KR100590137B1 - Vinylic Monomer and Polymer Containing Sulfonated PEO and Preparation Thereof - Google Patents

Abstract

The present invention relates to vinyl monomers containing sulfonated polyethylene oxide (PEO, poly (ethylene oxide)), polymers thereof, and methods for their preparation.

Since the polymer and the surface graft modifier made of the monomer of the present invention are excellent in antithrombogenicity, it can be applied as a medical material in contact with blood.

Sulfonated PEO-containing vinyl monomer, antithrombogenic polymer, medical material

Description

Vinyl Monomer and Polymer Containing Sulfonated PEO and Preparation Thereof}

The present invention relates to novel vinyl monomers containing the sulfonated polyethylene oxides (PEO, poly (ethylene oxide), also called polyethylene glycol (PEG, poly (ethylene glycol)), polymers thereof and methods for their preparation.

Many studies have been conducted on hydrophilic, hydrophobic, hydrophilic / hydrophobic micro-domain structures and anionic surfaces to improve the antithrombotic properties of materials. Among them, the surface where PEO is bound has been reported to reduce adhesion of blood components such as proteins and platelets and thus improve antithrombogenicity. This is because flexible water-soluble PEO chain motion prevents adhesion of blood components and interfacial energy. Is due to small size (see JDAndrade et al., Biomaterials 11, 455, 1990).

The present inventors have previously announced that sulfonated PEO exhibits antithrombogenicity (14% of heparin) similar to heparin (Kim Young-Ha et al., Korean Patent No. 131,058; Biomaterials 16, 467, 1995), It has been reported that the binding adds an antithrombotic effect of sulfonic acid groups to the non-adhesion of PEO, thereby significantly increasing antithrombogenicity (Kim Young-ha et al., Korean Patent No. 62,921; J. Biomed. Mat. Res., 25 , 561, 1991). In addition, the present inventors have reported that a block polymer composed of a hydrophilic polymer of sulfonated PEO and a hydrophobic polymer of alkyl ester, alkyl ether or propylene oxide shows excellent antithrombogenicity (Kim Young-ha et al., Korean Patent No. 175,975).

Several researchers have published many studies that improve the antithrombotic and biocompatibility of materials by using surface graft polymerization of monomers containing PEO-containing polymers or PEO derivatives (M.Harris et al., PEG Chemistry and Biological Applications, ACS). , 1997). Representative monomers containing PEO are commonly available as vinyl compounds in which hydroxyl groups at the usual PEO end are substituted with either acrylic or methacrylic groups at one or both ends. However, in order to prepare a vinyl monomer containing sulfonated PEO, it is difficult to prepare a sulfonic acid group only at one end and an acryl group or methacryl group at the other end. This is because it is difficult to substitute a hydroxyl group, which is a normal PEO terminal, with a sulfonic acid group, an acrylic group, or a methacryl group at only one terminal. It is possible to substitute one terminal hydroxyl group of the acrylic acid or methacrylic acid ester monomer containing PEO described above with a sulfonic acid group (see Scheme 1 below), but the reaction conditions are difficult and the yield is low, such as the use of sodium.

CH ₂ = CRH-CO-O- (CH ₂ -CH ₂ -O) _n -H + Na / propanesultone → CH ₂ = CRH-CO-O- (CH ₂ -CH ₂ -O) _n- (CH ₂ ) ₃ -SO ₃ Na

Wherein R is H or CH ₃ .

Accordingly, it is an object of the present invention to have a sulfonic acid group at one end and to introduce a vinyl group at the other end, with a more reliable route starting from diaminoPEO, where only one terminal amino group is optionally substituted with a sulfonic acid group and a vinyl group is introduced at the other end. One sulfonated PEO-containing monomer and a method of making the same are provided. This novel monomer has a structure in which only one amino group of diaminoPEO is selectively substituted with a sulfonic acid group and a vinyl group is introduced to the other terminal group.

Another object of the invention relates to the preparation and application of homopolymers of said monomers and copolymers with other monomers. Polymers containing sulfonated PEO have excellent antithrombotic properties by adding the anti-thrombotic effect of sulfonic acid groups to the non-adhesiveness of PEO, so medical devices in contact with blood, especially vascular catheter, vascular stent, artificial kidney membrane, artificial It can be applied to surface coating or material modification of heart valve materials.

The novel vinyl monomer containing sulfonated PEO of the present invention has a structure represented by the following formula (1).

