Antibacterial and anticoagulant sodium alginate-graphene oxide coating dialysis catheter and preparation method thereof

Abstract

The invention belongs to the field of functional medical catheter preparation, and particularly relates to an antibacterial and anticoagulant dialysis catheter with a sodium alginate-graphene oxide coating and a preparation method of the antibacterial and anticoagulant dialysis catheter. The preparation method comprises the following steps: (1) mixing a graphene oxide dispersion liquid with a sodium alginate solution, then adding a water / alcohol mixed solvent, and then carrying out ultrasonic dispersion treatment to obtain a mixed solution; (2) performing plasma pretreatment on the polyurethane dialysis catheter to obtain a pretreated catheter; (3) immersing the pretreated conduit into the mixed solution, and after dip-coating is completed, sequentially standing and drying to obtain a primary gel layer conduit; and (4) immersing the primary gel layer catheter into a cross-linking solution, and then sequentially cleaning, gradient heating and curing. Efficient antibiosis and anticoagulation are achieved through the synergistic effect of materials, the coating is firm in combination and excellent in biocompatibility, the problems of thrombus formation, infection and the like of an existing dialysis catheter can be solved, and the coating is suitable for hemodialysis vascular access.

Description

Technical Field

[0001] This invention belongs to the field of functional medical catheter preparation, specifically relating to an antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter and its preparation method. Background Technology

[0002] End-stage renal disease (ESRD) is the final stage of irreversible kidney function decline caused by various kidney diseases. With the increasing incidence of obesity, hypertension, and type 2 diabetes, the prevalence of chronic kidney disease (CKD) is rising year by year. As the final stage of CKD development, the number of ESRD patients is also constantly increasing, and my country will face a huge medical and economic burden from ESRD in the future. It is reported that more than 500 million people worldwide suffer from different types of kidney disease, accounting for 8.33% of the world's total population. The prevalence of CKD in China is 10.8%, and the estimated number of ESRD patients is 200-250 per million people. In recent years, the global incidence of ESRD has been increasing year by year, and it has a poor prognosis, long duration, and high cost, becoming a serious public health problem that endangers human health and increases the economic burden worldwide.

[0003] For patients with end-stage renal disease (ESRD), renal replacement therapy is the only way to prolong their lives and slow the progression of the disease. This includes three treatment methods: kidney transplantation, hemodialysis, and peritoneal dialysis. Although kidney transplantation is the best renal replacement therapy for ESRD patients, due to a severe shortage of kidney donors, less than one-quarter of ESRD patients worldwide have the opportunity to receive a kidney transplant. Hemodialysis and peritoneal dialysis are both commonly used renal replacement therapies in clinical practice. Hemodialysis can quickly and effectively remove water and toxins, while peritoneal dialysis offers simpler operation, greater autonomy, more stable hemodynamics, lower cost, and lower risk of cross-infection. Studies show that 90% of ESRD patients in my country choose hemodialysis as their treatment method, and the number of hemodialysis patients in China increased from 234,632 in 2011 to 692,736 in 2020.

[0004] Hemodialysis is a process in which a dialysis machine draws the patient's blood outside the body, a dialysis membrane separates the dialysate from the blood, and various harmful and excess metabolic wastes are removed through diffusion, convection, and adsorption. The purified blood is then returned to the body to achieve blood purification. For hemodialysis treatment, establishing ideal vascular access is the primary preparation before treatment and a necessary condition for achieving the desired therapeutic effect. Vascular access is the lifeline for dialysis patients, profoundly impacting dialysis effectiveness and long-term patient survival. Research results show that among patients undergoing hemodialysis for the first time, the highest proportion (76.8%) used a central venous catheter (CVC) as the vascular access.

