Synthesis and characterization of heparinized polyurethanes using plasma glow discharge

• Published in: Biomaterials Vol. 20; no. 6; pp. 529 - 537
• Main Authors: Bae, Jung-Sook, Seo, Eun-Jin, Kang, Inn-Kyu
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.03.1999; Elsevier Science
• Subjects: Biocompatible Materials - chemical synthesis; Biocompatible Materials - chemistry; Biological and medical sciences; Biosynthesis; Biotechnology; Carboxylic acids; Carboxylic Acids - analysis; Catalysis; Chemistry, Organic - methods; Contact angle; Copolymerization; ESCA; Fundamental and applied biological sciences. Psychology; Glow discharges; Grafting (chemical); Heparin; Heparin immobilization; Immobilization of organelles and whole cells; Immobilization techniques; Indicators and Reagents; Methods. Procedures. Technologies; Peroxides; Plasma glow discharge; Polyacrylates; Polyurethane; Polyurethanes; Polyurethanes - chemical synthesis; Polyurethanes - chemistry; Proteins; Surface Properties; Surface treatment; Heparin immobilization; Plasma glow discharge; ESCA; Polyurethane; Manufacturing process; Immobilization; Surface properties; Glycosaminoglycan; Anticoagulant; Heparin; Technique; Chemical synthesis; Glow discharge polymerization; Physicochemical properties; Biomedical engineering
• ISSN: 0142-9612; 1878-5905
• DOI: 10.1016/S0142-9612(98)00204-X

Polyurethanes (PU) were synthesized from 4,4′-diphenylmethane diisocyanate and polytetramethylene glycol, and subsequently with ethylene diamine as a chain extender. The PU film was exposed to oxygen plasma glow discharge to produce peroxides on the surfaces. These peroxides were then used as catalysts for the copolymerization of acrylic acid (AA) and methyl acrylate (MA) in order to prepare carboxyl group-introduced PU (PU-C). Heparin-immobilized PU was prepared using the coupling reaction of PU-C with polyethylene oxide (PEO) followed by the reaction of grafted PEO with heparin. The surface-modified PUs were then characterized by attenuated total reflection Fourier transform infrared spectroscopy, electron spectroscopy for chemical analysis (ESCA), and a contact angle goniometer. The concentration of carboxylic acid groups on the PU surfaces could be controlled within the range of 0.47–1.68 μmol cm -2 by the copolymerization of AA and MA. The amounts of heparin coupled to terminus amino groups on PU-6 and PU-33 were 1.30 and 1.16 μg cm -2, respectively. The water contact angle of the PU was decreased by AA grafting, and further decreased by PEO grafting and heparin immobilization, showing an increased hydrophilicity of the modified PUs. A 3% loss from the originally bound heparin appeared within several hours and thereafter almost no heparin was released when heparin-immobilized PUs were immersed in a physiological solution for 100 h, indicating the covalent immobilization of heparin on the surfaces.