CH ₂ = CR-X-NH-AO- (CH ₂ -CH ₂ -O) _n -B-NH- (CH ₂ ) ₃ -SO ₃ H

Wherein R is -H or -CH ₃ ,

-X- is -CO-, -CO-O-CH ₂ -CH ₂ -NH-CO-, -CH ₂ -NH-CO- or -CH ₂ -O-CHOH-CH _2- ,

-A- and -B- are-(CH ₂ ) _m- , the same or different from each other,

m is 2 or 3,

n is from 10 to 200.

The molecular weight of the PEO unit of the sulfonated PEO derivative is approximately 400-9,000. If the molecular weight of the PEO is less than 400, the physiological function of the PEO, that is, the function of reducing the adhesion of proteins, blood and cells is very small and ineffective, if greater than 9,000 such function does not increase in proportion to the molecular weight.

The first step in the synthesis of a monomer of Formula 1 (simply referred to as CH ₂ = CR-PEO-SO ₃ H) involves the selective substitution of only one amino group of one end of PEO (diaminoPEO), with both ends substituted with amino groups. will be. The amino end groups are generally converted into sulfonated derivatives by quantitative reaction with propanesultone. Reaction of diaminoPEO with 1/2 equivalents of propanesultone produces a mixture of derivatives reacted at one end, derivatives reacted at both ends, and unreacted derivatives. A derivative in which only one terminal amino group is optionally substituted with a sulfonic acid group (hereinafter simply referred to as H ₂ N-PEO-SO ₃ H) forms a zwitter ion complex (see Scheme 2 below).

Since the complexes tend to aggregate with each other, they are precipitated and separated from a suitable organic solvent, so that only one terminal amino group of diaminoPEO can be separated purely from derivatives substituted with sulfonic acid groups. At this time, the selection of the organic solvent is very important. Precipitation does not occur in solvents with high solubility of the complex, such as chloroform, and all PEO derivatives precipitate together in solvents with low solubility of PEO derivatives, such as hexane, so that only H ₂ N-PEO-SO ₃ H cannot be separated. Solvents such as tetrahydrofuran and dioxane are suitable because of the high solubility of other PEO derivatives and the precipitation of the H ₂ N-PEO-SO ₃ H complex.

The remaining amino groups of H ₂ N-PEO-SO ₃ H obtained can be converted into monomers of formula 1 by reaction with a suitable compound having a vinyl group. Compounds having such vinyl groups include acrylic acid or methacrylic acid and their acid chlorides and acid anhydrides; An epoxy compound having an allyl group; Compounds containing an isocyanate and a vinyl group together, such as allyl isocyanate, methacryloyloxyethyl isocyanate (MOI) and acryloyloxyethyl isocyanate. The amidation reaction between the amino group of H ₂ N-PEO-SO ₃ H and the organic acid, acid chloride and acid anhydride or the addition reaction of the amino group and the isocyanate group and the epoxy group are generally well known reactions using appropriate reaction conditions and catalysts. To prepare a monomer represented by Formula 1 (CH ₂ = CR-PEO-SO ₃ H).

The monomer of Chemical Formula 1 (CH ₂ = CR-PEO-SO ₃ H) may be prepared as a homopolymer or copolymer by conventional radical, anion, and cationic polymerization processes like other general monomers. Radical polymerization is carried out in bulk and in solution using well-known polymerization initiators such as benzoylperoxide (BPO), azobisisobutyronitrile (AIBN), or by ultraviolet, gamma irradiation. Alternatively, other polymer substrate surfaces may be irradiated with ultraviolet and gamma rays or oxidized with ozone to generate radicals for graft polymerization or graft polymerization in a plasma state, and such methods are well known in the literature (Ikada et al., Biomaterials, 15, 725-736, 1994).

CH ₂ = CR-PEO-SO ₃ H can also be copolymerized like other conventional monomers. The copolymer monomer selected may be selected from virtually any monomer having a vinyl group, and hydrophobic monomers such as styrene, (meth) acrylic, vinyl ester, vinyl chloride, vinyl acetate, vinyl propionic acid, vinylpyrrolidone and hydride. Hydrophilic monomers, such as oxyalkyl (meth) acrylate, are included. In particular, coating or blending a copolymer of hydrophilic CH ₂ = CR-PEO-SO ₃ H with a hydrophobic monomer onto another polymer causes the hydrophilic units to migrate or protrude to the surface, while the hydrophobic units migrate to the substrate polymer surface. It acts as an anchoring material to prevent rinsing, which is very effective for practical application of medical products (see Kim Young-ha et al., Colloid and Surfaces B: Biointerfaces, 18, 355-370, 2000).