[0005] Central venous catheters (CVCs) offer advantages such as low-cost placement and replacement, high availability, minimal trauma, and adequate blood flow during hemodialysis. However, there are some issues with their use. For example, because the catheter is in continuous contact with blood within the blood vessel, it is prone to clotting and thrombus formation, which can affect blood flow during treatment, cause catheter blockage, and lead to serious embolic complications. There is also a risk of bloodstream infection, venous injury, and other catheter-related complications, which can interrupt treatment and affect its effectiveness.

[0006] Therefore, based on this, the technical solution of the present invention is proposed. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a method for preparing an antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter, the method comprising the following steps: (1) Mix the graphene oxide (GO) dispersion with sodium alginate (SA) solution, add water / alcohol mixed solvent, and then use ultrasonic dispersion to obtain the mixture; (2) The polyurethane dialysis catheter was pretreated with plasma to obtain a pretreated catheter; (3) Immerse the pretreated conduit in the mixture, and after the immersion coating is completed, let it stand and dry in sequence to obtain the nascent gel layer conduit; (4) Immerse the nascent gel layer catheter in the cross-linking solution, and then clean and cure it in sequence by gradient heating to obtain the antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter.

[0008] Preferably, in step (1): The graphene oxide sheets have a diameter of 0.5-5 μm and an oxygen content of 20-30 at%; the concentration of the graphene oxide dispersion is 2-3 mg / mL. And / or, the molecular weight of sodium alginate is 80-120 kDa; the concentration of the sodium alginate solution is 3-4 wt%; And / or, the mass ratio of the graphene oxide dispersion to the sodium alginate solution is 1:8-10.

[0009] Preferably, in step (1), the water / alcohol mixed solvent is a mixed solvent of water and ethanol in a volume ratio of 7-8:3-2.

[0010] Preferably, in step (1), the ultrasonic dispersion power is 300-400W, the ultrasonic dispersion time is 30-40min, and the ultrasonic dispersion temperature is ≤40℃.

[0011] Preferably, in step (2), the plasma pretreatment is performed by treating for 15-20 minutes under the conditions of oxygen introduction, discharge power of 200-300W, and gas pressure of 50-100Pa.

[0012] Preferably, in step (3), the immersion time is 60-90s, the standing time is 10-15min, and the drying time is 10-15min.

[0013] Preferably, in step (4), the crosslinking solution is a 0.3-0.4M CuCl2 solution.

[0014] Preferably, in step (4), the gradient temperature curing method is as follows: first dry at 40-42℃ for 1-1.5h, then dry at 60-62℃ for 2-2.5h, and finally cure at 80-82℃ for 1-1.5h.

[0015] Based on the same technical concept, another aspect of the present invention is to provide an antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter obtained by the above preparation method.

[0016] The beneficial effects of this invention are as follows: 1. Excellent antibacterial properties: Through the synergistic effect of sodium alginate, graphene oxide and copper ions, it can effectively inhibit the adhesion and survival of common clinical pathogens such as Staphylococcus aureus and Escherichia coli, significantly reduce the risk of catheter-related bloodstream infections, and solve the core problem of existing central venous catheters being prone to infection.

[0017] 2. Outstanding anticoagulant effect: The physical barrier effect of graphene oxide combined with the chemical inhibition effect of copper ions catalyzing the generation of NO can effectively reduce platelet adhesion, activation and aggregation, reduce the risk of thrombosis and catheter blockage, and ensure stable blood flow during hemodialysis.

[0018] 3. Good biocompatibility: The hemolysis rate of the coating material is less than 5%, which meets the safety standards for biomedical materials, avoids damage to red blood cells, and reduces complications such as venous injury.

[0019] 4. Strong coating adhesion: After plasma pretreatment, the surface of the polyurethane conduit forms a micro-nano structure and is grafted with polar groups, which significantly improves the bonding strength between the coating and the conduit substrate and prevents the coating from falling off during use.

