Evaluation of the antithrombogenicity of poly-2-methoxyethylacrylate-coated catheters

Background and objectives: The blood compatibility of indwelling intravascular catheters is facilitated by the use of antithrombogenic materials. Heparin has typically been used for this purpose; however, since heparin-coated catheters are considered combination products, difficulties meeting the relevant Food and Drug Administration safety recommendations have disrupted commercialization. Other issues include coating durability and the occurrence of heparin-induced thrombocytopenia. Polymer coatings are a potential alternative; however, polymer antithrombogenicity in circulating human blood has yet to be demonstrated. The present study aimed to establish the ex vivo antithrombogenicity of a poly-2-methoxyethylacrylate (PMEA) polymer coating applied to a central venous catheter using an artificial human blood circulation system. Methods: The present study used an artificial human blood circulation system to conduct an ex vivo evaluation of the antithrombogenicity of poly-2-methoxyethylacrylate (PMEA)-coated catheters. Human blood samples obtained from volunteer donors were loaded into a circulation system fitted with either a PMEA-coated or uncoated catheter. After 3-h, the catheter was removed and examined using scanning electron microscopy. Protein adsorption on the catheter surface was investigated by shredding the catheter that had contacted the blood inside the circulation system and immersing the pieces in 1 mL of 0.5 N NaOH for 2 days. The amount of protein in the 0.5 N NaOH was determined according to the Lowry method. Results: Adherent fibrin, which forms a sheath on the catheter surface, was observed on uncoated, but not PMEA-coated catheters. Furthermore, the amount of protein adsorption was significantly less with PMEA-coated than uncoated catheters (p = 0.043). Conclusions: The present findings demonstrated the antithrombogenicity of PMEA-coated catheters in circulating human blood.