The obtained monomer was confirmed by Fourier transform infrared spectrometer (FT-IR, Alpha Century, Mattson Instruments) and nuclear magnetic resonance analyzer (Varian Gemini 200MHz), and also the elemental analyzer (Elemental Analyses System, GmbH Vario) EL) was used. The viscosity of the polymer was measured at 25 ° C. using a Ubbelohde viscometer (SCHOTT GERAETE AVS 400) with 0.5 g / dl chloroform solution.

The obtained homopolymer or copolymer, especially the hydrophilic-hydrophobic copolymer, is coated on the polymer surface, and the dynamic contact angle is measured by Wilhelmy plate method (DCA 315, Cahn Instruments, USA) to evaluate the hydrophilicity of the coated surface. Measured. In addition, anti-thrombotic properties were evaluated by measuring the degree of adhesion of platelets. The coated polymer specimen is placed in a disposable syringe and 2 ml phosphate buffer is added, the buffer is replaced with 2 ml of platelet rich plasma (52 x 10 mm / ul) of platelet and the syringe is 37 ° C. Walk in a controlled shaking incubator and hold for a period of time. The syringes were recovered and the non-adhesive platelets in the plasma were measured by a coulter or cytometer to inversely calculate the adherent platelets (see Hee Jung et al., Polymer (Korea), 21, 1045-1052, 1997).

The present invention is explained in more detail with reference to the following examples, but the present invention is not limited to these examples.

<Example 1>

To a tetrahydrofuran 10% w / v solution of diaminoPEO (NOF Japan, molecular weight 1,000 of PEO) was added dropwise a half equivalent of a 10% w / v solution of tetrahydrofuran of propanesultone (Aldrich) at 50 ° C. After 3 hours of further reaction and standing at room temperature, a precipitate was formed. The obtained precipitate was washed with cold tetrahydrofuran and dried under vacuum at room temperature to obtain H ₂ N-PEO-SO ₃ H (yield 75%).

The elemental analysis of the product was 51.8% carbon, 9.0% hydrogen, 2.1% nitrogen, and 2.7% sulfur, which was generally in agreement with theoretical values of 52.5%, 9.2%, 2.5%, and 2.9%, respectively. Infrared spectroscopic analysis confirmed the absorption band of the sulfonic acid group at 1038 cm ⁻¹ . Nuclear magnetic resonance analysis showed that hydrogen in PEO units was large at 3.5-3.8 δ, hydrogen on both sides of three -CH ₂ -in propanesultone units appeared as a complex absorption band at 2.6-3.2 δ and central hydrogen at 2.2 δ Was observed.

In contrast, in the case of HO ₃ S-PEO-SO ₃ H substituted at both ends, the hydrogen of PEO unit was the same at 3.5-3.8 δ and the hydrogen at the center of propanesultone unit was the same at 2.2 δ. The hydrogen difference between the two sultone units was found to be much simpler at 2.8-3.2 δ.

<Example 2>

H ₂ N-PEO-SO ₃ H having a molecular weight of 3,000 was synthesized in the same manner except that the molecular weight of diaminoPEO used in Example 1 was 3,000.

<Example 3>

To a 0.1 M solution of H ₂ N-PEO-SO ₃ H obtained in Example 1, an equivalent amount of MOI (Aldrich) and a small amount of dibutyltin dilaurate were added and reacted at 40 ° C for 3 hours. A large amount of chloroform was distilled under reduced pressure, and the remaining solution was precipitated in anhydrous ethyl ether, separated, and dried in vacuo to give MOI-HN-PEO-SO ₃ H (yield 95%).

As a result of nuclear magnetic resonance analysis, vinylidene hydrogen in MOI was further shown at 5.5 and 6.1 δ, and CH ₃ was further shown at 1.9 δ, confirming that MOI was bound.

<Example 4>

To a 0.1 M solution of H ₂ N-PEO-SO ₃ H obtained in Example 2, an equivalent of methacrylic anhydride (MAH, Aldrich) and a small amount of triethylamine were added and reacted at 50 ° C for 10 hours. was precipitated in anhydrous ethyl ether and dried under vacuum separation to give a _{MAH-HN-PEO-SO 3} H ( 90% yield).

As a result of nuclear magnetic resonance analysis, vinylidene hydrogen of the MAH unit was further shown at 5.3 and 5.8 δ, and CH ₃ was also present at 1.95 δ, confirming that MAH was bound.

