Surface coating of stearyl poly(ethylene oxide) coupling-polymer on polyurethane guiding catheters with poly(ether urethane) film-building additive for biomedical applications

Three types of stearyl poly(ethylene oxide) (SPEO) with Mn of 2300, 6000 an d 12000 were synthesized: accordingly, three types of amphiphilic coupling- polymer SPEO-MDI-SPEO (MSPEO) were prepared by the reactions with 4.3'-meth ylene diphenyl diisocyanate (MDI), As the surface-modifying additives (SMA) , MSPEOs were coated unto the outer wall of the medical guiding catheters. Due to the lack of stability. when coated, MSPEO blended with the film buil ding agent (FBA), poly(ether urethane) (PEL). The process of coating was pe rformed with a lifter. With invariable speed, the PU guiding catheter was v ertically dipped into the coating mixture of SMA-MSPEO and FBA-PEL. The sur face analysis was carried out by ATR-FTIR and contact angle measurements. I t was proved that the surface enrichment of PEO on water interface was much higher than that on air interface. Three kinds of static clotting time tes ts, PRT, PT and TT, as well as the static platelet adhesion experiment were performed. The results indicated that the coated surface could resist the blood coagulation effectively. In order to test the blood compatibility of the coated catheters under a shear of blood Row. the dynamic experiment was performed with a closed-loop tubular system under a shear rate of 1500 s(- 1). The blood regular testing was carried out on the samples taken out at s ix different times (0, 5, 10, 20, 30 and 60 min). The results were ideal. F inally, the SMA-MSPEO was proved to be non-acute-toxic by LD50 test. (C) 20 01 Elsevier Science Ltd. All rights reserved.