[0020] 5. The preparation process is simple and controllable: the parameters of each step are clear and easy to adjust, the raw materials are readily available, it is suitable for large-scale production, and the production cost is controllable, which has broad clinical application prospects. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 These are images related to antibacterial and bacteriostatic testing; among them: Figure 1 In the figure, 'a' shows the colony growth after the uncoated dialysis catheter was incubated with Staphylococcus aureus in a 37°C incubator for 12 hours. Figure 1 In the figure, b is a diagram showing the colony growth of Staphylococcus aureus after the coated dialysis catheter was incubated with Staphylococcus aureus in a 37°C incubator for 12 hours. Figure 1 In the diagram, 'c' represents the colony growth of Escherichia coli after the uncoated dialysis catheter was incubated with Escherichia coli under the same conditions. Figure 1 In the figure, d represents the colony growth of the coated dialysis catheter after incubation with Escherichia coli under the same conditions. Figure 1 In the image, 'e' is a scanning electron microscope image of Staphylococcus aureus colony growth on the surface of an uncoated dialysis catheter. Figure 1 f in the image is a scanning electron microscope image of Staphylococcus aureus colony growth on the surface of the coated dialysis catheter. Figure 1 In the image, 'g' is a scanning electron microscope image of Escherichia coli colony growth on the surface of the uncoated dialysis catheter. Figure 1 In the image, 'h' is a scanning electron microscope image of Escherichia coli colony growth on the surface of the coated dialysis catheter.

[0023] Figure 2 These are scanning electron microscope images of platelet adhesion from different samples.

[0024] Figure 3 This is a graph showing the hemolysis rate of the coating. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0026] Example 1 This invention provides a method for preparing an antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter, the method comprising the following steps: (1) Graphene oxide (GO) dispersion (concentration 2 mg / mL) and sodium alginate (SA) solution (concentration 3 wt%) were mixed at a mass ratio of 1:8. Then, a water / ethanol mixed solvent (volume ratio of water to ethanol of 7:3) was added. The mixture was then ultrasonically dispersed (power of 300 W) for 30 min. During the treatment, the temperature was kept ≤40℃ to avoid damage to the graphene oxide sheet structure, and a GO-SA mixture was obtained. The graphene oxide sheet diameter was 0.5-5 μm, the oxygen content was about 20 at%, and the molecular weight of sodium alginate was 80-120 kDa. (2) Plasma pretreatment of polyurethane dialysis catheters: oxygen is introduced and the catheters are treated for 15 minutes under the conditions of discharge power of 200W and pressure of 50Pa. This process generates a honeycomb micro-nano structure on the surface of the catheter and grafts polar groups such as hydroxyl (-OH) and carboxyl (-COOH), which increases the surface energy and significantly enhances the coating bonding strength. After completion, the pretreated catheter is obtained. (3) Immerse the pretreated conduit in the GO-SA mixture for 60 seconds to form a wet film. After immersion, let it stand for 10 minutes to allow the solution to spread fully. Then transfer it to an oven to air dry for 10 minutes to form a primary gel layer and obtain a primary gel layer conduit. (4) Immerse the nascent gel layer conduit in a 0.3M CuCl2 crosslinking solution, so that Cu... 2+ The SA carboxyl group forms an "egg-box" structure coordination bond. After cross-linking, the catheter is removed and rinsed with deionized water to remove free ions. Then, it is placed in a vacuum oven for gradient temperature curing: first, pre-drying at 40℃ for 1 hour, then main drying at 60℃ for 2 hours, and finally final curing at 80℃ for 1 hour, thus obtaining the antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter (containing a sodium alginate / graphene oxide / copper ion composite coating, denoted as SA+GO / Cu).

