Heparinized polycaprolactone coating as well as preparation method and application thereof
By grafting heparin onto the surface of polycaprolactone through chemical bonding, the problem of excessive heparin release was solved, and a highly stable heparinized polycaprolactone coating was prepared, which is suitable for medical devices and achieves a long-lasting anticoagulant effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-18
- Publication Date
- 2026-03-10
AI Technical Summary
In existing technologies, the binding of heparin and polycaprolactone is unstable, resulting in heparin release that is too rapid and the anticoagulant effect is not long-lasting, making it difficult to achieve long-term anticoagulation.
Heparin was grafted onto the surface of polycaprolactone using a chemical bonding method. The heparin carboxyl groups were activated by EDC/NHS, and poloxamer 188 was added to adjust compatibility, thus preparing a heparinized polycaprolactone coating to ensure a strong bond between heparin and the substrate.
It significantly reduces the local release of heparin, achieves sustained anticoagulation, maintains the anticoagulant activity of heparin, and obtains a coating with good stability, making it suitable for medical devices.
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Abstract
Description
Technical Field
[0001] This application relates to the technical field of medical materials, specifically to a heparinized polycaprolactone coating, its preparation method, and its application. Background Technology
[0002] Heparin, as a natural anticoagulant, is widely used in the surface modification of blood contact materials. Traditional heparinization methods mainly include physical adsorption and ionic bonding, but these methods suffer from problems such as rapid heparin release and short-lasting anticoagulant effects. In recent years, polycaprolactone (PCL) has been widely used in medical device coating materials due to its good biocompatibility and biodegradability.
[0003] However, achieving stable binding of heparin to PCL while preserving heparin's anticoagulant activity remains a challenge in the current technological field. Therefore, developing a heparinized coating with long-lasting anticoagulant properties and high stability is of significant clinical importance. Summary of the Invention
[0004] To address the aforementioned technical problems, this application provides a heparinized polycaprolactone coating, its preparation method, and its application.
[0005] In a first aspect, this application provides a method for preparing a heparinized polycaprolactone coating, comprising the following steps: Polycaprolactone was dissolved in an organic solvent to prepare a polycaprolactone solution with a concentration of 0.3-0.5 g / mL. Add poloxamer 188 to a MES buffer solution with pH 5.8-6.2, add heparin and stir until homogeneous, then add EDC and NHS, and stir for 40-120 min to obtain an activated heparin solution containing 0.7-0.9 g / mL heparin, 0.001-0.003 g / mL poloxamer 188, 0.007-0.009 g / mL EDC, and 0.008-0.010 g / mL NHS. Polycaprolactone solution was added dropwise to activated heparin solution at a volume ratio of 2-3:1. The reaction was carried out at room temperature for 90-180 min. Then, the complex was dissolved in chloroform by rotary evaporation. After washing with water, drying with anhydrous MgSO4, precipitation with methanol, filtration of the precipitate, and drying under vacuum at 30-40℃, the final product was obtained.
[0006] In this application, polycaprolactone is selected as the substrate. Polycaprolactone in this molecular weight range has suitable mechanical properties and degradation rate, which can meet the requirements for use in medical device coatings. Heparin is grafted onto the surface of polycaprolactone through chemical bonding, which ensures a strong bond between heparin and the substrate, avoids the shedding of heparin in the blood environment, significantly reduces the local release of heparin, achieves a continuous anticoagulant effect, and extends the anticoagulant efficacy of the coating.
[0007] The preparation method described in this application involves activating the heparin carboxyl groups via EDC / NHS followed by a grafting reaction. The process is simple, with mild reaction conditions, requiring no complex equipment or reagents, making it suitable for industrial production. By optimizing process parameters such as the concentration of the polycaprolactone solution and the heparin activation conditions, the coating performance can be further improved to meet the requirements of medical devices.
[0008] During the heparin activation process, the addition of non-cytotoxic poloxamer 188 provides amphiphilic regulatory function: the balanced ratio of hydrophilic polyoxyethylene segments and hydrophobic polyoxypropylene segments in its molecular structure can improve the compatibility of polycaprolactone and heparin, and alleviate the problems of easy aggregation and uneven dispersion during the compounding process; at the same time, in the coating preparation system, it can promote the uniform spreading of heparin molecules on the surface of polycaprolactone substrate by reducing interfacial tension, without destroying the anticoagulant activity of heparin and the structural stability of polycaprolactone.
