in vacuum at 40 ° C., and as a white powder solid, poly (L-lactide) 25-mer-polyethylene oxide-poly ( (L-lactide) 25-mer triblock copolymer (HOOC-PLLA25-PEO-PLLA25-COOH TBC) was obtained. (Yield: 1.67 g, _{yield: 84.2%, GPC (CHCl 3} ): M w / M n = 1.22) 1 H NMR (500 MHz, CDCl 3): 5.16 (q, 1H, COC H (CH 3) O ), 3.64 (s, 4H, OC 2 H 4), 2.73 (t, 4H, OCO (C H 2) 2 COOH) 1.59 (d, 3H, COCH (C H 3) O)

  (Step 3) Synthesis of poly (L-lactide) 50-mer-polyethylene oxide copolymer (PLLA50-PEO alternating MBC)

The triblock copolymer (0.5 g, 0.0541 mmol) synthesized in (Step 1) and the triblock copolymer (0. 511 g, 0.0541 mmol), DPTS (dimethylaminopyridine p-toluenesulfonic acid) (2.64 mg, 0.0108 mmol), and DMAP (dimethylaminopyridine) (2.64 mg, 0.0216 mmol), and then dehydrated dichloromethane. 5 mL was added and stirred to dissolve. Thereafter, DIPCI (N, N′-diisopropylcarbodiimide) (25.0 μL, 0.162 mmol) was added, and the mixture was stirred and reacted for 15 hours. After the reaction, methanol was reprecipitated, suction-filtered, and vacuum-dried at 40 ° C. As a white fibrous solid, poly (L-lactide) 50-mer-polyethylene oxide copolymer (PLLA50-PEO alternating MBC (PLLA) : PEO = 78: 22)). (Yield: 0.797 g, _{yield: 79.2%, GPC (CHCl 3} ): M w = 113000, M w / M n = 1.73) 1 H NMR (500 MHz, CDCl 3): 5.16 (q, 1H, COC H _{(CH 3) O), 3.64} (s, 4H, OC 2 H 4), 2.73 (t, 4H, OCO (C H 2) 2 COOH) 1.59 (d, 3H, COCH (C H 3) O), PLLA / PEO weight ratio: 78/22,

The different multi-block copolymers shown below were synthesized with different weight ratios of PLLA and PEO.
PLLA26-PEO alternating MBC (PLLA: PEO = 64: 36) (yield: 0.860 g, 86.0%, GPC (CHCl ₃ ): M _w = 137,000, M _w / M _n = 1.86) ¹ H NMR (500 _{MHz, CDCl 3): 5.16 (} q, 1H, COC H (CH 3) O), 3.64 (s, 4H, OC 2 H 4), 2.73 (t, 4H, OCO (C H 2) 2 COOH) 1.59 ( d, 3H, COCH (C H 3) O)
PLLA / PEO weight ratio: 64/36

<Comparative Synthesis Example 1>
Synthesis of poly (L-lactide-co-glycolide) 25-mer-poly (ε-caprolactone) 25-mer alternating multiblock copolymer (PLGA-PCL alternating MBC) (Step 1) Poly (ε-caprolactone) oligomer 25 Synthesis of monomer

DPP (diphenyl phosphate) (0.45 g, 1.79 mmol) was added to a Schlenk tube which was baked with a heat gun and purged with nitrogen, and 25 mL of dehydrated toluene was added and dissolved.
To this were added ε-caprolactone (5 mL, 44.6 mmol) and benzyl alcohol (187 μL, 1.79 mmol) and reacted at room temperature for 3 h. After the reaction, Amberlyst A21 was added and shaken for 30 minutes, and Amberlyst A21 was removed by filtration. The filtrate was concentrated with an evaporator, reprecipitated with ice bath in diethyl ether, and dried at 40 ° C. overnight to obtain a benzyl-terminated poly (ε-caprolactone) oligomer 25-mer as a white solid (yield: 4.66 g) , Yield: 83%,
^{1 H NMR (500 MHz, CDCl} 3): 7.19 (m, 5H, Ar H), 5.34 (s, 2H, ArC H 2), 4.08 (t, 2H, CH 2 C H 2 O), 2.31 (t, _{2H, COC H 2 CH 2)} , 1.66 (m, 4H, COCH 2 C H 2 CH 2, CH 2 C H 2 CH 2 O), 1.39 (m, 2H, COCH 2 CH 2 C H 2 CH 2 CH 2 O)).

(Step 2) Synthesis and deprotection of poly (L-lactide-co-glycolide) 25-mer-poly (ε-caprolactone) 25-mer diblock copolymer

