Synthesis and surface characterization of heparin-immobilized polyetherurethanes

✍ Scribed by Inn-Kyu Kang; Dong Ki Baek; Young Moo Lee; Yong Kiel Sung

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 151 KB
• Volume: 36
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19980930)36:13<2331::aid-pola20>3.0.co;2-a

✦ Synopsis

Novel poly(ether urethanes) containing diester groups in the side chains (PU) were synthesized from 4,4Ј-diphenylmethyl diisocyanate, polytetramethylene glycol, and diethyl bis(hydroxymethyl)malonate as a chain extender. The surface modification of the PU film was carried out by a hydrolysis reaction, poly(ethylene oxide) (PEO) grafting, and heparin immobilization, and the surface-modified PUs were then characterized by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, electron spectroscopy for chemical analysis (ESCA), and a contact angle goniometer. The concentration of carboxylic acid groups introduced on the PU surfaces as determined by the rhodamine interaction method was 61 nmol/cm 2 when treated with 4N NaOH/methanol (1 : 2 v/v) for 30 min and subsequently with a citric acidmethanolic aqueous solution. The amounts of heparin coupled to the carboxyl groups on the PU surfaces and to the terminus amino groups on the PU-PEO were 0.92 and 0.84 g/cm 2 , respectively. There was almost no heparin released from the immobilized surface of a physiological solution for 100 h, thereby indicating the strong stability of immobilized heparin.