[0027] Example 2 This invention provides a method for preparing an antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter, the method comprising the following steps: (1) Graphene oxide (GO) dispersion (concentration 3 mg / mL) and sodium alginate (SA) solution (concentration 4 wt%) were mixed at a mass ratio of 1:10. Then, a water / ethanol mixed solvent (volume ratio of water to ethanol was 8:2) was added. The mixture was then ultrasonically dispersed (power 400 W) for 30 min. During the treatment, the temperature was kept ≤40℃ to avoid damage to the graphene oxide sheet structure, and a GO-SA mixture was obtained. The graphene oxide sheet diameter was 0.5-5 μm, the oxygen content was about 30 at%, and the molecular weight of sodium alginate was 80-120 kDa. (2) Plasma pretreatment of polyurethane dialysis catheters: oxygen is introduced and treated for 20 minutes under the conditions of discharge power of 300W and pressure of 100Pa. This process generates a honeycomb micro-nano structure on the surface of the catheter and grafts polar groups such as hydroxyl (-OH) and carboxyl (-COOH), which increases the surface energy and significantly enhances the coating bonding strength. After completion, the pretreated catheter is obtained. (3) Immerse the pretreated conduit in the GO-SA mixture for 90 seconds to form a wet film. After coating, let it stand for 15 minutes to allow the solution to spread fully. Then transfer it to an oven to air dry for 15 minutes to form a primary gel layer and obtain a primary gel layer conduit. (4) Immerse the nascent gel layer conduit in a 0.4M CuCl2 crosslinking solution, so that Cu... 2+ The SA carboxyl group forms an "egg-box" structure coordination bond. After cross-linking, the catheter is removed and rinsed with deionized water to remove free ions. Then, it is placed in a vacuum oven for gradient temperature curing: first, pre-drying at 42℃ for 1.5h, then main drying at 62℃ for 2.5h, and finally final curing at 82℃ for 1.5h, thus obtaining the antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter (containing a sodium alginate / graphene oxide / copper ion composite coating, denoted as SA+GO / Cu).

[0028] Example 3 This invention provides a method for preparing an antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter, the method comprising the following steps: (1) Graphene oxide (GO) dispersion (concentration 2.5 mg / mL) and sodium alginate (SA) solution (concentration 3.5 wt%) were mixed at a mass ratio of 1:9. Then, a water / ethanol mixed solvent (volume ratio of water to ethanol of 7:3) was added. The mixture was then ultrasonically dispersed (power of 350 W) for 35 min. During the treatment, the temperature was kept ≤40℃ to avoid damage to the graphene oxide sheet structure, and a GO-SA mixture was obtained. The graphene oxide sheet diameter was 0.5-5 μm, the oxygen content was about 25 at%, and the molecular weight of sodium alginate was 80-120 kDa. (2) Plasma pretreatment of polyurethane dialysis catheters: oxygen is introduced and treated for 20 minutes under the conditions of discharge power of 250W and pressure of 75Pa. This process generates a honeycomb micro-nano structure on the surface of the catheter and grafts polar groups such as hydroxyl (-OH) and carboxyl (-COOH), which increases the surface energy and significantly enhances the coating bonding strength. After completion, the pretreated catheter is obtained. (3) Immerse the pretreated conduit in the GO-SA mixture for 80 seconds to form a wet film. After coating, let it stand for 12 minutes to allow the solution to spread fully. Then transfer it to an oven to air dry for 12 minutes to form a primary gel layer and obtain a primary gel layer conduit. (4) Immerse the nascent gel layer conduit in a 0.4M CuCl2 crosslinking solution, so that Cu... 2+ The SA carboxyl group forms an "egg-box" structure coordination bond. After cross-linking, the catheter is removed and rinsed with deionized water to remove free ions. Then, it is placed in a vacuum oven for gradient temperature curing: first, pre-drying at 42℃ for 1.5h, then main drying at 62℃ for 2.5h, and finally final curing at 82℃ for 1.5h, thus obtaining the antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter (containing a sodium alginate / graphene oxide / copper ion composite coating, denoted as SA+GO / Cu).