L-lactide (2.12 g, 14.7 mmol), glycolide (0.190 g, 1.64 mmol), thiourea (0.302 g, 0.744 mmol), and a benzyl end are contained in a Schlenk tube that has been burned with a heat gun and purged with nitrogen. PCL oligomer 25 (1.64 g, 0.512 mmol) was added, dissolved in 8 mL of dehydrated dichloromethane, Me ₆ TREN (209 μL, 0.744 mmol) was added, and reacted at room temperature for 3 h. After the reaction, the reaction solution was quenched by adding 0.10 g of benzoic acid, reprecipitated in an ice bath methanol, filtered by suction, and then dried in vacuo at 40 ° C. overnight to obtain poly (L-lactide-co-glycolide) 25 as a white solid. A dimer-poly (ε-caprolactone) 25-mer diblock copolymer was obtained (yield: 3.81 g, yield: 96%, GPC (CHCl ₃ ): M _w / M _n = 1.11,
^{1 H NMR (500 MHz, CDCl} 3): 7.38 (m, 5H, Ar H), 5.18 (q, 1H, COC H (CH 3) O), 5.14 (s, 2H, ArC H 2), 4.81 (m _{, 2H, COC H 2 O)} , 4.08 (t, 2H, CH 2 C H 2 O), 2.31 (t, 2H, COC H 2 CH 2), 1.66 (m, 4H, COCH 2 C H 2 CH 2, _{CH 2 C H 2 CH 2 O} ), 1.39 (m, 2H, COCH 2 CH 2 C H 2 CH 2 CH 2 O).
2.0 g of the diblock copolymer was dissolved in 80 mL of THF, and 0.20 g of Pd / C was added. After this was replaced with nitrogen, the mixture was reacted at room temperature under a hydrogen atmosphere for 24 hours. This was replaced with nitrogen, the solvent was replaced with chloroform, and the mixture was stirred for 3 hours, and then Pd / C was removed by celite filtration. The filtrate was concentrated by an evaporator to reprecipitate methanol, collected by suction filtration, and dried in vacuo at 40 ° C. to obtain a deprotected diblock copolymer (yield: 1.86 g, yield: 91%, ^{1 H NMR (500 MHz, CDCl} 3): 5.18 (q, 1H, COC H (CH 3) O), 4.81 (m, 2H, COC H 2 O), 4.08 (t, 2H, CH 2 C H 2 O ), 2.31 (t, 2H, COC H 2 CH 2), 1.66 (m, 4H, COCH 2 C H 2 CH 2, CH 2 C H 2 CH 2 O), 1.58 (d, 3H, COCH (C H 3 ) O), 1.39 (m, 2H, COCH 2 CH 2 C H 2 CH 2 CH 2 O)).

(Step 3) Synthesis of poly (L-lactide-co-glycolide) 25-mer-poly (ε-caprolactone) 25-mer alternating multiblock copolymer (PLGA-PCL alternating MBC)

A poly (L-lactide-co-glycolide) 25-mer-poly (ε-caprolactone) 25-mer diblock copolymer (1.00 g, 0.138 mmol), dimethyl Aminopyridine p-Toluenesulfonic acid (8.8 g, 0.028 mmol) and dimethylaminopyridine (7.4 g, 0.055 mmol) were added, and 3 mL of dehydrated dichloromethane was added to dissolve. Thereafter, molecular sieves were added for dehydration, and the mixture was shaken overnight. DIPCI (40.9 μL, 0.276 mmol) was added, and the mixture was reacted at room temperature with shaking for 24 hours. After the reaction, reprecipitation of methanol was performed, followed by suction filtration and vacuum drying at 40 ° C. to obtain the desired product (yield: 0.95 g, yield: 94%, GPC (CHCl ₃ ): M _w = 320,000, M _w / ^{_{M n = 1.73, 1 H NMR}} (500 MHz, CDCl 3): 5.18 (q, 1H, COC H (CH 3) O), 4.81 (m, 2H, COC H 2 O), 4.08 (t, 2H, CH _{2 C H 2 O), 2.31} (t, 2H, COC H 2 CH 2), 1.66 (m, 4H, COCH 2 C H 2 CH 2, CH 2 C H 2 CH 2 O), 1.58 (d, 3H, _{COCH (C H 3) O)} , 1.39 (m, 2H, COCH 2 CH 2 C H 2 CH 2 CH 2 O)).

<Comparative Synthesis Example 2>
Synthesis of poly (1,5-dioxepan-2-one) (PDXO homopolymer)

After heating and drying the 20 ml Schlenk tube using a heat gun, the tube was degassed and replaced with nitrogen using a diaphragm pump. DXO (1.357 mL) and Sn (Oct) ₂ (4.80 μL) as a catalyst were added, and the mixture was stirred in an oil bath at 100 ° C. for 0.5 hour. Thereafter, the mixture was stirred at 130 ° C. for 8 hours to be reacted. After completion of the reaction, several drops of acetic acid and 4 ml of chloroform were added to deactivate the catalyst. Thereafter, diethyl ether was reprecipitated in an ice bath. It was collected by suction filtration and vacuum dried at room temperature. (Yield: 1.44 g, Yield: 95.8%, GPC (CHCl ₃ ): M _w = 128,000, M _w / M _n = 6.48)
^{1 H NMR (500 MHz, CDCl} 3): 4.23 (t, 2H, OCH 2 C H 2 OCO), 3.76 (t, 2H, OCOCH 2 C H 2 O), 3.67 (t, 2H, OC H 2 CH 2 OCO), 2.62 (t, 2H , OCOC H 2 CH 2 O).

<Comparative Synthesis Example 3>
Synthesis of poly (L-lactide-co-glycolide) (PLGA homopolymer)

A poly (L-lactide-co-glycolide) 25-mer (0.50 g, 0.138 mmol) and dimethylaminopyridine p-toluenesulfonic acid (8.8 g, 0.028 mmol) were placed in a Schlenk tube which was baked with a heat gun and purged with nitrogen. ) And dimethylaminopyridine (7.4 g, 0.055 mmol) were added, and 2 mL of dehydrated dichloromethane was added and dissolved. Thereafter, molecular sieves were added for dehydration, and the mixture was shaken overnight. DIPCI (40.9 μL, 0.276 mmol) was added, and the mixture was reacted at room temperature by shaking for 24 hours. After the reaction, reprecipitation of methanol was performed, followed by suction filtration and vacuum drying at 40 ° C. to obtain the desired product (yield: 0.46 g, yield: 90%,
_{GPC (CHCl 3): M w} = 180,000, M w / M n =, 1.49, 1 H NMR (500 MHz, CDCl 3): 5.18 (q, 1H, COC H (CH 3) O), 4.81 (m, _{2H, COC H 2 O),} 1.58 (d, 3H, COCH (C H 3) O).

