In vitro and in vivo studies on antithrombogenicity of poly(propylene oxide) segmented nylon 610 in relation to its...

In vitro and in vivo antithrombogenicity of poly(propylene oxide) segmented nylon 610 was investigated. For the in vitro simulation of thrombosis on copolymer surfaces, a modified microsphere column method evaluated the thrombosis time of the copolymer column. For the in vivo evaluation of the antithrombogenicity of copolymer surfaces, small diameter tubing, precoated with copolymer, was implanted in rabbits as an arteriovenous shunt to determine the time of patency for the copolymer tubing. In both the in vitro and in vivo tests, the copolymer having a particular size and distribution of crystalline and amorphous microphases on its surface exhibited excellent antithrombogenicity; the copolymer with a long period of approximately 12 nm and a crystallite thickness of 6.5 nm suppressed the activation process of adhering platelets to show thromboresistant property. This paper emphasizes the importance of controlling the crystalline-amorphous microstructure for the antithrombogenicity of polymer surfaces with a semicrystalline microstructure.