Hydrophilic surface modification of Tecoflex® polyurethane (PU) catheters was performed by grafting poly(1-Vinylimidazole) (PVim) and poly(N-isopropylacrylamide) (PNIPAAm) using the grafting-radiation method. The first graft was achieved by the pre-irradiation oxidative technique and the second one by the simultaneous one. Grafting yields were adjusted by varying factors such as monomer concentration, absorbed dose, and reaction time. All this to improve the hydrophilicity of the medical device and endow it with the functional groups able to host an anti-inflammatory agent to prevent the undesirable side-effects related to a polymeric implant. Grafted catheters were well characterized by several methods such as Infrared Spectroscopy (IR-ATR), Nuclear Magnetic Resonance ¹³C (¹³C-NMR), X-ray Diffraction (XDR), Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA). Modified catheters proved to have a good affinity to water after the grafting process; they presented responsiveness to pH and temperature changes; exhibiting a critical pH of 6 and a Lower Critical Solution Temperature (LCST) of 28 °C. Furthermore, the stimuli-sensitive catheters were able to load sodium diclofenac which released it for a prolonged time in serum saline 0.9 % at different pH and temperature.

通过使用接枝-辐射方法接枝聚（1-Vilimlimidazole）（PVim）和聚（N-异丙基丙烯酰胺）（PNIPAAm），对Tecoflex®聚氨酯（PU）导管进行亲水表面改性。第一个接枝是通过预辐射氧化技术实现的，第二个接枝是通过同时辐射的技术实现的。接枝产率通过各种因素进行调节，例如单体浓度，吸收剂量和反应时间。所有这些改善了医疗装置的亲水性，并赋予其能够承载抗炎剂的官能团，从而防止了与聚合物植入物有关的不良副作用。嫁接导管已通过多种方法进行了很好的表征，例如红外光谱（IR-ATR），核磁共振¹³ C（¹³C-NMR），X射线衍射（XDR），差示扫描量热法（DSC）和热重分析（TGA）。经证实，改良的导管在接枝过程后对水具有良好的亲和力。他们表现出对pH和温度变化的响应；表现出临界pH值为6和较低的临界溶液温度（LCST）为28°C。此外，刺激敏感的导管能够加载双氯芬酸钠，从而在不同pH和温度下在0.9％的血清盐水中长时间释放双氯芬酸钠。