Example 5

To a 0.1 M solution of H ₂ N-PEO-SO ₃ H obtained in Example 1, an equivalent amount of allylglycidyl ether (AGE, Aldrich) and a small amount of triethylamine were added and reacted at 50 ° C for 12 hours. It was then precipitated in anhydrous ethyl ether, separated and dried in vacuo to give AGE-HN-PEO-SO ₃ H (yield 85%).

As a result of nuclear magnetic resonance analysis, vinylidene hydrogen of allylglycidyl ether unit was further shown at 5.0 and 5.5 δ to confirm that allylglycidyl ether was bound.

<Example 6>

MOI-HN-PEO-SO ₃ H monomer obtained in Example 3 was dissolved in chloroform at a concentration of 5% w / v, and 3 mol% of azobisisobutyronitrile polymerization initiator was added to the monomer, followed by polymerization at 70 ° C for 10 hours. After precipitation, the mixture was precipitated in hexane, separated, and dried in vacuo to prepare a homopolymer. This homopolymer was water soluble and had an intrinsic viscosity of 0.1-1.2.

<Example 7>

MAH-HN-PEO-SO ₃ H monomer obtained in Example 4 was dissolved in toluene at a concentration of 5% w / v, and twice the equivalents of octadecylacrylate (ODA, M _W = 325, Aldrich) and benzoyl peroxide ( 2 mole% relative to the monomer) was added to polymerize at 60 ° C. for 10 hours, precipitated in anhydrous ethyl ether, separated, and dried in vacuo to prepare a hydrophilic-hydrophobic copolymer (molar ratio 1: 2). The copolymer had an inherent viscosity of 0.2-1.3 and was insoluble in water but dissolved in chloroform and toluene. Nuclear magnetic resonance analysis of the actual composition ratio of the hydrophilic and hydrophobic moieties of the copolymer showed that the PEO absorption band (3.5-3.8 δ) of MAH-HN-PEO-SO ₃ H and the -CH ₂ -absorption band (0.6-) of ODA 2 δ) confirmed that the actual composition ratio was 1: 2.

<Example 8>

The AGE-HN-PEO-SO ₃ H monomer obtained in Example 5 was dissolved in chloroform at a concentration of 5% w / v, and 60 times by adding 1.5-fold equivalents of styrene (Aldrich) and benzoyl peroxide (0.2 mol% relative to monomer). After the polymerization at 10 ° C for 10 hours, precipitated in anhydrous ethyl ether and separated by vacuum drying to prepare a hydrophilic hydrophobic copolymer (molar ratio 4: 6). The copolymer had an inherent viscosity of 0.2-1.0 and was insoluble in water but dissolved in chloroform and toluene. The actual composition ratio of the hydrophilic and hydrophobic portions of the copolymer was analyzed by nuclear magnetic resonance, and the results showed that from the PEO absorption band of AGE-HN-PEO-SO ₃ H (3.5-3.8 δ) and the peak of aromatic hydrogen of toluene (6.7 δ) It was confirmed that the actual composition ratio was 4: 6.

Example 9

The polymethyl methacrylate (PMMA) sheet (LG Chemistry, 1 x 3 cm) was placed in an ozone generator (Model 0Z06, Peak Scientific Instrument) and oxygenated (4.5 L / min and 1 bar pressure) for 1 hour to ozone oxidation Treated. A 20% w / v aqueous solution of the monomer MOI-HN-PEO-SO ₃ H obtained in Example 3 was prepared, the ozone treated sample was soaked in the solution, replaced with nitrogen, sealed, and reacted at 60 ° C for 10 hours. After washing thoroughly with distilled water and drying in vacuo, a surface obtained by graft polymerization of MOI-HN-PEO-SO ₃ H on the surface of the PMMA sheet was obtained. Surface analysis with an Attenuated total reflectance-Fourier transform infrared spectrometer (ATR-FTIR) confirmed the presence of the grafted polymer. In addition, the dynamic contact angle of the modified PMMA sheet surface was 37.8 °, which was considerably reduced than the contact angle of the untreated PMMA 50.2 °, increasing hydrophilicity, demonstrating that the sulfonated PEO was graft polymerized to the surface.

PMMA surface grafted with MOI-HN-PEO-SO ₃ H had a 70% decrease in platelet adsorption compared to untreated PMMA, resulting in a significant increase in antithrombogenicity.