[0009] Preferably, the preparation method of the polycaprolactone is as follows: stannous 2-ethylhexanoate and 1,4-butanediol are added to ε-caprolactone and mixed evenly. The mixture is stirred in nitrogen for 20-40 min, and then degassed for more than 1 h. The reaction solution is transferred to a vacuum condition at a temperature of 140-160℃ and polymerized for 20-48 h. The obtained product is dissolved in chloroform, then precipitated in methanol. The precipitate is filtered and dried under vacuum overnight to obtain the product. The molar ratio of stannous 2-ethylhexanoate, 1,4-butanediol, and ε-caprolactone is 1.7-2.3:0.8-1.2:0.80-0.95.
[0010] Preferably, the molar ratio of stannous 2-ethylhexanoate, 1,4-butanediol, and ε-caprolactone is 1.8-2.2:0.9-1.1:0.85-0.90.
[0011] Preferably, the organic solvent is selected from one or more of tetrahydrofuran, dimethyl sulfoxide, and N,N-dimethylformamide.
[0012] Preferably, the concentration of the polycaprolactone solution is 0.35-0.45 g / mL.
[0013] In one specific embodiment, the concentration of the polycaprolactone solution is 0.3 g / mL, 0.35 g / mL, 0.4 g / mL, 0.45 g / mL, or 0.5 g / mL.
[0014] Experimental analysis shows that controlling the concentration of the polycaprolactone solution within the above-mentioned range can further improve the performance of the coating.
[0015] Preferably, the activated heparin solution contains 0.75-0.85 g / mL heparin, 0.0015-0.0025 g / mL poloxamer 188, 0.0075-0.0085 g / mL EDC, and 0.0085-0.0095 g / mL NHS.
[0016] In one specific embodiment, the activated heparin solution contains 0.8 g / mL heparin, 0.002 g / mL poloxamer 188, 0.008 g / mL EDC, and 0.009 g / mL NHS.
[0017] Experimental analysis shows that by controlling the concentration of each raw material in the activated heparin solution within the above-mentioned range, the performance of the coating can be further improved.
[0018] Preferably, the volume ratio of the polycaprolactone solution to the activated heparin solution is 2.2-2.8:1.
[0019] Secondly, this application provides a heparinized polycaprolactone coating, which is prepared using the aforementioned preparation method.
[0020] Thirdly, this application provides the application of the heparinized polycaprolactone coating in medical device coatings.
[0021] Preferably, the application method of the heparinized polycaprolactone coating in medical device coatings is as follows: the heparinized polycaprolactone coating is dissolved in chloroform to prepare a dip-coating solution, which is then coated onto the medical device product, and dried in a vacuum oven at room temperature to obtain a medical device coated with the heparinized polycaprolactone coating.
[0022] In summary, the technical solution of this application has the following effects: The technical solution of this application improves the binding method of heparin and polycaprolactone, and prepares the heparinized polycaprolactone coating by chemical bonding, which significantly reduces the local release of heparin and achieves a continuous anticoagulant effect; while retaining the anticoagulant activity of heparin, a coating with good stability is obtained.
[0023] The heparinized polycaprolactone coating provided by this application combines the biocompatibility and controllable degradation of polycaprolactone with the anticoagulant activity of heparin. It has high biocompatibility, can effectively inhibit platelet adhesion and thrombus formation, reduce the risk of complications after medical device implantation, is suitable for the surface of various medical devices, and has good biocompatibility and clinical application prospects.
[0024] The method for preparing heparinized polycaprolactone coating provided by this application is simple and efficient, with mild reaction conditions, allowing for precise control of coating performance, and is suitable for large-scale production. Detailed Implementation
[0025] The present application will be further described in detail below with reference to embodiments, comparative examples and performance test results. These embodiments should not be construed as limiting the scope of protection claimed in this application.
[0026] Example
[0027] Example 1
[0028] Example 1 provides a heparinized polycaprolactone coating and its preparation method.
[0029] The preparation method of the heparinized polycaprolactone coating in this embodiment is as follows.
[0030] Preparation of polycaprolactone and polycaprolactone solution: 0.2 mmol of stannous 2-ethylhexanoate and 0.1 mmol of 1,4-butanediol were added to a container containing 0.087 mol of ε-caprolactone; the mixture was stirred in nitrogen for 30 min, then degassed for at least 1 h; the container was sealed and transferred to an oil bath at 150 °C, and polymerized under vacuum for 24 h; the resulting product was dissolved in chloroform, then precipitated three times in excess methanol, the precipitate was filtered and dried under vacuum overnight to obtain polycaprolactone. A 0.4 g / mL polycaprolactone solution was prepared by dissolving 10 g of polycaprolactone in 25 mL of tetrahydrofuran.
[0031] Preparation of activated heparin solution: 0.02 g poloxamer 188 was dissolved in 10 mL of MES (2-(N-morpholino)ethanesulfonic acid, pH=6.0) buffer solution, 8.0 g heparin was added and stirred until homogeneous, then 0.08 g EDC and 0.09 g NHS were added. The solution was stirred at 400 rpm for 60 min to activate heparin, resulting in an activated heparin solution containing 0.8 g / mL heparin, 0.002 g / mL poloxamer 188, 0.008 g / mL EDC, and 0.008 g / mL NHS.