  A 15 mg / mL chloroform solution of the polymer synthesized according to the above synthesis examples and comparative synthesis examples was prepared and cast on a glass substrate to form a thin film. As a mixed film of a homopolymer of poly (1,5-dioxepan-2-one) and poly (L-lactide-co-glycolide), 1 mL of 7.5 mg of each homopolymer synthesized in Comparative Synthesis Examples 2 and 3 was used. In chloroform and cast on a glass substrate in the same manner as described above to form a thin film.

<Human platelet adhesion test>
Six quick eye partners (sodium citrate: anticoagulant (Nipro Corporation)) were added to the centrifuge tube, and 6.7 mL of human blood was collected and stirred. This was centrifuged at 900 rpm for 10 minutes, and the supernatant (PRP (= platelet rich plasma, plasma containing many platelets)) was collected. After that, the mixture was centrifuged at 3000 rpm for 10 minutes, and the supernatant (PPP (= platelet poor plasma, plasma with few platelets)) was collected. The platelet counts of both PRP and PPP were counted (PRP = 7.08 × 10 ⁸ platelets / mL, PPP = 1.50 × 10 ⁷ pletelets / mL). 0.1 mL of PRP and 1.9 mL of PPP were added to prepare a 2 mL platelet sample so that the platelet concentration became 5.0 × 10 ⁷ platelets / mL.

  A hydrophobic circle was drawn with a liquid blocker on the glass substrate on which the sample thin film was cast, and about 200 μL of the prepared platelet sample was dropped. This was incubated at 37 ° C. for 1 h, the glass substrate after the incubation was washed with PBS (aqueous phosphate buffer solution), and a 1% glutaraldehyde solution (immobilizing reagent, 20% glutaraldehyde purchased from Wako Pure Chemical Industries, Ltd.) About 200 μL of the aldehyde solution was diluted with PBS, and the mixture was again incubated at 37 ° C. for 30 minutes. After the incubation, the glass substrate was washed, and a BD Perm / Wash solution (prepared by diluting a reagent for permeation, purchased from Becton, Dickinson and Company by 10 times with PBS) into the membrane was dropped by about 200 μL, and the membrane was dropped at room temperature for 10 minutes. It was left still. Thereafter, an ActinGreen solution (1 mL of BD Perm / Wash solution to which 2 drops of ActinGreen was added, and ActinGreen purchased from Life Technologies Corporation) was prepared, dropped in about 200 μL, and allowed to stand at room temperature for 30 minutes while shielding from light. The still glass substrate was washed with PBS and observed with a microscope. The number of adhered platelets was counted from an image obtained by a microscope, and a significant difference test was performed by Student's t test. The significance level was P = 0.01.

<Example 1>
1 and 2 show the results of the human platelet adhesion test (Example 1) performed as described above.
FIG. 1 shows a microscope observation image (dark field). FIG. 2 shows the results of the obtained platelet adhesion number. "PMEA" is mentioned as an example having a surface on which platelets are hardly adhered, and "PLGA-PCL alternating MBC" is mentioned as an example having a surface on which platelets are easily adhered.

(PMEA)
The above test was performed using a thin film made of poly (2-methoxyethyl acrylate) (PMEA) (synthesized by radical polymerization).
(PLGA-PDXO RMBC 50:50)
The above test was performed using the thin film composed of PLGA-PDXO RMBC 50:50 obtained in Synthesis Example 2.
(PLGA-PDXO alternate MBC)
The above test was performed using the thin film composed of the PLGA-PDXO alternating MBC obtained in Synthesis Example 1.
(PLGA-PCL alternate MBC)
The above test was performed using the thin film composed of the PLGA-PCL alternating MBC obtained in Comparative Synthesis Example 1.

  “PLGA-PDXO alternate MBC” and “PLGA-PDXO RMBC 50:50” both had lower platelet adhesion numbers than “PLGA-PCL alternate MBC”. In addition, there was no significant difference in the platelet adhesion number between “PLGA-PDXO alternate MBC” and “PLGA-PDXO RMBC 50:50”.

<Example 2>
3 and 4 show the results of the human platelet adhesion test (Example 2) performed as described above.
FIG. 3 shows a microscope observation image (dark field). FIG. 4 shows the results of the obtained platelet adhesion number. "PMEA" is mentioned as an example having a surface on which platelets are hardly adhered, and "PLGA-PCL alternating MBC" is mentioned as an example having a surface on which platelets are easily adhered.

(PMEA)
The above test was performed using a thin film made of poly (2-methoxyethyl acrylate) (PMEA) (synthesized by radical polymerization).
(PLGA-PDXO RMBC 13:87)
The above test was performed using the thin film composed of PLGA-PDXO RMBC 13:87 obtained in Synthesis Example 2.
(PLGA-PDXO RMBC 40:60)
The above test was performed using the thin film composed of PLGA-PDXO RMBC 40:60 obtained in Synthesis Example 2.
(PLGA-PDXO RMBC 50:50)
The above test was performed using the thin film composed of PLGA-PDXO RMBC 50:50 obtained in Synthesis Example 2.
(PLGA-PDXO RMBC 64:36)
The above test was performed using the thin film composed of PLGA-PDXO RMBC 64:36 obtained in Synthesis Example 2.
(PLGA-PDXO RMBC 71:29)
The above test was performed using the thin film composed of PLGA-PDXO RMBC 71:29 obtained in Synthesis Example 2.
(PLGA-PDXO RMBC 81:19)
The above test was performed using the thin film composed of PLGA-PDXO RMBC 81:19 obtained in Synthesis Example 2.
(PLGA-PDXO RMBC 94: 6)
The above test was performed using the thin film composed of PLGA-PDXO RMBC 94: 6 obtained in Synthesis Example 2.
(PLGA-PCL alternate MBC)
The above test was performed using the thin film composed of the PLGA-PCL alternating MBC obtained in Comparative Synthesis Example 1.