[0029] Detection example (a) Antibacterial and bacteriostatic detection The coated dialysis catheter was then exposed to a bacterial solution (1×10⁻⁶) at levels far exceeding those commonly seen in clinical bacteremia. 8 CFU / mL Escherichia coli, 1×10 8 When co-incubated with CFU / mL Staphylococcus aureus, plate counting revealed a large number of colonies growing on the surface of the uncoated dialysis catheter (e.g., CFU / mL Staphylococcus aureus). Figure 1 (As shown in a and c in the figure), after the dialysis tubing loaded with the coating was incubated with the bacterial solution, only a very small number of Escherichia coli colonies were observed during plate counting, and no Staphylococcus aureus colonies were observed (as shown in a figure). Figure 1 (As shown in b and d in the diagram). Under scanning electron microscopy, a large number of bacteria can be found adhering to and surviving on the surface of the uncoated catheter (e.g., ...). Figure 1As shown in e and g), the number of bacteria on the surface of the dialysis catheter with the loaded coating was significantly reduced, and the bacterial cells were visibly shriveled (as shown in e and g). Figure 1 (as shown in f and h in the figure) is a typical manifestation of bacterial death.

[0030] (II) Anticoagulation performance testing First, polyurethane (PU, i.e., untreated polyurethane catheters), sodium alginate / copper ion coating (SA / Cu), and sodium alginate / graphene oxide / copper ion composite coating (SA+GO / Cu) samples were immersed in phosphate-buffered saline (PBS) at pH 7.4 and equilibrated overnight in a 37°C constant-temperature shaker. Second, platelet-rich plasma (PRP) was prepared: whole rabbit blood anticoagulated with sodium citrate (anticoagulant:whole blood = 1:4 volume ratio) was centrifuged at 1000 rpm (approximately 200 × g) for 10 min, and the supernatant was collected as PRP. The equilibrated sample was then immersed in 200 μL of PRP. Human blood contains free NO donors, nitrosothiols (RSNO) and reduced glutathione (GSH), but RSNO has a very short half-life and poor stability. Therefore, the SA+GO / Cu coating was divided into two groups. The donor group, denoted as SA+GO / Cu(+), received an additional 10 μL of S-nitroso-N-acetyl-D-penicillamine (SNAP) and 10 μL of GSH. The non-donor group, denoted as SA+GO / Cu(-), received no additional donors. The samples were incubated at 37°C in the dark for 1 hour. After incubation, the samples were gently rinsed three times with PBS to thoroughly remove any unadhered platelets and plasma proteins. Cell fixation was then performed: the samples were immersed in 2.5 vol.% glutaraldehyde solution and fixed at room temperature for 4 hours. After fixation, the samples were rinsed three times with pure water to remove residual fixative. Dehydration was performed using an ethanol gradient method: the samples were sequentially immersed in 25%, 50%, 75%, and 100% ethanol-water solutions (v / v), each for 10 minutes, and finally sent for scanning electron microscopy.

[0031] like Figure 2 As shown, based on scanning electron microscopy observation, the polyurethane (PU) surface exhibited significant platelet adhesion and high activation, manifested as deformed pseudopodia extension and aggregation. In contrast, the sodium alginate / graphene oxide / copper ion composite coating (SA+GO / Cu(-)) significantly reduced platelet adhesion density and activation level through the physical barrier effect of graphene oxide, with platelets mainly maintaining a rounded morphology. Supplementation with nitrosoacetylpenicillamine and reduced glutathione (SA+GO / Cu(+)) further enhanced the anticoagulant effect, with a dual mechanism synergistically inhibiting the coagulation cascade: copper ions, acting as a catalyst for NO, promote the release of donors to generate NO, preventing platelet activation, thereby inhibiting platelet aggregation and thrombus formation.