[0032] The polycaprolactone solution was added dropwise to the heparin solution (the volume ratio of polycaprolactone solution to the activated heparin solution was 2.5:1), and the reaction was carried out at room temperature for 120 min. Then, the complex was redissolved in 50 mL of chloroform by rotary evaporation. The chloroform solution was washed twice with 20 mL of water and dried with anhydrous MgSO4. The dried chloroform solution was precipitated with an excess of 100 mL of methanol. To remove residual solvent, the precipitate was filtered and dried under vacuum at 35 °C for 24 h to obtain the heparinized polycaprolactone coating.
[0033] Examples 2-5 Examples 2-5 provide a heparinized polycaprolactone coating and its preparation method, respectively.
[0034] The difference between the above embodiments and Embodiment 1 is that the concentration of the polycaprolactone solution is different, as shown below.
[0035] In Example 2, the concentration of the polycaprolactone solution was 0.35 g / mL.
[0036] In Example 3, the concentration of the polycaprolactone solution was 0.45 g / mL.
[0037] In Example 4, the concentration of the polycaprolactone solution was 0.3 g / mL.
[0038] In Example 5: the concentration of the polycaprolactone solution was 0.5 g / mL.
[0039] Examples 6-11 Examples 6-11 provide a heparinized polycaprolactone coating and its preparation method, respectively.
[0040] The specific difference between the above embodiments and Embodiment 1 is that the concentrations of heparin or poloxamer 188 in the activated heparin solution are different, as shown below.
[0041] In Example 6: The concentration of heparin in the activated heparin solution was 0.75 g / mL.
[0042] In Example 7: the concentration of heparin in the activated heparin solution was 0.85 g / mL.
[0043] In Example 8: the concentration of heparin in the activated heparin solution was 0.7 g / mL.
[0044] In Example 9: the concentration of heparin in the activated heparin solution was 0.9 g / mL.
[0045] In Example 10: the concentration of poloxamer 188 in the activated heparin solution was 0.001 g / mL.
[0046] In Example 11: the concentration of poloxamer 188 in the activated heparin solution was 0.003 g / mL.
[0047] All other process parameters in the above embodiments are the same as those in Embodiment 1.
[0048] Comparative Example Comparative Example 1 Comparative Example 1 provides a heparinized polycaprolactone coating and its preparation method.
[0049] The difference between the above comparative example and Example 1 is that the concentration of the polycaprolactone solution is different, as shown below.
[0050] In Comparative Example 1, the concentration of the polycaprolactone solution was 0.2 g / mL.
[0051] All other process parameters in the above comparative examples are the same as those in Example 1.
[0052] Comparative Examples 2-6 Comparative Examples 2-6 provide a heparinized polycaprolactone coating and its preparation method, respectively.
[0053] The difference between the above comparative example and Example 1 is that the composition of the activated heparin solution is different, as shown below.
[0054] In Comparative Example 2: the concentration of heparin in the activated heparin solution was 0.5 g / mL.
[0055] In Comparative Example 3: the concentration of heparin in the activated heparin solution was 1.1 g / mL.
[0056] In Comparative Example 4: no poloxamer 188 was added to the activated heparin solution.
[0057] In Comparative Example 5: Poloxamer 188 was replaced with an equal amount of poloxamer 407 in the activated heparin solution.
[0058] In Comparative Example 6: the concentration of poloxamer 188 in the activated heparin solution was 0.005 g / mL.
[0059] All other process parameters in the above comparative examples are the same as those in Example 1.
[0060] Performance testing Heparin release: The heparin content was analyzed using the toluidine blue colorimetric method. 0.1 mL of toluidine blue solution was aliquoted into test tubes. 0.1 mL of heparin standard solutions of various concentrations were added to the toluidine blue solution. Hexane (1.0 mL) was added to each solution, and the solution was vortexed for 30 seconds to allow phase separation. The absorbance of the aqueous layer was measured at 631 nm using a UV-Vis spectrophotometer to establish a standard curve. The heparinized polycaprolactone coating was cut into 0.5 cm pieces. 2 A rectangle of area was prepared and placed in a test tube containing 0.1 mL of toluidine blue solution and 0.1 mL of 0.2% NaCl solution. After shaking for half an hour, 1 mL of hexane was added and the mixture was shaken for another 10 minutes. The absorbance of the aqueous layer was measured using a UV-Vis spectrophotometer, and the surface heparin content could be calibrated using a standard curve. To determine the surface heparin content of the heparinized polycaprolactone coating during in vitro degradation, the membrane was immersed in PBS solution and removed at intervals of 24 h, 72 h, and 120 h.