  In “PLGA-PDXO RMBC 94: 6”, it was also observed that the platelet adhesion number was smaller than “PLGA-PCL alternate MBC”. Platelet adhesion number decreased with increasing PDXO segment ratio. On the other hand, “PLGA-PDXO MBC 13:87” showed a platelet adhesion number equivalent to “PLGA-PCL alternating MBC”.

<Example 3>
5 and 6 show the results of the human platelet adhesion test (Example 3) performed as described above.
FIG. 5 shows a microscope observation image (dark field). FIG. 6 shows the results of the obtained platelet adhesion number. "PMEA" is mentioned as an example having a surface on which platelets are hardly adhered, and "PLGA-PCL alternating MBC" is mentioned as an example having a surface on which platelets are easily adhered.

(PMEA)
The above test was performed using a thin film made of poly (2-methoxyethyl acrylate) (PMEA) (synthesized by radical polymerization).
(PDXO homopolymer)
The above test was performed using the thin film made of the PDXO homopolymer obtained in Comparative Synthesis Example 2.
(PLGA-PDXO RMBC 13:87)
The above test was performed using the thin film composed of PLGA-PDXO RMBC 13:87 obtained in Synthesis Example 2.
(PLGA-PDXO RMBC 26:74)
The above test was performed using the thin film composed of PLGA-PDXO RMBC 26:74 obtained in Synthesis Example 2.
(PLGA PDXO mixture)
The above test was performed using a thin film composed of a mixture of the PDXO homopolymer obtained in Comparative Synthesis Example 2 and the PLGA homopolymer obtained in Comparative Synthesis Example 3.
(PLGA-PCL alternate MBC)
The above test was performed using the thin film composed of the PLGA-PCL alternating MBC obtained in Comparative Synthesis Example 1.

  “PLGA-PDXO RMBC 26:74” had a low platelet adhesion number, while “PLGA-PDXO13: 87” had a high platelet adhesion number. Both the “PDXO homopolymer” and the “PLGA-PDXO mixture” had higher platelet adhesion numbers.

  The reason for this is considered to be the difference in the state of the film surface. FIG. 7 shows a phase image of each sample by an atomic force microscope (AFM). The bright part is the domain formed from the PDXO component. It can be seen that "PLGA-PDXO RMBC 26:74", which has a low platelet adhesion number, forms a microphase-separated structure of both components. In “PLGA-PDXO RMBC 13:87”, the PDXO component occupied the majority, and the domains of the PLGA segment were dispersed. In the “PLGA-PDXO mixture”, it can be seen that the aggregate of the PDXO component forms a large domain. In the case of “PDXO homopolymer”, a uniform surface of PDXO was observed. From these results, it is considered that platelet adhesion occurs when the PDXO component itself or a large domain of PDXO is formed on the surface, and is suppressed when this becomes a microphase-separated structure.

<Example 4>
8 and 9 show the results of the human platelet adhesion test (Example 4) performed as described above.
FIG. 8 shows a microscope observation image (dark field). FIG. 9 shows the results of the obtained platelet adhesion number. "PMEA" is mentioned as an example having a surface on which platelets are hardly adhered, and "PLGA-PCL alternating MBC" is mentioned as an example having a surface on which platelets are easily adhered.

(PLGA-PCL alternate MBC)
The above test was performed using the thin film composed of the PLGA-PCL alternating MBC obtained in Comparative Synthesis Example 1.
(MBC5)
The above test was performed using a thin film composed of PLGA-PDXO alternating MBC (segment length pentamer) synthesized in the same manner as in Synthesis Example 1.
(MBC10)
The above test was conducted using a thin film composed of PLGA-PDXO alternating MBC (segment length 10 mer) synthesized in the same manner as in Synthesis Example 1.
(MBC25)
The above test was conducted using a thin film composed of PLGA-PDXO alternating MBC (segment length 25 mer) synthesized in the same manner as in Synthesis Example 1.
(PMEA)
The above test was performed using a thin film made of poly (2-methoxyethyl acrylate) (PMEA) (synthesized by radical polymerization).
Even with “MBC5”, the platelet adhesion number was smaller than “PLGA-PCL alternate MBC”. The adhesive number decreased with increasing segment length.

  AFM measurement was performed on the surface state of each sample (FIG. 10). In “MBC10” and “MBC25”, a microphase-separated structure was observed on the surface, which is considered to be effective in suppressing platelet adhesion. On the other hand, “MBC5” had a uniform film surface. Although the platelet adhesion is suppressed by the effect of the PDXO component, it is considered that the number of adhesions was larger than that of the surface forming the microphase separation structure.

<Example 5>
11 and 12 show the results of the human platelet adhesion test (Example 5) performed as described above.
FIG. 11 shows a microscope observation image (dark field). FIG. 12 shows the results of the obtained platelet adhesion number. "PMEA" is mentioned as an example having a surface on which platelets are hardly adhered, and "PLGA-PCL alternating MBC" is mentioned as an example having a surface on which platelets are easily adhered.

(PLGA-PCL alternate MBC)
The above test was performed using the thin film composed of the PLGA-PCL alternating MBC obtained in Comparative Synthesis Example 1.
(DBC)
The above test was performed using the thin film made of PLGA-PDXO DBC obtained in Synthesis Example 3.
(TBC)
The above test was performed using the thin film composed of PLGA-PDXO-PLGA TBC obtained in Synthesis Example 4.
(MBC)
The above test was performed using the thin film composed of the PLGA-PDXO alternating MBC obtained in Synthesis Example 1.
(PMEA)
The above test was performed using a thin film made of poly (2-methoxyethyl acrylate) (PMEA) (synthesized by radical polymerization).

