Julio C A, de-Queiroz A A, Higa O Z, Marques E F, Maizato M J
Instituto de Pesquisas Energéticas e Nucleares, IPEN/CNEN-SP, Brasil.
Braz J Med Biol Res. 1994 Nov;27(11):2565-8.
Tubular polymeric materials modified by radiation techniques can be used as vascular prosthesis and components of prosthetic devices. The biological interaction between these materials and blood was studied by in vitro and ex vivo methods. Silicone rubber tubes were copolymerized with acrylamide and N-vinylpyrrolidone by radiation-grafting techniques. The irradiation was performed with gamma-rays from a 60Co source at a constant dose rate (0.2 kGy/h) for various time intervals (4-15 h). To evaluate the antithrombogenicity of the grafted tubes, the surface adsorption of 125I-albumin and 125I-fibrinogen was studied. All graft copolymers show a preference for albumin, and the degree of preference appears to correlate with antithrombogenic tendency. In the ex vivo experiment with animals, tubes were implanted in the carotid artery of dogs and the blood flow in the graft copolymers was detected with an ultrasonic flow meter. The blood flow rate in the ungrafted implants decreased more rapidly (stopped completely after 15 to 210 min) compared to the flow rate in the grafted ones (decreased slowly from 38 to 35 ml/min and 70 to 60 ml/min). There was a direct relationship between both methods in the study of blood compatibility of the materials. The results suggest that the graft copolymers can be used as biomaterials for long-term use in cardiovascular systems.
经辐射技术改性的管状聚合物材料可用作血管假体和假体装置的部件。通过体外和离体方法研究了这些材料与血液之间的生物相互作用。通过辐射接枝技术将硅橡胶管与丙烯酰胺和N-乙烯基吡咯烷酮共聚。使用来自60Co源的γ射线以恒定剂量率（0.2 kGy/h）在不同时间间隔（4 - 15小时）进行辐照。为了评估接枝管的抗血栓形成性，研究了125I-白蛋白和125I-纤维蛋白原的表面吸附。所有接枝共聚物都表现出对白蛋白的偏好，并且偏好程度似乎与抗血栓形成趋势相关。在动物离体实验中，将管子植入狗的颈动脉，并使用超声流量计检测接枝共聚物中的血流。与接枝管中的流速（从38降至35 ml/min和从70降至60 ml/min缓慢下降）相比，未接枝植入物中的血流速度下降更快（15至210分钟后完全停止）。在材料血液相容性研究中，这两种方法之间存在直接关系。结果表明，接枝共聚物可作为生物材料在心血管系统中长期使用。