<Example 10>

In a hydrophilic / hydrophobic MAH-HN-PEO-SO ₃ H / ODA copolymer obtained in the same manner as in Example 7, 1% w / w chloroform solution of a copolymer having a composition (molar ratio 3: 7) insoluble in water was prepared. It was. The copolymer solution prepared in the polyurethane sheet (1 × 3 cm) was repeatedly coated three times and completely dried at room temperature under vacuum.

Polyurethane sheets coated with the copolymer were immersed in water for 1, 3, and 10 days, respectively, and analyzed by attenuated total reflectance-Fourier transform infrared spectrometer (ATR-FTIR). In addition, the dynamic contact angle of the polyurethane sheet was 32.3 °, which was significantly lower than 60.0 ° of the untreated polyurethane, which greatly increased the hydrophilicity, and it was confirmed that the coated copolymer was stably adsorbed since it did not change even after soaking in water.

In addition, platelet adsorption on the copolymer-coated polyurethane sheet was reduced by 80% compared to the untreated polyurethane surface, which greatly increased antithrombogenicity.

According to the present invention, the vinyl monomer containing sulfonated PEO has a structure in which only an amino group at one terminal of diaminoPEO is selectively substituted with a sulfonic acid group and a vinyl group is introduced at the other terminal group. The polymer composed of the monomer containing sulfonated PEO has excellent antithrombotic effect by adding anti-thrombotic effect of sulfonic acid group to non-adhesiveness of PEO, and thus, medical devices in contact with blood, in particular vascular catheter, vascular stent, artificial It can be applied as a material for kidney separation membrane and artificial heart valve. Particularly, the hydrophilic / hydrophobic copolymer composed of the hydrophilic monomer and the general hydrophobic monomer of the present invention has excellent antithrombogenicity as the hydrophilic unit shows the role of adsorbing on the surface of the substrate polymer, so that the coating or blending is prevented from being washed away. It is very effective for real medical application.

Claims (14)

Vinyl monomer of the formula (1) containing sulfonated PEO. <Formula 1> CH ₂ = CR-X-NH-AO- (CH ₂ -CH ₂ -O) _n -B-NH- (CH ₂ ) ₃ -SO ₃ H Wherein R is -H or -CH ₃ , -X- is -CO-, -CO-O-CH ₂ -CH ₂ -NH-CO-, -CH ₂ -NH-CO- or -CH ₂ -O-CHOH-CH _2- , -A- and -B- are-(CH ₂ ) _m- , the same or different from each other, m is 2 or 3, n is from 10 to 200. The vinyl monomer of claim 2, wherein the PEO unit —O— (CH ₂ —CH ₂ —O) _n − has a molecular weight of 440 to 8,800. Claim 1 or 2, characterized in that the step of selectively replacing only the amino group of one end of the PEO substituted at both ends with an amino group, and reacting the amino group of the other end with a vinyl compound having a vinyl group. The manufacturing method of the vinyl monomer of description. The method of claim 3, wherein the vinyl compound is acrylic acid or methacrylic acid and their acid chlorides, acid anhydrides; An epoxy compound having an allyl group; And allyl isocyanate, methacryloyloxyethyl isocyanate and acryloyloxyethyl isocyanate. The method according to claim 3, wherein an amidation catalyst or an addition reaction catalyst is used to bond the amino group and the vinyl compound present at the terminal of the PEO derivative. A polymer derived from the vinyl monomer of claim 1. The polymer of claim 6 which is a homopolymer. The polymer of claim 6 which is a copolymer of a vinyl monomer with another hydrophilic or hydrophobic comonomer. The polymer of claim 8, wherein the hydrophilic comonomer is vinylpyrrolidone or hydroxyalkyl (meth) acrylate. The polymer of claim 8 wherein the hydrophobic comonomer is selected from the group consisting of styrene, alkylacrylates, alkylmethacrylates, vinyl chloride, vinylacetic acid and vinylpropionic acid. A process for preparing the polymer of claim 6 comprising polymerizing the vinyl monomer of claim 1 or optionally the comonomer of claim 9 or 10 in a bulk or solution state by a polymerization initiator or ultraviolet or gamma irradiation. Irradiating ultraviolet or gamma rays on the surface of the polymer substrate or oxidizing with ozone to generate radicals to graft polymerize the vinyl monomers of claim 1 or optionally the comonomers of claims 9 or 10 or to graf in a plasma state. How to Twist. An antithrombogenic medical material coated or blended with the polymer of claim 6. An antithrombogenic medical material in which the vinyl monomer of claim 1 or 2 and optionally the comonomer of claim 9 or 10 are graft-polymerized on the material surface.