  "DBC" and "TBC" had low platelet adhesion numbers, and the numbers were equivalent to "MBC".

<Example 6>
13 and 14 show the results of the human platelet adhesion test (Example 6) performed as described above.
FIG. 13 shows a microscope observation image (dark field). FIG. 14 shows the results of the obtained platelet adhesion number. "PMEA" is mentioned as an example having a surface on which platelets are hardly adhered, and "PLGA-PCL alternating MBC" is mentioned as an example having a surface on which platelets are easily adhered.

(PLGA-PCL alternate MBC)
The above test was performed using the thin film composed of the PLGA-PCL alternating MBC obtained in Comparative Synthesis Example 1.
(DL)
In the same manner as in Synthesis Example 1, an alternating multiblock copolymer of PDLLA (25-mer) and PDXO (25-mer) using D-lactic acid and L-lactic acid for the hard segment was synthesized, and this thin film was used. The above test was conducted.
(RC)
The above test was performed using the thin film obtained in Synthesis Example 5 and comprising a random copolymer (RC) of PLLA and PDXO.
(PMEA)
The above test was performed using a thin film made of poly (2-methoxyethyl acrylate) (PMEA) (synthesized by radical polymerization).

  In both “DL” and “RC”, the platelet adhesion number was smaller than “PLGA-PCL alternate MBC” of the control.

<Example 7>
FIG. 15 shows the results of the human platelet adhesion test (Example 7) performed as described above, and shows the relationship between the hard segment molecular structure and the platelet adhesion number in the multi-block copolymer.
"PLGA-PCL alternating MBC" was mentioned as an example having a surface to which platelets tend to adhere.

(PLGA-PCL alternate MBC)
A PLGA-PCL alternating MBC (Mw = 142,000) was synthesized in the same manner as in Comparative Synthesis Example 1, and the above test was performed using this thin film.
(PLGA-PDXO alternate MBC)
PLGA-PDXO alternating MBC (Mw = 129,000) was synthesized by the same method as in Synthesis Example 1, and the above test was performed using this thin film.
(PLLA-PDXO alternate MBC)
In the same manner as in Synthesis Example 1, an alternating multi-block copolymer (Mw = 54,000) of PLLA (25-mer) and PDXO (25-mer) using L-lactic acid for the hard segment was prepared. The above test was performed using a thin film.

  The platelet adhesion numbers of “PLGA-PDXO alternating MBC” and “PLLA-PDXO alternating MBC” were both lower than “PLGA-PCL alternating MBC”, and no significant difference was observed between the PLGA system and the PLLA system.

<Example 8>
FIG. 16 shows the results of the human platelet adhesion test (Example 8) performed as described above, and shows the relationship between the hard segment molecular structure and the platelet adhesion number in the multi-block copolymer.
"PLGA-PCL alternating MBC" was mentioned as an example having a surface to which platelets tend to adhere.

(PLGA-PCL alternate MBC)
A PLGA-PCL alternating MBC (Mw = 142,000) was synthesized in the same manner as in Comparative Synthesis Example 1, and the above test was performed using this thin film.
(PDLLA-PDXO alternate MBC)
In the same manner as in Synthesis Example 1, an alternating multiblock copolymer (Mw = 37,000) of PDLLA (25-mer) and PDXO (25-mer) using D-lactic acid and L-lactic acid for the hard segment was prepared. The thin film was synthesized, and the above test was performed using this thin film.
(PDLA-PDXO alternating MBC)
In the same manner as in Synthesis Example 1, an alternating multiblock copolymer (Mw = 116,000) of PDLA (25-mer) and PDXO (25-mer) using D-lactic acid for the hard segment was synthesized. The above test was performed using a thin film.
(PMEA)
The above test was performed using a thin film made of poly (2-methoxyethyl acrylate) (PMEA) (synthesized by radical polymerization, Mw = 365,000).

  "PDLLA-PDXO alternating MBC" and "PDLA-PDXO alternating MBC" also showed a low platelet adhesion number, indicating that PLGA, PLLA, PDLLA, and PDLA were all effective as hard segments.

<Example 9>
17 and 18 show the results of the human platelet adhesion test (Example 9) performed as described above.
FIG. 17 shows a microscope observation image (dark field). FIG. 18 shows the results of the obtained platelet adhesion number. "PMEA" is mentioned as an example having a surface on which platelets are hardly adhered, and "PLGA-PCL alternating MBC" is mentioned as an example having a surface on which platelets are easily adhered.

(PMEA)
The above test was performed using a thin film made of poly (2-methoxyethyl acrylate) (PMEA) (synthesized by radical polymerization).
(PLGA-PDXO alternate MBC)
PLGA-PDXO alternating MBC (Mw = 130,000, Mw / Mn = 1.22) was synthesized by the same method as in Synthesis Example 1, and the above-described test was performed using this thin film.
(PLGA-PDO alternate MBC)
The above test was performed using the thin film composed of PLGA-PDO alternating MBC obtained in Synthesis Example 6.
(PLGA-PCL alternate MBC)
The above test was performed using the thin film composed of the PLGA-PCL alternating MBC obtained in Comparative Synthesis Example 1.

  From these results, it was confirmed that the platelet adhesion number for the PLGA-PDO alternating MBC was lower than that of the PLGA-PCL alternating MBC, and that the platelet was usable as an antithrombotic material.

<Example 10>
(Human platelet adhesion test)
A 10 mg / mL chloroform solution of the polymer synthesized according to the above synthesis example was prepared and cast on a glass substrate to form a thin film. Thereafter, the prepared film was subjected to a platelet adhesion test by the method described in the above-mentioned human platelet adhesion test, and its use as an antithrombotic material was examined.