[0032] (III) Hemolytic performance test According to the standard hemolysis test method, polyurethane (PU) and sodium alginate / graphene oxide / copper ion composite coating samples were placed in test tubes, 10 mL of physiological saline was added, and pre-incubated in a 37℃ constant temperature water bath for 30 minutes. Then, 0.2 mL of diluted rabbit whole blood was added to each test tube, gently mixed, and incubated at 37℃ for another hour. After incubation, the mixture was centrifuged at 3000 r / min for 5 minutes, and 150 μL of the supernatant was transferred to an ELISA plate. The absorbance was measured at 545 nm using an ELISA reader. The negative control was a mixture of 10 mL of physiological saline and 0.2 mL of diluted rabbit whole blood, and the positive control was a mixture of 10 mL of deionized water and 0.2 mL of diluted rabbit whole blood. Each experiment had three replicates. The hemolysis rate was calculated using the formula: Hemolysis rate (%) = (Sample absorbance - Negative control absorbance) / (Positive control absorbance - Negative control absorbance) × 100% This formula standardizes the degree of hemolysis by comparing the absorbance difference between a positive control (complete hemolysis induced by deionized water) and a negative control (no hemolysis induced by physiological saline), thus quantitatively assessing the material's ability to damage red blood cells. For example... Figure 3 As shown, the results indicate that a hemolysis rate of less than 5% proves that the material has no risk of hemolysis.

[0033] The experimental data presented above demonstrate that the antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter prepared in this invention exhibits superior antibacterial properties and the ability to reduce clinical thrombotic events compared to commercially available dialysis catheters. The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing an antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter, characterized in that, The preparation method includes the following steps: (1) Mix the graphene oxide dispersion with sodium alginate solution, add water / alcohol mixed solvent, and then use ultrasonic dispersion to obtain a mixture; (2) The polyurethane dialysis catheter was pretreated with plasma to obtain a pretreated catheter; (3) Immerse the pretreated conduit in the mixture, and after the immersion coating is completed, let it stand and dry in sequence to obtain the nascent gel layer conduit; (4) Immerse the nascent gel layer catheter in the cross-linking solution, and then clean and cure it in sequence by gradient heating to obtain the antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter.

2. The method for preparing the antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter according to claim 1, characterized in that, In step (1): The graphene oxide sheets have a diameter of 0.5-5 μm and an oxygen content of 20-30 at%; the concentration of the graphene oxide dispersion is 2-3 mg / mL. And / or, the molecular weight of sodium alginate is 80-120 kDa; the concentration of the sodium alginate solution is 3-4 wt%; And / or, the mass ratio of the graphene oxide dispersion to the sodium alginate solution is 1:8-10.

3. The method for preparing the antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter according to claim 1, characterized in that, In step (1), the water / alcohol mixed solvent is a mixed solvent of water and ethanol in a volume ratio of 7-8:3-2.

4. The method for preparing the antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter according to claim 1, characterized in that, In step (1), the ultrasonic dispersion power is 300-400W, the ultrasonic dispersion time is 30-40min, and the ultrasonic dispersion temperature is ≤40℃.

5. The method for preparing the antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter according to claim 1, characterized in that, In step (2), the plasma pretreatment is performed by 15-20 minutes under the conditions of oxygen introduction, discharge power of 200-300W, and gas pressure of 50-100Pa.

6. The method for preparing the antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter according to claim 1, characterized in that, In step (3), the immersion time is 60-90s, the standing time is 10-15min, and the drying time is 10-15min.

7. The method for preparing the antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter according to claim 1, characterized in that, In step (4), the crosslinking solution is a 0.3-0.4M CuCl2 solution.

8. The method for preparing the antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter according to claim 1, characterized in that, In step (4), the gradient temperature curing method is as follows: first dry at 40-42℃ for 1-1.5h, then dry at 60-62℃ for 2-2.5h, and finally cure at 80-82℃ for 1-1.5h.

9. The antibacterial and anticoagulant sodium alginate-graphene oxide coated dialysis catheter obtained by the preparation method according to any one of claims 1-8.

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