[0061] Anticoagulant activity: The anticoagulant activity of the heparinized polycaprolactone coating was determined by the APTT assay. Heparinized polycaprolactone-coated films were cut into 1×0.5cm rectangles and placed in test tubes. Citrate-standard plasma (100 μL) and Patromtin SL (100 μL) were then pipettes into the preheated 37°C test tubes and incubated at 37°C for 3 minutes. Fibrinogen quantification was initiated using a TEChrom IV plus (China) device upon addition of calcium chloride solution (100 μL, 0.025 M) at 37°C.
[0062] Test results are shown in Table 1.
[0063] Table 1. Performance test results of heparinized polycaprolactone coatings in the examples or comparative examples.
[0064] As can be seen from the test results in Table 1 above, the heparinized polycaprolactone coating prepared using the technical solution provided in this application has a low heparin release amount, indicating that the heparinized polycaprolactone coating significantly reduces the local release of heparin and achieves a continuous anticoagulant effect; moreover, the heparinized polycaprolactone coating has a longer clotting time, indicating that the heparinized polycaprolactone coating meets the performance requirements for anticoagulation.
[0065] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.
Claims
1. A method for preparing a heparinized polycaprolactone coating, characterized by, The method comprises the following steps: polycaprolactone is dissolved in an organic solvent to obtain a polycaprolactone solution with a concentration of 0.3-0.5 g / mL; poloxamer 188 is added to a MES buffer solution with a pH of 5.8-6.2, heparin is added and stirred uniformly, then EDC and NHS are added, and stirred for 40-120 min to obtain an activated heparin solution containing 0.7-0.9 g / mL heparin, 0.001-0.003 g / mL poloxamer 188, 0.007-0.009 g / mL EDC, and 0.008-0.010 g / mL NHS; the polycaprolactone solution is added dropwise to the activated heparin solution at a volume ratio of 2-3:1, and reacted at room temperature for 90-180 min, then the conjugate is dissolved in chloroform, washed with water, dried with anhydrous MgSO4, precipitated in methanol, filtered, and dried in a vacuum at 30-40°C to obtain the product.
2. The method of claim 1, wherein the heparinized polycaprolactone coating is prepared by, The preparation method of the polycaprolactone comprises the following steps: 2-ethylhexanoic acid stannous and 1,4-butanediol are added to ε-caprolactone, mixed uniformly, the mixture is stirred in nitrogen for 20-40 min, then degassed for more than 1 h; the reaction solution is transferred to a vacuum condition at a temperature of 140-160°C and polymerized for 20-48 h; the obtained product is dissolved in chloroform, then precipitated in methanol, the precipitate is filtered and dried in a vacuum overnight to obtain the product; the molar amount ratio of the 2-ethylhexanoic acid stannous, 1,4-butanediol and ε-caprolactone is 1.7-2.3:0.8-1.2:0.80-0.
95.
3. The method of claim 2, wherein the heparinized polycaprolactone coating is prepared by, The molar amount ratio of the 2-ethylhexanoic acid stannous, 1,4-butanediol and ε-caprolactone is 1.8-2.2:0.9-1.1:0.85-0.
90.
4. The method of claim 1, wherein the heparinized polycaprolactone coating is prepared by, The organic solvent is selected from any one or more of tetrahydrofuran, dimethyl sulfoxide and N,N-dimethylformamide.
5. The method of claim 1, wherein the heparinized polycaprolactone coating is prepared by, The concentration of the polycaprolactone solution is 0.35-0.45 g / mL.
6. The method of claim 1, wherein the heparinized polycaprolactone coating is prepared by, The activated heparin solution contains 0.75-0.85 g / mL heparin, 0.0015-0.0025 g / mL poloxamer 188, 0.0075-0.0085 g / mL EDC and 0.0085-0.0095 g / mL NHS.
7. The method of claim 1, wherein the heparinized polycaprolactone coating is prepared by, The volume ratio of the polycaprolactone solution to the activated heparin solution is 2.2-2.8:
1.
8. A heparinized polycaprolactone coating characterized by, The preparation method is prepared by any one of claims 1-7.
9. A heparinized polycaprolactone coating prepared by the preparation method of any one of claims 1-7 or the heparinized polycaprolactone coating of claim 8 for use in a medical device coating.
10. Use according to claim 9, characterized in that, The heparinized polycaprolactone coating is dissolved in chloroform to obtain a dip coating solution, then the dip coating solution is coated on a medical device product, and then dried in a vacuum oven at room temperature to obtain a medical device coated with a heparinized polycaprolactone coating.