(PMEA)
The above test was performed using a thin film made of poly (2-methoxyethyl acrylate) (PMEA) (synthesized by radical polymerization).
(PLLA50-PEO alternate MBC)
The above test was performed using a thin film composed of PLLA50-PEO alternating MBC obtained in Synthesis Example 7.
(PLLA26-PEO alternate MBC)
The above test was performed using a thin film composed of PLLA26-PEO alternating MBC obtained in Synthesis Example 7.
(PLGA-PCL alternate MBC)
The above test was performed using the thin film composed of the PLGA-PCL alternating MBC obtained in Comparative Synthesis Example 1.

  19 and 20 show the results of the human platelet adhesion test performed as described above. FIG. 19 shows a microscope observation test image (dark field). FIG. 20 shows the results of the obtained platelet adhesion number. "PMEA" is mentioned as an example having a surface on which platelets are hardly adhered, and "PLGA-PCL alternating MBC" is mentioned as an example having a surface on which platelets are easily adhered. From these results, it was confirmed that the platelet adhesion number of each of the PLLA50-PEO alternating MBC and the PLLA26-PEO alternating MBC was lower than that of the PLGA-PCL alternating MBC, and that they were usable as antithrombotic materials.

<Example 11>
(Cell culture test, Hela cells, PLGA-PDXO alternate MBC)
For comparison, PLGA-PDXO alternating MBC and Cellmatrix Type IC (Nitta Gelatin Co., Collagen, Type I, 3 mg / mL, pH 3.0) as a positive control and LIPIDURE as a negative control for comparison. (Registered trademark) -CM5206 (MPC polymer) was prepared. The culture of HeLa cells, which are cells derived from human cervical cancer, was monitored, and cell counts and WST tests were performed 1 day, 2 days, and 3 days after seeding the cells, and the cell growth behavior was evaluated.
PLGA-PDXO alternating MBC chloroform solution (4.75 mg / 250 μL) is directly cast on an autoclave-sterilized glass Petri dish in a clean bench (aseptic state), left for 3 hours, and dried in vacuum overnight to alternate PLGA-PDXO A Petri dish coated with MBC was prepared. A methanol solution of LIPIDURE (registered trademark) -CM5206 (4.75 mg / 250 μL) was similarly cast, allowed to stand for 3 hours, and then vacuum-dried overnight to prepare a petri dish coated with LIPIDURE (registered trademark) -CM5206. . Cellmatrix Type IC was diluted 10 ⁶ times with an aqueous HCl solution, placed on an autoclave-sterilized glass Petri dish, allowed to stand for 30 minutes or more, and then washed 3 to 4 times with a Minimum Essential Media (MEM) medium before use. .

1 mL of the prepared HeLa cell solution (4.0 × 10 ⁴ cells / mL) was dropped on a Petri dish coated with PLGA-PDXO alternating MBC, Cellmatrix Type IC, and LIPIDURE (registered trademark) -CM5206, respectively, and was heated at 37 ° C. And cultured. In the case of cell count, the number of cells after 1 day, 2 days, and 3 days was counted using a hemocytometer. In the case of the WST test, Cell Coating Kit-8 (WST-1) was added to a glass Petri dish in 50 μL cell culture, and the cells were cultured at 37 ° C. for 3 hours. Then, 150 μL was placed in a 96-well plate, and the absorbance at 450 nm was measured. FIG. 21 shows the state of the culture after 72 hours, FIG. 22 shows the result of cell count, and FIG. 23 shows the result of the WST test. From all the results, it was confirmed that HeLa cells proliferated on the PLGA-PDXO alternate MBC, and that the substrate was a cell culture-capable substrate.

(Cell culture test, HUVEC cells, PLGA-PDXO alternating MBC)
For comparison, PLGA-PDXO alternating MBC and Cellmatrix Type IC (Nitta Gelatin Co., Collagen, Type I, 3 mg / mL, pH 3.0) as a positive control and LIPIDURE as a negative control for comparison. (Registered trademark) -CM5206 (MPC polymer) was prepared. As the human umbilical vein endothelial cell HUVEC cells used for the test, cells of passages 5 to 7 are used, and the culture medium EGM (registered trademark) -2 SingleQuots (registered trademark) (Lonza Japan, 0.2 mL Hydrocortisone solution, 0.5mL GA-1000, 10mL Fetal Bovine Serum, 2mL Human Fibroblast Growth Factor basic (hFGFb), 0.5mL Human Vascular Growth GF Long R3-IGF-1, 0.5 mL Ascorbic Acid Sol union, 0.5 mL Human Epidermal Growth Factor (hEGF), including 0.5 mL Heparin) was used. After the start of the test, the proliferation of HUVEC cells was monitored, and cell counts and WST tests were performed one day, two days, and three days after seeding the cells, and the cell growth behavior was evaluated.

PLGA-PDXO alternating MBC chloroform solution (4.75 mg / 250 μL) is directly cast on an autoclave-sterilized glass Petri dish in a clean bench (aseptic state), left for 3 hours, and dried in vacuum overnight to alternate PLGA-PDXO A Petri dish coated with MBC was prepared. A methanol solution of LIPIDURE (registered trademark) -CM5206 (4.75 mg / 250 μL) was similarly cast, allowed to stand for 3 hours, and then vacuum-dried overnight to prepare a petri dish coated with LIPIDURE (registered trademark) -CM5206. . Cellmatrix Type IC was diluted 10 ⁶ times with an aqueous HCl solution, placed on an autoclave-sterilized glass Petri dish, allowed to stand for 30 minutes or more, and then washed 3 to 4 times with a Minimum Essential Media (MEM) medium before use. .

1 mL of the adjusted HUVEC cell suspension (2.0 × 10 ⁴ cells / mL) was dropped on a Petri dish coated with PLGA-PDXO alternating MBC, Cellmatrix Type IC, and LIPIDURE®-CM5206, respectively. The cells were cultured at 37 ° C. In the case of cell count, the number of cells after one day, two days, and three days was counted using a hemocytometer. In the case of the WST test, Cell Counting Kit-8 (WST-8) was added to a glass Petri dish in 50 μL cell culture, cultured at 37 ° C. for 4 hours, 150 μL of the supernatant was placed in a 96-well plate, and the absorbance at 450 nm was measured. FIG. 24 shows the state of culture after 72 hours, FIG. 25 shows the result of cell count, and FIG. 26 shows the result of the WST test. From all the results, it was confirmed that the HUVEC cells proliferated on the PLGA-PDXO alternating MBC, and that the cells were a substrate capable of cell culture.

(Cell culture test, HeLa cells, PLGA-PDO alternating MBC)
PLGA-PDO alternating MBC synthesized in Synthesis Example 6 above, and Cellmatrix Type IC (Nitta Gelatin Co., Ltd., Collagen, Type I, 3 mg / mL, pH 3.0) as a positive control and LIPIDURE as a negative control for comparison. (Registered commercial) -CM5206 (MPC polymer), and PLGA-PDXO alternating MBC synthesized in Synthesis Example 1 were prepared as a comparative object.
In this example, the culture of HeLa cells, which are cells derived from human cervical cancer, was followed up, and after 1 day, 2 days, and 3 days after the cells were dropped, cell count and WST test were performed. The purpose of use was discussed.
A chloroform solution (12.5 mg / 250 μL) of PLGA-PDO alternating MBC was directly cast on a glass petri dish sterilized in an autoclave in a clean bench (aseptic condition), the lid of the petri dish was closed, and the mixture was heated at 40 ° C. on a hot plate. After leaving still for 1 hour, vacuum drying was performed overnight to prepare a Petri dish coated with PLGA-PDO alternating MBC. A PLGA-PDXO alternating MBC chloroform solution (4.75 mg / 250 μL) was directly cast on an autoclave-sterilized glass Petri dish in a clean bench (aseptic condition), allowed to stand for 3 hours, and dried in vacuo overnight to remove PLGA- Petri dishes coated with PDXO alternating MBC were made. A methanol solution of LIPIDURE (registered trademark) -CM5206 (4.75 mg / 250 μL) was similarly cast, allowed to stand for 3 hours, dried in vacuo overnight, and coated with LIPIDURE (registered trademark) -CM5206 (MPC polymer). A petri dish was prepared. Cellmatrix Type IC was diluted 10 ⁶ times with an aqueous HCl solution, placed on an autoclave-sterilized glass Petri dish, allowed to stand for 30 minutes or more, and then washed 3 to 4 times with a Minimum Essential Media (MEM) medium before use. .

In the cell solution used for the cell culture test, the medium on the 10 cm dish in which HeLa cells were cultured was removed, 2 mL of a trypsin / ethylenediaminetetraacetate (EDTA) enzyme solution was added, and the mixture was incubated at 37 ° C. for 3 minutes. Thereafter, 8 mL of medium was added to stop the function of the enzyme, and then centrifuged at 1500 rpm for 3 minutes. After removing the supernatant, the number of cells was counted using a microscope, a medium was added, and a cell solution was prepared so that the seeding density was 2.0 × 10 ⁴ cells / mL.
A Petri dish obtained by casting 1 mL of the prepared HeLa cell suspension (2.0 × 10 ⁴ cells / mL) with PLGA-PDO alternating MBC, PLGA-PDXO alternating MBC, and LIPIDURE®-CM5206 (MPC polymer). And Cellmatrix Type 1-C were dropped on a Petri dish, and cultured at 37 ° C. In the case of cell count, the number of cells after one day, two days, and three days was counted using a hemocytometer. In the case of the WST test, Cell Counting Kit-8 (WST-8) was added to a glass Petri dish in 50 μL cell culture, cultured at 37 ° C. for 4 hours, 150 μL of the supernatant was placed in a 96-well plate, and the absorbance at 450 nm was measured. 27 and 28 show the state of culture after 72 hours, FIG. 29 shows the results of cell count, and FIG. 30 shows the results of the WST test. From all the results, it was confirmed that HeLa cells proliferated on the PLGA-PDO alternating MBC, and that the substrate was a substrate on which cell culture was possible.

(Cell culture test, HUVEC cells, PLGA-PDO alternating MBC)
PLGA-PDO alternating MBC synthesized in Synthesis Example 6 above, and Cellmatrix Type IC (Nitta Gelatin Co., Ltd., Collagen, Type I, 3 mg / mL, pH 3.0) as a positive control and LIPIDURE as a negative control for comparison. (Registered commercial) -CM5206 (MPC polymer), and PLGA-PDXO alternating MBC synthesized in Synthesis Example 1 were prepared as a comparative object.
Human umbilical vein endothelial cells, HUVEC cells, which are cells used for the test, use cells at passages 5 to 7, and during culture, medium EGM (registered trademark) -2 SingleQuots (registered trademark) (Lonza Japan, 0.2 mL Hydrocortisone solution, 0.5mL GA-1000, 10mL Fetal Bovine Serum, 2mL Human Fibroblast Growth Factor basic (hFGFb), 0.5mL Human Vascular Eng. Long R3-IGF-1, 0.5 mL Ascorbic Acid Sol union, 0.5 mL Human Epidermal Growth Factor (hEGF), including 0.5 mL Heparin) was used. After the start of the test, the proliferation of HUVEC cells was monitored, and cell counts and WST tests were performed one day, two days, and three days after seeding the cells, and the cell growth behavior was evaluated.

A chloroform solution (12.5 mg / 250 μL) of PLGA-PDO alternating MBC was directly cast on an autoclave-sterilized glass Petri dish in a clean bench (aseptic condition), the lid of the Petri dish was closed, and heated at 40 ° C. on a hot plate. After standing for 1 hour, vacuum drying was performed overnight to prepare a Petri dish coated with PLGA-PDO alternating MBC. A PLGA-PDXO alternating MBC chloroform solution (4.75 mg / 250 μL) was directly cast on an autoclave-sterilized glass Petri dish in a clean bench (sterile state), allowed to stand for 3 hours, and dried in vacuum overnight to remove PLGA- Petri dishes coated with PDXO alternating MBC were made. A methanol solution of LIPIDURE (registered trademark) -CM5206 (4.75 mg / 250 μL) was similarly cast, allowed to stand for 3 hours, dried in vacuo overnight, and coated with LIPIDURE (registered trademark) -CM5206 (MPC polymer). A petri dish was prepared. Cellmatrix Type IC was diluted 10 ⁶ times with an aqueous HCl solution, placed on an autoclave-sterilized glass Petri dish, allowed to stand for 30 minutes or more, and then washed 3 to 4 times with a Minimum Essential Media (MEM) medium before use. .

In the cell solution used for the cell culture test, the medium on the 10 cm dish in which the HUVEC cells were cultured was removed, about 2 mL of MEM medium was added, and the cell solution was washed once. After removing the MEM medium, trypsin / ethylenediaminetetraacetic acid was removed. 2 mL of an ion (EDTA) enzyme solution was added and incubated at 37 ° C. for 3 minutes. Thereafter, 8 mL of medium was added to stop the function of the enzyme, and then centrifuged at 1500 rpm for 3 minutes. After removing the supernatant, the number of cells was counted using a microscope, a medium was added, and a cell solution was prepared so that the seeding density was 2.0 × 10 ⁴ cells / mL.
A petri dish prepared by casting 1 mL of the prepared HUVEC cell suspension (2.0 × 10 ⁴ cells / mL) with PLGA-PDO alternating MBC, PLGA-PDXO alternating MBC, and LIPIDURE®-CM5206 (MPC polymer). And Cellmatrix Type I-C were dropped on a Petri dish, and cultured at 37 ° C. In the case of cell count, the number of cells after one day, two days, and three days was counted using a hemocytometer. In the case of the WST test, Cell Counting Kit-8 (WST-8) was added to a glass Petri dish in 50 μL cell culture, cultured at 37 ° C. for 4 hours, 150 μL of the supernatant was placed in a 96-well plate, and the absorbance at 450 nm was measured. 31 and 32 show the state of culture after 72 hours, FIG. 33 shows the result of cell count, and FIG. 34 shows the result of the WST test. From all the results, it was confirmed that the HUVEC cells proliferated on the PLGA-PDO alternating MBC, and that the substrate was capable of cell culture.

<Example 12>
(Hydrolysis behavior)
FIGS. 35 and 36 show a phosphate buffer (pH 7.4) of the PLGA-PDXO alternating multi-block copolymer (segment degree of polymerization 25, M _w = 129,000, M _w / M _n = 2.03) synthesized in Synthesis Example 1. Shows the hydrolysis behavior of. As the hydrolysis progressed, a decrease in the contact angle, a decrease in the weight, and a decrease in the molecular weight were observed. In FIG. 35, it can be seen that the contact angle becomes extremely hydrophilic at 10-20 ° with the progress of hydrolysis from a relatively hydrophobic surface of about 70 ° in the initial stage. A weight loss was confirmed slowly with the hydrolysis, and after 14 weeks, a 24% weight loss was observed. FIG. 36 shows the molecular weight of the remaining component. The molecular weight of the remaining components was about 25,000-30,000.

<Example 13>
(Mechanical properties)
FIG. 37 shows a self-standing film of the PLGA-PDXO alternating multi-block copolymer (segment length 25 mer) synthesized in Synthesis Example 1. The film cast from the chloroform solution showed self-sustainability even when peeled from the glass substrate, and was in a state that was easy to handle. FIG. 38 shows a stress-strain curve of this film obtained by a tensile test, and Table 1 shows mechanical characteristic data. The high Young's modulus (elastic modulus) calculated from the initial gradient of the stress-strain curve is unique to the multi-block copolymer and reflects the ease of handling as a self-supporting film. ). The average of the elongation at break exceeded 800%, and it was confirmed that the film was stretched well and was a tough film. These properties cannot be achieved with polymers having a glass transition temperature of room temperature or lower, such as conventional antithrombotic materials such as PMEA, PMPC, and polytrimethylene carbonate.

Claims (6)

Aliphatic polyester which is a copolymer of a hydrophobic component and a hydrophilic component,
The hydrophilic component comprises at least one of poly (1,5-dioxepan-2-one), poly (1,4-dioxan-2-one), or polyethylene oxide;
A biodegradable copolymer exhibiting antiplatelet adhesion, wherein the molar ratio of the hydrophilic component is 5% or more and 85% or less.   The hydrophobic component comprises at least one of poly (L-lactic acid), poly (D-lactic acid), poly (D, L-lactic acid), or a polylactic acid-polyglycolic acid copolymer. The copolymer according to the above.   3. The copolymer according to claim 1, wherein the bond between the hydrophilic component and the hydrophobic component is any of random, block, and multi-block. 4.   A thin film having antiplatelet adhesion and biodegradability, comprising the copolymer according to claim 1.   A molded article having antiplatelet adhesion and biodegradability, comprising the copolymer of claim 1.   A medical device wherein the thin film or the molded article according to claim 4 or 5 is provided at a position where the thin film or the molded body comes into contact with a living tissue.